450 Non Warming Graphs (2)


Rosenthal et al., 2017

“Here we review proxy records of intermediate water temperatures from sediment cores and corals in the equatorial Pacific and northeastern Atlantic Oceans, spanning 10,000 years beyond the instrumental record. These records suggests that intermediate waters [0-700 m] were 1.5-2°C warmer during the Holocene Thermal Maximum than in the last century. Intermediate water masses cooled by 0.9°C from the Medieval Climate Anomaly to the Little Ice Age. These changes are significantly larger than the temperature anomalies documented in the instrumental record. The implied large perturbations in OHC and Earth’s energy budget are at odds with very small radiative forcing anomalies throughout the Holocene and Common Era. … The records suggest that dynamic processes provide an efficient mechanism to amplify small changes in insolation [surface solar radiation] into relatively large changes in OHC.”



Abbot and Marohasy, 2017

The proxy measurements suggest New Zealand’s climate has fluctuated within a band of approximately 2°C since at least 900 AD, as shown in Figure 2. The warming of nearly 1°C since 1940 falls within this band. The discrepancy between the orange and blue lines in recent decades as shown in Figure 3, suggests that the anthropogenic contribution to this warming [1°C since 1940] could be in the order of approximately 0.2°C. [80% of the warming since 1940 may be due natural factors]. … [T]he increase in temperature over the last 100 years can be largely attributed to natural phenomena.

Gennaretti et al., 2017

Loisel et al., 2017

“In this study, we demonstrate that the Little Ice Age (LIA, ~1400–1850 CE) might be more representative of future hydroclimatic variability than the conditions during the MCA megadroughts for the American Southwest, and thus provide a useful scenario for development of future water-resource management and drought and flood hazard mitigation strategies.”

Kong et al., 2017     

“The general SST [sea surface temperatures] variation pattern matches well with total solar irradiance (TSI) changes.”

Moffa-Sánchez and Hall, 2017

Moffa-Sánchez and Hall, 2017  (supplemental)

Fuentes et al., 2017

“The summer (June through August) temperature reconstruction, extending back to 1038 CE, exhibits three warm periods in 1040–1190 CE, 1370–1570 CE and the 20th century and one extended cold period between 1570 and 1920 CE.”

Parker and Ollier, 2017

“The Global Historical Climatology Network (GHCN) v2 temperature time series (GISS Surface Temperature Analysis, 2012) in Alice Spring and all the 36 other stations located in a circle of 1,000 km from Alice Spring do not show any warming. There are stations covering different time windows having very close patterns of temperatures. In this circle of 3,141,593 km2 (roughly 50% of Australia) that is mostly underdeveloped, none of the stations […] has a warming trend.  … It is therefore only an artefact by BOM to produce the warming. Homogenization is supposed to be used to account for upwards biases such as Urban Heat Island, not to introduce upwards biases.  …  In the centre of Australia, all the stations available in a circle of radius 1,000 km were showing very little or no warming, as still acknowledged in the GHCN v2 data set up to October 2011 (Fig. 6). … Table 1 presents the warming trend for the 30 longest temperature records of Australia collected in a single location, with measurements started before 1900 and continued until after 1985.  … In the 30 locations, the monthly mean maximum temperature is warming 0.0004°C/year, or 0.04°C/century. That means there is no change within the limits of accuracy of the measurements. … The climate trend maps compiled by Bureau of Meteorology in their climate change section are completely unreliable, as the alleged increasing temperature is obtained by lowering temperatures of the past by “adjustments”. The longest of the Australian temperature records that were considered the most reliable by Bureau of Meteorology on February 2009 (BOM 2009) are still available as raw temperatures in the climate data online section and consistently show no warming and no increased extreme events within the limit of accuracy of measurements.”

Lüdecke and Weiss, 2017

By wavelet analysis, a new proof has been provided that at least the ~190-year climate cycle has a solar origin.  … G7 [global temperature over the last 2000 years], and likewise the sine representations have maxima of comparable size at AD 0, 1000, and 2000. We note that the temperature increase of the late 19th and 20th century is represented by the harmonic temperature representation, and thus is of pure multiperiodic nature. It can be expected that the periodicity of G7, lasting 2000 years so far, will persist also for the foreseeable future. It predicts a temperature drop from present to AD 2050, a slight rise from 2050 to 2130, and a further drop from AD 2130 to 2200.”

Büntgen et al., 2017

“Spanning the period 1186-2014 CE, the new reconstruction reveals overall warmer conditions around 1200 and 1400, and again after ~1850. … Little agreement is found with climate model simulations that consistently overestimate recent summer warming and underestimate pre-industrial temperature changes. … [W]hen it comes to disentangling natural variability from anthropogenically affected variability the vast majority of the instrumental record may be biased. …

Abrantes et al., 2017

The transition from warm to colder climatic conditions occurs around 1300 CE associated with the Wolf solar minimum. The coldest SSTs are detected between 1350 and 1850 CE, on Iberia during the well-known Little Ice Age (LIA) (Bradley and Jones, 1993), with the most intense cooling episodes related with other solar minima events, and major volcanic forcing and separated by intervals of relative warmth (e.g. (Crowley and Unterman, 2013; Solanki et al., 2004; Steinhilber et al., 2012; Turner et al., 2016; Usoskin et al., 2011). During the 20th century, the southern records show unusually large decadal scale SST oscillations in the context of the last 2 millennia, in particular after the mid 1970’s, within the Great Solar Maximum (1940 – 2000 (Usoskin et al., 2011)) and the “greater salinity anomaly” event in the northern Atlantic (Dickson et al., 1988), or yet the higher global temperatures of the last 1.4 ky detected by (Ahmed et al., 2013).”

Cheung, 2017

Kawakubo et al., 2017 

“Spring-summer climate south of Japan is mainly controlled by solar radiation and surface heat fluxes, with lesser ocean current influence on SST, with a few exceptions as mentioned above for the summers of 1998 and 2001. … The cold period between 1660-1700 in the coral record aligns with the minimum total solar irradiance that defines the Maunder Minimum (MM) ca. 1645-1715 (Steinhilber et al., 2009).”

Werner et al., 2017

Deng et al., 2017

The results indicate that the climate of the Medieval Climate Anomaly (MCA, AD 900–1300) was similar to that of the Current Warm Period (CWP, AD 1850–present) … As for the Little Ice Age (LIA, AD 1550–1850), the results from this study, together with previous data from the Makassar Strait, indicate a cold and wet period compared with the CWP and the MCA in the western Pacific. The cold LIA period agrees with the timing of the Maunder sunspot minimum and is therefore associated with low solar activity.”

Wang et al., 2017

“Our results show that: (1) the mean annual temperature (TANN) was relatively high from 4000-2700 cal yr BP, decreased gradually from 2700-1270 cal yr BP, and then fluctuated drastically during the last 1270 years. (2) A cold climatic event in the Era of Disunity, the Sui-Tang Warm Period (STWP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can all be recognized in the paleotemperature record, as well as in many other temperature reconstructions in China.”

Balanzategui et al., 2017

Kaczka et al., 2017

Yashayaev and Loder, 2017

“As a result of this intermittent recurrence of intensified Labrador Sea Water formation, the annual average temperature and density in the region’s upper 2000m have predominantly varied on a bi-decadal time scale, rather than having a long-term trend as might be expected from anthropogenic climate change. … [I]ntermittent recurrence of enhanced deep convection periods in the Labrador Sea, and the associated formation of major LSW classes, are contributing to a predominant decadal-scale variation in hydrographic properties which makes it difficult to determine whether anthropogenic changes are occurring. … This strong, apparently natural, decadal-scale variability makes it very difficult to determine whether significant anthropogenic changes in LSW formation and properties have occurred.”

Lan et al., 2017

“The results show that the centennial HCA [High Central Asia] temperature changes not only significantly correlate with those in China (Yang et al., 2002a) and northwestern China (He et al., 2013), but also with those in Northern Hemisphere (Moberg et al., 2005; Ljungqvist, 2010), implying that the centennial HCA [High Central Asia] temperature changes may have similar driving forces with those in Northern Hemisphere at least over the past two millennia, like solar forcing (Bond et al., 2001; Gray et al., 2010; Moffa-Sanchez et al., 2014) and volcanic eruption (Schurer et al., 2014; Sigl et al., 2015; Stoffel et al., 2015), etc.”

Chand et al., 2017

The LIA [Little Ice Age] is a globally documented cooling event that began around the 13th or 14th century and culminated between the mid- 16th and mid-19th centuries. Although the cause of LIA glaciation is not fully understood, climatologists contend that reduced solar output, changes in atmospheric circulation as a result of a reversal of the North Atlantic Oscillation and explosive volcanism could have decreased the global temperature. … Based on the GSI’s repeated photographs of 1906, 1956 and 1963, and the position of the recessional moraine ridges, it is clear that the lower frontal tongue of the Bara Shigri Glacier changed significantly from 1906 to 1965 (59 years). During this period, a loss 1.8 +/- 0.52 km2 in glacier area occurred at an annual rate of 0.03 +/- 0.02 km2 … The total frontal area vacated by the glacier for the period between 1965 and 2014 is 1.1 +/- 0.01 km2 with an annual rate of 0.02 +/- 0.0003 km2.” [Glacier recession was 1.8 km2 and -0.03 km2 per year for 1906-1965 (59 years), with a 30-40% deceleration to 1.1 km2 and -0.02 km2 per year for 1965-2014 (59 years)]

Dieng et al., 2017

“We can note that the correlation between GMST [global mean surface temperature] trends and AMO trends is quite high. It amounts 0.88 over the whole time span. At the beginning of the record, the correlation with PDO trends is also high (equal to 0.8) but breaks down after the mid-1980s.  The GMST and AMO trends shown in Figure 6 show a low in the 1960s and high in the 1990s, suggestive of a 60-year oscillation, as reported for the global mean sea level by Chambers et al. (2012). Thus the observed temporal evolution of the GMST [global mean surface temperature] trends may just reflect a 60-year natural cycle driven by the AMO.”

Gong et al., 2017

“The inter-annual relationship between the boreal winter Arctic Oscillation (AO) and summer sea surface temperature (SST) over the western tropical Indian Ocean (TIO) for the period from 1979 to 2015 is investigated. The results show that the January–February–March AO [Arctic Oscillation] is significantly correlated with the June–July–August SST and SST tendency.”

Chapanov et al., 2017

“A good agreement exists between the decadal cycles of LOD [length of day], MSL [mean sea level], climate and solar indices whose periods are between 12-13, 14-16, 16-18 and 28-33 years.”

Ge et al., 2017

“This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3◦C and 0.7◦C, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56◦ ± 0.42◦C (100 yr)−1; however, temperatures recorded in the 20th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD 1201–70 are comparable to the present.”

Williams et al., 2017

“Reconstructed SSTs significantly warmed 1.1°C … from 1660s to 1800 (rate of change: 0.008°C/year), followed by a significant cooling of 0.8°C …  until 1840 (rate of change: 0.02°C/year), then a significant warming of 0.8°C from 1860 until the end of reconstruction in 2007 (rate of change: 0.005°C/year).” [The amplitude of sea surface temperature warming and cooling was higher and more rapid from 1660s-1800 than from 1860-2007.]
‘In fact, the SST reconstruction significantly co-varied with a reconstruction of solar irradiance [Lean, 2000] on the 11-year periodicity only from ~1745 to 1825. In addition, the reconstructed SSTs were cool during the period of lower than usual solar irradiance called the Maunder minimum (1645–1715) but then warmed and cooled during the Dalton minimum (1795–1830), a second period of reduced solar irradiance. … The Dalton solar minimum and increased volcanic activity in the early 1800s could explain the decreasing SSTs from 1800 to 1850.”

Stenni et al., 2017

“A recent effort to characterize Antarctic and sub-Antarctic climate variability during the last 200 years also concluded that most of the trends observed since satellite climate monitoring began in 1979 CE cannot yet be distinguished from natural (unforced) climate variability (Jones et al., 2016), and are of the opposite sign [cooling, not warming] to those produced by most forced climate model simulations over the same post-1979 CE interval. … (1) Temperatures over the Antarctic continent show an overall cooling trend during the period from 0 to 1900CE, which appears strongest in West Antarctica, and (2) no continent-scale warming of Antarctic temperature is evident in the last century.”

Pontius, 2017

In general, ensemble model forecasts have been found unreliable for long-term climate prediction (Green and Armstrong, 2007, Mihailović et al., 2014). … Historical evidence of a significant increase in surface temperatures due to increases in atmospheric CO2 is absent from these data.  … If atmospheric CO2 continues to increase at its current rate the small annual temperature increase expected at Riverside will likely be insignificant (e.g. < 0.01°C/yr) compared to natural temperature variability.”

Leonelli et al., 2017


Li et al., 2017

Kobashi et al., 2017

“After the 8.2 ka event, Greenland temperature reached the Holocene thermal maximum with the warmest decades occurring during the Holocene (2.9 ± 1.4 °C warmer than the recent decades) at 7960 ± 30 years B.P.


For the most recent 10 years (2005 to 2015), apart from the anomalously warm year of 2010, mean annual temperatures at the Summit exhibit a slightly decreasing trend in accordance with northern North Atlantic-wide cooling.  The Summit temperatures are well correlated with southwest coastal records (Ilulissat, Kangerlussuaq, Nuuk, and Qaqortoq).”

Demezhko et al., 2017

“GST [ground surface temperature] and SHF [surface heat flux] histories differ substantially in shape and chronology. Heat flux changes ahead temperature changes by 500–1000 years.”

Luoto and Nevalainen, 2017

Li et al., 2017

“The main driving forces behind the Holocene climatic changes in the LYR [Lower Yangtze Region, East China] area are likely summer solar insolation associated with tropical or subtropical macro-scale climatic circulations such as the Intertropical Convergence Zone (ITCZ), Western Pacific Subtropical High (WPSH), and El Niño/Southern Oscillation (ENSO).”

Larsen et al., 2017

[K]nowledge remains sparse of GICs [glaciers and ice caps] fluctuations in Greenland and whether they survived past warmer conditions than today, e.g. the Holocene Thermal Maximum (HTM) ~8-5 cal. ka BP and the Medieval Climate Anomaly (MCA) ~1200-950 C.E. Only a few available studies have provided continuous records of Holocene glacier fluctuations in east Greenland (Lowell et al., 2013; Levy et al., 2014; Balascio et al., 2015) and west Greenland (Schweinsberg et al., 2017). These records show that local GICs [glaciers and ice caps] were significantly reduced and most likely completely absent during the HTM [Holocene Thermal Maximum].”

Zywiec et al., 2017

Ogurtsov et al., 2017

“Our analyses reveal appreciable and stable positive correlation between summer temperatures in Northern Fennoscandia and sea surface temperature in North Atlantic over AD 1567–1986. Thus a connection between climates of Northern Fennoscandia and North Atlantic basin is established for more than the last four centuries. Significant correlation was found between SST [sea surface temperatures] in NA [the North Atlantic] and solar activity (both instrumental data and proxies) during AD 1716–1986. … Thus, the connection between Northern Fennoscandian climate and solar activity, which has been previously established at century-scale (Ogurtsov et al., 2001, 2002, 2013) and millennial-scale (Helama et al., 2010), is confirmed for AD 1716–1986 over the entire frequency range using unfiltered records (with the exception for AMO reconstruction after Mann et al. (2009)).”

Arppe et al., 2017

“Factoring in respective age-model uncertainties, it appears that all major negative shifts, that is, ‘cold’ periods, in the δ18Olw record are roughly synchronous with periods of major negative anomalies in total solar irradiation and high modeled probabilities for extremely cold years in the Nordic Seas (Renssen et al., 2006), and widespread evidence of North Atlantic ‘cold spells’ (Bond et al., 2001; Sarnthein et al., 2003; Solomina et al., 2015; Wanner et al., 2008) linked to solar forcing.”

Mayewski et al., 2017

Turney et al., 2017

Occupying about 14% of the world’s surface, the Southern Ocean plays a fundamental role in ocean and atmosphere circulation, carbon cycling and Antarctic ice-sheet dynamics. … As a result of anomalies in the overlying wind, the surrounding waters are strongly influenced by variations in northward Ekman transport of cold fresh subantarctic surface water and anomalous fluxes of sensible and latent heat at the atmosphere–ocean interface. This has produced a cooling trend since 1979.”


Rydval et al., 2017

“[T]he recent summer-time warming in Scotland is likely not unique when compared to multi-decadal warm periods observed in the 1300s, 1500s, and 1730s“

Yeager and Robson, 2017 

“[W]hile the late twentieth century Atlantic was dominated by NAO-driven THC [thermohaline circulation] variability, other mechanisms may dominate in other time periods. … More recently, the SPNA [sub polar North Atlantic] upper ocean has again been cooling, which is also thought to be related to a slowdown in the THC. A continued near-term cooling of the SPNA has been forecast by a number of prediction systems, with implications for pan-Atlantic climate.”

Li, 2017

In the Southern Ocean, the increasing trend of the total OHC [ocean heat content] slowed down and started to decrease from 1980, and it started to increase again after 1995. In the warming context over the whole period [1970-2009], the Pacific was losing heat, especially in the deep water below 1000 m and in the upper layer above 300 m, excluding the surface 20 m layer in which the OHC kept increasing through the time.”

Piecuch et al., 2017

In 2004–2005, SPNA [sub-polar North Atlantic] decadal upper ocean and sea-surface temperature trends reversed from warming during 1994–2004 to cooling over 2005–2015.”

Li et al., 2017

“We suggest that solar activity may play a key role in driving the climatic fluctuations in NC [North China] during the last 22 centuries, with its quasi ∼100, 50, 23, or 22-year periodicity clearly identified in our climatic reconstructions. … It has been widely suggested from both climate modeling and observation data that solar activity plays a key role in driving late Holocene climatic fluctuations by triggering global temperature variability and atmospheric dynamical circulation

Guillet et al., 2017

Goursaud et al., 2017

Wilson et al., 2017

Tegzes et al., 2017

Our sortable-silt time series show prominent multi-decadal to multi-centennial variability, but no clear long-term trend over the past 4200 years. … [O]ur findings indicate that variations in the strength of the main branch of the Atlantic Inflow may not necessarily translate into proportional changes in northward oceanic heat transport in the eastern Nordic Seas.”

Tejedor et al., 2017

Fernández-Fernández et al., 2017

Cai and Liu et al., 2017

“2003– 2009 was the warmest period in the reconstruction. 1970– 2000 was colder than the last stage of the Little Ice Age (LIA).”

Bi et al., 2017   

[T]he MWT [minimum winter temperature] values and rate of warming over the past seven decades [southwest China] did not exceed those found in the reconstructed temperature data for the past 211 years. …  Larger scale climate oscillations of the Western Pacific and Northern Indian Ocean as well as the North Atlantic Oscillation probably influenced the region’s temperature in the past.”

Köse et al., 2017

“The reconstruction is punctuated by a temperature increase during the 20th century; yet extreme cold and warm events during the 19th century seem to eclipse conditions during the 20th century. We found significant correlations between our March–April spring temperature reconstruction and existing gridded spring temperature reconstructions for Europe over Turkey and southeastern Europe. … During the last 200 years, our reconstruction suggests that the coldest year was 1898 and the warmest year was 1873. The reconstructed extreme events also coincided with accounts from historical records. …  Further, the warming trends seen in our record agrees with data presented by Turkes and Sumer (2004), of which they attributed [20th century warming] to increased urbanization in Turkey.”

Alter et al., 2017

From 1910- 1949 (pre-agricultural development, pre-DEV) to 1970-2009 (full agricultural development, full-DEV), the central United States experienced large-scale increases in rainfall of up to 35% and decreases in surface air temperature of up to 1°C during the boreal summer months of July and August … which conflicts with expectations from climate change projections for the end of the 21st century (i.e., warming and decreasing rainfall)(Melillo et al., 2014).”

Reeves Eyre and Zeng, 2017

Flannery et al., 2017

The early part of the reconstruction (1733–1850) coincides with the end of the Little Ice Age, and exhibits 3 of the 4 coolest decadal excursions in the record. However, the mean SST estimate from that interval during the LIA is not significantly different from the late 20th Century SST mean. The most prominent cooling event in the 20th Century is a decade centered around 1965. This corresponds to a basin-wide cooling in the North Atlantic and cool phase of the AMO.”

Bolton and Beaudoin, 2017

“Major late Holocene fluctuations include intervals of warmer (e.g. Medieval Warm Period) and cooler (e.g. Little Ice Age) climate. … The modern period [21st century] had temperature and precipitation values which were about 4% less than the Holocene average (Figure 6).”

Kim et al., 2017

He et al., 2017

“As pointed out by Cohen et al. (2014) that continental winter SAT [surface temperature] trends since 1990 exhibit cooling over the midlatitudes. The negative trends extend from Europe eastward to East Asia, with a center of maximum magnitude to the west of the Baikal.  As reviewed above, the AO/NAO [Arctic Oscillation/North Atlantic Oscillation] shows an in-phase relationship with the SAT [surface temperatures] over Eurasia. … [T]he negative trend in the AO/NAO might explain the recent Eurasian winter cooling.  …  It is evident that a positive winter AO causes warmer winters over East Asia through enhancing Polar westerly jet which prevents cold Arctic air from invading low latitudes.”

Robson et al., 2017

Robertson and Chilingar, 2017

“One can summarize our findings as follows: • The anthropogenic impact on the global atmospheric temperature is negligible, i.e., 5% (Matthews, 1998). • Changes in the solar irradiation (global temperature) precede the corresponding changes in the carbon dioxide concentration in the atmosphere. • Any attempt to mitigate undesirable climatic changes using restrictive regulations are condemned to failure, because global forces of nature are at least 4 orders of magnitude greater than the available human controls”


Simon et al., 2017

“The Holocene coldest temperatures were observed during the Early Holocene, but temperature followed a gradual rise (from ca. 11.7 to 8 kyr cal. BP) to reach its maximal value during the Holocene Thermal Maximum (from ca. 8 to 4.5 kyr cal. BP). Holocene Thermal Maximum was characterized by summer air temperatures about 2.5 °C degrees higher than present.”

Kryk et al., 2017

“Our study aims to investigate the oceanographic changes in SW Greenland over the past four centuries (1600-2010) based on high-resolution diatom record using both, qualitative and quantitative methods.  July SST during last 400 years varied only slightly from a minimum of 2,9 to a maximum of 4,7 °C and total average of 4°C. 4°C is a typical surface water temperature in SW Greenland during summer. … The average April SIC was low (c. 13%) [during the 20th century], however a strong peak of 56,5% was recorded at 1965. This peak was accompanied by a clear drop in salinity (33.2 PSU).”

Zheng et al., 2017

From 11.5 to 10.7 ka [11,500 to 10,700 years ago], corresponding to the Preboreal event, MAATpeat indicates even higher [temperature] values, from 7.0 to 12 °C. MAATpeat continued to vary during the Holocene. From 10.7 to 6.0 ka, temperatures rose stepwise, with 2 cool events at 10.6–10.2 and 8.6 ka, before reaching maximum values of ~11 °C during the early Holocene from 8.0 to 6.0 ka. Following the early Holocene, temperatures at Hani gradually decreased to values of ~5 °C, close to the observed temperature at Hani across the past 60 yr (4–7.5 °C).” [Modern temperatures are about 5-6°C colder than 6,000 to 8,000 years ago.]

Bertrand et al., 2017     

During the last 4000 years, particularly low [sea surface temperature] values occur at 3500-3300 cal yr BP and during the most recent decades, and high values persisted between 2400 and 1600 cal yr BP. … [I]t is likely that the abrupt increases in SST around 3300-3200 and 2400-2200 cal yr BP participated in triggering the meltwater events at 3250-2700 and 2000-1200 cal yr BP, respectively. … [T]he marked cooling of the last ~800 years may have very little to do with meltwater input and may rather represent the regional decrease in ocean temperatures during the last ~900 years (Caniupan et al., 2014).”

Mangerud and Svendsen, 2017

“Shallow marine molluscs that are today extinct close to Svalbard, because of the cold climate, are found in deposits there dating to the early Holocene. The most warmth-demanding species found, Zirfaea crispata, currently has a northern limit 1000 km farther south, indicating that August temperatures on Svalbard were 6°C warmer at around 10.2–9.2 cal. ka BP, when this species lived there. … After 8.2 cal. ka, the climate around Svalbard warmed again, and although it did not reach the same peak in temperatures as prior to 9 ka, it was nevertheless some 4°C warmer than present between 8.2 and 6 cal. ka BP. Thereafter, a gradual cooling brought temperatures to the present level at about 4.5 cal. ka BP. The warm early-Holocene climate around Svalbard was driven primarily by higher insolation and greater influx of warm Atlantic Water, but feedback processes further influenced the regional climate.”

Nan et al., 2017

Repschläger et al., 2017       

Lasher et al., 2017

“This paper presents a multi proxy lake record of NW Greenland Holocene climate. … Summer temperatures (2.5–4 °C warmer than present) persisted until 4 ka [4,000 years ago] … Continual cooling after 4 ka led to coldest temperatures after 1.2 ka, with temperature anomalies 2-3°C below present.  Approximately 1000 km to the south, a 2-3°C July temperature anomaly (relative to [warmer than] present) between 6 and 5 ka was reported based upon chironomid assemblages near Illulisat and Jakobshavn (Axford et al., 2013). Across Baffin Bay on northeastern Baffin Island, HTM summer temperatures were an estimated ~5°C warmer than the pre-industrial late Holocene and 3.5°C warmer than present, based upon chironomid assemblages (Axford et al., 2009; Thomas et al., 2007). … Following deglaciation, the GrIS [Greenland Ice Sheet] retreated behind its present margins (by as much as 20-60 km in some parts of Greenland) during the HTM [Holocene Thermal Maximum] (Larsen et al., 2015; Young and Briner, 2015).”

Li et al., 2017


Chang et al., 2017

“The chironomid-based record from Heihai Lake shows a summer temperature fluctuation within 2.4°C in the last c. 5000 years from the south-east margin of the QTP [Qinghai–Tibetan Plateau]. … The summer temperature changes in this region respond primarily to the variation in the Asian Summer Monsoon. The variability of solar activity is likely an important driver of summer temperatures, either directly or by modifying the strength and intensity of the Indian Ocean Summer Monsoon. … We observed a relatively long-lasting summer cooling episode (c. 0.8°C lower than the 5000-year average) between c. 270 cal. BP and AD c. 1956. … The record shows cooling episodes occurred at c. 3100, 2600, 2100 and 1600 cal. BP.  This is likely related to the period defined as the Northern Hemisphere Little Ice Age (LIA; c. AD 1350–1850, equivalent to 600–100 cal. BP). These possibly relate to the 500-year quasi-periodic solar cycle. Cooling stages between c. 270 and 100 cal. BP were also recorded and these are possibly linked to the LIA suggesting a hemisphere-wide forcing mechanism for this event.”

Lan et al., 2017

“The results show that the centennial HCA [High Central Asia] temperature changes not only significantly correlate with those in China (Yang et al., 2002a) and northwestern China (He et al., 2013), but also with those in Northern Hemisphere (Moberg et al., 2005; Ljungqvist, 2010), implying that the centennial HCA [High Central Asia] temperature changes may have similar driving forces with those in Northern Hemisphere at least over the past two millennia, like solar forcing (Bond et al., 2001; Gray et al., 2010; Moffa-Sanchez et al., 2014) and volcanic eruption (Schurer et al., 2014; Sigl et al., 2015; Stoffel et al., 2015), etc.”

Oliveira et al., 2017     

“The transient simulations under the combined effect of insolation and CO2 indicate that the interglacial vegetation and climate dynamics over SW Iberia have no apparent relationship to atmospheric CO2 concentration, as suggested by the pollen-based reconstructions (Fig. 8a, b). Although the direct impact of CO2 changes on the vegetation growth is not included in the model, a prominent example for this negligible CO2 forcing is given by its relatively high concentrations over the end of the interglacials, in particular for MIS 1 and MIS 11c, while the forest cover, annual temperature and annual precipitation achieved minimum values (Fig. 8a, b).”

Krossa et al., 2017

Xu et al., 2017

Albot, 2017

Growing paleoclimatic evidence suggests that the climatic signals of Medieval Warm Period and the Little Ice Age events can be detected around the world (Mayewski et al., 2004; Bertler et al., 2011). … [T]he causes for these events are still debated between changes in solar output, increased volcanic activity, shifts in zonal wind distribution, and changes in the meridional overturning circulation (Crowley, 2000; Hunt, 2006).”

Ön et al., 2017

[T]he abrupt decline in both precipitation and temperature around 3.5 ka, 2.8 ka and 1.8 ka BP, which were also documented in the seismic records (Eris¸ et al., submitted), may have been the result of a coincidence of the strengthening of the Siberian high pressure system during winters (Rohling et al., 2002; Çagatay et al., 2014), and the gradual decrease in solar irradiance, especially around 2.8 ka BP (Roth and Joos, 2013), in accordance with changes in the North Atlantic (Bond et al., 2001). For the Holocene, the most striking result is that the spikes in precipitation and temperature records appear to closely follow the North Atlantic Bond events, whereas the trends do not. If the cause of the Bond events is indeed solar forcing, as claimed by Bond et al. (2001), then we can also state that the climate oscillations in the region were also greatly influenced by solar forcing.”

Chu et al., 2017

Zhang et al., 2017

“[S]ummer temperature variability at the QTP [Qinghai-Tibetan Plateau] responds rapidly to solar irradiance changes in the late Holocene”

Kotthoff et al., 2017

Yao et al., 2017

Jara et al., 2017

Li et al., 2017

“Overall, the strong linkage between solar variability and summer SSTs is not only of regional significance, but is also consistent over the entire North Atlantic region.”

Jones et al., 2017

Zhang et al., 2017

Vachula et al., 2017


Fischel et al., 2017

Li et al., 2017

Anderson et al., 2017

Woodson et al., 2017

The last ca. 1000 years recorded the warmest SST averaging 28.5°C. We record, for the first time in this region, a cool interval, ca. 1000 years in duration, centered on 5000 cal years BP concomitant with a wet period recorded in Borneo. The record also reflects a warm interval from ca. 1000 to 500 cal years BP that may represent the Medieval Climate Anomaly. Variations in the East Asian Monsoon (EAM) and solar activity are considered as potential drivers of SST trends. However, hydrology changes related to the El Nino-Southern Oscillation (ENSO) variability, ~ shifts of the Western Pacific Warm Pool and migration of the Intertropical Convergence Zone are more likely to have impacted our SST temporal trend. …  The SA [solar activity] trends (Steinhilber et al., 2012) are in general agreement with the regional cooling of SST (Linsley et al., 2010) and the SA [solar activity] oscillations are roughly coincident with the major excursions in our SST data.”

Koutsodendris et al., 2017

“Representing one of the strongest global climate instabilities during the Holocene, the Little Ice Age (LIA) is marked by a multicentennial-long cooling (14-19th centuries AD) that preceded the recent ‘global warming’ of the 20th century. The cooling has been predominantly attributed to reduced solar activity and was particularly pronounced during the 1645-1715 AD and 1790-1830 AD solar minima, which are known as Maunder and Dalton Minima, respectively.”

Browne et al., 2017

Perșoiu et al., 2017

Kawahata et al., 2017

“The SST [sea surface temperature] shows a broad maximum (~17.3 °C) in the mid-Holocene (5-7 cal kyr BP), which corresponds to the Jomon transgression. … The SST maximum continued for only a century and then the SST [sea surface temperatures] dropped by 3.5 °C [15.1 to 11.6 °C] within two centuries. Several peaks fluctuate by 2°C over a few centuries.”

Saini et al., 2017

Dechnik et al., 2017

Wu et al., 2017

Sun et al., 2017

“Our findings are generally consistent with other records from the ISM [Indian Summer Monsoon]  region, and suggest that the monsoon intensity is primarily controlled by solar irradiance on a centennial time scale. This external forcing may have been amplified by cooling events in the North Atlantic and by ENSO activity in the eastern tropical Pacific, which shifted the ITCZ further southwards.”

Wu et al., 2017

“The existence of depressed MAAT [mean annual temperatures] (1.3°C lower than the 3200-year average) between 1480 CE and 1860 CE (470–90 cal. yr BP) may reflect the manifestation of the ‘Little Ice Age’ (LIA) in southern Costa Rica. Evidence of low-latitude cooling and drought during the ‘LIA’ has been documented at several sites in the circum-Caribbean and from the tropical Andes, where ice cores suggest marked cooling between 1400 CE and 1900 CE.  Lake and marine records recovered from study sites in the southern hemisphere also indicate the occurrence of ‘LIA’ cooling. High atmospheric aerosol concentrations, resulting from several large volcanic eruptions and sea-ice/ocean feedbacks, have been implicated as the drivers responsible for the ‘LIA’.”

Park, 2017

Late Holocene climate change in coastal East Asia was likely driven by ENSO variation.   Our tree pollen index of warmness (TPIW) shows important late Holocene cold events associated with low sunspot periods such as Oort, Wolf, Spörer, and Maunder Minimum. Comparisons among standard Z-scores of filtered TPIW, ΔTSI, and other paleoclimate records from central and northeastern China, off the coast of northern Japan, southern Philippines, and Peru all demonstrate significant relationships [between solar activity and climate]. This suggests that solar activity drove Holocene variations in both East Asian Monsoon (EAM) and El Niño Southern Oscillation (ENSO).”

Dong et al., 2017

Nazarova et al., 2017

“The application of transfer functions resulted in reconstructed T July fluctuations of approximately 3 °C over the last 2800 years. Low temperatures (11.0-12.0 °C) were reconstructed for the periods between ca 1700 and 1500 cal yr BP (corresponding to the Kofun cold stage) and between ca 1200 and 150 cal yr BP (partly corresponding to the Little Ice Age [LIA]). Warm periods (modern T[emperatures] July or higher) were reconstructed for the periods between ca 2700 and 1800 cal yr BP, 1500 and 1300 cal yr BP and after 150 cal yr BP.”

Samartin et al., 2017

Thienemann et al., 2017

“[P]roxy-inferred annual MATs[annual mean air temperatures] show the lowest value at 11,510 yr BP (7.6°C). Subsequently, temperatures rise to 10.7°C at 9540 yr BP followed by an overall decline of about 2.5°C until present (8.3°C).”

Li et al., 2017

“Contrary to the often-documented warming trend over the past few centuries, but consistent with temperature record from the northern Tibetan Plateau, our data show a gradual decreasing trend of 0.3 °C in mean annual air temperature from 1750 to 1970 CE. This result suggests a gradual cooling trend in some high altitude regions over this interval, which could provide a new explanation for the observed decreasing Asian summer monsoon. In addition, our data indicate an abruptly increased interannual-to decadal-scale temperature variations of 0.8 – 2.2 °C after 1970 CE, in terms of both magnitude and frequency, indicating that the climate system in high altitude regions would become more unstable under current global warming.”

Krawczyk et al., 2017

Markle et al., 2017

Bird et al., 2017

Dodrill et al., 2017

“These archaeological reconstructions of average palaeo-SST during the 1500–1100 cal BP time-period suggest that the nearshore environments of Palau were slightly warmer than those today by approximately 1–2°C.”

Pendea et al., 2017  (Russia)

The Holocene Thermal Maximum (HTM) was a relatively warm period that is commonly associated with the orbitally forced Holocene maximum summer insolation (e.g., Berger, 1978; Bartlein et al., 2011). Its timing varies widely from region to region but is generally detected in paleorecords between 11 and 5 cal ka BP (e.g., Kaufman et al., 2004; Bartlein et al., 2011; Renssen et al., 2012).  … In Kamchatka, the timing of the HTM varies. Dirksen et al. (2013) find warmer-than-present conditions between 9000 and 5000 cal yr BP in central Kamchatka and between 7000 and 5800 cal yr BP at coastal sites.”

Stivrins et al., 2017 (Latvia)

“Conclusion: Using a multi-proxy approach, we studied the dynamics of thermokarst characteristics in western Latvia, where thermokarst occurred exceptionally late at the Holocene Thermal Maximum. …  [A] thermokarst active phase … began 8500 cal. yr BP and lasted at least until 7400 cal. yr BP. Given that thermokarst arise when the mean summer air temperature gradually increased ca. 2°C beyond the modern day temperature, we can argue that before that point, the local geomorphological conditions at the study site must have been exceptional to secure ice-block from the surficial landscape transformation and environmental processes.”

Bañuls-Cardona et al., 2017 (Spain)

“During the Middle Holocene we detect important climatic events. From 7000 to 6800 [years before present] (MIR 23 and MIR22), we register climatic characteristics that could be related to the end of the African Humid Period, namely an increase in temperatures and a progressive reduction in arboreal cover as a result of a decrease in precipitation. The temperatures exceeded current levels by 1°C, especially in MIR23, where the most highly represented taxon is a thermo-Mediterranean species, M. (T.) duodecimcostatus.”

Reid, 2017 (Global)

The small increase in global average temperature observed over the last 166 years is the random variation of a centrally biased random walk. It is a red noise fluctuation. It is not significant, it is not a trend and it is not likely to continue.”

Åkesson et al., 2017 (Norway)

“Reconstructions for southern Norway based on pollen and chironomids suggest that summer temperatures were up to 2 °C higher than present in the period between 8000 and 4000 BP, when solar insolation was higher (Nesje and Dahl, 1991; Bjune et al., 2005; Velle et al., 2005a).”

Molnár and Végvári, 2017 (SE Central Europe)

“Our study provides an estimate for the value of MAT of HTM of Pannon region with an interval of 0.4°C, relying on macroecological considerations. We calculate the temperature of the HTM [Holocene Thermal Maximum] 1.3–1.7°C warmer than the present temperature.”

Lusas et al., 2017 (East Greenland)

“The lack of glacio-lacustrine sediments throughout most of the record suggests that the ice cap was similar to or smaller than present throughout most of the Holocene. This restricted ice extent suggests that climate was similar to or warmer than present, in keeping with other records from Greenland that indicate a warm early and middle Holocene. Middle Holocene magnetic susceptibility oscillations, with a ~200-year frequency in one of the lakes, may relate to solar influence on local catchment processes. … Air temperatures in Milne Land, west of our study area, based on preliminary estimates from chironomids, may have been 3–6°C warmer than at present (Axford et al. 2013), and in Scoresby Sund itself, warm ocean fauna, including Mytilus edulis and Chlamys islandica, both of which live far to the south today, occupied the fjords (Sugden and John 1965; Hjort and Funder 1974; Street 1977; Funder 1978; Bennike and Wagner 2013; Fig. 13).  … Recession of Istorvet ice cap in the last decade has revealed plant remains that show that the glacier was smaller than at present during the early stages of the Medieval Warm Period, but expanded during the late Holocene ca. AD 1150 (Lowell et al. 2013).”

Hu et al., 2017  (Yellow River, China)

“According to the pollen records in the HRYR [Headwater Region of the Yellow River], the climate in the Holocene thermal maximum was warmer and wetter than present (temperature was 2 -3 °C higher than present)

Elmslie, 2017  (NE Ontario, Canada)

The Holocene Thermal Maximum (HTM) was a period of enhanced warmth during the early-to- mid Holocene period largely caused by enhanced solar insolation. In northwestern Ontario, the HTM was characterized by a lower abundance of Picea pollen and an increase in Cupressaceae and Ambrosia pollen. Pollen-based inferences suggest HTM temperatures were elevated by approximately 2-3°C [above present], and lake levels were regionally lower than today, suggesting warmer and more arid conditions than today. This warming resulted in increased algal production and associated cyanobacteria blooms in lakes in northwestern Ontario. In northeastern Ontario, climate projections suggest the HTM was 2-3°C warmer.”

Imada et al., 2017  (Japan)

Since the late 1990s, land surface temperatures over Japan have increased during the summer and autumn, while global mean temperatures have not risen in this duration (i.e., the global warming hiatus). In contrast, winter and spring temperatures in Japan have decreased.”

Oliva et al., 2017   (West Antarctic Peninsula)

“However, a recent analysis (Turner et al., 2016) has shown that the regionally stacked temperature record for the last three decades has shifted from a warming trend of 0.32 °C/decade during 1979–1997 to a cooling trend of − 0.47 °C/decade during 1999–2014. … This recent cooling has already impacted the cryosphere in the northern AP [Antarctic Peninsula], including slow-down of glacier recession, a shift to surface mass gains of the peripheral glacier and layer of permafrost in northern AP islands.”

Latif et al., 2017      (Southern Ocean)

“The Southern Ocean featured some remarkable changes during the recent decades. For example, large parts of the Southern Ocean, despite rapidly rising atmospheric greenhouse gas concentrations, depicted a surface cooling since the 1970s, whereas most of the planet has warmed considerably. In contrast, climate models generally simulate Southern Ocean surface warming when driven with observed historical radiative forcing. The mechanisms behind the surface cooling and other prominent changes in the Southern Ocean sector climate during the recent decades, such as expanding sea ice extent, abyssal warming, and CO2 uptake, are still under debate. Observational coverage is sparse, and records are short but rapidly growing, making the Southern Ocean climate system one of the least explored. It is thus difficult to separate current trends from underlying decadal to centennial scale variability.”

Kusahara et al., 2017  (Southern Ocean)

“In contrast to a strong decrease in Arctic sea ice extent, overall Antarctic sea ice extent has modestly increased since 1979. Several hypotheses have been proposed for the net Antarctic sea ice expansion, including atmosphere/ocean circulation and temperature changes, sea ice-atmospheric-ocean feedback, increased precipitation, and enhanced basal meltwater from ice shelves. Concomitant with this positive trend in Antarctic sea ice, sea surface temperatures (SSTs) over the Southern Ocean south of approximately 45°S have cooled over this period [since 1979].”

Xing et al., 2016 as adapted from Figure 7

Wilson et al., 2016

De Jong et al., 2016

“[T]he reconstruction…shows that recent warming (until AD 2009) is not exceptional in the context of the past century. For example, the periods around AD 1940 and from AD 1950–1955 were warmer. This is also shown in the reanalysis data for this region and was also observed by Neukom et al. (2010b) and Neukom and Gergis (2011) for Patagonia and central Chile. Similarly, based on tree ring analyses from the upper tree limit in northern Patagonia, Villalba et al. (2003) found that the period just before AD 1950 was substantially warmer than more recent decades.”

Zhu et al., 2016

“[W]e should point out that the rapid warming during the 20th century was not especially obvious in our reconstructed RLST [surface temperatures].”

Zhang et al., 2016

[P]resent-day global mean air temperatures may have been equally high around 1000 years ago during the so-called Medieval Climate Anomaly (MCA; Lamb, 1969; Grove and Switsur, 1994). However, since regional temperature reconstructions display large variability in the timing and magnitude of the MCA (PAGES 2k Consortium, 2013), this issue has not yet been adequately settled. Hence, there is still a great need to produce and improve empirical proxy data to further our understanding of near and distant climate changes.”

Zafar et al., 2016

“[O]ur results indicate that Karakorum temperature has remained decidedly out of phase with hemispheric temperature trends for at the least the past five centuries”

Zhao et al., 2016

Sunkara and Tiwari, 2016

Turner et al., 2016

“Absence of 21st century warming on Antarctic Peninsula consistent with natural variability”

Tejedor et al., 2016

Chandler et al., 2016

“Analysis of climate data for SE Iceland also indicates that the three periods of ice-frontal retreat [1936-’41, 1951-’56, and 2006-’11] identified are associated with similar summer air temperature values, which has previously been shown to be a key control in terminus variations in Iceland. We, therefore, demonstrated that the coincidence of the most recent phase of ice-frontal retreat at Skálafellsjökull (2006–2011) and warming summer temperatures is not unusual in the context of the last ~80 years. This highlights the need to place observations of contemporary glacier change in a broader, longer-term (centennial) context.”

Jones et al., 2016

[C]limate model simulations that include anthropogenic forcing are not compatible with the observed trends. … Over the 36-year satellite era, significant linear trends in annual mean sea-ice extent, surface temperature and sea-level pressure are superimposed on large interannual to decadal variability. Most observed trends, however, are not unusual when compared with Antarctic palaeoclimate records of the past two centuries.”

Zhu et al., 2016

“We identified four major cold periods (1839–1846, 1884–1901, 1906–1908 and 1941–1958) and three major warm periods (1855–1880, 1918–1932 and 1998–2013) in the past 211 years. The multi-taper method spectral analysis revealed significant cycles at 48.8, 11.5, 8.9, 3.9, 3.5 and 2–3 years, which might be associated with global climate oscillations and land-sea thermal contrasts, such as the sea surface temperatures, El Niño-Southern Oscillation, Atlantic Multidecadal Oscillation and solar activity.”

Rydval et al., 2016

Hasholt et al., 2016

“We determined that temperatures for the ablation measurement periods in late July to early September were similar in both 1933 and the recent period [1990s – present], indicating that the temperature forcing of ablation within the early warm period and the present are similar.”

Incarbona et al., 2016

“Solar activity modulates patterns in surface temperature and pressure that resemble NAO phases, through dynamical coupling processes between the stratosphere and the troposphere that transmit the solar signal to the Earth’s surface.”

Tipton et al., 2016

Serykh, 2016

“The very fast climate warming of the Euro-Asian continent that began in the 1970s may be associated with the enhanced heat transport from the North Atlantic in this period. This is evident from the fields and time series obtained in the present paper. The hiatus of this warming after 1999 may be due to the decreased heat transfer from the North Atlantic Ocean to the Eurasian territory.”

Ogi et al, 2016

Zinke et al., 2016

“We calibrate individual robust Sr / Ca records with in situ SST and various gridded SST products. The results show that the SST record from Cabri provides the first Indian Ocean coral proxy time series that records the SST signature of the PDO in the south-central Indian Ocean since 1945. … Marked negative Sr /Ca anomalies (warmer) are observed during the first half of the 20th century centred at 1918/19, 1936–1941 and in the period 1948–1951 that exceed anomalies in the 1961 to 1990 reference period.”


de Jong and de Steur, 2016

O’Donnell et al., 2016

Christy and McNider, 2016

“The time frame is 1883-2014. … Varying the parameters of the construction methodology creates 333 time series with a central trend-value based on the largest group of stations of -0.07 °C decade-1 with a best-guess estimate of measurement uncertainty being -0.12 to -0.02 °C decade-1. This best-guess result is insignificantly different (0.01 C decade-1) from a similar regional calculation using NOAA nClimDiv data beginning in 1895. … Finally, 77 CMIP-5 climate model runs are examined for Alabama and indicate no skill at replicating long-term temperature and precipitation changes since 1895.”

van As et al., 2016

“We conclude that at our study sites annual net ablation is likely to be larger in recent years than during any previous period in the instrumental era, covering up to 150 years. … [I]n southern Greenland ablation peaked significantly around 1930. While most of Greenland underwent relatively warm (summer) conditions in the 1930s (Cappelen 2015), this was most notable at the more southern locations, resulting in amplified ablation values according to our estimates. JJA [summer] temperatures were higher in 1928 and 1929 than in any other year of the Qaqortoq record, both attaining values of 9.2°C. This suggests that ablation in those years may have exceeded the largest net ablation measured on the Greenland ice sheet ( 2010).”

Ellenburg et al., 2016

Fudge et al., 2016

Harning et al., 2016

“Distal lakes document rapid early Holocene deglaciation from the coast and across the highlands south of the glacier. Sediment from Skorarvatn, a lake to the north of Drangajokull, shows that the northern margin of the ice cap reached a size comparable to its contemporary limit by ~10.3 ka. Two southeastern lakes with catchments extending well beneath modern Drangajokull confirm that by ~9.2 ka, the ice cap was reduced to ~20% of its current area.”

Jalali et al., 2016

“Several proxy records have documented surface water variability of the Mediterranean Sea during the Holocene (Kallel et al., 1997a, b, 2004; Cacho et al., 2001; Guinta et al., 2001; Rohling et al., 2002; Emeis et al., 2003; Essalami et al., 2007; Frigola et al., 2007; Castañeda et al., 2010; Boussetta et al., 2012; Martrat et al., 2014). Most of them reveal that Mediterranean Sea surface temperatures (SSTs) have undergone a long-term cooling punctuated by several cold relapses (CRs; Cacho et al., 2001; Frigola et al., 2007). While orbital forcing likely explains this long-term tendency, solar activity and volcanism contribute to forced variability (Mayewski et al., 2004; Wanner et al., 2011) together with internal variability (i.e. Atlantic multi-decadal variability (AMV), North Atlantic Oscillation; NAO) all together embedded in the multi-decadal scale variability seen in paleorecords.”

Steinman et al., 2016

Aizen et al., 2016

“[R]ecent air temperatures (1993–2003) are, on average, 0.5 °C lower than air temperatures estimated during the MWP [Medieval Warm Period] and Holocene Climate Optimum. … [P]eriods warmer than modern periods occurred for 6.5 ka [6,500 years] including during the HCO and Medieval Warm Period.”

Finsinger et al., 2016

Ge et al., 2016

“Results of this study show that warm intervals over the last 2000 years were in AD 1-200, AD 551-760, AD 951-1320, and after AD 1921, while cold intervals were in AD 201-350, AD 441-530, AD 781-950, and AD 1321-1920. Interestingly, temperatures during AD 981-1100 and AD 1201-1270 were comparable to those of our Present Warm Period, but have an uncertainty of 0.28°-0.42°C at 95% confidence level. Temperature variations over the whole of China are typically in phase with those of the Northern Hemisphere (NH) after AD 1000, the period which covers the Medieval Climate Anomaly, the Little Ice Age (LIA), and the Present Warm Period.”

Thomas et al., 2016

Paired climate and ice sheet records from previous warm periods can elucidate the factors influencing GrIS mass balance on time scales longer than the observational record [Briner et al., 2016]. During the middle Holocene, temperature on Greenland was ~ 2°C higher than present [Cuffey and Clow, 1997; Axford et al., 2013].

Thirumalai et al., 2016

Sanchez-Lopez et al., 2016

The dominant warm and arid conditions during the MCA [Medieval Climate Anomaly, 900-1300  CE], and the cold and wet conditions during the LIA [Little Ice Age, 1300-1850 CE] indicate the interplay of the NAO+, EA+ and NAO- , EA- [positive/negative North Atlantic Oscillation, East Atlantic phases], respectively. Furthermore, the higher solar irradiance during the [“warm conditions”] RP [Roman Period, 200 BCE – 500 CE] and MCA [Medieval Climate Anomaly, 900-1300 CE] may support the predominance of the EA+ [positive East Atlantic] phase, whereas the opposite scenario [“colder temperatures”] during the EMA [Early Middle Age, 500-900 CE] and LIA [Little Ice Age, 1300-1850 CE] may support the predominance of the EA- [negative East Atlantic] phase, which would favour the occurrence of frequent and persistent blocking events in the Atlantic region during these periods.”

Lyu et al., 2016

Wang et al., 2016


Mark, 2016

Much of the North Atlantic shows a maximum between 5000-8000 years B.P. Bradley et. al (2003) compiled a number of marine and terrestrial paleoclimatic proxies from throughout the Holocene which show fairly consistent broad trends in the climatic history of the North Atlantic region. Drawing from isotopic concentrations in ice cores, diatoms, pollen, and dendrochronological analyses, a clear period of elevated temperature, beginning at about 10,000 B.P and concluding at about 6,000 B.P precedes a slow and steady trend of cooling until present day.”








Otto and Roberts, 2016

“In addition to temperature records limited to the past 4000 years, data for the past few thousand years were tested. When the data were explored over the past 10,000 years, greater fluctuations in the temperature can be seen with a significant rise in temperature beginning at about 11,000 BCE and ending at 2000 CE with a maximum at about 5,000 BCE.”

Bügelmayer-Blaschek et al., 2016

Luterbacher et al., 2016

Foster et al., 2016

“The Antarctic and sub-Antarctic GDGT–temperature reconstruction for Fan Lake showed the warmest conditions between c. 3800 to 3300 cal yr BP with additional peaks in temperature at c. 2600 and 600 cal yr BP.”

Tamura et al., 2016

Moreno et al., 2016

“The major external forcing of the climate system derives from the Sun. A solar signature has been found in global mean surface temperatures, with evidence directly related to two noticeably different features of the Sun’s dynamics: its short-term irradiance fluctuations and secular patterns of 22-year and 11-year cycles (Scafetta and West, 2008). … [I]t is recognized that solar forcing manifestations denote a strong spatial and seasonal variability (Usoskin et al., 2006), and this would be the reason why it might be illusive to seek a single global relationship between climate and solar activity (de Jager, 2005). Thus, Le Mouël et al. (2009) stated that a regional approach may allow one to identify specific forms of solar forcing, where and when the solar input is most important. … [S]olar footprints on terrestrial temperatures [are] due to the strong non-linear hydrodynamic interactions across the Earth’s surface, and the accepted longerterm solar activity influence creating temperature oscillations for tens or even hundreds of years (Scafetta and West, 2003, 2007, 2008). … These spectral analysis results appear to support a solar forcing with regards to Minho GHD [grape harvest dates]”

Yamamoto et al., 2016

Jansen et al., 2016

We suggest that deviations in ELA fluctuations between Scandinavian maritime and continental glaciers around 7150, 6560, 6000, 5150, 3200 and 2200 cal. yr BP reflect the different response of continental and maritime glaciers to drops in total solar irradiance (TSI).”

Fortin and Gajewski, 2016

“A study of chironomid remains in the sediments of Lake JR01 on the Boothia Peninsula in the central Canadian Arctic provides a high-resolution record of mean July air temperatures for the last 6.9 ka …. Biological production decreased again at ~ 2 ka and the rate of cooling increased in the past 2 ka, with coolest temperatures occurring between 0.46 and 0.36 ka [460 and 360 years ago], coinciding with the Little Ice Age. Although biological production increased in the last 150 yr, the reconstructed temperatures do not indicate a warming during this time. … Modern inferred temperatures based on both pollen and chironomids are up to 3°C cooler than those inferred for the mid-Holocene.”

Barbara et al., 2016


Briner et al., 2016

The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites). The Greenland Ice Sheet retracted to its minimum extent between 5 and 3 ka [5,000 and 3,000 years ago], consistent with many sites from around Greenland depicting a switch from warm to cool conditions around that time.”
“The temperature record, which integrates all seasons, shows rapid warming from the onset of the Holocene until ~9.5 ka [9,500 years ago], relatively uniform temperature at the millennial scale until ~7 ka [7,000 years ago], followed by ~3.5 °C temperature decline to the Little Ice Age [1250-1850 C.E.], followed by ~1.5 °C warming to today.  [Today’s Greenland Ice Sheet temperatures are 2.0 °C colder than the Early and Middle Holocene] .  The record also shows centennial-scale variability on the order of 1-2 °C, and a ~3 °C temperature oscillation during the 8.2 ka event.”

Brocas et al., 2016

“[W]ithin the mid-LIG [Last Interglacial, ~125,000 years ago], a significantly higher than modern SST seasonality of 4.9°C (at 126 ka) and 4.1°C (at 124 ka) is observed. These findings are supported by climate model simulations and are consistent with the evolving amplitude of orbitally induced changes in seasonality of insolation throughout the LIG, irrespective of wider climatic instabilities that characterised this period.”

Gjerde et al., 2016

“The resulting Pw record is of higher resolution than previous reconstructions from glaciers in Norway and shows the potential of glacier records to provide high-resolution data reflecting past variations in hydroclimate. Complete deglaciation of the Ålfotbreen occurred ~9700 cal yr BP, and the ice cap was subsequently absent or very small until a short-lived glacier event is seen in the lake sediments ~8200 cal yr BP. The ice cap was most likely completely melted until a new glacier event occurred around ~5300 cal yr BP, coeval with the onset of the Neoglacial at several other glaciers in southwestern Norway. Ålfotbreen was thereafter absent (or very small) until the onset of the Neoglacial period ~1400 cal yr BP. The ‘Little Ice Age’ (LIA) ~650-50 cal yr BP [1350 to 1950] was the largest glacier advance of Ålfotbreen since deglaciation, with a maximum extent at ~400-200 cal yr BP, when the ELA was lowered approximately 200 m relative to today.”

Yu et al, 2016

“The period at 900–600 cal B.P. was coldest as indicated by ice advance, abundance of kill ages from ice-entombed mosses exposed recently from retreating glacial ice, and apparent gap in peatbank initiation. Furthermore, the discovery of a novel Antarctic hairgrass (Deschampsia antarctica) peatland at 2300–1200 cal B.P. from the mainland Antarctic Peninsula suggests a much warmer climate than the present. … [T]he sea surface temperature record from Palmer Deep off Anvers Island suggests a pronounced climate warming of ~3°C at 1600–500 cal B.P. [Shevenell et al., 2011].”

Solomina et al., 2016 (Caucasus Mountains)

The climate was warmer and glaciers were likely receding in the beginning of the past millennium CE (the “Arkhyz break in glaciation”). … In this pass, remains of wood radiocarbon dated to 700 ± 80 BP  (1180–1420 CE) were buried in a 1.5-m-thick layer of alluvium (Kaplin et al., 1971; Kotlyakov et al., 1973). Currently, the upper tree limit is located 800–900 m below this elevation. … According to indirect estimates based on pollen analyses, the upper tree limit in the “Arkhyz” period was 200–300 m higher than today (Tushinsky, Turmanina, 1979). The remains of ancient buildings and roads were also found in the Klukhorsky pass at an elevation of 2781 a.s.l. [above sea level] (Tushinsky et al., 1966), and the glacier was still present at this elevation in the mid 20th century.  …  [I]n Central and East Transcaucasia, there are artificial terraces at elevations where agriculture is not currently possible and that there are remnants of forests in places where forests have not grown since the 16th century CE.”
“Turmanina (1988), based on pollen analysis, suggested that, in the Elbrus area, the climate during the “Arkhyz” time was dryer and warmer than in the late 20th century by 1–2 °C. … Solomina et al. (2014) determined the Medieval warming in the Caucasus to be approximately 1 °C warmer than the mean of the past 4500 years. According to the Karakyol palynological and geochemical reconstructions, the warm period was long and lasted for five centuries. Considering the suggestion of Turmanina (1988) that it was also less humid, the likelihood that many glaciers, especially those located at relatively low elevation, disappeared is very high.  … The maximum glacier extent in the past millennium was reached before 1598 CE.  The advance of the 17th century CE, roughly corresponding to the Maunder Minimum, is recorded at Tsey Glacier. … General glacier retreat started in the late 1840s CE and four to five minor readvances occurred in the 1860s–1880s CE.  In the 20th century CE, the continued retreat was interrupted by small readvances in the 1910s, 1920s and 1970s–1980s.”

Lundeen and Brunelle, 2016  (Idaho, United States)

“Together, the proxies suggest that the early Holocene experienced larger than average snowpacks but very warm summers. Warmer than modern summer temperatures were maintained through much of the mid-Holocene, but snowpacks decreased dramatically, creating the most extreme xeric conditions in the Holocene between ~7100 and 6000 BP.”

Spolaor et  al., 2016 (Arctic Ocean, Region)

“Researchers have found that 8000 years ago the Arctic climate was 2 to 3 degrees warmer than now, and that there was also less summertime Arctic sea ice than today.”

MacGregor et al., 2016  (Greenland Ice Sheet)

[T]he interior of the GrIS [Greenland Ice Sheet] is flowing 95% slower now than it was on average during the Holocene [the last 9,000 years].”

Sun et al., 2016  (Xi’an, China)

“Comparing the climate between the mid-Holocene and present in the Xi’an area, the MAT [mean annual temperature] was about 1.1°C higher than today and the AP [annual precipitaion] was about 278 mm higher than today, similar to the modern climate of the Hanzhong area in the southern Qinling Mountains.”

Paus and Haugland, 2016  (Scandinavia)

“Around [9,500 years ago], pine suddenly established vertical belts of at least 200 m. These represent the highest pine-forests during the Holocene, ca. 210–170 m higher than today when corrected for land uplift. By this, summer temperatures at least 1–1.3°C warmer than today are indicated for the early Holocene thermal maximum around [8,500 to 9,500 years ago].”

Easterbrook, 2016  (Greenland)

“In the past 500 years, Greenland temperatures have fluctuated back and forth between warming and cooling about 40 times, with changes every 25–30 years. … Comparisons of the intensity and magnitude of past warming and cooling climate changes show that the global warming experienced during the past century pales into insignificance when compared to the magnitude of profound climate reversals over the past 25,000 years. At least three warming events were 20–24 times the magnitude of warming over the past century, and four were 6–9 times the magnitude of warming over the past century.”

Schneider et al., 2015

Stoffel et al., 2015

Soon et al., 2015

“[M]ost of the temperature trends since at least 1881 can be explained in terms of solar variability, with atmospheric greenhouse gas concentrations providing at most a minor contribution.”

Thapa et al., 2015

[T]emperature in Central Asia and northern Hemisphere revert back towards cooling trends in the late twentieth century.”

Yan et al., 2015

Boldt et al., 2015

Matskovsky and Helama, 2015

“The DIRECT reconstruction reveals long-term cooling during the LIA [Little Ice Age, 1300-1900 AD]  and considerable warming during the MCA [Medieval Climate Anomaly/Medieval Warm Period, 800-1200 AD]. The 20th century marks a period of generally warm temperatures; however, the temperatures of the MCA were reconstructed to be warmer and the long duration of the former makes the MCA incomparable to the 20th-century warmth (Matskovsky and Helama, 2014).”

Munz et al., 2015

Wei et al., 2015

Sánchez-Sesma, 2015

Krusic et al., 2015

Jiang et al., 2015

de Frietas et al., 2015

Larsen et al., 2015

“Southern Greenland proxy-inferred atmospheric temperatures also peaked between ca. 7 and 4 cal. kyr B.P. at 2–4 °C higher than present, followed by a Neoglacial cooling reaching a minimum during the LIA [Little Ice Age] (Fréchette and de Vernal, 2009; D’Andrea et al., 2011; Axford et al., 2013). The second phase of ice retreat behind the present-day extent in southwest and south Greenland was from ca. 1.5 to 1 cal. kyr B.P.”

Naulier et al., 2015

Gajewski, 2015

Hou et al., 2015

Lake Qinghai also displays significant temperature oscillations in the past 3000 years, which may reflect an amplified response to volcanic and/or solar forcings [Stuiver et al., 1995]. The warm period peaking around 2 ka coincides with the Roman warm period, which is followed by cooling into the little ice age, peaking at about 500 years ago (Figure 2). The most distinct and unusual feature of Lake Qinghai summer temperature record is a temperature decrease of more than 4°C between 5 and 3.5 ka. Such temperature changes have not been observed in ice core records in Greenland and speleothem records in China and East Asia. Here we show, however, that this “unusual” feature is in fact prevalent in regional records.”

Loomis et al., 2015

Rebolledo et al., 2015

Kolansky et al., 2015

Esper et al., 2014

Rinne et al., 2014

Luoto et al., 2014

Yan et al., 2014

The results suggested that the mean SSTs around AD 990 (±40) and AD 50 (±40) were 28.1 °C and 28.7 °C, 0.8 °C and 1.4 °C higher than that during AD 1994–2005, respectivelyThese records, together with the tree ring, lake sediment and literature records from the eastern China and northwest China, imply that the temperatures in recent decades do not seem to exceed the natural changes in MCA [Medieval Climate Anomaly], at least in eastern Asia from northwest China to northern SCS.”

Gennaretti et al., 2014

Zinke et al., 2014

Bertrand et al., 2014

Silveira and Pezzi, 2014

Wunsch and Heimbach, 2014

A very weak long-term [1993-2011] cooling is seen over the bulk of the rest of the ocean below that depth [2000 m], including the entirety of the Pacific and Indian Oceans, along with the eastern Atlantic basin.”

Schneider et al. 2014

Böll et al., 2014

Caniupán et al., 2014

Rella and Uchida, 2014

Meyer et al., 2014

Eldevik et al., 2014

“Through the LH [Late Holocene], ocean temperatures [North Atlantic, Nordic Seas] are comparable to the present, but up to 1°C warmer

Elbert et al., 2013

Miles et al., 2013

Lecavalier et al., 2013

Saunders et al., 2013

Ault et al., 2013

de Jong et al., 2013

Rosenthal et al., 2013

“We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1°C and 1.5°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades.”

Hanhijärvi et al., 2013

“According to Chylek et al. (2009), the Arctic warming from 1900 to 1940 proceeded at a significantly faster rate than the warming during the more recent decades and was highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting that the Arctic temperature variability is highly linked to the Atlantic Ocean thermohaline circulation at various temporal scales.”

Butler et al., 2013

Massaferro and Larocque-Tobler, 2013

Bostock et al., 2013

Levy et al., 2013

Kylander et a., 2013

Antinao and McDonald, 2013

Christiansen and Lungqvist (2012) 

Sinclair et al., 2012

“A 125-yr ice core record of climate from the Whitehall Glacier ice divide provides exceptionally highresolution stable isotope data from the northwest margin of the Ross Sea, Antarctica. … Reconstructed mean annual temperatures show no significant change between 1882 and 2006. However, a decrease in cold season [April–September (AMJJAS)] temperatures of -1.59°C ±0.84°C decade -¹(at 90% confidence) is observed since 1979.”

Esper et al., 2012

Delong et al., 2012

Pitman and Smith, 2012

 Liñán et al., 2012

Cronin, 2012

Esper et al., 2012

Mulvaney et al., 2012

“A marine sediment record from off the shore of the western Antarctic Peninsula also shows an early Holocene optimum during which surface ocean temperatures were determined to be 3.5°C higher than present. Other evidence suggests that the George VI ice shelf on the southwestern Antarctic Peninsula was absent during this early-Holocene warm interval but reformed in the mid Holocene.”

Durantou et al., 2012

Sea surface temperature [Arctic Ocean] between ∼ AD 1885–1935 are warmer by up to 3°C with respect to the average modern temperature at the coring site.  For the period ∼ AD 1887–1945, reconstructed sea ice cover values are on average 8.3 months per year which is 1.1 months per year lower than the modern values.”

Kilian and Lamy, 2012

Li et al., 2011

Yamanouchi, 2011

Neukom et al., 2011

The reconstructed SSA [Southernmost South America] mean summer temperatures between 900 and 1350 are mostly above the 1901–1995 climatology. After 1350, we reconstruct a sharp transition to colder conditions, which last until approximately 1700. The summers in the eighteenth century are relatively warm with a subsequent cold relapse peaking around 1850. In the twentieth century, summer temperatures reach conditions similar to earlier warm periods.”

Divine et al, 2011

Liu et al., 2011

“Climate events worldwide, such as the MWP and LIA, were seen in a 2485-year temperature series. The largest amplitude and rate of temperature both occurred during the EJE [Eastern Jin Event (343–425 AD)], but not in the late 20th century. The millennium-scale cycle of solar activity determined the long-term temperature variation trends, while century-scale cycles controlled the amplitudes of temperature. Sunspot minimum events were associated with cold periods. The prediction results obtained using caterpillar-SSA showed that the temperature would increase until 2006 AD on the central-eastern Plateau, and then decrease until 2068 AD, and then increase again.”

Bird et al., 2011

Hanna et al., 2011

Shevenell et al., 2011

Govil et al., 2011

Ilyashuk et al. 2011

Shevenell et al., 2011

Godad et al., 2011

Saenger et al., 2011

“A prominent feature of this record is the ∼1°C warm anomaly that occurred between 1930 and 1950. … Carolina Slope SST does not exhibit the warming trend seen in the AMO since the 1970s suggesting that other factors also impact SST variability at our site.”

Ljungqvist, 2010

Ran et al., 2010

Yang et al., 2010

Bonnet et al., 2010

Sea-surface temperature (SST) estimates suggest warmer conditions than present (anomaly∼+2 °C) averaging at 7 °C in summer until 300 cal. years BP, although cooling pulses are recorded around 1700, 1500, 1200 and 800 cal. years BP. The last 300 years were marked by a cooling from 7.6 to 3.5 °C and sea-ice cover increasing up to 7 months/yr. … From 2500 to 300 cal. years BP, SSTs were relatively high with mean values of about 2 °C and 7 °C in winter and summer, respectively. Warm phases are recorded around 1900, 1600, 1320, 1120 and 325 cal. years BP, with an optimum centered at 1320 cal. years BP. After 300 cal. years BP, SSTs were significantly lower with mean values of about 0 °C and 3.5–4 °C in winter and summer, respectively. … The record of sea-surface conditions from core JM04 indicates warmer winter SSTs during the last 2500 years than the modern average. The only exception is the interval spanning from 250 to 50 years BP, which is characterized by particularly low temperatures both in winter and summer.”

Ran et al., 2010

Gerhard, 2004

 Briffa et al., 2002

Box et al., 2009

“Meteorological station records and regional climate model output are combined to develop a continuous 168-yr (1840–2007) spatial reconstruction of monthly, seasonal, and annual mean Greenland ice sheet near-surface air temperatures. The annual whole ice sheet 1919–32 warming trend is 33% greater in magnitude than the 1994–2007 warming.”


Mangini et al., 2005



Saenger et al, 2009

Cook et al., 2009

Yadav and Singh, 2002

The 1945–1974 period was the warmest 30-yr mean period of the 20th century. However, this warming, in the context of the past four centuries, appears well within the range of normal limits. The 30-yr mean temperature anomaly for 1662–1691 (0.19°C) exceeds in magnitude (although not significantly, p = 0.23) the 1945–1974 mean (0.05°C).”

Renssen et al., 2009

Yadav, 2009

The decreasing temperature trend in late 20th century is consistent with trends noted in Nepal (Cook et al. 2003), Tibet (Briffa et al. 2001) and Central Asia (Briffa et al. 2001).

Rosenberg et al., 2004

Grudd et al., 2002

Schneider et al., 2006

Cook et al., 2006

von Gunten et al., 2009

Fan et al., 2009

Tyson et al., 2000

“The climate of the interior of South Africa was around 1°C cooler in Little Ice Age [AD 1300 to 1800] and may have been over 3°C higher than at present during the extremes of the medieval warm period [AD 1000 to 1300]. … It was variable throughout the millennium, but considerably more so during the warming of the eleventh to thirteenth centuries.  The lowest temperature events recorded during the Little Ice Age in South Africa are coeval with the Maunder and Sporer Minima in solar irradiance.  The medieval warming is shown to have coincided with … the Medieval Maximum in solar radiation.”

Doran et al., 2002

“[O]ur spatial analysis of Antarctic meteorological data demonstrates a net cooling on the Antarctic continent between 1966 and 2000, particularly during summer and autumn.”

Cook et al., 2002

“This record is the longest yet produced for New Zealand and shows clear evidence for persistent above-average temperatures within the interval commonly assigned to the MWP [Medieval Warm Period]. Comparisons with selected temperature proxies from the Northern and Southern Hemispheres confirm that the MWP was highly variable in time and space. Regardless, the New Zealand temperature reconstruction supports the global occurrence of the MWP.”

Hanna and Cappelen, 2003

“Analysis of new data for eight stations in coastal southern Greenland, 1958–2001, shows a significant cooling (trend-line change −1.29°C for the 44 years), as do sea-surface temperatures in the adjacent part of the Labrador Sea”

Chuine et al., 2004

“Figure 1 [below] shows two early warm decadal fluctuations: one in the 1380s (0.72 °C) and one in the 1420s (0.57 °C), both above the 95th percentile. The warm period of the 1420s was followed by a cold period that lasted from the mid-1430s to the end of the 1450s (0.45 °C, under the 10th percentile). Our series also reveals particularly warm events, above the 90th percentile, in the 1520s and between the 1630s and the 1680s. These decades were as warm as the end of the twentieth century. The high-temperature event of 1680 was followed by a cooling, which culminated in the 1750s (under the 5th percentile) — the start of a long cool period that lasted until the 1970s.”

Menzel, 2005

Khiyuk and Chilingar, 2006

Hantemirov and Shiyatov, 2002

Drinkwater, 2006

Sano et al., 2005

“March–September temperature was reconstructed for the past 249 years, which shows a warming trend from 1750s until approximately 1790, followed by cooling until 1810, then by a gradual warming trend extending to 1950, and a notable cold period continuing up to the present. No evidence of a consistent warming trend over the last century or two commonly appearing in higher latitudes was found in the present reconstruction”

Etien et al., 2008

Box, 2002

“Temporal and spatial variability are analysed in Greenland instrumental temperature records from 24 coastal and three ice sheet locations. … The standard period 1961–90 was marked by 1–2°C statistically significant cooling.”

Bhattacharyya and Chaudhary, 2003

Moore et al., 2001

Summer temperatures at Donard Lake [Canadian Arctic] over the past 1250 yrs averaged 2.9 °C.  At the beginning of the 13th century, Donard Lake experienced one of the largest climatic transitions in over a millennium. Average summer temperatures rose rapidly by nearly 2 °C from 1195–1220 AD [+0.80 C per decade], ending in the warmest decade in the record (~4.3 °C).”

Fettweis et al., 2008

“The rate of warming in 1920– 1930 is the most spectacular as pointed out by Chylek et al. (2006). Finally, Greenland climate was colder around 1920 and, in the 1970s and 1980s. The temperature minimum (resp. maximum) seems to have occurred in 1992 after the Mont Pinatubo eruption (resp. in 1931). The warm summers of recent years (1998, 2003, 2005), associated with large melt extent areas (Fettweis et al., 2007), seem to be less warm than these of the 1930s, as also pointed out by Hanna et al. (2007). … The absolute minimum [surface mass balance] occurred around 1930 with a SMB anomaly near −300 km3 yr−1 . Secondary (minor) SMB minima appear to have occurred in 1950 and 1960, equalling the surface mass loss rates of the last few years (1998, 2003, 2006). … After the 1990s, the GrIS SMB decreases slowly to reach the negative anomalies of the last few years, although the summers of the 2000s were not exceptional compared to 70 yr ago

Goodkin et al., 2008

Holmgren et al., 2003

Huguet et al., 2006

Andersen et al., 2004

Richey et al, 2007

Jiang et al., 2005

Sepúlveda et al., 2009

Kim et al., 2007

Goni et al., 2004

“The highest [proxy]-derived SST estimates (over 26.5°C) were measured during the Medieval Warm Period (MWP)”

Viau and Gajewski, 2009

Dupont et al., 2004

Weldeab et al, 2005

Masson-Delmotte et al., 2004

Birks and Seppä, 2004

Heiri and Lotter, 2005

Richter et al., 2009

Li et al., 2009

“The highest temperature was 22.7°C which was recorded at 1.01 cal ka BP. … Cooling period from 0.85 cal. ka BP to present. SST declined obviously in this period, with the maximum decrease amplitude of 2℃. … No global climate warming due to the greenhouse effect since the Industrial Revolution occurs in the study area.”

Tarasov et al., 2009


Powers et al., 2005

“… temperature reversals of ∼2°C during the Younger Dryas (12.5 ka BP) and at 8.2 ka BP.”

Millar et al., 2006

The paleoclimate modeled for Whitewing [Sierra Nevada, CA] during the Medieval period was significantly warmer and slightly drier than present. Medieval mean annual minimum temperature was warmer than current by 3.2°C. with large differences in winter (+3.5°C, January) and summer (+4.0°C, July). Mean annual maximum temperature was also greater in the Medieval period (+2.3°C), with greater differences in winter (+3.2°C, January) than summer (+2.6°C, July). Annual precipitation was less by 24 mm.”

Yadav et al., 1997

The most striking feature of the present reconstruction is the absence of any warming trend in the 20th century

Dahl-Jensen et al., 1998

Scuderi, 1993

‘Long-term trends in the temperature reconstruction are indicative of a 125-year periodicity that may be linked to solar activity as reflected in radiocarbon and auroral records. The results indicate that both the warm intervals during the Medieval Warm Epoch (-A.D. 800 to 1200) and the cold intervals during the Little Ice Age (-A.D. 1200 to 1900) are closely associated with the 125-year [solar activity] period.”

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