Part 3. Unsettled Science, Failed Climate Modeling
Climate Model Unreliability/Biases/Errors and the Pause
Collins et al., 2018 Here there is a dynamical gap in our understanding. While we have conceptual models of how weather systems form and can predict their evolution over days to weeks, we do not have theories that can adequately explain the reasons for an extreme cold or warm, or wet or dry, winter at continental scales. More importantly, we do not have the ability to credibly predict such states. Likewise, we can build and run complex models of the Earth system, but we do not have adequate enough understanding of the processes and mechanisms to be able to quantitatively evaluate the predictions and projections they produce, or to understand why different models give different answers. … The global warming ‘hiatus’ provides an example of a climate event potentially related to inter-basin teleconnections. While decadal climate variations are expected, the magnitude of the recent event was unforeseen. A decadal period of intensified trade winds in the Pacific and cooler sea surface temperatures (SSTs) has been identified as a leading candidate mechanism for the global slowdown in warming.
Shen et al., 2018 The results showed that both future climate change (precipitation and temperature) and hydrological response predicted by the twenty GCMs [climate models] were highly uncertain, and the uncertainty increased significantly over time. For example, the change of mean annual precipitation increased from 1.4% in 2021–2050 to 6.5% in 2071–2100 for RCP4.5 in terms of the median value of multi-models, but the projected uncertainty reached 21.7% in 2021–2050 and 25.1% in 2071–2100 for RCP4.5.
Christy et al., 2018 [A]s new versions of the datasets are produced, trend magnitudes have changed markedly, for example the central estimate of the global trend of the mid-troposphere in Remote Sensing System’s increased 60% from +0.078 to +0.125°C decade−1, between consecutive versions 3.3 and 4.0 (Mears and Wentz 2016). … As an experiment, Mears et al. recalculated the RSS overall trend by simply truncating NOAA-14 data after 1999 (which reduced their long-term trend by 0.02 K decade−1). However, this does not address the problem that the trends of the entire NOAA-12 and −14 time series (i.e. pre-2000) are likely too positive and thus still affect the entire time series. Additionally, the evidence from the Australian and U.S. VIZ comparisons support the hypothesis that RSS contains extra warming (due to NOAA-12, −14 warming.) Overall then, this analysis suggests spurious warming in the central estimate trend of RSS of at least +0.04°C decade−1, which is consistent with results shown later based on other independent constructions for the tropical belt. … When examining all of the evidence presented here, i.e. the correlations, magnitude of errors and trend comparisons, the general conclusion is that UAH data tend to agree with (a) both unadjusted and adjusted IGRA radiosondes, (b) independently homogenized radiosonde datasets and (c) Reanalyses at a higher level, sometimes significantly so, than the other three [NOAA, RSS, UW]. … One key result here is that substantial evidence exists to show that the processed data from NOAA-12 and −14 (operating in the 1990s) were affected by spurious warming that impacted the four datasets, with UAH the least affected due to its unique merging process. RSS, NOAA and UW show considerably more warming in this period than UAH and more than the US VIZ and Australian radiosondes for the period in which the radiosonde instrumentation did not change. … [W]e estimate the global TMT trend is +0.10 ± 0.03°C decade−1. … The rate of observed warming since 1979 for the tropical atmospheric TMT layer, which we calculate also as +0.10 ± 0.03°C decade−1, is significantly less than the average of that generated by the IPCC AR5 climate model simulations. Because the model trends are on average highly significantly more positive and with a pattern in which their warmest feature appears in the latent-heat release region of the atmosphere, we would hypothesize that a misrepresentation of the basic model physics of the tropical hydrologic cycle (i.e. water vapour, precipitation physics and cloud feedbacks) is a likely candidate.
Abbott and Marohasy, 2018 While general circulation models are used by meteorological agencies around the world for rainfall forecasting, they do not generally perform well at forecasting medium-term rainfall, despite substantial efforts to enhance performance over many years. These are the same models used by the Intergovernmental Panel on Climate Change (IPCC) to forecast climate change over decades. Though recent studies suggest ANNs [artificial neural networks] have considerable application here, including to evaluate natural versus climate change over millennia, and also to better understand equilibrium climate sensitivity.
Luo et al., 2018 Over the recent three decades sea surface temperate (SST) in the eastern equatorial Pacific has decreased, which helps reduce the rate of global warming. However, most CMIP5 model simulations with historical radiative forcing do not reproduce this Pacific La Niña-like cooling. Based on the assumption of “perfect” models, previous studies have suggested that errors in simulated internal climate variations and/or external radiative forcing may cause the discrepancy between the multi-model simulations and the observation…. Based on the total 126 realizations of the 38 CMIP5 model Historical simulations, the results show that none of the 126 model historical realizations reproduce the intensity of the observed eastern Pacific cooling (Fig. 1d) and only one simulation produces a weak cooling (−0.007 °C per decade).
Ding et al., 2018 [W]e find that there was a warming hiatus/slowdown since 2005 at Ny-Ålesund. Additionally, the variation of air temperature lags by 8–9 years, which implies that the warming hiatus probably exists in the Arctic but lags behind, globally. This phenomenon is not an isolated instance, An et al.  reported that the warming rate above 4000 m of the Tibetan Plateau has been slowing since the mid-2000s. In the Antarctic Peninsula, the slowdown of the increasing temperature trend was also found after 1998/1999, however, the reason is attributed to local phenomena, such as the deepening of Amundsen Sea Low and not due to the global hiatus [Turner et al., 2016]. … From the correlation analysis, we found Ny-Ålesund could represent most Arctic areas, especially the Atlantic-Arctic sector. … Especially air temperature, the record of Ny-Ålesund can capture the variation of surface temperature over most of [the] Arctic. … The oscillations of atmospheric dynamic systems, the methods of energy transport from low to high latitudes, and feedback mechanisms of the Arctic on climate change may contribute to the warming hiatus. … [C]limate changes in polar areas remain difficult to predict, which indicates that the underlying mechanisms of polar amplification remain uncertain and debatable.
Hanna et al., 2018 Recent changes in summer Greenland blocking captured by none of the CMIP5 models … Recent studies note a signiﬁcant increase in high-pressure blocking over the Greenland region (Greenland Blocking Index, GBI) in summer since the 1990s. … We ﬁnd that the recent summer GBI increase lies well outside the range of modeled past reconstructions (Historical scenario) and future GBI projections (RCP4.5 and RCP8.5). The models consistently project a future decrease in GBI (linked to an increase in NAO), which highlights a likely key deﬁciency of current climate models if the recently-observed circulation changes continue to persist. Given well-established connections between atmospheric pressure over the Greenland region and air temperature and precipitation extremes downstream, e.g. over Northwest Europe, this brings into question the accuracy of simulated North Atlantic jet stream changes and resulting climatological anomalies […] as well as of future projections of GrIS mass balance produced using global and regional climate models.
Lean, 2018 Climate change detection and attribution have proven unexpectedly challenging during the 21st century. Earth’s global surface temperature increased less rapidly from 2000 to 2015 than during the last half of the 20th century, even though greenhouse gas concentrations continued to increase. A probable explanation is the mitigation of anthropogenic warming by La Niña cooling and declining solar irradiance. Physical climate models overestimated recent global warming because they did not generate the observed phase of La Niña cooling and may also have underestimated cooling by declining solar irradiance. Ongoing scientific investigations continue to seek alternative explanations to account for the divergence of simulated and observed climate change in the early 21st century, which IPCC termed a “global warming hiatus.” … Understanding and communicating the causes of climate change in the next 20 years may be equally challenging. Predictions of the modulation of projected anthropogenic warming by natural processes have limited skill. The rapid warming at the end of 2015, for example, is not a resumption of anthropogenic warming but rather an amplification of ongoing warming by El Niño. Furthermore, emerging feedbacks and tipping points precipitated by, for example, melting summer Arctic sea ice may alter Earth’s global temperature in ways that even the most sophisticated physical climate models do not yet replicate.
Hunziker et al., 2018 About 40 % of the observations are inappropriate for the calculation of monthly temperature means and precipitation sums due to data quality issues. These quality problems undetected with the standard quality control approach strongly affect climatological analyses, since they reduce the correlation coefficients of station pairs, deteriorate the performance of data homogenization methods, increase the spread of individual station trends, and significantly bias regional temperature trends. Our findings indicate that undetected data quality issues are included in important and frequently used observational datasets and hence may affect a high number of climatological studies. It is of utmost importance to apply comprehensive and adequate data quality control approaches on manned weather station records in order to avoid biased results and large uncertainties.
Roach et al., 2018 Consistent biases in Antarctic sea ice concentration simulated by climate models … The simulation of Antarctic sea ice in global climate models often does not agree with observations. [M]odels simulate too much loose, low-concentration sea ice cover throughout the year, and too little compact, high-concentration cover in the summer. [C]urrent sea ice thermodynamics contribute to the inadequate simulation of the low-concentration regime in many models.
Scanlon et al., 2018 The models underestimate the large decadal (2002–2014) trends in water storage relative to GRACE satellites, both decreasing trends related to human intervention and climate and increasing trends related primarily to climate variations. The poor agreement between models and GRACE underscores the challenges remaining for global models to capture human or climate impacts on global water storage trends. … Increasing TWSA [total water storage anomalies] trends are found primarily in nonirrigated basins, mostly in humid regions, and may be related to climate variations. Models also underestimate median GRACE increasing trends (1.6–2.1 km3/y) by up to a factor of ∼8 in GHWRMs [global hydrological and water resource models] (0.3–0.6 km3/y). Underestimation of GRACE-derived TWSA increasing trends is much greater for LSMs [global land surface models], with four of the five LSMs [global land surface models] yielding opposite trends (i.e., median negative rather than positive trends) … Increasing GRACE trends are also found in surrounding basins, with most models yielding negative trends. Models greatly underestimate the increasing trends in Africa, particularly in southern Africa. .. TWSA trends from GRACE in northeast Asia are generally increasing, but many models show decreasing trends, particularly in the Yenisei. … Subtracting the modeled human intervention contribution from the total land water storage contribution from GRACE results in an estimated climate-driven contribution of −0.44 to −0.38 mm/y. Therefore, the magnitude of the estimated climate contribution to GMSL [global mean sea level] is twice that of the human contribution and opposite in sign. While many previous studies emphasize the large contribution of human intervention to GMSL [global mean sea level], it has been more than counteracted by climate-driven storage increase on land over the past decade. … GRACE-positive TWSA trends (71 km3/y) contribute negatively (−0.2 mm/y) to GMSL, slowing the rate of rise of GMSL, whereas models contribute positively to GMSL, increasing the rate of rise of GMSL.
van Oldenborgh et al., 2018 [I]t was widely assumed that the probability and severity of heat waves in India are increasing due to global warming, as they do in other parts of the world. However, we do not find positive trends in the highest maximum temperature of the year in most of India since the 1970s (except spurious trends due to missing data). Decadal variability cannot explain this, but both increased air pollution with aerosols blocking sunlight and increased irrigation leading to evaporative cooling have counteracted the effect of greenhouse gases up to now. Current climate models do not represent these processes well and hence cannot be used to attribute heat waves in this area.
Urban Heat Island: Raising Surface Temperatures Artificially
Han et al., 2018 In all three regions, the stations surrounded by large urban land tend to experience rapid warming, especially at minimum temperature. This dependence is particularly significant in the southeast region, which experiences the most intense urbanization. In the northwest and intermediate regions, stations surrounded by large cultivated land encounter less warming during the main growing season, especially at the maximum temperature changes. These findings suggest that the observed surface warming has been affected by urbanization and agricultural development represented by urban and cultivated land fractions around stations in with land cover changes in their proximity and should thus be considered when analyzing regional temperature changes in mainland China.
Failing Renewable Energy, Climate Policies
Schäfer et al., 2018 Multiple types of fluctuations impact the collective dynamics of power grids and thus challenge their robust operation.
(press release) More renewables mean less stable grids, researchers find … [I]ntegrating growing numbers of renewable power installations and microgrids onto the grid can result in larger-than-expected fluctuations in grid frequency.
Jewell et al., 2018 Hopes are high that removing fossil fuel subsidies could help to mitigate climate change by discouraging inefficient energy consumption and levelling the playing field for renewable energy. Here we show that removing fossil fuel subsidies would have an unexpectedly small impact on global energy demand and carbon dioxide emissions and would not increase renewable energy use by 2030. Removing subsidies in most regions would deliver smaller emission reductions than the Paris Agreement (2015) climate pledges and in some regions global subsidy removal may actually lead to an increase in emissions, owing to either coal replacing subsidized oil and natural gas or natural-gas use shifting from subsidizing, energy-exporting regions to non-subsidizing, importing regions.
Cradden and McDermott, 2018 Prolonged cold spells were experienced in Ireland in the winters of 2009–10 and 2010–11, and electricity demand was relatively high at these times, whilst wind generation capacity factors were low. Such situations can cause difficulties for an electricity system with a high dependence on wind energy.
Blazquez et al., 2018 However, promoting renewables –in liberalized power markets– creates a paradox in that successful penetration of renewables could fall victim to its own success. With the current market architecture, future deployment of renewable energy will necessarily be more costly and less scalable. Moreover, transition towards a full 100% renewable electricity sector is unattainable. Paradoxically, in order for renewable technologies to continue growing their market share, they need to co-exist with fossil fuel technologies. … The paradox is that the same market design and renewables policies that led to current success become increasingly less successful in the future as the share of renewables in the energy mix grows. … Full decarbonization of a power sector that relies on renewable technologies alone, given the current design of these markets, is not possible as conventional technologies provide important price signals. Markets would collapse if the last unit of fossil fuel technologies was phased out. In the extreme (theoretical) case of 100 percent renewables, prices would be at the renewables marginal cost, equal to zero or even negative for long periods. These prices would not be capturing the system’s costs nor would they be useful to signal operation and investment decisions. The result would be a purely administered subsidy, i.e., a non-market outcome. This is already occurring in Germany as Praktiknjo and Erdmann  point out and is clearly an unstable outcome. Thus, non-dispatchable technologies need to coexist with fossil fuel technologies. This outcome makes it impossible for renewables policy to reach success, defined as achieving a specified level of deployment at the lowest possible cost. With volatile, low and even negative electricity prices, investors would be discouraged from entering the market and they would require more incentives to continue to operate.
Marques et al., 2018 The installed capacity of wind power preserves fossil fuel dependency. … Electricity consumption intensity and its peaks have been satisfied by burning fossil fuels. … [A]s RES [renewable energy sources] increases, the expected decreasing tendency in the installed capacity of electricity generation from fossil fuels, has not been found. Despite the high share of RES in the electricity mix, RES, namely wind power and solar PV, are characterised by intermittent electricity generation. … The inability of RES-I [intermittent renewable energy sources like wind and solar] to satisfy high fluctuations in electricity consumption on its own constitutes one of the main obstacles to the deployment of renewables. This incapacity is due to both the intermittency of natural resource availability, and the difficulty or even impossibility of storing electricity on a large scale, to defer generation. As a consequence, RES [renewable energy sources] might not fully replace fossil sources … The literature proves the existence of a unidirectional causality running from RES [renewable energy sources] to NRES [non-renewable energy sources] (Almulali et al., 2014; Dogan, 2015; Salim et al., 2014). This unidirectional causality proves the need for countries to maintain or increase their installed capacity of fossil fuel generation, because of the characteristics of RES production. … In fact, the characteristics of electricity consumption reinforce the need to burn fossil fuels to satisfy the demand for electricity. Specifically, the ECA results confirm the substitution effect between the installed capacity of solar PV and fossil fuels. In contrast, installed wind power capacity has required all fossil fuels and hydropower to back up its intermittency in the long-run equilibrium. The EGA outcomes show that hydropower has been substituting electricity generation through NRES [non-renewable energy sources], but that other RES have needed the flexibility of natural gas plants, to back them up. … [D]ue to the intermittency phenomenon, the growth of installed capacity of RES-I [intermittent renewable energy sources – wind power] could maintain or increase electricity generation from fossil fuels. … In short, the results indicate that the EU’s domestic electricity production systems have preserved fossil fuel generation, and include several economic inefficiencies and inefficiencies in resource allocation. … [A]n increase of 1% in the installed capacity of wind power provokes an increase of 0.26%, and 0.22% in electricity generation from oil and natural gas, respectively in the long-run.
Sterman et al., 2018 [G]overnments around the world are promoting biomass to reduce their greenhouse gas (GHG) emissions. The European Union declared biofuelsto be carbon-neutral to help meet its goal of 20% renewable energy by 2020, triggering a surge in use of wood for heat and electricity (European Commission 2003, Leturcq 2014, Stupak et al 2007). … But do biofuels actually reduce GHG emissions? … [A]lthough wood has approximately the same carbon intensity as coal (0.027 vs. 0.025 tC GJ−1 of primary energy […]), combustion efficiency of wood and wood pellets is lower (Netherlands Enterprise Agency; IEA 2016). Estimates also suggest higher processing losses in the wood supply chain (Roder et al 2015). Consequently, wood-fired power plants generate more CO2 per kWh than coal. Burning wood instead of coal therefore creates a carbon debt—an immediate increase in atmospheric CO2 compared to fossil energy—that can be repaid over time only as—and if— NPP [net primary production] rises above the flux of carbon from biomass and soils to the atmosphere on the harvested lands. … Growth in wood supply causes steady growth in atmospheric CO2 because more CO2 is added to the atmosphere every year in initial carbon debt than is paid back by regrowth, worsening global warming and climate change. The qualitative result that growth in bioenergy raises atmospheric CO2 does not depend on the parameters: as long as bioenergy generates an initial carbon debt, increasing harvests mean more is ‘borrowed’ every year than is paid back. More precisely, atmospheric CO2 rises as long as NPP [net primary production] remains below the initial carbon debt incurred each year plus the fluxes of carbon from biomass and soils to the atmosphere. … [C]ontrary to the policies of the EU and other nations, biomass used to displace fossil fuels injects CO2 into the atmosphere at the point of combustion and during harvest, processing and transport. Reductions in atmospheric CO2 come only later, and only if the harvested land is allowed to regrow.
Fanous and Moomaw, 2018 These nations fail to recognize the intensity of CO2 emissions linked to the burning of biomass. The chemical energy stored in wood is converted into heat or electricity by way of combustion and is sometimes used for combined heat and power cogeneration. At the point of combustion, biomass emits more carbon per unit of heat than most fossil fuels. Due to the inefficiencies of biomass energy, bioenergy power plants emit approximately 65 percent more CO2, per MWH than modern coal plants, and approximately 285 percent more than natural gas combined cycle plants. Furthermore, the Intergovernmental Panel on Climate Change (IPCC) states that combustion of biomass generates gross greenhouse gas (GHG) emissions roughly equivalent to the combustion of fossil fuels. In the case of forest timber turned into wood pellets for bioenergy use, the IPCC further indicates that the process produces higher CO2 emissions than fossil fuels for decades to centuries.
Wind Power Harming The Environment, Biosphere
Millon et al., 2018
Wind turbines impact bat activity, leading to high losses of habitat use … Island bats represent 60% of bat species worldwide and the highest proportion of terrestrial mammals on isolated islands, including numerous endemic and threatened species (Fleming and Racey, 2009). … We present one of the first studies to quantify the indirect impact of wind farms on insectivorous bats in tropical hotspots of biodiversity. Bat activity [New Caledonia, Pacific Islands, which hosts nine species of bat] was compared between wind farm sites and control sites, via ultrasound recordings at stationary points [A bat pass is defined as a single or several echolocation calls during a five second interval.] The activity of bent winged bats (Miniopterus sp.) and wattled bats (Chalinolobus sp.) were both significantly lower at wind turbine sites. The result of the study demonstrates a large effect on bat habitat use at wind turbines sites compared to control sites. Bat activity was 20 times higher at control sites compared to wind turbine sites, which suggests that habitat loss is an important impact to consider in wind farm planning. … Here, we provide evidence showing that two genera of insectivorous bat species are also threatened by wind farms. … To our knowledge, this is one of the first studies quantifying the indirect negative impact of wind turbines on bat activity in the tropics. … The lower attractiveness of the foraging habitat under wind turbines, both in a tropical and in a temperate climate, indicates that the indirect impact of wind turbine is a worldwide phenomenon.
Lopucki et al., 2018
Living in habitats affected by wind turbines may result in an increase in corticosterone levels in ground dwelling animals … Environmental changes and disturbance factors caused by wind turbines may act as potential stressors for natural populations of both flying and ground dwelling animal species. The physiological stress response results in release of glucocorticoid hormones. … The common vole showed a distinct physiological response − the individuals living near the wind turbines had a higher level of corticosterone [physiological stress affecting regulation of energy, immune reactions]. … This is the first study suggesting impact of wind farms on physiological stress reactions in wild rodent populations. Such knowledge may be helpful in making environmental decisions when planning the development of wind energy and may contribute to optimization of conservation actions for wildlife.
Ferrão da Costa et al., 2018
According to a review by Lovich and Ennen (2013), the construction and operation of wind farms have both potential and known impacts on terrestrial vertebrates, such as: (i) increase in direct mortality due to traffic collisions; (ii) destruction and modification of the habitat, including road development, habitat fragmentation and barriers to gene flow; (iii) noise effects, visual impacts, vibration and shadow flicker effects from turbines; (iv) electromagnetic field generation; (v) macro and microclimate change; (vi) predator attraction; and (vii) increase in fire risks. … Helldin et al. (2012) also highlighted that the development of road networks associated with wind farms could promote increased access for traffic related to recreation, forestry, agriculture and hunting. The consequence, particularly on remote places, is the increase in human presence, affecting large mammals via significant disturbance, habitat loss and habitat fragmentation. These negative effects are expected to be particularly relevant for species that are more sensitive to human presence and activities, such as large carnivores. Large carnivores, such as the wolf, bear, lynx or wolverine, tend to avoid areas that are regularly used by humans and—especially for breeding—show a preference for rugged and undisturbed areas (Theuerkauf et al. 2003; George and Crooks 2006; May et al. 2006; Elfstrom et al. 2008; Sazatornil et al. 2016), which are often chosen for wind power development (Passoni et al. 2017). … Results have shown that the main impact of wind farms on wolves is the induced reduction on breeding site fidelity and reproductive rates. These effects, particularly when breeding sites shift to more unsuitable areas, may imply decreasing survival and pack viability in the short term.
Watson et al., 2018
The global potential for wind power generation is vast, and the number of installations is increasing rapidly. We review case studies from around the world of the effects on raptors of wind-energy development. Collision mortality, displacement, and habitat loss have the potential to cause population-level effects, especially for species that are rare or endangered.
Aschwanden et al., 2018
The extrapolated number of collisions was 20.7 birds/wind turbine (CI-95%: 14.3–29.6) for 8.5 months. Nocturnally migrating passerines, especially kinglets (Regulus sp.), represented 55% of the fatalities. 2.1% of the birds theoretically exposed to a collision (measured by radar at the height of the wind turbines) were effectively colliding.
While wind energy provides a viable solution for emission reductions, it comes at an environmental cost, particularly for birds. As wind energy grows in popularity, its environmental impacts are becoming more apparent. Recent studies indicate that wind power has negative effects on proximate wildlife. These impacts can be direct—collision fatalities—and indirect—habitat loss (Fargione et al. 2012; Glen et al. 2013). Negative impacts associated with operational wind farms include collision mortalities from towers or transmission lines and barotrauma for bats. Habitat loss and fragmentation, as well as avoidance behavior, are also consequences resulting from wind farm construction and related infrastructure. The potential harm towards protected and migratory bird species are an urgent concern, especially for wind farms located along migratory flyways. In terms of mortality, wind turbines kill an estimated 300,000 to 500,000 birds, annually (Smallwood 2013). The high speed at which the fan wings move and the concentration of turbines create a gauntlet of hazards for birds to fly through. … [T]he height of most wind turbines aligns with the altitude many bird species fly at (Bowden 2015). Birds of prey— raptors—are of particular concern because of their slow reproductive cycles and long lifespans relative to other bird species (Kuvlesky 2007).
Lange et al., 2018
Results from our surface water extractions and aerial surveys suggest that the wind farm has negatively affected redheads through altered hydrology and disturbance displacement. Our surface water extraction analysis provides compelling evidence that the local hydrology has been greatly affected by the construction of the wind farm. … Our results suggest the occurrence of direct habitat loss and disturbance displacement of redheads from the wind farm along the lower Texas coast. Although our study was directed solely toward redheads, it is likely that this wind farm has affected other species that use these wetlands or migrate along the lower Texas coast (Contreras et al. 2017). Studies in Europe investigating the effects on waterfowl by wind turbines have reported similar results, showing that turbines have likely compromised foraging opportunities for waterfowl through disturbance displacement (Larsen and Madsen 2000).
Elevated CO2: Greens Planet, Higher Crop Yields
Pau et al., 2018 Long-term increases in tropical flowering activity across growth forms in response to rising CO2 and climate change … Here, we analyze a 28-year record of tropical flower phenology in response to anthropogenic climate and atmospheric change. We show that a multidecadal increase in flower activity is most strongly associated with rising atmospheric CO2 concentrations using yearly aggregated data. Compared to significant climatic factors, CO2 had on average an approximately three-, four-, or fivefold stronger effect than rainfall, solar radiation, and the Multivariate ENSO Index, respectively.
Zeng et al., 2018 Leaf area index (LAI) is increasing throughout the globe, implying the Earth greening. Global modelling studies support this contention, yet satellite observations and model simulations have never been directly compared. Here, for the first time, we used a coupled land-climate model to quantify the potential impact of the satellite-observed Earth greening over the past 30 years on the terrestrial water cycle. The global LAI enhancement by 8% between the early 1980s and the early 2010s is modelled to have caused increases of 12.0 ±2.4 mm yr-1 in evapotranspiration and 12.1 ±2.7 mm yr-1 in precipitation — about 55 ±25% and 28 ±6% of the observed increases in land evapotranspiration and precipitation, respectively.
Warming Beneficial, Does Not Harm Humans, Wildlife
Feng et al., 2018 [E]nvironmental conditions in years with less ice cover were more favorable for C. glacialis development than those with more ice cover. The highest success rate (85.3%) occurred in 2012, coincident with the year of the lowest sea ice extent among the 35-year study period. Transition-zone annual mean temperature was negatively correlated with September-mean sea ice extent (r = −.92, p < .01), as was food availability (r = −.96, p < .01). Annual mean temperature and food for the transition-zone individuals also showed significant upward trends although temperature appeared to have much higher variability than food. In the Chukchi Sea, significant increases in the biomass and abundance of zooplankton (particularly C. glacialis) were found in recent warm years as compared to the earlier cold years (Ershova et al., 2015). The strong positive correlation between mean developmental stage of C. glacialis and sea surface temperature from that study agreed with our modeling results, both suggesting that warmer temperatures sped up C. glacialis cohort developmental process.
Yang et al., 2018 Adélie penguin populations as inferred from […] southern Cape Bird declined slightly from ∼1450 to ∼1600 AD, began to rise afterward and reached their highest level in ∼1700 AD, then declined with fluctuations to the lowest levels through ∼1900 AD. For the past 100 yr, Adélie penguin populations experienced a sharp rise and drop. Monitoring data have shown that Adélie penguins at Cape Bird had an increasing trend in the 1970s, likely linked with changes in sea-ice extent and polynya size, but also with variation in competition with minke whales (Ainley et al., 2005; Wilson et al., 2001). Our study suggests that the penguin populations increased in the 1960s as well, consistent with their research. … Over the past 500 yr at Cape Bird, Adélie penguin populations increased during the cold period (∼1600–1825 AD), which is inconsistent with the general pattern in other studies, for example, penguin populations increased when climate became warmer, and vice versa (Emslie et al., 2007; Huang et al., 2009; Sun et al., 2000).
Laforest et al., 2018 Traditional Ecological Knowledge of Polar Bears […] Québec, Canada … Communities also differed in their perception of the prevalence of problem polar bears and the conservation status of the species, with one-third of participants reporting that polar bears will be unaffected by, or even benefit from, longer ice-free periods. A majority of participants indicated that the local polar bear population was stable or increasing. … [Participants] indicated that polar bear body condition is stable; they cited the fact that polar bears are capable of hunting seals in open water as a factor contributing to the stable body condition of the bears. … None of the participants explicitly linked the effects of a warming climate to specific impacts on polar bears. … Five participants indicated that polar bears are adept swimmers capable of hunting seals in open water. Residents of communities along Baffin Bay have also expressed this viewpoint (Dowsley and Wenzel, 2008), whereas Inuvialuit of the Western Arctic had variable perceptions of the ability of bears to catch seals in open water (Joint Secretariat, 2015). The view of polar bears as effective open-water hunters is not consistent with the Western scientific understanding that bears rely on the sea ice platform for catching prey (Stirling and McEwan, 1975; Smith, 1980). The implications of this disagreement are paramount, given that scientists suggest that the greatest threat to polar bears associated with a decrease in sea ice is a significant decrease in access to marine mammal prey (Stirling and Derocher, 1993; Derocher et al., 2004) … A recent aerial survey of the Southern Hudson Bay subpopulation concluded that the abundance of polar bears has remained steady since 1986 (943 bears; SE: 174) (Obbard et al., 2015). The survey included the entire coastal range and offshore island habitat of the Southern Hudson Bay subpopulation, except for the eastern James Bay coast. Taken together, the results of the aerial survey and the participant responses from Wemindji and Chisasibi indicate that the local population has remained stable. However, the unanimous responses from participants in Whapmagoostui/Kuujjuarapik suggest that there has been a localized increase in the number of bears near Whapmagoostui/Kuujjuarapik.
Warming, Acidification Not Harming Oceanic Biosphere
Thor et al., 2018 Uptake of anthropogenic CO2 is changing the chemistry of the global ocean . When entering the sea, CO2 reacts with water to form carbonic acid, and this ocean acidification (OA) has lowered the global ocean mean surface pH from 8.13 during the pre-industrial age to the present day 8.05. This trend is predicted to continue and current models estimate a further decrease of up to 0.4 pH units by the year 2100. [A pH unit change of 0.08 in 250 years, 0.0003 per year, vs. a projected pH unit change of 0.4 over the next 85 years.] … We incubated females at present day conditions (pHT 8.0) and year 2100 extreme conditions (pHT 7.5) during oogenesis and subsequently reciprocally transplanted laid eggs between these two conditions. Statistical tests showed no effects of maternal or direct exposure to OA [ocean acidification] at this level [7.5 pHT].
McCulloch et al., 2018 For example, over seasonal time-scales Porites corals from the Great Barrier Reef (GBR) have a large range in pHcf of ~8.3 to ~8.5, significantly greater (~×2 to ~×3) than that of reef-water (pHT ~8.01 to ~8.08), and an order of magnitude greater than that expected from ‘static’ laboratory experiments. Strong physiological controls, but of a different character, are found in corals grown in a Free Ocean Carbon Enrichment Experiment (FOCE) conducted in situ within the Heron Island lagoon (GBR). These corals exhibit near constant pHcf values regardless of external changes in temperature and seawater pH. This pattern of strong physiologically controlled ‘pH-homeostasis’, with elevated but constant pHcf has been found despite large natural seasonal variations in the pH (±0.15 pH units) of the lagoon waters, as well as the even larger super-imposed decreases in seawater pH (~0.25 pH units) designed to simulate year 2100 conditions. In natural reef environments we thus find that the processes influencing the up-regulation of pHcf in symbiont-bearing corals are subject to strong physiological controls, behaviour that is not well simulated in the current generation of aquaria-based experiments with fixed seawater pH and temperature.
Sswat et al., 2018 Over a period of 32 days, larval survival, growth in size and weight, and instantaneous growth rate were assessed in a crossed experimental design of two temperatures (10°C and 12°C) with two CO2 levels (400 μatm and 900 μatm CO2) at food levels mimicking natural levels using natural prey. Elevated temperature alone led to increased swimming activity, as well as decreased survival and instantaneous growth rate (Gi). The comparatively high sensitivity to elevated temperature in this study may have been influenced by low food levels offered to the larvae. Larval size, Gi and swimming activity were not affected by CO2, indicating tolerance of this species to projected “end of the century” CO2 levels. A synergistic effect of elevated temperature and CO2 was found for larval weight, where no effect of elevated CO2 concentrations was detected in the 12°C treatment, but a negative CO2 effect was found in the 10°C treatment. Contrasting CO2 effects were found for survival between the two temperatures. Under ambient CO2 conditions survival was increased at 12°C compared to 10°C.
Hernandez et al., 2018 Decreased pH [ocean “acidification”] had a positive effect on short-term production of the studied species. Algae with tropical affinity increased their production at higher temperatures. Respiration rates were higher at the lower temperature treatments. Future pH and temperature conditions benefit tropical algal species. … The results suggest that biomass and productivity of the more tropical species in coastal ecosystems would be enhanced by future ocean conditions.
No Increasing Trends In Intense Hurricanes
Truchelut and Staeling, 2018 The extremely active 2017 Atlantic hurricane season concluded an extended period of quiescent continental United States tropical cyclone landfall activity that began in 2006, commonly referred to as the landfall drought. We introduce an extended climatology of U.S. tropical cyclone activity based on accumulated cyclone energy (ACE) and use this data set to investigate variability and trends in landfall activity. The [hurricane landfall] drought years between 2006 and 2016 recorded an average value of total annual ACE [accumulated cyclone energy] over the U.S. that was less than 60% of the 1900–2017 average. Scaling this landfall activity metric by basin-wide activity reveals a statistically significant downward trend since 1950, with the percentage of total Atlantic ACE expended over the continental U.S. at a series minimum during the recent drought period.
Klotzbach et al., 2018 Continental United States (CONUS) hurricane-related inflation-adjusted damage has increased significantly since 1900. However, since 1900 neither observed CONUS [Continental United States] landfalling hurricane frequency nor intensity show significant trends, including the devastating 2017 season.
Zhang et al., 2018
Over the 1997–2014 period, the mean frequency of western North Pacific (WNP) tropical cyclones (TCs) was markedly lower (~18%) than the period 1980–1996. Here we show that these changes were driven by an intensification of the vertical wind shear in the southeastern/eastern WNP tied to the changes in the Walker circulation, which arose primarily in response to the enhanced sea surface temperature (SST) warming in the North Atlantic, while the SST anomalies associated with the negative phase of the Pacific Decadal Oscillation in the tropical Pacific and the anthropogenic forcing play only secondary roles.
Zhao et al., 2018
A vigorous debate has currently focused on the relationship between increasing TC [tropical cyclone] activity and increasing SST [sea surface temperatures] (Knutson et al. 2010). … [O]ver the WNP [Western North Pacific] basin, a significant decrease of TCF [tropical cyclone frequency] has been observed since 1998 (Liu and Chan 2013; Lin and Chan 2015; Zhao and Wang 2016). Global TCF [tropical cyclone frequency] has showed a similar reduction since the late 1990s (Maue 2011). Change of TCF over the past few decades does not appear to be consistent with changes in local SST. Observational analyses further pointed out that there is no significant correlation between the TCF [tropical cyclone frequency] and local SST [sea surface temperatures] over the WNP [Western North Pacific] basin (Chan 2006; Yeh et al. 2010).
No Increasing Trend In Drought/Flood Frequency, Severity
Guo et al., 2018 In drought-prone regions like Central Asia, drought monitoring studies are paramount to provide valuable information for drought risk mitigation. In this paper, the spatiotemporal drought characteristics in Central Asia are analyzed from 1966 to 2015 using the Climatic Research Unit (CRU) dataset. Central Asia showed an overall wetting trend with a switch to drying trend since 2003.
Mangini et al., 2018
The main objective of this paper is to detect the evidence of statistically significant flood trends across Europe using a high spatial resolution dataset. … Anticipated changes in flood frequency and magnitude due to enhanced greenhouse forcing are not generally evident at this time over large portions of the United States for several different measures of flood flows. … Thus, similarly to the main findings of Archfield et al. (2016) for the US, the picture of flood change in Europe is strongly heterogeneous and no general statements about uniform trends across the entire continent can be made.
Zheng et al., 2018
For the extreme drought and flood events in total, more frequent of them occurred in the 1770s and 1790s, 1870s–1880s, 1900s–1920s and 1960s, among which the 1790s witnessed the highest frequency of extreme drought and flood events totally.
Schedel, Jr. and Schedel, 2018
Flood events on the U.S. East Coast are not more severe or frequent than in the past. However, because of sea-level rise, these events are starting from a higher baseline height. Thus, the same severity of a flood event today reaches a greater absolute height than an identical flood would have reached 50 or 100 years ago. Based on current data, the good news is that the apparent worsening of flood events is due to a single, primary cause: sea level rise. Flood events are not getting stronger or occurring more frequently than in the past. They are instead starting from a higher point, allowing them to reach higher levels more often. The bad news is that sea-level rise will be a fact of life for many years into the future. Communities need to start now to make informed plans and decisions about how best to adapt.
Decreases In Extreme, Unstable Weather With Warming
Zou et al., 2018
The Tibetan Plateau (TP), one of the world’s most sensitive areas to climate change, became significantly warmer during recent decades. Since 1960 (1980), storm (hail) days have been decreasing by 6.2%/decade (18.3%/decade) in the region. … Based on 53‐year continuous weather records at 48 TP stations and reanalysis data, we show here for the first time that the consistent decline of storm days is strongly related to a drier midtroposphere since 1960. Further analysis demonstrated that fewer hail days are driven by an elevation of the melting level (thermodynamically) and a weaker wind shear (dynamically) in a warming climate. These results imply that less storm and hail may occur over TP when climate warms.
Natural CO2 Emissions A Net Source, Not A Net Sink
Biswas et al., 2018
The era of global warming and increased emission of greenhouse gases can be marked by the beginning of the industrial age. It is also true that under several conditions, natural ecosystems can be equally responsible for CO2 emission like any other anthropogenic activities which continuously release heat-trapping gases in the process of development. … East Kolkata Wetland (EKW) is an urban or peri-urban wetland located on the outskirts of the Kolkata City which performs multi-facet activities, carbon sink being one of them. The raw waste from the city is naturally treated in this wetland system, however, the aquaculture ponds situated in these wetlands which make use of this waste water for fishery is rarely studied. The present study aims to see whether the aquaculture ponds of EKW complex are acting as a source or a sink. Airwater carbon dioxide (CO2) flux was estimated for three consecutive seasons in a year and it was found that the system is acting as a CO2 source in all the three seasons.
Wang et al., 2018
We conducted a free‐water mass balance‐based study to address the rate of metabolism and net carbon exchange for the tidal wetland and estuarine portion of the coastal ocean and the uncertainties associated with this approach were assessed. We measured open water diurnal O2 and dissolved inorganic carbon (DIC) dynamics seasonally in a salt marsh‐estuary in Georgia, U.S.A. with a focus on the marsh‐estuary linkage associated with tidal flooding. We observed that the overall estuarine system was a net source of CO2 to the atmosphere and coastal ocean and a net sink for oceanic and atmospheric O2.
Li et al., 2018
Our calculated CO2 areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO2 degassing, to address a global data gap for these environments. … Rivers have been widely reported to be supersaturated in carbon dioxide (CO2) with respect to the atmosphere, and are a net source of atmospheric CO2 (Butman and Raymond, 2011; Raymond et al., 2013).
Warm/Cold Stanzas, Arctic (Bering) Sea Ice Expansion Between 2007-2013
Stabeno et al., 2018
From 2007 to 2013, the southeastern Bering Sea was dominated by extensive sea ice and below-average ocean temperatures. In 2014 there was a shift to reduced sea ice on the southern shelf and above-average ocean temperatures. These conditions continued in 2015 and 2016. … Historically, the dominant parameters controlling sea-ice extent are winds and air temperature, with the persistence of frigid, northerly winds in winter and spring resulting in extensive ice. After mid-March 2014 and 2016 there were no cold northerly or northeasterly winds. Cold northerly winds persisted into mid-April in 2015, but did not result in extensive sea ice south of 58°N. The apparent mechanism that helped limit ice on the southeastern shelf was the strong advection of warm water from the Gulf of Alaska through Unimak Pass. This pattern has been uncommon, occurring in only one other year (2003) in a 37-year record of estimated transport through Unimak Pass. During years with no sea ice on the southern shelf (e.g. 2001–2005, 2014–2016), the depth-averaged temperature there was correlated to the previous summers ocean temperature. … This latest string of three warm years apparently ended this year (2017). In March, sea ice had covered M4, and the ice edge was near or at M2 on 13 March 2017, but by June 2017 the depth-averaged temperatures at M2 were average, indicating that ocean temperature near M2 in 2017 (like the 2006 transition between the previous warm and cold stanzas) will likely be average. With this end of a warm stanza, questions arise. Will the Bering Sea continue in a pattern of warm/cold stanzas?
Post and Ramirez, 2018
The  German climate scientists largely confirm anthropogenic climate change. Almost two-thirds (63%) believe that “the climatic development in the past 50 years was predominantly influenced by human behavior,” and about a third (30%) believe it was “equally influenced by human behavior and natural factors.” Only one (1%) of the 131 climate scientists believe that it was “predominantly influenced by natural factors.” The rest (6%) did not answer the question or thinks that “this is hard to say.”
Temperature Change Leads CO2 Change, Processes Governing CO2 Changes ‘Poorly Understood’
Koutavas et al., 2018 The EEP [eastern equatorial Pacific] stack shows persistent covariation with Antarctic temperature on orbital and millennial timescales indicating tight coupling between the two regions. This coupling however cannot be explained solely by CO2 forcing because in at least one important case, the Marine Isotope Stage (MIS) 5e–5d glacial inception, both regions cooled ∼5–6.5 thousand years before CO2 decreased. More likely, their covariation was due to advection of Antarctic climate signals to the EEP by the ocean. … . The discovery that atmospheric CO2 covaries with Antarctic temperature and global ice volume (Lorius et al., 1990; Lüthi et al., 2008; Petit et al., 1999) has propelled CO2 to the forefront as climatic “globalizer”. However, the processes governing CO2 variability are themselves poorly understood, and likely require an oceanic/climatic trigger in the first place (Adkins, 2013; Ferrari et al., 2014; Sigman et al., 2010). Antarctic ice core records are furthermore ambiguous with regard to the causal relationship between CO2 and temperature. Phase relationships show CO2 lagging behind temperature in the obliquity band (Jouzel et al., 2007) and across some major transitions (Caillon et al., 2003; Fischer et al., 1999; Kawamura et al., 2007; WAIS Divide Project Members, 2013), most prominently during the Marine Isotope Stage (MIS) 5e–5d boundary, i.e. the last glacial inception. Antarctic cooling at this time was associated with a major Milankovitch signal, and appears to have transpired almost entirely before the change in CO2 concentration. It remains unclear whether the temperature lead was restricted to Antarctica or was broader.
Ozone ‘Hole’ Still Widening Since 1998 (Despite CFC Ban)
Ball et al, 2018 Here we report evidence from multiple satellite measurements that ozone in the lower stratosphere between 60° S and 60° N has indeed continued to decline since 1998. We find that, even though upper stratospheric ozone is recovering, the continuing downward trend in the lower stratosphere prevails, resulting in a downward trend in stratospheric column ozone between 60° S and 60° N. We find that total column ozone between 60° S and 60° N appears not to have decreased only because of increases in tropospheric column ozone that compensate for the stratospheric decreases. The reasons for the continued reduction of lower stratospheric ozone are not clear; models do not reproduce these trends, and thus the causes now urgently need to be established.
Arctic Methane Emissions Natural, Not Anthropogenic
Wallmann et al., 2018 Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming … Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming.
Mortality From Storm Surges/Flooding Decreasing
Bouwer and Jonkman, 2018 Global mortality from storm surges is decreasing … Changes in society’s vulnerability to natural hazards are important to understand, as they determine current and future risks, and the need to improve protection. Very large impacts including high numbers of fatalities occur due to single storm surge flood events. Here, we report on impacts of global coastal storm surge events since the year 1900, based on a compilation of events and data on loss of life. We find that over the past, more than eight thousand people are killed and 1.5 million people are affected annually by storm surges. The occurrence of very substantial loss of life (>10 000 persons) from single events has however decreased over time. Moreover, there is a consistent decrease in event mortality, measured by the fraction of exposed people that are killed, for all global regions, except South East Asia.
No Centennial-Scale Changes In Relative Humidity Since 1820s
Shi et al., 2018 Here, we average four tree-ring width chronologies from the southeastern Tibetan Plateau (TP) over their common intervals and reconstruct the variability in regional relative humidity (RH) from the previous May to the current March over 1751–2005. In contrast to the summer drying associated with centennial-scale warming and the weakening of the Asian summer monsoon, our RH [relative humidity] reconstruction shows no significant centennial trend from the 1820s through the 2000s.
Scientists: We Don’t Understand
O’Rourke and Smrekar, 2018
We searched for but failed to find systematic differences in plate thickness as functions of the geologic setting or extent of tectonic fractures. In general, we calculated heat flows that are larger than the global average on present‐day Earth—roughly twice typical values predicted for Venus, which may cool slowly or even heat up absent plate tectonics. Therefore, we conclude that coronae are sites of above average heat flow on Venus and in fact contribute a significant portion of the total heat loss budget.
(press release) https://eos.org/editor-highlights/elevated-heat-flow-at-coronae-on-venus
How does Venus, a planet similar in size to the Earth, lose heat? This question is at the heart of a long-standing conundrum of how these two planets of similar make up became so starkly different. … Their analysis indicates that the heat loss from most coronae exceeds the average expected on Venus, often by a factor of two or more. While coronae only cover approximately four percent of the surface of the planet, O’Rourke and Smrekar find that they may account for 25 percent or more of the total heat loss. Thus, coronae are a crucial component of how Venus loses heat and how its surface and interior evolves.