In 2020, more than 400 scientific papers were published that cast doubt on the position that anthropogenic CO2 emissions function as the climate’s fundamental control knob…or that otherwise serve to question the efficacy of climate models or the related “consensus” positions commonly endorsed by policymakers and mainstream media sources.

Over 400 scientific papers published in 2020 affirm the position that there are significant limitations and uncertainties inherent in our understanding of climate and climate changes, emphasizing that climate science is not settled.

More specifically, the papers in this compilation support these four main skeptical positions — categorized here as N(1) – N(4) — which question the climate alarm popularized in today’s headlines.

N(1) Natural mechanisms play well more than a negligible role (as claimed by the IPCC) in the net changes in the climate system, which includes temperature variations, precipitation patterns, weather events, etc., and the influence of increased CO2 concentrations on climatic changes are less pronounced than currently imagined.

N(2) The warming/sea levels/glacier and sea ice retreat/precipitation extremes…experienced during the modern era are neither unprecedented or remarkable, nor do they fall outside the range of natural variability.

N(3) The computer climate models are neither reliable or consistently accurate, the uncertainty and error ranges are irreducible, and projections of future climate states (i.e., an intensification of the hydrological cycle) are not supported by observations and/or are little more than speculation.

N(4) Current emissions-mitigation policies, especially related to the advocacy for renewables, are often ineffective and even harmful to the environment, whereas elevated CO2 and a warmer climate provide unheralded benefits to the biosphere (i.e., a greener planet and enhanced crop yields, lower mortality with warming).

In sharp contrast to the above, the corresponding “consensus” positions that these papers do not support are:

A(1) Close to or over 100% (110%) of the warming since 1950 has been caused by increases in anthropogenic CO2 emissions, leaving natural attribution at something close to 0%.

RealClimate.org: “The best estimate of the warming due to anthropogenic forcings (ANT) is the orange bar (noting the 1𝛔 uncertainties). Reading off the graph, it is 0.7±0.2ºC (5-95%) with the observed warming 0.65±0.06 (5-95%). The attribution then follows as having a mean of ~110%, with a 5-95% range of 80–130%. This easily justifies the IPCC claims of having a mean near 100%, and a very low likelihood of the attribution being less than 50% (p < 0.0001!).”

A(2) Modern warming, glacier and sea ice recession, sea level rise, drought and hurricane intensities…are all occurring at unprecedentedly high and rapid rates, and the effects are globally synchronous (not just regional)…and thus dangerous consequences to the global biosphere and human civilizations loom in the near future as a consequence of anthropogenic influences.

A(3) The climate models are reliable and accurate, and the scientific understanding of the effects of both natural forcing factors (solar activity, clouds, water vapor, etc.) and CO2 concentration changes on climate is “settled enough”, which means that “the time for debate has ended”.

A(4) The proposed solutions to mitigate the dangerous consequences described in N(4) – namely, wind and solar expansion – are safe, effective, and environmentally-friendly.

To reiterate, the 400+ papers compiled in 2020 support the N(1)-N(4) positions, and they undermine or at least do not support the “consensus” A(1)-A(4) positions.  These papers do not do more than that.   In other words, it is too ambitious to claim these papers prove that anthropogenic global warming (AGW) positions are invalid, or that AGW claims have now been “debunked”.

Below are the two links to the list of scientific papers for 2020 as well as an outline to their categorization.

Skeptic Papers 2020 (1)

Skeptic Papers 2020 (2)

1. Climate Change Observation, Reconstruction

A Warmer Past: Non-Hockey Stick Reconstructions 
No Net Warming Since Mid/Late 20th Century
Lack Of Anthropogenic/CO2 Signal In Sea Level Rise
Sea Levels Multiple Meters Higher When CO2 <280 ppm
Glaciers, Ice Sheets, Sea Ice
Ice Sheet Melting In High Geothermal Heat Flux Areas
Abrupt, Degrees-Per-Decade Natural Global Warming

2. Natural Mechanisms Of Weather, Climate Change

Solar Influence On Climate
ENSO, NAO, AMO, PDO Climate Influence
Climate/Precipitation Natural Variability
Cloud Climate Influence
The CO2 Greenhouse Effect – Climate Driver?
Unsettled Science, Failed Climate Modeling
Hydrological Trends Not Following Modeled Expectations
Failing Renewable Energy, Climate Policies
Wind Power Harming The Environment, Biosphere
Corals Thrive In Warm, High CO2 Environments
Elevated CO2, Warmth, Does Not Harm The Biosphere
Elevated CO2: Greens Planet, Higher Crop Yields
Global Warming Reduces Mortality. Cold Kills.
Warmer Temps “More Favorable” To Humans
No Increasing Trends In Intense Hurricanes
No Increasing Trend In Drought Frequency, Severity
Natural CO2 Emissions A Net Source, Not A Net Sink
Reforestation Cools The Surface Multiple Degrees
Mass Extinctions Due To Global Cooling
Doubling Atmospheric Pressure Warms Earth 7-10K
Miscellaneous

Below are a few samples of the papers contained in the database.

Sfîcă et al., 2020

The clouds represent a key element within the terrestrial climate system. In fact, clouds may be the most important parameter controlling the radiation budget, and, hence, the Earth climate (Hughes, 1983). This is related to the fact that clouds have a paramount importance in the radiation balance at global scale, especially due to their albedo (Ohring and Clapp, 1980). … Chiacchio and Wild (2010) have shown that more positive NAO during 1985–2000 is linked with the increase of solar radiation in Europe due to lower amounts of cloud cover which are characteristic for the southern part of the continent during positive NAO. They showed that NAO, generally anticorrelated with cloud cover at continental scale, represents one of the most important drivers of changes in solar radiation in Europe. Sfîcă et al. (2017) found that higher values of sunshine duration during winter in Romania are linked with an intense westerly circulation at continental scale. This supports the idea that there is an important link between atmospheric circulation and cloud cover. The effect on surface radiation of the decrease in cloud cover adds to the observed decrease of the optical thickness of aerosols leading to the so‐called brightening period during the last decennia (Russak, 2009; Pfeifroth et al., 2018a).

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Li et al., 2020

The shortwave cloud radiative effect (SWCRE) plays a critical role in the earth’s radiation balance, and its global mean magnitude is much larger than the warming effect induced by greenhouse gases. … Clouds strongly modulate the earth’s radiation balance. Clouds trap outgoing longwave radiation, inducing a warming effect, and also reflect incoming solar radiation back to space, leading to a cooling effect (Boucher et al., 2013).

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Smirnov, 2020

The contribution to the total radiative flux for the real (standard) atmosphere is 51% due to water molecules, 29% due to water microdroplets (clouds), 18% due to CO2 molecules, and 2% due to CH4 and N2O molecules. In addition, 98% of the flux of infrared radiation at wavelengths below 12.5 µm is created by H2O and CO2 molecules, whereas 85% of the radiative flux at wavelengths above 12.5 µm is due to clouds. If the concentration of atmospheric CO2 molecules is doubled without a change the other atmospheric param-eters, the change  of  the  radiative flux to the  Earth  due  to CO2 molecules is 7.2 W/m2, whereas the change of the total radiative flux with accounting for screening fluxes from other components is 1.3 W/m2 that corresponds to the global temperature change of 0.6 ± 0.3 K. Usually climatological models do not account for the interaction between greenhouse that leads components to a six times larger temperature change. One can compare the latter value with results of NASA programs for the analysis of evolution of the carbon dioxide concentration and the global temperature. From this it follows that doubling of the concentration of atmospheric CO2 molecules is accompanied by the change of the global temperature according to (14). Thus, in the real atmosphere only a fourth part of the global temperature change occurs due to variation of the concentration of CO2 molecules results from the greenhouse effect involving these molecules.

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Koutsoyiannis and Kundzewicz, 2020

We examine the relationship of global temperature and atmospheric carbon dioxide concentration at the monthly time step, covering the time interval 1980–2019, in which reliable instrumental measurements are available. While both causality directions exist, the results of our study support the hypothesis that the dominant direction is T → CO2.  … For the monthly scale the attained p-values in the direction T → [CO2] are always smaller than in direction [CO2] → T by about 4 to 5 orders of magnitude, thus clearly supporting T → [CO2] as dominant direction. … The results of the study support the hypothesis that both causality directions exist, with T → CO2 being the dominant, despite the fact that the former CO2 → T prevails in public, as well as in scientific, perception. Indeed, our results show that changes in CO2 follow changes in T by about six months on a monthly scale, or about one year on an annual scale. … The change in carbon fluxes due to natural processes is likely to exceed the change due to anthropogenic CO2 emissions, even though the latter are generally regarded as responsible for the imbalance of carbon in the atmosphere. … The opposite causality direction opens a nurturing interpretation question. We attempted to interpret this mechanism by noting that the increase of soil respiration, reflecting the fact that the intensity of biochemical process increases with temperature, leads to increasing natural CO2 emission.

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Singh et al., 2020

Low Antarctic continental climate sensitivity due to high ice sheet orography … The Antarctic continent has not warmed in the last seven decades, despite a monotonic increase in the atmospheric concentration of greenhouse gases. … [A]nalysis of surface radiative kernels indicates that anomalies in the downward longwave flux at the surface [greenhouse effect forcing] primarily arise as a consequence of surface temperature anomalies, rather than being the cause of those anomalies.