How we know the Earth is warming and humans are responsible

By Dana Nuccitelli, May 4, 2020

Air temperature in 2018 at a height of two meters, compared to 1981–2010 average. Data from the Copernicus Climate Change Service shows that 2018 was the fourth in a series of exceptionally warm years, with atmospheric CO2 concentrations continuing to rise. Source: Copernicus Climate Change Service, ECMWF

Only two-thirds of Americans are confident in the knowledge that global warming is happening, and a bare majority understand that it’s mostly caused by human activities. One-third of Americans continue to believe that global warming is mostly natural. In reality, the scientific evidence demonstrating that global warming is happening and human-caused is overwhelming, which is why there is a 90 to 100 percent expert consensus on human-caused global warming.This raises an oft-heard question, which can be loosely phrased as: How do the experts know that global warming is happening, and that humans are the cause? Herein is a summary of the evidence underlying what has been described as a “knowledge-based consensus.” Read this premium article here.

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