New U.S. Federal Climate Change Report Undeniably Places Global Warming Blame On Humans

Ashika Manu

A U.S. report on climate change that indisputably places the blame on humans for rising global temperatures and finds “no convincing alternative explanation” for global warming, was released by the federal government last week, seemingly at odds with the Trump administration’s stance on global warming.

The Climate Science Special Report is part of the fourth National Climate Assessment and is mandated by a 1990 law requiring the government to produce the report every four years. This year, the report is a two-part assessment that firstly addresses the science behind climate change, changes in the climate, causing factors, and resulting consequences, and secondly looks at the effects these changes will have on the U.S. The 2017 report was created by dozens of climate scientists and academics, peer-reviewed by the National Academy of Sciences, and vetted by 13 federal agencies, before being released by the government.

While some scientists expressed concerns that the government would attempt to block the parts of the report detailing humanity’s effect on rising global temperatures – something the administration has done in the past through other avenues – the report was approved with minimal policy-related edits.

The report found that in the last three years, the earth has experienced consistently high temperatures and six of the last 17 years have been the warmest on record for the globe. Katharine Hayhoe, one of the lead author’s of the report, stated, “This period is now the warmest in the history of modern civilization.”

These global rising temperatures are caused by increased fossil fuel burning, which deposits more and more carbon dioxide into the atmosphere. This has in turn caused larger quantities of ice to melt at both poles, resulting in at least 25 coastal U.S. cities to experience “nuisance” flooding at high tide in the past five years. The report estimated that by the year 2100, sea levels could have risen to four feet above today’s levels. In a worst case scenario, sea levels could even rise to eight feet. Warming oceans have also caused disruption to fishing industries.

Additionally, climate change has caused – and will likely continue to cause – extreme weather, including hurricanes, heavy rainfall, flooding, wildfires, heatwaves, and droughts. The report also outlined health risks associated with declining air quality due to an increase of ozone and smoke in the air as warmer, dryer months resulted in more fires. Lastly, climate change can also cause political instability and humanitarian crises, which the report stated could burden other countries in terms of humanitarian aid and disaster response.

The report clearly stated, “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” It also outlined the difficulties in preparing for every potential climate scenario due to the increased likelihood for rapid unpredictable changes.

Despite these clear findings and undeniable conclusions, the White House attempted to downplay the report. In a statement, White House Spokesman Raj Shah said, “The climate has changed and is always changing […] the magnitude of future climate change depends significantly on ‘remaining uncertainty in the sensitivity of Earth’s climate.’”

The Trump administration has often shown their disregard for climate change science and the human impact on global warming, most clearly demonstrated in President Trump’s decision to pull the U.S. out of the Paris Climate Agreement. Administrator of the Environmental Protection Agency (EPA) Scott Pruitt, along with Energy Secretary Rick Perry, have both expressed disbelief in the past of humanity’s role in global warming and denied rising carbon dioxide levels. Many federal agencies – including the EPA, Bureau of Land Management, and U.S. Geological Survey – have also attempted to block climate scientists from speaking or publishing their findings and have even removed pages on their websites relating to climate change.

While this report is extremely important and its full publication is a win for climate scientists, whether or not it can change public opinion or even the Trump administration’s approach to climate change remains unlikely. Past reports by the National Climate Assessment have reached similar conclusions and have not made any difference in changing public opinion about climate change and global warming, in either politicians or the general public.

However, Hayhoe has said it is possible to change public opinion about climate change, as clean energy – including wind and solar power – has slowly become more common across the U.S. Policy changes regarding climate change, however, are unlikely to come from the Trump administration according to Paul Bledsoe, a former White House climate change advisor in the Clinton administration. Nevertheless, the report details important points about the human impact on climate change that need to be heard in order for policies to have a chance to mitigate global warming before it is too late.