Compiled by the editorial desk with reference to the draft Climate Science Special Report, statements from federal agencies, and reporting by The New York Times and The Guardian.

A draft report prepared by scientists from 13 federal agencies concludes that human activity is the primary cause of recent climate change, and that its effects are already being felt across the United States. The findings, part of the National Climate Assessment required by Congress every four years, were obtained by The New York Times and published ahead of the Trump administration's approval.

The section, titled "Climate Science Special Report (CSSR)," states that average temperatures in the U.S. have risen significantly since the 1980s, and that the past few decades have been the warmest in 1,500 years. The report's authors write that "evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans," and that it is "extremely likely" that more than half of the global temperature increase since 1951 is linked to human influence.

Extreme Weather and Rising Seas

The report also validates concerns about rising sea levels, which are already affecting some U.S. coastal areas. It notes an "unmistakable link" between climate change and extreme weather, though the field of "attribution science" remains complex. The researchers found "relatively strong evidence" that human factors contributed to events like the 2003 European heat wave and the 2013 record heat in Australia, while other events, such as the 2011 Texas heat wave, were more complicated due to the influence of La Niña.

While the CSSR does not include policy recommendations, it projects that average annual temperatures in the U.S. could rise by 2.8 to 4.8 degrees Celsius (5.0 to 8.6 degrees Fahrenheit) by the end of the century, depending on future carbon emission levels. To keep global temperature increase below the 2-degree Celsius limit, the report says, worldwide emissions would need to be significantly reduced.

Political Tensions and the Paris Agreement

The draft comes as the U.S. has officially withdrawn from the Paris Climate Agreement, though a coalition of states and private-sector organizations remain committed to its goal of capping the global temperature increase at 1.5 degrees Celsius. Renewable energy is increasingly becoming a cheaper alternative to fossil fuels and a source of employment for many Americans.

However, the report's authors have expressed concern that the Trump administration might alter or suppress the findings. One anonymous scientist told The New York Times they are worried about potential changes. President Donald Trump has called climate change a hoax, and EPA Administrator Scott Pruitt has questioned the role of carbon dioxide in climate change. The EPA is one of the 13 agencies tasked with approving the report by August 18. Meanwhile, The Guardian reports that U.S. Department of Agriculture staff have been told to avoid using the term "climate change" in their work.

Michael Oppenheimer, a professor of geoscience and international affairs at Princeton University who was not involved in the report, described the situation as "fraught." He told The New York Times, "This is the first case in which an analysis of climate change of this scope has come up in the Trump administration, and scientists will be watching very carefully to see how they handle it."