Climate threatsGlobal warming is here, caused by human activity: Massive federal government report

Published 3 November 2017

The White House allowed the release on Friday of a report by U.S. government’s scientists – the Climate Science Special Report – which offers voluminous scientific evidence that climate change is real, it is already here, and that it has been caused – and is being exacerbated – by human activity. The report, which is mandated by Congress, is the most comprehensive report on climate change ever produced. The study, noting that the planet is now the warmest it has been in the history of modern civilization, says that “it’s extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-twentieth century.”

The White House allowed the release on Friday of a report by U.S. government’s scientists – the Climate Science Special Report – which offers voluminous scientific evidence that climate change is real, it is already here, and that it has been caused – and is being exacerbated – by human activity.

The report, which is mandated by Congress, is the most comprehensive report on climate change ever produced.

The study, noting that the planet is now the warmest it has been in the history of modern civilization, says that “it’s extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-twentieth century.”

For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence,” the report said.

Referring to the rapidly rising levels of greenhouse gases in the atmosphere, the report states: “there is no climate analog for this century at any time in at least the last 50 million years.”

USA Today reports that the report, which is the first of two volume of the National Climate Assessment, is federally mandated, and is prepared by the U.S. top scientists every four years for the president, the Congress, and the public.

This National Climate Assessment is the fourth such report. It has been researched and assembled by a team of more than 300 experts from thirteen government agencies who have analyzed more than 1,500 scientific studies and reports. They were guided by a 60-member Federal Advisory Committee.

The report was also peer reviewed by the National Academy of Sciences.

The second volume of the assessment, focusing on the regional impacts across the United States, was released Friday as a draft for public comment.

Combined, the two documents total more than 2,000 pages.

The contents of the report and the scientific evidence it presents flatly contradict claims by President Donald Trump that global warming is “a hoax” invented by the Chinese, and assertions by members of his team, especially by Scott Pruitt, the director of the Environmental Protection Agency, who have persistently downplayed the contributions human activity makes to climate change and questioned the ability of scientists to predict the effects of global warming.

Trump earlier this year announced that the United States would withdraw from the Paris climate agreement, which requires signatory nations to set and achieve ambitious targets to reduce the greenhouse gasses that cause global warming.