US report says humans cause climate change, contradicting top Trump officials

Thirteen different US federal agencies studied the dominant causes of climate change. And they all came to the same conclusion, which they issued in joint report Friday afternoon: The Earth is experiencing the warmest period in the history of civilization, and humans are the dominant cause of the temperature rise, reported the New York Times. (The Times article also has a terrific explainer, called “Climate change is complex. We’ve got answers to your questions.”)

The paper said: “The global, long-term warming trend is ‘unambiguous,’ the report says, and there is ‘no convincing alternative explanation’ that anything other than humans—the cars we drive, the power plants we operate, the forests we destroy—are to blame.”

The report is notable on several fronts: It was approved by the White House to be released, even though its conclusions directly contradict the Trump administration’s position. (Energy Secretary Rick Perry, for example, said as recently as this Wednesday that the science was still out as to whether humans cause climate change.) Consequently, many scientists who had worked on the individual climate reports it contains had feared that the Trump administration would try to suppress them.

And the timing is significant as well: The UN will hold its annual climate change convention this week.

The comprehensive study of climate science by US government researchers, known as the Climate Science Special Report, is part of a larger scientific review called the fourth National Climate Assessment. It is mandated by Congress to be released every four years. (An executive summary is here.) 

The report says that the past 115 years are “the warmest in the history of modern civilization.”

And we are now in the position where official US government policies are in direct opposition to the science it is producing.