In his speech announcing the decision to leave the Paris climate agreement, President Trump stated the move was partly based on research that indicated the agreement would not reduce global temperatures quickly enough to have a significant impact. In his speech, he specifically stated that with full compliance, the reduction in temperature would be 0.2 degrees Celsius by the year 2100. This claim was attributed to research by an MIT research paper titled “How Much of a Difference will the Paris Agreement Make?” in White House documents that were seen by Reuters. The 0.2 degree Celsius figure also appears to come from 2014 research by the same researchers.
The original analysis in the 2014 paper was completed before the Paris agreement was finalized. It did not include all of the commitments and did not assume pledges would be continued beyond 2030. The figure in the 2016 study, which includes all of the pledges made by the nations in the agreement, shows an expected reduction in the increase between 0.6 and 1.1 degrees Celsius, which is between a 30 to 55% reduction of the 2.0 degrees Celsius increase that is considered a dangerous level of climate change.
Trump’s use of the research was defended by a senior administration official at a press briefing saying, "It's not just MIT. I think there is a consensus, not only in the environmental community, but elsewhere that the Paris agreement in and of itself will have a negligible impact on climate."