A sweeping federal report on climate change concludes that there’s stronger evidence than before of global warming, and that “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.”
Dr. Katharine Hayhoe of Texas Tech, a leading climate scientist and one of the lead authors of the voluminous report, told The New York Times that the conclusions reached by scientists from 13 federal agencies are among “the most comprehensive climate science reports” published yet.
The final draft report, obtained by the Times, contradicts claims by President Trump and some in his administration who say that the link between global warming and humans is still unproven. The report is awaiting approval by the Trump administration.
It says in the executive summary, "For the warming over the last century, there is no convincing alternative explanation" to that of human influence.
It mentions the 2011 heat wave in Texas but says that event was more complicated than the 2003 European heat wave and record heat in Australia in 2013, which pointed to man-made contributions.
It cites one study that attributed the extreme heat in Texas to natural weather variability and La Niña, primarily, and another that concluded that climate change played a significant role in Texas’ extreme heat, the Times reported.
Because of those and other conflicting studies, it concludes that there was suggestive evidence of climate change playing a role in Texas but competing schools of thought. It also characterized the link between human activity and major droughts as “complicated.”
Hayhoe, director of the Climate Science Center at Texas Tech and a professor of political science, was also a contributor to the Second National Climate Assessment in 2009 and the Third National Climate Assessment in 2014.
She is an evangelical Christian who co-authored “Climate for Change: Global Warming Facts and Faith-Based Decisions” in 2009 with her husband, and has won numerous awards and honors, most recently being named one of the World’s Greatest Leaders by Fortune.