A report released today by 13 federal agencies says the Earth’s climate is changing and human activities are to blame, even though that position contradicts statements made by President Donald Trump and members of his administration, the New York Times reports.
“This report has some very powerful, hard-hitting statements that are totally at odds with senior administration folks and at odds with their policies,” the paper quoted Philip B Duffy, president of the Woods Hole Research Center, as saying. “It begs the question: Where are members of the administration getting their information from? They’re obviously not getting it from their own scientists.”
Knowing how these things work, I would say there’s a safe bet much of the work for this report, the Climate Science Special Report from the Fourth National Climate Assessment, started during the administration of Barack Obama and the information is now just making its way into a report. Either that, or Mr Trump didn’t read the report before approving its release. In any case, I doubt many more reports like this will be forthcoming during Mr Trump’s presidency.
Climate drivers of significance over the industrial era include both those associated with anthropogenic activity and, to a lesser extent, those of natural origin. The only significant natural climate drivers in the industrial era are changes in solar irradiance, volcanic eruptions, and the El Niño–Southern Oscillation. Natural emissions and sinks of GHGs and tropospheric aerosols have varied over the industrial era but have not contributed significantly to RF. The effects of cosmic rays on cloud formation have been studied, but global radiative effects are not considered significant.
In other words, there are some natural factors that contribute to a rise in global temperatures of about 1.8°F since the 1880s, but the impact of natural forces is very small compared to the impact human factors play.
In short, 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 likely range of the human contribution to the global mean temperature increase over the period 1951–2010 is 1.1° to 1.4°F (0.6° to 0.8°C), and the central estimate of the observed warming of 1.2°F (0.65°C) lies within this range (high confidence). This translates to a likely human contribution of 93%–123% of the observed 1951–2010 change.”