Our planet has just experienced three consecutive warmest years on record—2014, 2015, and 2016—which has made it difficult to find politicians who continue to deny the reality of global warming and climate change. However, denial of climate science has shifted to a new tactic: to claim that the indisputable heating of the planet is primarily a natural phenomenon, and that there is major uncertainty among scientists on the issue. These assertions are false. Based on the evidence, more than 97% of climate scientists have concluded
that human-caused climate change is happening; scientists’ “best estimate” is that ALL
of the global warming since 1950 has been human-caused, primarily through an increase in carbon dioxide due to the burning of fossil fuels. Many prominent members of the Trump administration, who all have ties to the fossil fuel industry
, have been making false claims about scientists’ understanding that global warming is human-caused. For example:
- During his hearing in January 2017 to become the new EPA administrator, Scott Pruitt
claimed: “There is a diverse range of views regarding the key drivers of our changing climate among scientists.”
- Former Exxon-Mobil CEO Rex Tillerson,
who is now President Trump’s Secretary of State, claimed in his confirmation hearing: “I agree with the consensus view that combustion of fossil fuels is a leading cause for increased concentrations of greenhouse gases in the atmosphere. I understand these gases to be a factor in rising temperatures, but I do not believe the scientific consensus supports their characterization as the ‘key’ factor.”
- On the February 21, 2014, edition of MSNBC’s The Daily Rundown, host Chuck Todd asked future Vice President Mike Pence
if he was “convinced that climate change is man-made.” Pence responded:
“I don't know that that is a resolved issue in science today.” Pence similarly stated on the May 5, 2009, edition of MSNBC’s Hardball that “I think the science is very mixed on the subject of global warming.”
- Rick Perry, Trump’s nominee for Secretary of Energy, told
the Senate Energy and Natural Resources committee in January: “I believe the climate is changing. I believe some of it's naturally occurring and some of it is caused by man-made activity.”Figure 1.
Global annual temperatures up to the year 2015 (thin light red, with an 11-year moving average shown as a thick dark red line) have increased steadily, even though the total amount of energy from the sun (the annual Total Solar Irradiance, thin light blue, with an 11-year moving average shown as a thick dark blue line) has decreased slightly. Climate in past eras has seen many instances of global warming, which have been caused by an increase in heat-trapping gases like carbon dioxide or an increase in the amount of solar energy being absorbed by the Earth. Since solar energy cannot be to blame for the increase in global temperatures since 1950, scientists are confident that the steadily rising levels of heat trapping gases like carbon dioxide due to human activities is causing the observed global warming. Image credit: skepticalscience.com.The best science says: ALL of the warming since 1950 is human-caused
Based on the evidence, more than 97% of climate scientists have concluded
that human-caused climate change is happening. That’s about the same certainty
with which scientists link smoking cigarettes to lung cancer. The latest 2013 Intergovernmental Panel on Climate Change (IPCC) report
—the enormous consensus scientific summary of the science of climate change prepared once every six years--had this to say about the observed warming of Earth since 1950:“The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.”
In other words, ALL
of the observed warming after 1950 (0.6°C, 1.1°F) is due to humans. A total of 0.85°C (1.5°F) total global warming has been observed since 1880. The IPCC further quantified that human activity is extremely likely (at least 95% chance) to be responsible for more than half of Earth's temperature increase after 1950.Figure 2.
The changing view of the IPCC's assessment reports on the human contribution to climate change.Related news and linksClimate change denial is not dead
(January 31 op-ed by climate scientist Michael Mann.)https://www.nytimes.com/2017/02/02/science/climate-change-republicans.html
(February 3 article by Justin Gillis of the New York Times.)Here’s how we know Trump’s cabinet picks are wrong on human-caused global warming
(January 30 article from Dana Nuccitelli of The Guardian.)The Trump Administration Is Filling Up With Koch Allies
(December 2016 post from Ben Jervey at DeSmogBlog.)Climate Science Legal Defense Fund (CSLDF) files brief to protect NOAA climate scientists
(CSLDF post on February 1.)Trump’s war on EPA regulations will kill jobs and a lot of people: Clean air and water standards create jobs, spur innovation, and save lives
(January 25 post by Joe Romm of ThinkProgress.)If You Liked the Inquisition, You'll Love the House Science Committee
(January 31 article from Mother Jones.)The March for Science
is set for April 22 (Earth Day) in Washington D.C.The People's Climate Movement
is happening in Washington D.C. on April 29.
Have a great weekend, everyone!