Scott Pruitt: Climate change-denying EPA chief is told carbon dioxide causes global warming

The American Meteorological Society has written to the new head of the US Environmental Protection Agency to correct him after he claimed carbon dioxide was not the primary cause of global warming.

Scott Pruitt, whose appointment by Donald Trump was highly controversial given his track record of denying climate science, also claimed there was “tremendous disagreement” over the issue.

However in its letter, the AMS said thousands of scientists worldwide had all reached the same conclusion that carbon dioxide and other greenhouse gases were driving the rise in temperature based on “multiple independent lines of evidence”.

Such findings were “indisputable”, the letter added. This echoed earlier remarks by the chief executive of the American Association for the Advancement of Science, Rush Holt, who compared denying climate science to disputing gravity.

In the letter to Mr Pruitt, a lawyer who has made a career out of suing the EPA, the AMS said: “In a recent CNBC interview, you stated that you do not agree that carbon dioxide is the primary driver of the global warming revealed by the temperature records over recent decades.

“In reality, the world’s seven billion people are causing climate to change and our emissions of carbon dioxide and other greenhouse gases are the primary cause.

“This is a conclusion based on the comprehensive assessment of scientific evidence.

"It is based on multiple independent lines of evidence that have been affirmed by thousands of independent scientists and numerous scientific institutions around the world.

“We are not familiar with any scientific institution with relevant subject matter expertise that has reached a different conclusion.”

The AMS said “these indisputable findings” had shaped the society's official statement about climate change.

This states: “It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases, including carbon dioxide (CO2), chlorofluorocarbons, methane, and nitrous oxide.

“The most important of these over the long term is CO2, whose concentration in the atmosphere is rising principally as a result of fossil-fuel combustion and deforestation.”

The AMS said it understood and accepted that people could “reach differing conclusions on the decisions and actions to be taken in the face of this reality”.

“That’s the nature of the political process in a democratic society,” the letter said.

“But mischaracterizing the science is not the best starting point for a constructive dialogue.

“We hope that you [Pruitt] will reconsider your stance on the science, and then help lead the nation and the world to consider, first, options for action, and then the course to be followed.”

Mr Pruitt was asked on a CNBC TV show called Squawk Box if he thought it had been proved that carbon dioxide was the “primary control knob for climate”.

He replied: “I think that measuring with precision human activity on the climate is something very challenging to do and there's tremendous disagreement about the degree of impact, so no, I would not agree that it's a primary contributor to the global warming that we see.

“But we don't know that yet as far as ... we need to continue the debate and continue the review and the analysis.”

The idea that there is still a debate about carbon dioxide’s impact on the climate is a standard line used by ‘sceptics’ and it may be that Mr Pruitt accidentally overstepped the mark by saying something that is scientifically illiterate.

The process by which carbon dioxide acts as a greenhouse gas has been understood for more than a century and can be demonstrated by a simple experiment.

The British sceptic think tank the Global Warming Policy Foundation largely accepts the science about what has happened up to the present date but argues predictions about the future exaggerate the potential dangers.

The Earth’s average temperature has risen by about one degree Celsius since the late 19th century. Scientists believe climate change will get particularly dangerous to humans – with devastating storms, severe droughts, increased wildfires, flooding and other such problems – if it rises by a further 1C.