Former Florida governor casts doubt on causes of climate change despite the world’s top climate scientists saying humans are unequivocally to blame

Jeb Bush said on Wednesday that the Earth’s climate is changing but that scientific research does not clearly show how much of the change is due to humans and how much is from natural causes.



Bush delved into climate politics during a campaign-style house party in New Hampshire at which he took questions from voters on his viewpoints as he considers whether to seek the Republican presidential nomination in 2016.

Although the US president, Barack Obama, and most climate scientists say humans are ‘unequivocally’ to blame for climate change, Bush said the degree of human responsibility is uncertain.

“Look, first of all, the climate is changing,” he said. “I don’t think the science is clear what percentage is man-made and what percentage is natural. It’s convoluted. And for the people to say the science is decided on, this is just really arrogant, to be honest with you.

“It’s this intellectual arrogance that now you can’t even have a conversation about it. The climate is changing, and we need to adapt to that reality.”

The former Florida governor’s views on climate change are dramatically at odds with national science academies, and the world’s most authoritative experts on the science, the UN’s Intergovernmental Panel on Climate Change (IPCC).



The IPCC said in a 2013 landmark report that it was extremely likely, or 95% certain, that more than half of the warming observed between 1951 and 2010 was manmade. A study found that of 4,000-plus papers published in academic journals that took a position on the causes of climate change, 97% said it was a a result of human activity.

Bush also challenged Obama’s determination earlier in the day that climate change was a threat to US national security.



“As a small part of US foreign policy,” Bush said, the US should encourage states that have had an increase in carbon emissions to take on the challenge.

But the overall country has had a reduction in carbon emissions due to new technologies, conservation measures, higher gas mileage in vehicles and a shift toward natural gas, he said.

“If the president thinks this is the gravest threat to our national security, it seems like he would say, ‘Let’s expand LNG [liquefied natural gas] as fast as we can to get it into the hands of higher carbon-intense economies like China and other places. Let’s figure out ways to use compressed natural gas for replacing importing diesel fuel, which has a higher carbon footprint,’ ” Bush said.

Although he does not believe climate change is the “highest priority”, the US should not ignore it, he said.