US climate change skeptics and deniers said Thursday that Pope Francis was wrong to urge action against global warming because continuing to burn cheap fossil fuels could actually help the poor.

The reactions to Pope Francis' encyclical on climate change ranged from anger to polite disagreement, with US Republican presidential candidate Jeb Bush saying he respects the Catholic leader but prefers to make decisions about the environment in the political realm.

"Look, the climate is changing," Bush said at a campaign event in Iowa, according to CNN.

"I believe there are technological solutions for just about everything. And I'm sure there's one for this as well. So I respect the Pope, I think he's an incredible leader, but I think it's better to solve this problem in the political realm."

Bush, who announced his candidacy for US president on Monday, is Catholic but said religion would not guide his leadership on climate change.

"I don't go to mass for economic policy or for things in politics," he said.

Some opponents of the Pope took to Twitter to express their disapproval.

"Red Pope calls for CULTURAL REVOLUTION.' Been there, done that," former energy executive and activist Steve Milloy posted from the Twitter handle @JunkScience, along with a picture of Chinese communist revolutionary Mao Tse-tung.

After a draft of the Pope's speech leaked on Wednesday, the conservative Heartland Institute took issue with the Pope's declaration that human activity, including the reliance on polluting fossil fuels, is harming the Earth.

"The Church should speak for the poor, who need cheap, reliable, base-load coal-fired power. Yet Pope Francis has sided with the rich profiteers of doom," wrote Christopher Monckton, chief policy advisor at the Heartland Institute.

Tom Sheahen, a physicist and policy advisor at the Heartland Institute, also said that inexpensive fuels could be leveraged to assist the poor.

"If the developing countries use fossil fuels for a century or two, thereby lifting themselves out of poverty, that will not subtract from the prosperity of the entire world," Sheahen said.

"There will be a better energy source in the future."

According to Marc Morano, the publisher of the denialist website Climate Depot, "the Vatican's partnering with the United Nations climate agenda is nothing short of an unholy alliance."

He said UN global warming solutions "are at odds with most Catholic teachings on issues such as abortion, contraception, overpopulation, and helping the poor nations develop."

"Ultimately, the pope's views on climate science will do little to alter the opinions of Catholics about global warming."