The encyclical on the environment that Pope Francis released Thursday offers blistering criticism of 21st-century capitalism, expressing skepticism about market forces, criticizing consumerism, and cautioning about the costs of growth.

But where Francis’ environmental and economic agendas meet, he leaves something of a paradox, and potentially ammunition for both sides in the debate over how to address climate change.

While urging swift action to curb the burning of fossil fuels that have powered economies since the Industrial Revolution, he also condemns the trading of carbon-emission credits, saying it merely creates new forms of financial speculation and does not bring about “radical change.” But carbon trading is the policy most widely adopted by governments to combat climate change, and it has been endorsed by leading economists as a way to cut carbon pollution while sustaining economic growth.

The approach has taken on increased importance in the push for governments to sign a United Nations climate change accord in Paris in December that would commit every nation to enacting ambitious policies to cut their use of fossil fuels.

Francis’ encyclical also amplifies the argument that rich countries should shoulder the economic burden of cutting emissions, an issue that has blocked progress in global climate change negotiations for years.

While environmentalists around the world praised the document, some of its core messages could give pause to environmental economists and negotiators who have sought to find a path to a new United Nations accord that is politically palatable to major economies and corporations.

In particular, environmental economists criticized the encyclical’s condemnation of carbon trading, seeing it as part of a radical critique of market economies.

“I respect what the pope says about the need for action, but this is out of step with the thinking and the work of informed policy analysts around the world, who recognize that we can do more, faster, and better with the use of market-based policy instruments — carbon taxes and/or cap-and-trade systems,” Robert N. Stavins, director of the environmental economics program at Harvard, said in an email.

The approach by the pope, an Argentine who is the first pontiff from the developing world, is similar to that of a “small set of socialist Latin American countries that are opposed to the world economic order, fearful of free markets, and have been utterly dismissive and uncooperative in the international climate negotiations,” Stavins said.

Francis’ embrace of the issue of climate change, and his broader critique of global capitalism, stem from his signature economic concern: eradicating poverty. He has won wide popularity, particularly on his home continent, for an economic agenda focused on the poor.

Over the past two years, the global development institutions most focused on addressing poverty, including the World Bank, the African Development Bank, and the Asian Development Bank, have published economic research identifying climate change as a leading driver of poverty, contributing to rising sea levels that harm coastal areas in Southeast Asia, causing crop failure in Africa, and driving a slowdown in growth across the developing world. That research has informed the pope’s focus on climate change.

In the encyclical, Francis writes of “the intimate relationship between the poor and the fragility of the planet,” and says, “Both everyday experience and scientific research show that the gravest effects of all attacks on the environment are suffered by the poorest.”

Jim Yong Kim, president of the World Bank, praised the document. “Today’s release of Pope Francis’ first encyclical should serve as a stark reminder to all of us of the intrinsic link between climate change and poverty,” he said.

He added, “As the effects of climate change worsen, we know that escaping poverty will become even more difficult.”

Francis has sought to use his moral authority to press for changes to economic policy, and environmentalists hope it will add weight to his push on climate change.

But the encyclical’s criticism of market forces, and its references to sacrificing economic growth to protect the environment, could have the unintended consequence of strengthening the arguments of opponents of climate change policy.

“Humanity is called to recognize the need for changes of lifestyle, production and consumption, in order to combat this warming or at least the human causes which produce or aggravate it,” the pope wrote. “At one extreme, we find those who doggedly uphold the myth of progress and tell us that ecological problems will solve themselves simply with the application of new technology and without any need for ethical considerations or deep change.”

For years, opponents of climate change policy have argued that a global push to cut fossil fuel pollution will impede economic growth, particularly in poor countries that are heavily dependent on cheap fossil fuels.

Francis’ encyclical could give ammunition to that argument, which is being pressed by Republicans in Congress and on the presidential campaign trail. But some liberal policy experts say the document aims to weaken that case.

“He’s rather brilliantly brought back a concept that has been lost for 30 years or so, since the beginning of the Reagan administration — he says profit-making can’t be the sole criteria for decision-making,” said Jay Hakes, a historian who focuses on energy issues and was a top energy official in the administration of Jimmy Carter. “The pope’s ideas will be jarring to a modern reader at first. He says that people should not ascribe to the market magical qualities that can solve all problems.”

While the pope’s arguments against markets are likely to play poorly in Washington, they could play well in Latin American nations, especially Brazil. That nation, one of the world’s largest polluters, has a majority Roman Catholic population and has resisted devising an aggressive climate change policy, in part because of its struggles with poverty.

Internationally, advocates of climate change policy, including many economists, have pushed government efforts to put a price on carbon pollution, either with a tax or a program known as cap-and-trade, in which governments charge a fee to carbon polluters, and industry and market players can buy and sell carbon credits among themselves. That system is in place in Europe, California, several Northeastern states, and some parts of Canada and China.

The government of China, the world’s largest polluter, is moving toward a national cap-and-trade system. Advocates of a UN climate deal have encouraged governments to link their systems and bring others into the fold. But Francis’ critique of that system, if it resonates with governments, could impede the efforts to expand cap-and-trade measures. The pope said several times that developed economies owe a debt to poor nations.

“A true ‘ecological debt’ exists, particularly between the global north and south, connected to commercial imbalances with effects on the environment, and the disproportionate use of natural resources by certain countries over long periods of time,” he said.

That rich-poor divide has long stood in the way of successful climate change negotiations, with developing nations such as India refusing in the past to enact policies without promises of aid from wealthy nations. But the aim of the December summit meeting is to commit every country, rich and poor, to plans that cut emissions.