ROME – Pope Francis is calling on the world to take action against global warming, and many conservatives in the United States are up in arms. The pope should stick to morality, they say, and not venture into science. But, as the climate debate unfolds this year, most of humanity will find Francis’s message compelling: we need both science and morality to reduce the risk to our planet. 

The first point to note is that an overwhelming majority of Americans agree with Francis’s call for climate action.

Unfortunately, their views are not represented in the US Congress, which defends Big Coal and Big Oil, not the American people. The fossil-fuel industry spends heavily on lobbying and the campaigns of congressmen such as Senators Mitch McConnell and James Inhofe. The world’s climate crisis has been aggravated by America’s democratic crisis.

In a survey of Americans conducted in January 2015, an overwhelming majority of respondents (78%) said that, "if nothing is done to reduce global warming,” the future consequences for the US would be "somewhat serious” or "very serious.” Roughly the same proportion (74%) said that if nothing is done to reduce global warming, future generations would be hurt "a moderate amount,” "a lot,” or "a great deal.” Perhaps most tellingly, 66% said that they would be "more likely” to support a candidate who says that climate change is happening and who calls for a shift to renewable energy, while 12% would be "less likely” to support such a candidate.

In March 2015, another survey examined the attitudes of US Christians, who constitute 71% of Americans. The responses were reported for three groups: Catholics, non-Evangelical Protestants, and Evangelicals. These groups’ attitudes mirror those of Americans more generally: 69% of Catholics and 62% of mainline Protestants responded that climate change is happening, with a smaller majority of Evangelicals (51%) agreeing. Majorities in each group also agreed that global warming will harm the natural environment and future generations, and that reducing global warming would help the environment and future generations.

Which minority of Americans, then, opposes climate action? There are three main groups. The first are free-market conservatives, who seem to fear government intervention more than climate change. Some have followed their ideology to the point of denying well-established science: because government intervention is bad, they tell themselves that the science simply cannot be true.

The second group comprises religious fundamentalists. They deny climate change because they reject earth science entirely, believing the world to be newly created, contrary to the overwhelming evidence of physics, chemistry, and geology.

But it is the third group that is by far the most powerful politically: oil and coal interests, which contributed hundreds of millions of dollars to the 2014 campaign. David and Charles Koch, America’s biggest campaign financiers, are simply oilmen out to multiply their gargantuan wealth, despite the costs to the rest of humanity.

Perhaps they are true climate deniers as well. Then again, as Upton Sinclair famously quipped, "It is difficult to get a man to understand something, when his salary depends on his not understanding it.”

Francis’s right-wing critics perhaps come from all three groups, but they are at least partly funded by the third.

When the Pontifical Academies of Sciences and Social Sciences and some of the world’s top earth and social scientists met at the Vatican in April, the libertarian Heartland Institute, supported over the years by the Koch brothers, mounted a fruitless protest outside of St. Peter’s Square. The scientists at the Vatican meeting took extra care to emphasize that climate science and policy reflect fundamental principles of physics, chemistry, geology, astronomy, engineering, economics, and sociology, key parts of which have been well understood for more than 100 years.

Yet the pope’s right-wing critics are as mistaken in their theology as they are in their science. The claim that the pope should stick with morality betrays a basic misunderstanding of Roman Catholicism. The Church champions the marriage of faith and reason. At least since the publication of Thomas Aquinas’s Summa Theologica (1265-74), natural law and the Golden Rule have been viewed as the fundamental pillars of the Church’s teachings.

Most people know that the Church opposed Galileo’s advocacy of Copernican heliocentrism, for which Pope John Paul II apologized in 1992. But many are unaware of the Church’s support for modern science, including many important contributions to biology, chemistry, and physics by world-leading Catholic clerics. Indeed, the founding of the Pontifical Academy of Sciences traces its origins back more than 400 years, to the Academy of Lynxes (Accademia dei Lincei), which inducted Galileo in 1611.

Francis’s purpose, of course, is to marry modern science, both natural and social, with faith and morality. Our hard-won scientific knowledge should be used to promote human wellbeing, protect the vulnerable and the poor, preserve Earth’s fragile ecosystems, and keep faith with future generations. Science can reveal the environmental dangers caused by humanity; engineering can create the tools to protect the planet; and faith and moral reasoning can provide the practical wisdom (as Aristotle and Aquinas would have said) to choose virtuously for the common good.

The Vatican gathering in April included not only world-leading climate scientists and Nobel laureates, but also senior representatives of the Protestant, Hindu, Jewish, Buddhist, and Muslim faiths. Like Francis, religious leaders of all the world’s major religions are urging us to take wisdom from faith and climate science in order to fulfill our moral responsibilities to humanity and to the future of Earth. We should heed their call.

Jeffrey D. Sachs, Professor of Sustainable Development, Professor of Health Policy and Management, and Director of the Earth Institute at Columbia University, is also Special Adviser to the United Nations Secretary-General on the Millennium Development Goals.

Copyright: Project Syndicate.