Among the many purported controversies committed by Pope Francis is his affirmation of the existence of anthropogenic climate change in his encyclical, Laudato si’, where he says this:

The climate is a common good, belonging to all and meant for all. At the global level, it is a complex system linked to many of the essential conditions for human life. A very solid scientific consensus indicates that we are presently witnessing a disturbing warming of the climatic system. In recent decades this warming has been accompanied by a constant rise in the sea level and, it would appear, by an increase of extreme weather events, even if a scientifically determinable cause cannot be assigned to each particular phenomenon. 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. It is true that there are other factors (such as volcanic activity, variations in the earth’s orbit and axis, the solar cycle), yet a number of scientific studies indicate that most global warming in recent decades is due to the great concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxides and others) released mainly as a result of human activity. As these gases build up in the atmosphere, they hamper the escape of heat produced by sunlight at the earth’s surface. The problem is aggravated by a model of development based on the intensive use of fossil fuels, which is at the heart of the worldwide energy system. Another determining factor has been an increase in changed uses of the soil, principally deforestation for agricultural purposes.[note] Laudato si'.[/note]

If it seems that the Holy Father is simply stating scientific facts here, it’s because he is. In 2014, the UN’s Intergovernmental Panel on Climate Change (IPCC) reported that human “influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems,”[note]IPCC Assessment Report.[/note] and that warming “of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.” What’s more, the IPCC said, “Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.”The IPCC is hardly alone. “That humans are causing global warming is the position of the Academies of Science from 80 countries plus many scientific organizations that study climate science,”[note]Skepticalscience.com.[/note] and surveys “of the peer-reviewed scientific literature and the opinions of experts consistently show a 97–98% consensus that humans are causing global warming.”[note]Ibid.[/note]Can the scientists be wrong? Of course they can. After all, there was a time when all respected astronomers held to the Ptolemaic model of the universe. That possibility is always present. But it is one thing to acknowledge the possibility and quite another to vociferously disagree with the findings of science, without knowledge, and without proof. And it is really quite another thing to insist that public policy decisions disregard the consensus of 97% of the relevant scientific experts.There are other areas in which the consensus of scientists are popularly called into question. Some, even though there is no inconsistency between the theory of evolution and the Catholic faith,[note]Pope Pius XII, Humani Generis.[/note] challenge the theory even though “evidence-based facts about the origins and evolution of the Earth and of life on this planet have been established by numerous observations and independently derived experimental results from a multitude of scientific disciplines.”[note]IAP Statement on the Teaching of Evolution.[/note] There are even those who refrain from having their children vaccinated against preventable diseases because of an anecdotal concern over the supposed ill effects of vaccination, including autism, although there “is increasingly convincing epidemiological and laboratory evidence against a causal relation of several alleged adverse events following immunization.”[note]"Current Opinion in Infectious Diseases," Vol. 20, no. 3 (June, 2007): 237-344.[/note] Perhaps the most striking science denials comes from the “pro-choice” camp. It is common to hear people refer to human embryos as nothing but “a clump of cells,” as if that designation conveys anything meaningful, disregarding the fact that from the moment of fertilization there exists a highly intricate organism with human parents.[note]"Life Begins at Fertilization with the Embryo's Conception," in Embryo Quotes.[/note]The simple experience of being a human being in the world should be sufficient to convince people with any capacity for reflection of the untruth of what is called “Scientism,” which is the belief “that science alone can render truth about the world and reality.” But it does not follow that science is not competent in its own sphere. It is certainly more so than non-evidence based opinions about scientific subjects.If Distributism is to be a practical movement that has a serious chance of effecting societal change, those of us who are distributists must endeavor to strictly abstain from science denialism, just as we must from conspiracy theories and all other presumptions on reality. There are two reasons for this.The first is that we can do positive harm. It might not matter much if Distributism was to be nothing more than an armchair philosophy whereby we entertained ourselves by discussing and debating issues in coffee houses and on the internet. But if we aim to have an impact on the world, if we want to build a Distributist society, the premises we bring to bear on the effort will matter a great deal.The modern day antivaccinationist movement has led to the “reemergence of other previously controlled diseases” resulting in “hospitalizations, missed days of school and work, medical complications, societal disruptions, and deaths.”[note]"The Age-old Struggle Against the Antivaccinationists," in The New England Journal of Medicine.[/note] Denying evolution may seem innocuous, but “evolutionary principles are important to understanding populations, genetics, infectious disease, diet, and other issues of public health—in diagnosis, treatment, and research.”[note]"Evolution in Medicine," in Science-Based Medicine.[/note] Abortion, of course, has killed millions. And regarding the effects of global warming, Pope Francis says this in Laudato si’:

Climate change is a global problem with grave implications: environmental, social, economic, political and for the distribution of goods. It represents one of the principal challenges facing humanity in our day. Its worst impact will probably be felt by developing countries in coming decades. Many of the poor live in areas particularly affected by phenomena related to warming, and their means of subsistence are largely dependent on natural reserves and ecosystemic services such as agriculture, fishing and forestry. They have no other financial activities or resources which can enable them to adapt to climate change or to face natural disasters, and their access to social services and protection is very limited. For example, changes in climate, to which animals and plants cannot adapt, lead them to migrate; this in turn affects the livelihood of the poor, who are then forced to leave their homes, with great uncertainty for their future and that of their children. There has been a tragic rise in the number of migrants seeking to flee from the growing poverty caused by environmental degradation. They are not recognized by international conventions as refugees; they bear the loss of the lives they have left behind, without enjoying any legal protection whatsoever. Sadly, there is widespread indifference to such suffering, which is even now taking place throughout our world. Our lack of response to these tragedies involving our brothers and sisters points to the loss of that sense of responsibility for our fellow men and women upon which all civil society is founded.

Presumably, as distributists, we want to make the world better, not worse. But refusing to acknowledge the findings of science could lead us to advocate policies that would result in objective harm. Should we ever get into a position where our proposals are acted upon, science denialism could cause us to inflict serious injury through misguided programs, and that is the opposite of what we seek to do.The second reason we must avoid science denialism is simply the credibility of the distributist movement. While a non-evidenced based rejection of scientific findings can enjoy popular support for a time, for example, climate change denial has captured an entire major political party in the United States, such positions cannot be sustained in the long-term. Science denialism as to any subject is, over time, more than likely to be overcome by the facts. It will do us no good to be observed championing such causes. On the other hand, no damage to our credibility will be incurred by recognizing the expertise of those who have had years of education and training in their subjects, even if they have to revise their findings at a later time.We must also consider those experts themselves, whom we presumably want to convince, along with everyone else, of the benefits of a society where the means of production are distributed as widely as possible. But if we try to do that while we are, at the same time, challenging the findings that their expertise has produced, not really knowing what we are talking about ourselves, we will be dismissed as silly, and we will have provided them ample cause to suspect that we have arrived at our political-economic ideas by means of a defective reasoning process.None of this is to say that distributists who are also scientists should never, within their competence, challenge the scientific consensus. But they should do so as scientists, not as distributists. Distributism, considered as a movement, should stay strictly away from science denialism, which will do nothing but embroil us in controversies that are extraneous to the effort to build a distributist society.