Is Climate Change Denial a Sin?

Let me begin by answering my own question:  yes, I think it is.  Below, I hope to make clear why I believe this to be the case.

But first, let me begin with some careful definitions.  Climate change, also known as (anthropogenic) global warming is the scientific theory that as the result of the burning of fossil fuels for the past 200 years (and particular since the beginning of the 20th century) the natural carbon cycle of the Earth has been thrown out of balance, resulting in a rapid increase in atmospheric carbon dioxide.  (Other so-called greenhouse gases, particularly methane, are also accumulating.  For simplicity I will lump them all together with CO2.)   As a consequence of this build up, the Earth is retaining more heat (the “greenhouse effect”) and the Earth’s climate is beginning to respond in ways which will have severe negative consequences in the future:  more extreme weather conditions, drought, species extinction, sea level rise.

In describing this body of knowledge as a “theory”, I am using the word in the precise sense it is used in the sciences:  a coherent explanation, based on empirical data, that explains said data and makes predictions that can be tested by gathering additional data.   It does not mean a mere supposition or guess,  or something that has not been proved.  Acceptance of a theory by scientists means that it has been scrutinized and tested, and is regarded as providing the best possible explanation of the evidence in light of other theories (in this case, for instance, the physics of heat transfer, atmospheric chemistry, etc.).

Global warming is nearly universally accepted by climate scientists.  The consensus understanding is encapsulated in the reports of the Intergovernmental Panel on Climate Change (IPCC).  The Pontifical Academy of Sciences recently issued its own report, which provides a nice summary of the consensus:

Warming of the Earth is unequivocal. Most of the observed increase in globally averaged temperature since the mid-20th century is ‘very likely’—defined as more than 90% likely—to be the result of the observed increase in anthropogenic greenhouse gas concentrations. This warming is occurring in spite of masking by cooling aerosol particles—many of which are co-emitted by CO2-producing processes.

Some of the current and anticipated impacts of climate change include losses of coral reefs, forests, wetlands, and other ecosystems; a rate of species extinction many times faster than the historic average; and water and food shortages for many vulner- able peoples. Increasing sea level rise and stronger storm surges threaten vulnerable ecosystems and peoples, especially those in low-lying islands and coastal nations. The loss of mountain glaciers discussed here threatens downstream populations, especially during the dry season when glacial runoff is most needed.

Ongoing discussions about the evolution of the theory and recent experimental data can be found on innumerable blogs—see for example, here and here.

By climate change denial I mean the refusal to accept the reality of climate change.  This generally takes the form of denying the validity of the theory or accepting the idea but downplaying or discounting the predictions of the theory to such an extent as to vitiate it.  Climate change denial has become an article of faith among conservative Republicans.  The earliest outspoken denial came from James Inhofe, who said, “I have offered compelling evidence that catastrophic global warming is a hoax.”   Sarah Palin denied it as well, putting her at odds with her running mate, John McCain:  “A changing environment will affect Alaska more than any other state, because of our location. I’m not one though who would attribute it to being man-made.”  Michelle Bachmann agrees with Inhofe:  “The big thing we are working on now is the global warming hoax. It’s all voodoo, nonsense, hokum, a hoax.”  Rick Perry has said that  global warming is “all one contrived phony mess that is falling apart under its own weight.”  Rick Santorum stated categorically that “There is no such thing as global warming.”   Tim Pawlenty, who once believed in it to the extent that he supported “cap and trade” legislation to lower carbon emissions, has since changed his stance:  he now says that “the weight of the evidence is that most of it, maybe all of it, is because of natural causes.”

It is important to note that most climate change deniers do not have any background in climate science or related fields.   There are a handful of exceptions, the most prominent being Roy Spencer and Richard Lindzen.  Many more have scientific credentials in unrelated fields or have no particular expertise in any scientific field.   And despite their credentials, the published work of both Spencer and Lindzen has met with a critical response from the broader climate science community.  (See, for example, here for Lindzen and here for Spencer.  Neither link is to peer-reviewed literature, but both provide good references for those interested.)  Neither has been able to convince their peers of the validity of their arguments.

Finally, I do not include among climate change deniers those who accept the reality of climate change but reject proposed solutions, such as “cap and trade” or a carbon tax.   The one prominent figure in this category that I am aware of is Mitt Romney, though there probably are others.  I might disagree with them on solutions—especially since I not seen any realistic alternatives proposed—but we are in agreement on the problem.   My concern is with those who deny that the problem exists.

We can now turn to my original question:  is climate change denial a sin?  I believe that it is.  More specifically, it is a sin against the eighth commandment:  you shall not bear false witness.  In a word, it is lying.  The Catechism defines lying as follows:  “To lie is to speak or act against the truth in order to lead into error someone who has the right to know the truth” (2483).  If the theory of climate change is true—and the overwhelming consensus of those qualified to hold an opinion is that it is—then denying it or calling it a hoax is to “speak against the truth.”  And given the gravity and universality of the impact that climate change will have in the future, every person has a right to know the truth about it.

One could argue that while those who deny the reality of climate change are in error, they are not deliberately lying since they are ignorant of the truth and express their beliefs sincerely.   This is possible, but it strains my credulity to believe it.  Further, it raises the question of whether this ignorance is involuntary or willful.  Thomas Aquinas explained the difference in this way:

It is clear that not every kind of ignorance is the cause of a sin, but that alone which removes the knowledge which would prevent the sinful act. …This may happen on the part of the ignorance itself, because, to wit, this ignorance is voluntary, either directly, as when a man wishes of set purpose to be ignorant of certain things that he may sin the more freely; or indirectly, as when a man, through stress of work or other occupations, neglects to acquire the knowledge which would restrain him from sin. For such like negligence renders the ignorance itself voluntary and sinful, provided it be about matters one is *bound and able to know.” (Summa I-II, q. 76, a. 1, a. 3)

Given the importance of determining whether or not the theory of climate change is correct, it seems obvious that everyone, but people in positions of authority in particular, have a positive obligation to learn the truth.   The evidence strongly suggests that, at least among Republicans in Congress, their actions are  “of set purpose to be ignorant of” the science of climate change.   Last March, the House Committee on Science, Space and Technology held a hearing on climate change.  The one witness allowed to the Democrats was Kerry Emmanuel, an atmospheric scientist at MIT, who testified,

I am here today to affirm my profession’s conclusion that human beings are influencing climate and that this entails certain risks. If we have any regard for the welfare of our descendents, it is incumbent on us to take seriously the risks that climate change poses to their future and to confront them openly and honestly.

The five witnesses that the Republicans called included a lawyer, an economist and a professor of marketing, none of whom had any expertise in the science of climate change.  Two were scientists:  one a well known climate change skeptic (John Christy, a colleague of Roy Spencer) and Richard Mueller of Berkeley.  Both were expected to disagree with the consensus; however, Mueller surprisingly testified in favor of the consensus view.  (He was quickly excoriated by climate change deniers, even though prior to his testimony they were lauding his work.)  Paul Krugman, in his weekly column, offered the following reflection on this witness list:

For years now, large numbers of prominent scientists have been warning, with increasing urgency, that if we continue with business as usual, the results will be very bad, perhaps catastrophic. They could be wrong. But if you’re going to assert that they are in fact wrong, you have a moral responsibility to approach the topic with high seriousness and an open mind. After all, if the scientists are right, you’ll be doing a great deal of damage.  But what we had, instead of high seriousness, was a farce: a supposedly crucial hearing stacked with people who had no business being there and instant ostracism for a climate skeptic who was actually willing to change his mind in the face of evidence. 

From this I can draw no other conclusion than that most if not all climate change deniers, including the Republicans in the House, and other  prominent Republican politicians, are willfully refusing to engage with the truth and are therefore deliberately sinning by propagating this error.   I do not want to parse their motivations, which are probably legion.  But I think it is important to establish this fact about their behavior clearly:  in denying the reality of climate change, they are lying.