The National Climate Assessment released this week is a thorough and authoritative report that also really shouldn’t be necessary in telling us what we need to know about the underlying problem.  The problem is that human activity is changing the global climate in major and mostly undesirable ways.  The evidence has long been very apparent, and the evidence is overwhelming.  It includes mountains of data and it includes principles of physics and chemistry.  What this latest report does is to relate real, not just projected, climate change to present conditions in the United States, not just to consequences that are more distant in either time or place.

 

Unfortunately denial is still commonplace, and denial reflects some unfortunate tendencies that discourse in the United States not only on this issue but also other issues often exhibits.  There is a tendency not to recognize genuine questions and the difficult decisions that must be made about them, but instead to wish all this away by denying the facts.  There is a further tendency for factual beliefs to stem from policy preferences rather than the other way around.  The policy preferences involved may relate to constellations of issues that go well beyond the issue at hand.  Thus there appear to be Republican facts and Democratic facts, or conservative facts and liberal facts—even on matters of chemistry and physics, and not just on the social phenomena that would be more closely related to political ideologies.

 

A related tendency is to discount or discredit facts communicated to us by those whose ideologies or political affiliations we do not like.  Al Gore has been the most prominent American politician sounding alarms about climate change, and so those who never liked Al Gore’s politics are predisposed to disparage any similar messages on the subject.  Because there is an issue today of whether to build the Keystone XL pipeline, with American politicians carefully calculating how the interests at stake translate into political support or opposition for themselves, we hear this week members of Congress denigrating the just-released report as supposedly just a tactical ploy timed to affect debate on the pipeline issue.

 

Perhaps none of this should be surprising in a polity in which, in the not distant past, people close to the policy process claimed that they could create their own reality.  As a saying of longer vintage reminds us, however, one is entitled to one’s own opinions but not one’s own facts.  Neither can one make reality go away through force of political will.

 

For those of us who are not natural scientists but instead dwell in matters of national security and foreign policy, one thought is that there is no more basic aspect of national security than the habitability of the physical environment in which a nation’s citizens live.  Another thought is that avoiding further environmental deterioration involves complex problems of international relations.  The climate change experienced in the United States and documented in this week’s report reflects not only activity in the United States but also the burning of forests in Indonesia and the spewing of carbon by coal-fired power plants in China.  If effective international measures on this subject are ever to be taken, a necessary first step is to discard the denial and to recognize explicitly the facts and the painful economic and other trade-offs involved.

 

The most recent episode of the television series Cosmos hosted by Neil De Grasse Tyson described some really awful previous periods in Earth’s climatological history, triggered by bombardment from space or by volcanism in Siberia igniting vast amounts of coal.  The good news is that since the end of the last Ice Age and for the next several tens of thousands of years mankind is likely to have a very hospitable planet on which to live—if, that is, mankind does not mess it up through its own activity.  As Tyson put it, the dinosaurs had no way of knowing about the asteroid that did them in; what’s our excuse?                      

Image: Wikimedia Commons/Gerdsch. CC BY-SA 3.0.