There has been renewed talk in recent weeks about whether this summer’s scattering of extreme weather events is linked to anthropogenic climate change.
True, humans have altered the radiatively active portions of the atmosphere by adding greenhouse gases and aerosols. We’ve also altered the planetary landscape. These alterations are now part of the integrated global climate system that produces daily weather events—both extreme and benign.
So can our influence change the intensity of weather events? Yes.
Can it cause an event to happen that otherwise wouldn’t have? Conceivably.
Does it always act to make the weather more severe? No.
Are the changes detectable? Hmmm.
It seems that it is this issue of detectability that we often get hung up on. Otherwise, how do we know that human changes are having any impact?
Well, we know because, like I said, we’ve altered the active system.
“Detectability” is really just about trying to determine whether our alterations have produced a loud enough signal that it can be heard through the collective natural noise.
At least that is the purely scientific/statistical aspect of detectability.
There is a social/political aspect as well. For once detectability is established, then blame can be meted out, and with blame comes calls for retribution and regulation.
The latter is the reason why the issue has become front page news. And why there are comments and speculation in seemingly every news story about the role that anthropogenic greenhouse gas emissions may have played in every severe weather event. Folks are looking for someone to blame.
Acts of God are typically exempt for retribution. But acts of man? By God, someone is going to have to pay!
Once detectability has been established, this will open the door to blaming everything on anthropogenic climate change, and to a disregard of the fact that weather (including severe events) existed previously. After all, if you are going to sue someone for your Gulf Coast beach house being destroyed in a hurricane, are you only going to sue for 5% of the damage? Or even consider whether you should have built your beach house there in the first place?
And yet it is this latter concept, more stuff being built in harm’s way, that is the primary cause of modern day weather catastrophes—much more so than the weather itself and much, much more so than any alterations to the weather (be they detectable or not) from human activities.
For example, a study in an upcoming issue of the Bulletin of the American Meteorological Society by Laurens Bouwer concluded:
Here I present a review and analysis of recent quantitative studies on past increases in weather disaster losses and the role of anthropogenic climate change. Analyses show that although economic losses from weather related hazards have increased, anthropogenic climate change so far did not have a significant impact on losses from natural disasters. The observed loss increase is caused primarily by increasing exposure and value of capital at risk.
In other words, “detectibility” has not (yet?) been achieved in damages statistics from extreme weather events.
But, the quest to establish a definitive link between weather events and human-caused climate change is charging forward, fueled, it seems to me, by the desire for retribution more so than for scientific knowledge.
In fact, it has already hit the courts, with mixed success.
Sensing that this could quickly get out of hand, the Obama Administration has just acted to try to put the kibosh on such lawsuits—a move which has shocked climate activists.
From the New York Times :
The Obama administration has urged the Supreme Court to toss out an appeals court decision that would allow lawsuits against major emitters for their contributions to global warming, stunning environmentalists who see the case as a powerful prod on climate change.
And if you think the climate activists are taking it hard, you can imagine how their lawyers are taking the news!
Matt Pawa, an attorney representing plaintiffs in the case, said he and his colleagues expected the White House to stay out of the matter. During a meeting with more than 30 administration lawyers at the solicitor general’s office on June 24, it seemed they had “a lot of friends in the room,” he said.
“We feel stabbed in the back,” Pawa said. “This was really a dastardly move by an administration that said it was a friend of the environment. With friends like this, who needs enemies?”
I hear a tiny violin playing a sad tune….
Over at his blog, Roger Pielke Jr. lays out the gist of the Administration’s brief:
The brief itself reads as a more general argument against seeking to implement climate policies — those focused on controlling greenhouse gas emissions — through the courts.
The brief states that the scope of potential harm from greenhouse gas emissions is so broad as to render the issue more appropriate to the legislative and executive branches (pp. 13-14, PDF):
[P]laintiffs proceed without relying on any statutory right or statutory cause of action, and have sued a handful of defendants from among a broad array of entities that emit greenhouse gases. Moreover, the types of harms they seek to redress could potentially be suffered by virtually any landowner, and to an extent, by virtually every citizen, in the United States (and, indeed, in most of the world). Prudential standing principles counsel in favor of leaving resolution of such claims to the representative Branches.
The brief states bluntly that (pp. 16, 17):
Courts—when no statute is in place to provide guidance—are simply not well-suited to balance the various interests of, and the burdens to be borne by, the many entities, groups, and sectors of the economy that, although not parties to the litigation, would be affected by a grievance that spans the globe. . .
The confluence in this case of several factors—including the myriad potential plaintiffs and defendants, the lack of judicial manageability, and the unusually broad range of underlying policy judgments that would need to be made—demonstrates that plaintiffs’ global warming nuisance claims should be resolved by the representative Branches, not federal courts.
And then Roger wonders aloud:
A question that I have for constitutional scholars: How does the argument in this brief also not undercut US vs. EPA?
Good question, Roger.
I am sure this will soon be directly asked in a more formal arena!
When and if Congress again attempts to take up the issue of trying to regulate climate change, the topic of detectibility will undoubtedly be bandied about by both sides.
However, the bigger, and more relevant issue, should be an examination of whether or not the proposed legislation will have a detectable impact on the human impact on the climate. As we are still struggling with indentifying, much less quantifying, the latter, the former is certainly beyond our grasp for the foreseeable future. As such, a harder look an the non-climate impacts (be they good or bad) should be the primary driver of any legislation.
This is basically the same conclusion that I always reach when examining greenhouse gas limiting legislation—the debate needs to center around things other than climate and whether or not we can be blamed for it.