Monday, March 10, 2014

Global Warming: Fred Singer is Skeptical

A few days ago I received an email from someone I deeply respect who is better connected in conservative political circles than I. He had forwarded it from a chain that included Tea Party members and email addresses at reagan.com, and everyone seemed impressed that PBS, that purported bastion of fuzzy-headed liberal mushiness, had published an interview with Fred Singer, a climatologist and renowned global warming skeptic. My correspondent joked with me, referring to global warming as "the Gore theory." That's funny! First Gore invents the internet without the help of technologists, then he single-handedly turns climate science on its ear by creating a new theory that no scientist had every considered or researched in any way.* But on to the interview.
 
First, all those Tea Party groups that were suddenly planning to join fund-raising campaigns for PBS might want to reconsider: the interview was one of five that PBS conducted with scientists in conjunction with their "What's Up with the Weather?" investigation, and the other four scientists all agree with the anthropogenic global warming theory. Kudos to PBS for airing a minority dissent along with the consensus, but there's no reason to conclude that PBS was endorsing Singer's views.
 
More importantly, Singer gave the interview in April 2000. Fourteen years ago. Fast-moving climate scientists have done a lot of research since this interview was published. Fourteen years ago, Singer identified some unanswered questions that had led him to dissent from the consensus, but do his critiques still apply in 2014?
 
Climate scientists, like the scientists in other disciplines, abhor a vacuum of knowledge, so they've been steadily pushing back the boundaries of ignorance and uncertainty. When I was a kid my dad, whose only barrier to being beatified by the Church is that he is still energetically and joyfully among the living, gave me a subscription to an "astronomy for kids" series that I loved. I still remember the plum-colored covers, the single-staple cardboard binding, and the serious questions about whether the universe was essentially steady-state (as Einstein believed) or had originated in a big bang. At that time the vast majority of astronomers subscribed to the Big Bang, but a few steady-state holdouts didn't believe the evidence was convincing. Winning them over to the consensus required the confirmation of cosmic background microwave radiation, which won its discoverers the Physics Nobel in 1978. What had seemed likely but not quite conclusive in the mid-1960s became accepted as fact after further research.**
 
Personally, I am always eager to hear out dissenters--with whom I feel a certain kinship--so I read Singer's arguments with a willingness to be convinced. But knowing its age, I wanted to find out if later research confirmed or refuted his ideas. Would subsequent developments support his contentions, or would his statements look like the last gasp of the steady-state astronomers in the 1960s? In the remainder of this post, I'd like to assess Singer's arguments in the light of subsequent research.

Singer Contention #1: The Earth has not been warming.

"Since 1979, our best measurements show that the climate has been cooling just slightly. Certainly, it has not been warming."
 
What does subsequent research show?
Oceans, which hold 80% of the heat energy from the sun, have actually been warming from 1979 to today. This August 2013 source looks back at the past decade of oceanic temperature research and concludes: "How do scientists resolve these kind of disputes – bearing in mind that such disputes are the very stuff of science, the essence of true scepticism? One way is to find more data sources – different ways of measuring the phenomenon in dispute. By using results from seven different teams of scientists, all using different tools and methods, we are able to see a clear trend. And while there is variation between team results due to the differences in technique and measurement methods, one thing they all agree on: long term, [oceanic] temperatures are going up."


Satellite measurements of troposphere heat content (most of the remainder of earth's solar heat energy) show warming. These are the measurements that Singer purports to trust ("I personally prefer to trust in weather satellites.")


Discrepancies that existed in 2000 between surface and satellite measurements of temperature have been subsequently resolved; the data irrefutably indicate a trend toward higher temperature now. The above link includes this paragraph: "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human-induced global warming... This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies."

Singer Contention #2: Global climate models are too imprecise and do not include cloud feedbacks.

"Until the observations and the models agree, or until one or the other is resolved, it's very difficult for people--and for myself, of course--to believe in the predictive power of the current models. ...  the clouds are not captured by the models. Models are not good enough to either depict clouds or to even discuss the creation of clouds in a proper way. So it's not possible at this time to be sure how much warming one will get from an increase in carbon dioxide."
 
What does subsequent research show?
 
Models are not perfect, but they have proven very useful, and in fact have been quite accurate in predicting trends over the past 24 years, in spite of their limitations.  As of 2013 models have successfully incorporated cloud interactions.

Singer Contention #3: The worst case scenario for rising sea level is not very bad.

"Of course, if the warming is extreme, and melts all the ice caps, all bets are off. But no one is talking about that."
 
What does subsequent research show?
 
The melting of the ice caps is a very serious long-term concern that portends devastating consequences.

Singer Contention #4: Jim Hansen is backpedaling on the predictive value of climate models.

"One of the leading climate modelists is Jim Hanson. [sic] He actually was the man who, ten years ago, went out on a limb and said he was sure the enhanced greenhouse effect was here. He now says we can't really tell. He says the forcings are so uncertain that they're much more important than the climate models. In other words, until we get the forcings straight, the climate-model predictions are not worth very much. That is basically what he said."
 
A 2013 interview with Jim Hansen, however, shows that he is strongly convinced by the climate models:
 
“If we burn even a substantial fraction of the fossil fuels, we guarantee there’s going to be unstoppable changes” in the climate of the earth, he said. “We’re going to leave a situation for young people and future generations that they may have no way to deal with.” 

Singer Contention #5: Hemispheric differentials in temperature increase refute climate models.

"Are the aerosol effects hiding the effect of carbon dioxide now? We can tell. We can find an answer to this, because we can look for fingerprints in the climate record. Since aerosols are mostly emitted in the northern hemisphere, where industrial activities are rampant, we would expect the northern hemisphere to be warming less quickly than the southern hemisphere. In fact, we would expect the northern hemisphere to be cooling. But the data show the opposite. Both the surface data and the satellite data agree that, in the last 20 years, the northern hemisphere has warmed more quickly than the southern hemisphere. So it contradicts the whole idea that aerosols make an important difference."
 
What does subsequent research show?
 
Climate models can and do account for the difference in hemispheric temperature increase. The two key factors are global ocean currents and hemispheric differences in land mass.
  • The Journal of Climate published two studies in April 2013 that show global ocean currents "transport heat away from southern waters and into the North Atlantic and North Pacific, helping to warm nearby land areas in the north even more." Researchers at Columbia University have confirmed this finding.
  • Per this 2013 research, "the Northern Hemisphere has more land and less ocean than the Southern Hemisphere, and oceans warm relatively slowly."

Conclusion: Singer Needs to Write a New Song

I am sure that tens of thousands of folks like my correspondent, maybe millions, have read the Singer interview without realizing just how much the field of climate science has changed in 14 years. The evidence for anthropogenic (human-caused) global warming has greatly strengthened since he gave the interview to PBS. The leadership of the Roman Catholic church, among many others, believes that we can no longer afford to wait for more scientific research: to be responsible stewards of God's creation, we must act now to counteract the consequences of global warming.*** I hope to explore the ethical implications of the scientific research in a future post. But for now, let the scientists have their say: the earth is warming because we have released carbon wastes into the environment, and the consequences will likely be grave.


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* Irony alert! Irony alert!


**Helping the formation of the Big Bang consensus was the lack of a well-funded industry, concerned about its long-term profitability and willing to fund dissident scientists, that needed to refute Big Bang astrophysics.

***Look for a discussion of views of Roman Catholic and evangelical leaders in a future post.