Once every couple of weeks, someone asks me, "What do you think about global warming?"
In today's media and political culture, I wonder if they really value what I think, or if they are trying to paint me into a corner as either an alarmist or a denier. So if you are more interested in inflaming the discussion and calling people names, then stop reading now.
This whole topic has devolved into a circus of science, politics, religion, spin, and bullying. It is painful to watch. I have numerous friends and colleagues in the meteorology field who are wildly apart on this issue. It's like being in a family that fights all the time: filled with grandstanding, snide comments, bickering, and chest thumping. Nonetheless, I do my best to keep up on it all, and overall, I think I am familiar with its most visible parts.
As a preface, the term climate change is more accurate, as global warming implies the entire planet will warm in a similar fashion, and the planet does not work that way.
Here's the core of where I am:
There is compelling physical and instrumental evidence demonstrating that the planet is warming due to an increase in greenhouse gases (more correctly, these are gases which are active in the infrared part of the spectrum). The only plausible explanation of the observed increase in these gases is from the combustion of carbon-based fuels. Given the primary drivers of surface temperature (terrestrial infrared and incoming solar energy), this signal should show up first, and most dramatically, in the Arctic.
Please note, nothing in that statement should lead you to believe that every time the weather is "bad" or unusual, it is because of climate change. Nor does it imply that it will never snow again, or that Richmond will become a seaport by 2100, or that hurricanes will routinely wipe cities off the map, or that we should put big mirrors in orbit to reflect away solar energy.
However, the premise that humans are too insignificant to affect the climate is demonstrably false. The recurring stratospheric ozone minimum that shows up in the Antarctic at the end of every (Southern Hemispheric) winter is sufficient proof. But also notice, I did not say that humans could control the climate. You can certainly affect something without controlling it.
But back to the family fight. And this is what I find fascinating: If you ask ten meteorologists about this issue, you will probably get ten different answers. In turn, this generates a new question: Do you trust that your favorite meteorologist knows what s/he is talking about?
Well, you probably shouldn't (and that includes me). At least not until you are convinced that your favorite meteorologist has done the appropriate research. You may be surprised to know that it is not necessary to take a course on global climates or natural climate variability to be a meteorologist.
As a side note, I wonder if the public understands that it takes no formal training in astronomy, seismology, volcanology, or horticulture to be a meteorologist. Yet we are the first people that our reporters and the public turn to when there is a question about the funny light in the sky, how a volcano erupts, what causes earthquakes, or when the leaves are going to change. We are just expected to know. After all, we are scientists. It turns out, the basic answers to those questions are pretty easy to look up, and there is little reason for the public to dispute the science in those answers, much less be threatened by it.
What troubles me most is to witness some irresponsible meteorologists dismiss climate change by immaturely stating s/he has a singular argument that renders all other data irrelevant. Back in 2007, with this type of noisemaking building, two veteran broadcast meteorologists, who have both earned my great respect, addressed this issue in a tremendous editorial. It is non-technical and a fairly easy read:
The climate system is, of course, complex. Their editorial underscores this point. No traditional single scientific discipline has all of the answers to this puzzle. Glaciologists need to converse with atmospheric physicists, who need to talk with oceanographers, who need to exchange data with geochemists. But enough evidence has come to light among the disciplines to allow several mainstream, professional scientific societies to reach strong conclusions and make public statements about the issue. Does the mainstream scientific community have all of the answers? Certainly not. That is why new data is being gathered. The drilling of a new ice core in the West Antarctic Ice Sheet is a prime example:
Return to the original core statement. I have technical reasons for reaching that conclusion, and I would not put it in print unless I was prepared to defend it, but getting into it here would make this blog intolerably long. When something about the topic does not seem right to me, I go after the answers. I have spoken directly with scientists from NCAR (National Center for Atmospheric Research). I have completed on-line courses and attended workshops. I have read papers in the scientific journals. And while some of those journal articles, admittedly, are using a level of mathematics that has long since rusted out on me, I still try. And I ask questions whenever I get the chance.
The large majority of my questions have been answered to my satisfaction. There are three concepts that I still need to grow more comfortable with: the validity of paleoclimatic reconstructions, the climate's reaction to changes in solar activity, and the geologic data that indicate carbon dioxide levels rise after temperatures rise.
And I want to be fair. I have read skeptical papers, including a popular one called the Skeptics Handbook. I have read dissenting articles from high-profile skeptics: Richard Lindzen, Fred Singer, Tim Ball, Joe D'Aleo, and Joe Bastardi. Some of their arguments have merit.
I have begun to read, for lack of a better term, more middle-of-the-road science blogs from Roger Pielke, Jr. and Judith Curry. Very recently, a profile on Dr. Curry has shown up in Scientific American magazine, and it is a fascinating insight into what is going on in the scientific trenches:
Still, the sum of everything I have read has left me with the conclusion I stated earlier. And during the times I cannot get a specific answer right away, I do have the good sense to defer to professional scientific societies. These societies represent current state of mainstream science.
The British Royal Society has recently published a booklet highlighting the current scientific understanding of climate change. This society is the oldest scientific academy in continuous existence. Its members have included Isaac Newton and Albert Einstein. Their booklet may be the best thing I have read on the topic:
Two of the most prominent earth science societies on our side of the Atlantic have concluded climate change is already occurring. Climate change statements from the American Meteorological Society (AMS) and the American Geophysical Union (AGU) are available to the public at the links below.
To say that the AMS, AGU, and Royal Society are part of some grand conspiracy is an extraordinary claim. And extraordinary claims require extraordinary proof.