"Look here," my stepfather said.
I was visiting my parents one day last summer, and to my surprise, he brought up the topic, "What do you think of this global warming? Is it real?"
"Yeah, it's real," I said.
"It's probably not as bad as what you've heard," I continued, "but it isn't something anyone just made up."
"Nahhh," he sneered, "It's just some of Al Gore's sh--."
* * *
I rarely discuss this subject publicly. The above conversation may give a little insight as to why. But my primary reasons are at a previous blog I wrote about a year ago. If you have not read it, please take a look before reading any further.
I still follow it all, but there is not much use in my jumping over every little story that comes down the pike. Too many loud people have too much emotionally and politically invested in the subject. However, it does make sense to review some of the bigger stories and try to put them into context once a year.
The most recent big story came from the West Coast. Richard Mueller, Professor of Physics at the University of California at Berkeley, led a team of physicists, statisticians, and atmospheric scientists in reconstructing the average global temperature back to 1800.
Mueller was not convinced that the three primary agencies working on this reconstruction had been thorough enough. Those three agencies are The Hadley Climatic Research Unit (UK), NASA Goddard Institute for Space Studies, and the National Oceanic and Atmospheric Administration (USA). The three agencies used different methods to calculate their results, but largely got the same answers.
In all science, a good experiment is repeatable. Mueller wanted to do it himself. So he did. And his group got the same results. Their research has been submitted for peer review, but they have already gone public with their findings. Their primary graphic is enclosed, but you can find all of their data here.
(Figure 1 - Berkeley temperature reconstruction, mapped with the other three agencies' results)
For another story, go back a month or so. Every September, ice extent in the Arctic reaches its annual minimum. This past September, the ice extent dropped to its second lowest level of the satellite era. Unfortunately, the period of satellite data is frustratingly small, only going back to 1979.
(Figure 2 - Arctic Ice Extent. Data available from the National Snow and Ice Data Center: http://nsidc.org/arcticseaicenews/)
However, a 2008 paper from the University of Ottawa and the Geological Survey of Canada suggested that the areal extent of Arctic ice over the last few years is at its lowest since 1870.
(Figure 3 - Maximum and Minimum Arctic Ice Extent Since 1870, link below)
They used a series of proxy measurements to make their determination, and you can find the rest of their paper here.
While there is a possibility that Arctic ice extent was smaller at some time between the present and 5500 years ago (when the final bit of year-round ice from the last ice age melted in north central Canada), there is no evidence to suggest that is the case. Professionally, I think it is reasonable to assume that areal extent of the ice in the Arctic these last few years is at its lowest point since the ice age ended.
A colleague of mine disagrees. He believes that the lack of evidence makes my assumption too risky. Perhaps he is correct, but we don't know. I would like to see some proxy data, but I have not seen any professional studies covering that period (if you know of one, please point me to it). He and I can only disagree over what assumption is best made given the lack of data between 3500 BC and AD 1870.
As a cool aside, watch the ice sheet melt through time at this link from the University of Colorado. Animation starts 21,400 years ago.
Another issue that has come up repeatedly is carbon dioxide saturation. The idea here is that only so much warming from carbon dioxide is possible, then any additional carbon dioxide has negligible effect. This was a stumbling block for me as well, as admittedly, my proficiency in radiative transfer could be better. So, I went to the American Institute of Physics (AIP), and while their explanation is a bit long-winded, it suggests this saturation effect is overstated.
From the link:
"The primitive infrared techniques of the laboratory measurements made at the turn of the century had given a misleading result. Studies from the 1940s on have shown that there is not nearly enough CO2 in the atmosphere to block most of the infrared radiation in the bands of the spectrum where the gas absorbs it. Nor does water vapor bring complete saturation, in desert regions where the air is extremely dry."
"There was also the old objection, which most scientists continued to find decisive, that the overlapping absorption bands of CO2 and water vapor already blocked all the radiation that those molecules were capable of blocking. [Guy Stewart] Callendar tried to explain that the laboratory spectral measurements were woefully incomplete. Gathering scattered observational data, he argued that there were parts of the spectrum where the CO2 bands did not overlap with water vapor absorption."
Callendar's 1941 paper was published in the Quarterly Journal of The Royal Meteorological Society.
Other issues have made the news, like the massive drought in Texas and Oklahoma. And while the drought is consistent with most climate change projections, it is imperative to remember one bad drought does not indicate a trend. If the droughts continue to increase in frequency and intensity in the coming couple of decades, that is an entirely different story.
Which leads to another bit of racket that is out there: Global warming has stopped. Or that there has not been any in the last decade. Any climate change, when compared to the timescale of a human lifetime, is dreadfully slow. While there will be people who tell you otherwise, it is important to remember that natural variations should be expected in an overall warming trend that goes through the rest of the century. The idea that the warming will be uniform and at a constant rate is simplistic and horribly misguided. There will be jumps and stalls along the way.
A good analogy is the crawl each year from winter to summer. Every day between March 21 and June 21 is not warmer than the last. There are pauses and accelerations. There is often a cool spell in May or an abnormally warm spell in April. But we always get to summer.
Certainly, there are numerous questions on climate change that cannot be addressed in one blog. But about a year ago, I came across www.skepticalscience.com. It is the most comprehensive site I have found on the subject, addressing most every question about the science. Before endorsing it, I spoke in person with two different climate scientists, and they both lent their support to it, which makes me feel comfortable passing it along. If you have a question about the science, it is probably on there.
A few months ago, at the suggestion of Bob Ryan, a meteorologist at our sister station in Washington, I read and reviewed a book on climate change called The Climate Fix.
I found it to be a refreshing voice against a cacophony of noise. You can find the review here.
The review got me some attacks from the political polar left. And my accepting the mainstream scientific position has invited attacks from the political polar right.
Which is fine by me. It is cold and desolate at the poles. Nothing grows there.
Of course, you are welcome to read whatever you want. And gravitate to the information that you already believe, you want to believe, or validates your opinion. Everyone is entitled to believe what they wish. Heck, according to one study from the University of Western Australia, you are entitled to believe that everyone really thinks like you anyway.
Taken even further, one sociologist at Michigan State published a paper this year illustrating why conservative white males tend to be skeptical of the mainstream scientific position.
And of course, narrative often trumps facts.
So, none of this is going away.
But the notion that "global warming is a fantasy of the left" is patently false.
And no three-sentence snide comment or self-gratifying television sound bite will change it.