Day 24 - Global warming

Earlier today, I was actually thinking about posting something about global warming, but decided that people have already heard enough of my opinion on that issue. Well, today I read a comment from my friend Norman wanting to hear my thoughts on this article, published today in the Independent -- only an hour or so after I finished reading several similar articles in the Guardian. Now I can't resist.

Global warming is a big issue here in the UK. After hearing that I'm a meteorologist and from America, it's one of the first things people ask me about. It appears to me that the theory that humans cause global warming by increasing atmospheric CO2 concentrations is taken for granted here. Of course, the same is generally true in America and most other countries as well.

One of the major reasons why some people in the UK (and around the world) have negative opinions about America is its refusal to adopt the Kyoto Protocol. I've seen this attributed to President Bush, though it President Clinton who first rejected it. I can see the other countries' point of view: The Americans pollute more than anyone else, yet they aren't willing accept measure to reduce it. Meanwhile, they are contributing to a change in the world's climate that affects all of us. They see the ones who oppose Kyoto (or question global warming) as unenlightented, ignorant of science, and selfish.

Well, I'm a research meteorologist who studies climate-related issues, and here are some of my thoughts about it, both scientifically and politically:

The scientific case for human-caused global warming is GREATLY overstated by environmentalists and political activists.

There is evidence that the earth has been warming over the past few decades, at least near the ground.

It is true that atmospheric CO2 concentrations have increased significantly over the past several decades

I think a majority (although a much smaller majority than environmentalists suggest) believe that elevated CO2 does/will increase the earth's temperature.

The relationship between these two is not known, and is a subject of debate.

Humans certainly do change the local climate by urbanization and deforestation, but it is unknown whether rises in CO2 have a significant impact on the global climate.

Much of the historic climate data is "tainted" by the fact that urban areas have moved closer to historic observing stations during recent decades.

Global Climate Models (GCMs) generally predict a rise in the earth's temperature (of a few degrees) over the next century or so.

GCMs are very crude, and do not represent many important processes that affect the climate.

A 4% error in cloud cover, for example, would completely eliminate the global warming forecasted by most GCMs.

The atmosphere is remarkable in the way it tries to reach equilibrium. For every process that would act to increase the temperature, other processes are there to counteract it. I think this is an example of God's wonderful design.

Many scientists believe recent climate changes are related to sunspots rather than CO2. Some have even bet large amounts of money that the earth's temperature will actually cool in 10-20 years.

It is very unlikely that America's adoption of the Kyoto treaty would have any significant impact on the earth's climate over the next hundred years.

Meteorologists involved in government policy seem more likely to believe in global warming than researchers outside Washington DC. (simply from my experience, I could be wrong here)

Politically conservative meteorologists seem more likely to reject human-induced global warming than liberal ones.

Scientists in other related disciplines, such as Botany and Geography, are more likely to believe in human-induced global warming than those in Meteorology.

On the other hand, there is financial incentive for meteorological institutions to promote global warming as an important issue and not to contradict the theor that humans cause it. (I'm not accusing anyone here, just stating a fairly obvious fact)

Some (particularly freshman) meteorology students (including myself before I knew better) simply dismiss global warming without seriously looking into it - I think it makes them feel superior in some way to people who blindly believe in it.

Otherwise, generally the people who are most sure that humans cause global warming (and that it's a problem) are the ones who know the least about the issue scientifically. Meteorologists/climatologists who actually study it tend to be much more unsure and divided about it.

The question that's usually not discussed (perhaps even taboo in many circles) is whether global warming is good or bad. Though there would definitely be drawbacks in some areas, I think a compelling case can be made that global warming might benefit the world as a whole, perhaps more so in the poorer countries.

So there you have it. I'm not trying to advocate a particular position here, either scientifically or politically. I don't know enough to say whether or not humans cause global warming (other than local microclimate changes) or whether the earth's temperature will rise over the next 100 years. But I can say that the case for global warming has definitely been exaggerated, and the harsh criticism of America for not signing the Kyoto treaty is unfair at the very least. In an ideal world, scientists would not let their political views influence their research, and people with political agendas would not make bold claims about scientific issues they know little about. But I think both will continue for a long time, especially with regard to global warming.

posted by Matt @ 11:52 PM