Impact of global warming looms on the horizon

By Glenn ShawPublished April 22, 2007
http://newsminer.com/2007/04/22/6603

In the 1970s as a young scientist at the Geophysical Institute I wrote passionate letters complaining that for the first time in the geologic era man was changing the atmosphere of the planet. I argued that continued dumping of carbon dioxide into the atmosphere would be associated with a warming of the entire Earth and pled for attention to this matter. The letters were ignored.
They were ignored because in the 1970’s Newsweek, the Christian Science Monitor, the New York Times and countless books and articles were warning of the dangers of global cooling.
Things have changed. Global warming is now being noted, and I in the meantime have become a little skeptical about some of the claims being put forth. I’m skeptical despite the fact that “everybody knows that the science is in.” The science isn’t even close to being in.
A significantly large fraction of the science being done on global climate change is perhaps not wrong, but not enough, a little naive, repetitive and incorporating only a fraction of the complexity required to base policy on. Though we scientists don’t advertise it much, science is often muddled when it is working on difficult new problems and most especially when the problems start to become political. And the issue of global warming has become massively political. Special interests abound. Try getting funding while being a skeptic.
There are many instances in which so-called objective science became crossed up in early investigations. Science advances in paradigm shifts and by falsification. One paradigm shift was made a century ago when Arrenhius discovered that carbon dioxide was warming the earth. Another was made by Twomey twenty years ago; he discovered that pollution affects clouds and rain distribution in ways that promote cooling and though the underlying physics is valid, we know little about it and clouds are poorly parameterized in models.
Let me illustrate how viewpoints on “global climate” can suddenly shift by sharing a few personal examples. Thirty years ago there was a strong consensus when my colleague Ken Rahn and I discovered that the entire arctic’s air mass is contaminated. Up to that point “everybody knew” that the arctic air mass was the cleanest in the world, especially in winter. All the electronic computer modelers had that fact incorporated. Quite the opposite proved to be true. Now we understand that arctic haze is the largest contamination cloud on the planet, so large it could be noticed from Mars. It also has a larger impact on arctic climate than carbon dioxide.
Nor was there consensus, in fact there was a great deal of hostility, when I wrote a paper in 1979, proposing that desert dust blown into the air over the Gobi Desert crosses the Pacific Ocean and makes its way to the Hawaiian Islands. This was an unpopular idea and it made a lot of people angry. One reviewer even wrote, “this idea is obviously erroneous and I reject the paper unequivocally.”
But in spite of that, we got the paper published and now we realize that the dust not only commonly reaches Hawaii, but California and Alaska also. Additionally, this dust contains pollutants in increasing amounts as China expands its industrial activities. The dust impacts climate. None of these things are in the models. These are two examples on which virtually the whole science community had adopted wrong ideas.
There is much more in climate science that we simply do not understand. Believe it or not, nobody has any sustainable theory, other than a few clues, about the causes of the ice ages. They are resonant with some of the orbital movements of the planets, but only roughly so and other things are going on that cause and end these spectacular events. We do not know.
I wish to end this column in a way that may surprise you. In spite of my slight skepticism, global-scale impacts are indeed beginning to loom. We are perturbing Earth’s cloud cover with human-induced condensation nuclei and over exploiting. Concern about the environment is needed and is a clarion call now adopted by increasing numbers of the world’s great spiritual leaders. The interest in “global warming” might yet prove to be a good cause if its end result is promoting conservation and better stewardsmanship of this gorgeous planet.

Glenn Shaw is an atmospheric scientist specializing in global environmental feedback mechanisms. He is a professor of physics at the Geophysical Institute, University of Alaska Fairbanks.