crux wrote:Out of curiousity...
As a question for those of you who believe that global warming is a serious problem, can you say for how long you've held this belief, and how and when you became convinced?
I came to believe that global warming is a problem back in the 1980s, when I became aware of the exponential increases in atmospheric CO2. I already knew about the greenhouse effect and the discovery that Venus is hot as Hades beneath its CO2 cloud. As for thinking that it is a serious problem, I'll say something about that below.
What parts of the science, if any, do you consider uncontrovertible?
I would say none, but I think that it is pretty clear that the world is round and smoother than a billiard ball, that there are tectonic plates, that the sun is fueled by nuclear fusion, that it creates carbon, that there is a Yellowstone super-volcano, that singers can break glasses by means of resonant frequencies, etc.
Are there areas where you think the science is uncertain?
Virtually all of science is uncertain. As topazg says, the question is the degree of uncertainty.
What made me think that global warming is a serious problem? The political resistance to it. OC, there are powerful economic factors at work that put CO2 and other greenhouse gases into the atmosphere at increasing rates. We have built our economies on burning fossil fuels, and we are cutting down trees at a rapid rate, destroying tropical rain forests. Forests help to reduce atmospheric CO2. Changes to stabilize the natural carbon cycle must be widespread, and they will be costly in the short run. Therefore they will meet stiff resistance by those who profit from increasing atmospheric CO2, which is pretty much everybody. Overcoming that resistance is the work of generations. That is why it is urgent now.
Rain forests do not rely upon nutrients in the ground. The forest floor itself is rich in nutrients. Once you destroy a rain forest, the next phase is unlikely to be a grassland. It is likely to be a desert. The soil is simply not rich enough to support much vegetation. It does not even support the rain forest now. I saw on TV (on Nova, I think) several years ago, maybe even in the 80s, a report that in some areas of Brazil where the rain forest had been cleared, local temperatures had risen by 15 degrees Fahrenheit in only a few years.
Eventually humans will live in ecological balance with nature or go extinct. Do we want a future where humans, except perhaps for a favored few, eke out a hard scrabble existence next to our waste products? Suppose that we burn up all our fossil fuel and cut down all our rain forests. (The latter is more likely than the former.) How likely is it that we will have generated a runaway feedback cycle ending in a planetary greenhouse like Venus? Will people die in droves from smog? It is plain that at that point we will have generated ecological conditions that have never existed on earth since we have had an oxygen atmosphere.
Now, I don't think that we will get there. It is a slippery slope argument. Slippery slope arguments are suspect because they ignore negative feedback. But in recent history the forces of negative feedback in regard to the environment have been weak. Around 1980 I watched a Nova show that illustrates the point. During the Dustbowl of the 1930s new conservation techniques for farming were discovered and adopted to help prevent future dustbowls. However, those techniques cut crop yields by 5% by comparison with non-conservation techniques. By the 1980s the conservation techniques had been abandoned, particularly by agribusiness. 5% is too much of an edge to give your competitors. OC, everybody knew that the abandonment of conservation techniques made another dustbowl almost certain in the 21st century. But hey! your competition will be in the dustbowl too.
To me the urgency lies more with human nature than with climate science. We know that we are on a road that ends in disaster. The question is how and when we will put on the brakes. We can do without New York City, Los Angeles, and the Cayman Islands. Too bad about Hawai'i and New Orleans, though. We can even survive our wheat fields becoming desert. We'll adapt. But why should we bring disaster on ourselves?
One night I was driving home, about 50 miles, when a thick fog enveloped the highway. It was a two lane highway in the middle of nowhere, so stopping was not an option. I slowed to below 15 mph and kept an eye on the side of the road. The fog increased my uncertainty about what lay ahead, and I took prudent safety measures. The uncertainty of science is not an argument for barreling on, full speed ahead. If disaster strikes, Whocuddanood is cold comfort.