The topic of global warming has transformed during the last decades from a vague scientific hypothesis to a fierce political debate. Today, there are strong reasons to believe the scientific conclusions made about global warming are no longer in the hands of scientists, and that these conclusions are rather oriented by various political agendas. When politics gets involved in science to such an extent, the outcome can only be negative- for instance, democrats and republicans will find reasons to disagree regardless of the truth about the question. The question of global warming is very deep and it therefore has to be studied very carefully.
We, scientists, often try to mimic nature through models. For instance, we try to simulate the propagation of a seismic wave field in an acoustic model of the earth. Sometimes, we try to do better and simulate it through an elastic model of the earth. In both cases, however, we know that the propagation inside the earth is much more complicated. And so, despite all the efforts to understand seismic wave field propagation, no reasonable scientists would claim that we know how to model the earth and simulate the seismic wave field propagation. Our quest in trying to achieve that is full of uncertainty. The best scientists are usually the ones who acknowledge that. The beauty of science is it teaches to be humble with respect to how you view the world.
The question of global warming is much more involved than the seismic wave field propagation. It involves the atmosphere, the oceans, the clouds, the forests etc … Here also, scientists working on this question use models to try to describe the world we live in. Any intelligent person would know in advance that these models can only be limited, because the world we live in is full of things we don’t really understand. To give a simple example, how many times did it occur that the weather forecast turned out to be inaccurate or completely wrong: rainy instead of sunny day, or vice versa. Statistically, there is a reason to believe that the models used by climatologists to predict weather aren’t sufficiently reliable. Weather is only one element of the global warming puzzle. To truly assess the uncertainties in the global warming question, you have to add up all the uncertainties of the different elements involved.
There is no problem with having models that do not fully describe the world we live in. This simply means there is more space for research. The possibility to explore the unknown is one of the most exciting things about science. However, there is a big problem when scientists start believing blindly in the models they use, or worse, when they omit the assumptions (often unrealistic) made by these models. This is where the whole credibility of scientists becomes shaky. If we can’t rely on scientists anymore to faithfully represent the facts, how else can we rely on politicians to do that?
We have a problem today with how the global warming problem is presented to the public. Re-orienting the discourse towards sound science should be the way to go. Politics should help in securing funding for the un-biased scientists who seek the truth about the question of global warming to do their research. Only then can these findings have the credibility needed to motivate a strong will to preserve our planet. Scientists working on this question need to know that their conclusions are as crucial as the ones made in other disciplines where the findings are immediately testable and can have severe outcomes if wrong.
For more on this question, here is a good essay by Freeman Dyson.