First off, the climate has always changed. The biggest question is how much of the change is anthropogenic. This is very difficult, if not impossible, to quantify. From radiative transfer theory, we know that increasing the levels of CO2 will result in some warming. However, this effect is not large enough to be of concern. There needs to be other effects from the slight warming caused by CO2 increases. One thought is that some warming will increase the amount of water vapor in the atmosphere and since water vapor has a much stronger greenhouse impact than CO2 the net result will be greater warming. Of course, this will lead to more clouds which will reflect more incoming solar radiation and lead to cooling. However, the clouds also act to trap long wave radiation which can lead to warming. Needless to say, it is complicated, non-linear, hard to quantify, and difficult to numerically model with fidelity. This was the area I primarily worked in.
There is no actual proof that the increase in CO2 from man's activities is increasing the global temperature. There are short term temperature records but there has been some homogenization of the data. There are longer term data from ice cores. Interestingly, some of the data suggests the CO2 increases follow temperature increases. The "evidence" that man's activities will catastrophically increase global temperatures comes from numerical modeling. This is an area of ongoing research and I don't believe the results are usable, yet, for developing public policy. It is difficult to numerically model important processes such as clouds. There continues to be a lot of money (relatively) spent on numerical modeling worldwide for investigating anthropogenic warming. Again, we don't know the quantitive impact or the time scale. As a scientist, I cringe every time I hear somebody say the "science is settled".
Quote:
Originally Posted by graciegirl
I believe that both sides are aware and concerned about global warming, but how to deal with it is the problem. I don't think being the major funder in the Paris meeting is doing something. I don't think that passing laws about drilling or pipe lines is doing something. As long as you gas your car, you prove that argument invalid. Industrialization is a major cause of greenhouse gases. Texas has windmills just like Germany and so does Massachusetts. So far scientists are incapable of changing the world to alternate power. Moving your arms and legs and worrying about plastic straws all day and night are not going to stop global warming or save the oceans. The trouble is that not one valid solution has been offered in any of these posts to stop global warming. Talk is cheap.
|