golfcart wrote:Models aren't perfect but you hope they can get the big picture correct and that we can make informed decisions about how those trends might impact us in the near-term and long-term.
The current climate models literally have NO CHANCE of being predictive of long-term climate. There are four main reasons for this: 1) Many of the underlying physical processes are unknown or partially unknown. For instance, scientists are still learning about what causes clouds to form. And even the detailed physics-based models are incapable of predicting whether a given particle will grow into a water droplet. Since clouds are the most significant driver there is for climate, this lack of knowledge means the models do not have the necessary skill to be able to predict the climate. 2) There is insufficient computer capability to be able to accurately predict the climate in the future faster than the climate itself evolves. Making simplifications and assumptions can speed the process, but reduces the effort to an elaborate curve-fitting exercise. 3) Extreme temporal and spatio-temporal chaos in the climate system mean that it is quite impossible to make accurate predictions about the climate very far into the future. A good example of this is that ENSO is fairly well understood. Yet it would be quite impossible to predict when the future El Ninos will occur. Currently, we are lucky if the ENSO predictions are accurate only six months out.
golfcart wrote:There is, in fact, still a lot of debate in the scientific community about the details of climate change. But there is little to no debate about the simple fact that, all other things equal, increasing the level of greenhouse gasses will tilt the planets energy balance towards the more of the incoming solar radiation remaining in the earth system.
Sure. But all things are not equal and the impact of CO2 is so small as to be completely inconsequential.
There should also be little debate about the following facts:
1) The temperature of the Earth's atmosphere is almost completely dominated by the temperature of the surface of the global oceans.
2) The greenhouse effect does NOT heat the oceans.
3) The greenhouse effect can reduce the rate of cooling of the oceans. Clouds have been measured to reduce the temperature of drop of the surface of the oceans by as much as 0.1K relative to clear skies. This is with 100 W/m^2 difference when compared with clear skies.
(Note that it is currently impossible to measure the effect of CO2 on the surface temperature of the ocean.)
4) However, a doubling of CO2 would only be about 1/100th this amount of forcing as the maximum range seen with clouds. We are currently below a doubling of CO2. So CO2's maximum effect on the world's global oceans is a reduction of of the temperature drop of the top micron of water by approximately 0.0005K versus what it was about 100 years ago. Simply put, there is virtually no impact of CO2 on the temperature of the global oceans.
5) The GLOBAL MEASURED greenhouse effect on Earth has not changed in the past 25 years
. Over that time, humans have dumped about a third of all the CO2 into the atmosphere that they have been able to release. The simple conclusion of these two observations is that man's contribution of CO2 to the atmosphere is NOT driving the global greenhouse effect. It is completely dominated by clouds and water vapor, in that order.
6) The temperature changes we have seen on Earth can be almost completely explained by changes in global cloud cover. Unlike CO2, the relationship between global cloud cover and temperature is very strong.
7) The additional CO2 in the atmosphere has caused an amount of greening of the biosphere equal to twice the area of the United States.
The bottom line is quite clear. CO2 is a don't-care molecule when it comes to the temperature of the Earth. As such, spending ANY money trying to reduce our emissions of CO2 is shear nonsense and completely against the clear message of the science.
Instead, we need to focus our efforts on cleaning up pollution, much of which comes from the extraction and burning fossil fuels.