Re: Global Cooling on it's way
Posted by Dale on Jan 15, 2002 at 10:40
Re: Global Cooling on it's way (Natalie L. Smith)Logically, one would expect that an increase in CO2 would cause a greenhouse effect, all other things being equal.
Agreed except that “all other things being equal” sort of makes it a moot point. All other things aren’t ever equal. If they were, there would be a much larger problem. Water vapor is a more potent greenhouse gas. If a little CO2 caused a small increase in temperature, then the atmosphere would hold a little more water vapor and the oceans would be eager to fill that void. That would result in an even warmer atmosphere. If all other things were equal, then we would either evaporate the oceans or freeze them. This might even explain the demise of oceans on Mars over the relatively recent past.Granted, it is that last qualifier and the over-riding complexity of any real-world problem that leads to all the debate.
And that is what baffles me. Why the debate? Obviously the system is very complex and there are mitigating factors. Whenever the temperature rises a little SOMETHING causes it to decrease almost back to where it started and vice versa. Anyone who looks at the temperature record of the earth and CO2 over the past few million years can see that the CO2 level has some effect but it is very small compared to what it should be. Obviously the earth has a very good thermostat that turns the heat up and down as the measured temperature changes.Let's say, for the sake of sheer argument, that we are heading into another ice age and that our burning of fossil fuels tempers the degree of cooling observed. So, what happens next? What causes the larger scale hot and cold swings of our earth (sun cycles?) and, if we dampen a cold swing, would that alter any ensuing warm age? Would we really fry then?
Or would we get just a little warmer? Yes, CO2 is a greenhouse gas that should cause a temperature increase. But, as Danny so correctly points out, there were palm trees during the ice ages and polar bears during the tropical episodes. Life adapts. Tree species move north and south. The only way we could have a real serious problem would be if we could somehow change the temperature in a period of time measured in centuries rather than millennia. But we already have evidence that we can’t do that. We have the CO2 increase from the start of the Industrial revolution to the present and a record of temperature that shows little real change. We have already proven that we don’t change the temperature by 20 degrees when we drastically increase atmospheric CO2. Mankind is just too small to make the really large changes needed to change the temperature faster than the environment can compensate.