Thursday, November 16, 2006

Global Warming - AAPG's Climate Card

AAPG has published a "climate card" that disputes the prevailing notion that the current global warming is primarily a result of anthropogenic greenhouse gases.

In general I agree with their conclusion, but I am still concerned about the very high CO2 level of 380 ppm that is mostly a result of man's activities. This level of CO2 is probably unhealthy for reasons other than increasing temperature. On the plus side without this high level of CO2, it is not unlikely the next ice age could have already begun.

The strongest evidence presented on the AAPG climate card comes from the ice cores that show CO2 increases lagging temperature increases, clearly showing that historically temperature drives CO2 increases and not the reverse. At the same time, it is clear that increased CO2 can affect temperature, so we have a feedback effect which helps explain some of the wild temperature swings in the last ice age. Something must break these feedback loops, one way or he other in order for temperature and CO2 to swing back the other way.

Obviously playing with feedback loops of this kind is not a good idea, so we cannot really predict what might happen when we add something to the natural equation. This is why we need to be concerned about the high CO2 values we now have.

Now let us consider the other side of the coin. The most remarkable thing about the temperature in the current interglacial period is how flat it is compared to previous interglacial periods. Something very odd is going on, or the glacial ages may be coming to an end. I doubt the glacial ages are coming to an end. The odd thing that is going on is that men have been tearing up the natural environment over the last 8000 years and the effect may actually have been to stabilize an otherwise erratic temperature regime. Does this mean we should expect this effect to continue? Not necessarily, we cannot really predict how our impact will play out, particularly as it appears to be exponentially increasing.

What really needs to be done is to stop the exponential growth. Stop adding variables to the global environment whose effects we cannot adequately estimate. In my estimation, the only real solution is a stable or slightly declining human population. Unless we achieve this, there are no solutions that can work; they all amount to putting bandaids on bullet wounds.

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