Monday, March 12, 2012

Mysterious arguments about AGW

There are two interacting climate change hypotheses. The well known one (AGW) is that human induced increases in atmospheric CO2 are increasingly making it warmer. The other is that when the sun is weak it allows more cosmic rays to get to lower levels of the atmosphere, increasing cloud cover and making it cooler. There is good reason to think we are moving into this weak sun period.

The two sides of the AGW debate have a clear interest in the 2nd question. For people that want something done about CO2, it is important to let people know that if we enter a period where natural climate variability runs against AGW then we must not relax, because soon they'll be pushing in the same direction and by then it will be too late to reduce CO2. On the other side of the AGW debate, those who don't want anything done about CO2 should keep quiet about natural climate change so that they can claim that the temperature falling (or not rising) disproves AGW.

But what we see is the reverse. AGW proponents like to deny that there is any such thing as natural climate change. Meanwhile those on the other side seem equally keen to argue that there is natural climate change.

Go figure.