The IPCC has issued their report on global warming states that, given present understanding, it will take centuries to balance the carbon dioxide and other gases that have caused global warming.

The next time some one tells you how ineffectual the UN is, realize that the IPCC has been one of the drivers of getting climate change on the agenda globally.

The summary of this report is that several important steps in understanding global warming have happened. One is that models now give better ranges of possible results for global warming. The other is that the feedback from water vapor - which is what moves and stores most of the heat in the atmosphere, and is, essentially "weather" from our viewpoint - is better understood.

These two factors together allow us to both give better predictions about how bad it is going to be, and how bad the results are. One not about most of the models is that almost all of the uncertainty is to the upside. That is for any given amount of carbon dioxide released, it is very unlikely to be better, and it is not impossible to say it could be much worse. These are the kind of situations that attract the attention of even hard heads - it's bad, it probably won't be better and it could be a lot worse.

The report makes a near term prediction - namely that warming will continue for at least 20 years at the rate that it has bee going for the last 10 years - about .2 degrees centigrade per year. This while the planet is hotter than it has been for millions of years. It also says that even if we freeze carbon emissions, that global warming will continue at about half that rate, because the oceans will still have stored heat. And that is the good news.

The bad news is that global warming is likely to accelerate for the same amount of carbon in the future, that is not only have we warmed the atmosphere, we are overwhelming its ability to cope with it, secondary effects - such as the reductions in albedo because of ice melt and so on - will mean that there will be more global warming bang for each molecule of global warming gasses.

The graphs on page 15, which make the "hockey stick" of carbon concentration and temperature abundantly clear, should be the opposition killer. There is a problem, it is our fault, and we aren't going to fix it by sticking our head in the tar sands.

Page 20 however has the killer data - it is the "Lowell's Mars Scenario". A century ago an astronmer thought he saw "canals" on mars, and even hypothesized that intelligent martians built them, to draw water from the poles to the equator. The climate models are in broad agreement that devastating levels of percipitation reduction could occur in the equatorial regions - at very least creating the possibility of "water wars". However there is a great deal of uncertainty about where. If the droughts hit the tropical rain forests, then this could have cascading effects well beyond water use, and into the amount of oxygen available. The doomsday scenario, not meentioned in the report, is that the ecosystems ability to turn CO2 back into O2 could be compromised and dramatically reduced.

Executive summary - even if we held carbon constant at 2000 levels - a number being left behind in the rear view mirror of SUVs everywhere - there will be permanent effects on the environment. Given the scenarios we are facing, the results could be a great deal worse.

For comparison it is useful to look at the response to the "population explosion" of the 20th century - that was the "green revolution" which involved much greater use of petroleum in agriculture. This is, in effect, the next follow on problem - the use of combustion has powered most of the improvements in human living - without it we would be running a smarter subsistence economy, with dramatically lower standards of living. If we do not find a way to take that economy and convert it, the costs will be larger than the petty costs of the cars and other sunk capital we have. It is passed time to allow aging technologies and aging factories to dictate what the future course of policy will be.