As the Copenhagen meeting on climate change opens, we are getting mixed signals. At one extreme are the "disbelievers," who say that serious consequences from global warming, if it is really happening, are still decades away so why should people be saddled with higher energy costs now.

At the other extreme are the climate scientists who are telling every media outlet that will listen that the proposals being discussed at Copenhagen are nowhere near enough to save mankind from destruction. Some are saying that a five degree Centigrade increase in the average global temperature may be enough to do in mankind. Food will no longer grow in sufficient quantity to keep all 8 billion of us fed. Rising sea levels and more violent storms will make coastal cities - even Washington - largely uninhabitable. A recent survey of 3,000 climate scientists indicates that 82 percent agree that human activity is making a significant contribution to global warming. Of the 77 climate scientists who are actively studying and publishing about global warming, 97 percent say that human activity is involved.

For the last 30 years the average global temperature has been warming at 0.18 degrees Celsius every decade. If the temperatures continue increasing at this rate, it would take another 270 years to get to the magic number. There is no guarantee, however, that the rate of global temperature increase won't speed up so that somewhere in the 22^nd century the earth may become uninhabitable.

The 2007 UN estimate for sea level rise is that by 2095 it could be anywhere from 7 to 31 inches. However, a recent report says that sea level increase is likely to be twice what the UN estimated two years ago so that we could be facing five or more feet by the end of the century. If you want some really scary numbers, then keep in mind that if the East Antarctic ice sheet ever melts, we are looking at a sea level increase of 180 feet. This ice sheet was not expected to melt for thousands of years, but some scientists think we are starting to see melting down there already. Even losing 5 or 10 percent of this ice sheet into the oceans would be devastating.

The message here is simple. If the scientists watching this are right, and there is no reason to believe they are not, in 100 or 200 years there will not be many (or any) people left. We already have precedents for higher forms of life on earth being wiped out by meteors and really big volcanoes. Remember the dinosaurs?

Unlike the previous extinctions, it seems that the next one will be caused by people, not Mother Nature. We understand the problem (too much carbon going into the air) and how to solve it (stop putting so much carbon into the air). The problem is that for most of the world current lifestyles and prospects for a better life all involve using more fossil fuels. Nobody wants to give up what they have or the prospects for a better future. The situation is further complicated by the huge disparities in the per capita consumption of fossil fuels and populations.

While the richer European countries can see their way to major reductions in fossil fuel consumption, very few other developed countries can. In the United States which has until very recently enjoyed 300 years of nearly continuous economic prosperity, giving up our current lifestyle is unthinkable for many (perhaps most). Thus they prefer to listen to false prophets who tell them all will be well.

China is an interesting case as it pumps the most carbon into the air and until recently had no intention to stop pumping until all 1.3 billion Chinese citizens were as rich as the Americans or at least the Europeans. Despite the fact that Beijing is coming to Copenhagen with a plan that allows them to increase their emissions as they continue to grow their economy, there are signs that they are starting to worry. Last week China's chief meteorologist published a paper warning that fluctuations caused by global warming could reduce China's grain crop some years by as much as 50 percent. If you have 1.3 billion people to feed, this is a problem. Given China's vulnerability to the effects of global warming, it is likely that we will see major changes in Beijing's attitude to carbon emissions to the extent that they could easily become the world leaders in efforts to mitigate the consequences.

While some progress will be made at Copenhagen, especially since the US and Chinese Presidents are lending their prestige to the occasion, it seems likely that whatever is agreed upon will be inadequate and that discussions and negotiations will continue for many years.

Although world oil production is likely to start declining in the next few years, followed by world coal production in another 20 or so years, neither of these are likely to reduce emissions enough for many decades to have much of an impact on increasing carbon emissions. The decline in world oil production and much higher prices are likely to have a major impact on economic growth however.

The Obama-China-EU alliance is a powerful one, but so far only the EU seems willing to make major economic sacrifices necessary to contain carbon emissions. It will probably be another 50 years before we will know whether global warming has been contained or whether we have gone over the legendary tipping point beyond which the situation will be beyond man's ability to control. In the meantime get ready for hard times, sell your beach front property, and start thinking about higher ground.