Thursday, January 19, 2006

Extreme climate change now irreversible.

Global warming has reached the point of no return and our planet can only keep heating up according to the leading scientist Sir James Lovelock who developed the theory that the Earth is like a living organism in totality. Known as the Gaia hypothesis it was first broached in 1975 and introduced the concept of the earth's biomass having homeostasis, or self-regulating feedback systems, to a non technical audience. These regulatory feedback loops maintain the conditions to sustain life on the planet.

While Gaia hypothesis has had it's critics it was a model that helped facilitate my understanding of complex interactions like the carbon cycle, so it is with interest that I note of Lovelock's predictions in his new book The Revenge of Gaia. Predictions based on his assertion that the feedback mechanisms that are used to cool the earth are now working to amplify anthropogenic warming from our CO2 emissions:
  • by 2100 Europe and southern Australia would be 8 degrees hotter than they are today
  • he cannot see the United States or the economies of China and India cutting back in time and they are the main source of CO 2 emissions
  • he predicts efforts to slow it may already be doomed
  • billions would die by the end of the century, and civilisation as it is known would be unlikely to survive
  • the few breeding pairs of people that survive will be in the Arctic, where the climate remains tolerable
These climate change preditions make for a gloomy outlook and I'm the glass half full type, so how much weight should The Revenge of Gaia be approached with?
Professor Lovelock is a controversial but respected scientist who gave a briefing on global warming in 1989 to the then prime minister, Margaret Thatcher. Two years ago he caused a furore in the environment movement by urging greens to embrace nuclear power to reduce global warming gases.

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1 comment:

8daysawk said...

Would some degree of warming be bad for most societies and natural environments? Probably not.

During the 20th century,we have already proceeded more than half way to doubling the natural carbon dioxide greenhouse effect. Here is what resulted: Life expectancy doubled in the free and developed world. The developing world is catching up as their emissions rise. Corn production per acre increased five-fold. The growing season in the coldest latitudes increased slightly, but enough to increase greenness by 10 percent.

The small amount of warming that occurred during the past century consisted primarily of increased minimum temperatures at night and during winters. This means higher average temperatures, should they occur, would not result in more daytime evaporation, which some claim would lead to droughts and desertification.

Warmer winters would mean longer growing seasons and less stress on most plants and wildlife, producing a substantial benefit for the global ecosystem. Finally, past warming has been accompanied by increased cloudiness, a phenomenon also predicted by most global climate models. This means a warmer world would probably be a wetter world, which once again would be beneficial to most plant and animal life.

Ex-Vice President Al Gore claimed that "hundreds of millions of people may well become even more susceptible to the spread of diseases when populations of pests, germs, and viruses migrate with the changing climate patterns." Gore has also claimed that global warming will cause floods, droughts, heavy rainfall, forest fires, retreating glaciers, and heavier snowfall.

In addition to often being at odds with each other, Gore's claims are at odds with most scientific research. The two historical epidemics described by Gore to validate his prediction were unrelated to climate change. The Black Death, for example, was transmitted by rats, which flourish in cool as well as warm climates. Cholera has been a threat in warm as well as cold climates, and is readily brought under control by treating water supplies with chlorine.

The latest research suggests that sea levels would decline, not rise, if temperatures rise, due to increased evaporation from the oceans and subsequent precipitation over land. Increasing polar temperatures by a few degrees would not cause ice or snow to melt because the original temperatures are so low that an increase of a few degrees would leave them well below freezing.

The "torrential" rainfalls Gore fears turn out to be any rainfall of 2 inches or more in a 24-hour period, something every farmer knows would likely be a blessing rather than a curse. The number and intensity of hurricanes occurring over the Atlantic Ocean (the ocean basin with the highest quality data) has steadily fallen since aircraft reconnaissance began in 1944.

The IPCC itself found "inadequate data to determine whether consistent global changes in climate variability or weather extremes have occurred over the 20th century," with some regions exhibiting greater variability and others less.

In short, a slightly warmer world would probably be greener and a little cloudier than our world today, but otherwise not much different.