Wednesday, January 28, 2009

What Could Happen?

The best summary of what global warming could bring that I have seen is in the book “Six Degrees” and the National Geographic DVD of the same name. The author of the book (Mark Lynas) compiled the information from many scientific papers to get an idea of what changes we can expect if the average global temperature increases from 1 degree to 6 degrees Centigrade above the current temperature. I encourage everyone who is even slightly curious about the future to read the book and watch the DVD. The book goes into more detail and has a lot of information that the DVD does not have, but the DVD is more compelling and has some information that didn’t make it into the book.

Even the DVD doesn’t convey what actually living in such a world would be like. Without this knowledge, it is difficult to put the problem into perspective. Knowing that rising sea levels will force millions to relocate is not the same as the experience of losing your home, property, and neighborhood and having to find a new place to live and a way to make a living at the same time that millions of others are doing the same thing. I want to try to convey this kind of thing, even though I know I can only hint at the experience.

I want to focus first on one of the things that scientists think will happen with a one degree C temperature increase, partly because I don’t think we will avoid that much increase at this point, partly because few people understand what such a seemingly small increase could mean. Many scientists think that the Western part of the United States will be like it was during the Medieval Warm Period (around 800-1300 AD), the last time the temperature was that warm. I will focus on this region, because it is where I live, and I have paid special attention to predictions about this area. Scientists can see from tree rings and from trees that died when the water in lakes and river beds rose again that drought was the norm in the West during this period. In fact, the droughts were so severe and long that they call them mega-droughts.

Nowadays when a severe drought goes into its third year in California, we have to start rationing water so that we don’t run out. That means lawns don’t get watered, swimming pools and hot tubs don’t get filled, cars don’t get washed as often, showers are shorter, toilets are not flushed with each use, and so on. Since California has been a state, severe droughts have never lasted more than a few years. Three or four years is the longest I can remember experiencing. But during the Medieval Warm Period, droughts lasted as long as 50 or 60 years with no break. In a three year drought, you can still use more water than comes down from the sky, because the first year or two there is a surplus from the previous year, and the last year you can hope that it will rain and snow more in the coming winter. But when a drought lasts much longer than that, you only get what comes down each year, which is not much during a drought. When that happens for years in a row, California will not be able to grow the crops it is famous for, because there will not even be enough water to support the population, much less crops. People would have to move to other locations where water is more plentiful, and the people who stay would lead a very different life.

The Great Plains, our nation’s “breadbasket” could be even drier than California. During the Medieval Warm Period that part of the United States was a desert. I don’t mean that figuratively – it was literally made of sand dunes, and you can still find sand under the thin topsoil. This area included Texas, Oklahoma, Kansas, Colorado, Wyoming, N. Dakota, S. Dakota, Saskatchewan, and Manitoba. Obviously you can’t grow wheat or corn or soy in a desert. So grain and soy production will go down dramatically, and so will meat production. Every type of food will be scarce and expensive. (Even without global warming, fish are supposed to be extremely scarce in a few years, mainly because of over-fishing, and California grows most of our other vegetables and fruits, so that covers most of what we eat.)

Of course, the United States could import most of our food, but only if there is enough to import, and only if we could afford it. Canada should be able to produce more food at that stage of global warming, so we might buy a lot of our food from there. But Mexico and Central America will be suffering mega-droughts just like our West. (In fact, the Maya civilization ended during the Medieval Warm period, likely because of the long droughts they suffered.) Australia, another major food producer, will also be suffering drought conditions most of the time, as will many parts of Africa. And all over the world, people who depend on mountain glaciers for water will begin to suffer severe water shortages. Those glaciers have already shrunk dramatically, but it will get much worse. That means many other countries, including China and India, will not be able to produce nearly enough food for their own people. The recent food shortages that caused riots in several countries is nothing compared to the shortages we will see then. The dust bowl caused a lot of suffering when it occurred, and anyone who has read “The Grapes of Wrath” has gotten a taste of those times. But that is nothing compared to what will happen with a one degree temperature rise. Back then people moved from the drought-stricken states to California, but if California is in the middle of a mega-drought, people will be moving away from there too. Where will all those people go? And where will their food come from? Will Canada have to build a wall to keep out illegal American immigrants?

It is impossible to adequately describe or imagine what life will really be like then. But we can get some hints by looking at the past. There are some ruins in New Mexico where the most advanced civilization north of Mexico was located, and they either abandoned their buildings and migrated or died out during the mega-droughts of the Medieval Warm Period. On the top of their largest buildings are human bones with human teeth marks on them and signs that they were killed. Maybe people from other tribes killed and ate them, or maybe their own civilization broke up into competing factions. In Egypt there was at least one drought that went on for so long that people resorted to eating their own children. They must have already eaten all the other animals and edible plants at that point. Try to imagine what level of suffering would lead someone to eat their own children. Any sane person would want to avoid such a fate for himself, for his children, and for others. So why are we not doing what we need to do to avoid it? I can only conclude that people still don’t understand the threat of global warming.

We are much more advanced technologically than those older civilizations. But if there is such a severe, worldwide food shortage, at the very least many millions of people will starve to death in the poorer and less advanced countries. I think it will also throw our financial systems into complete chaos. The Pentagon did a study and said that the mass migrations will increase the likelihood of wars and conflict when these types of things begin to happen.

Water shortages caused by droughts and melting glaciers are not the only things that will happen with an increase in global temperatures of only one degree Centigrade. According to “Six Degrees”, here are other things that are predicted:

The Arctic ocean (North-West Passage) will be open (water instead of ice) half of the year.
Permafrost will melt even faster than now, releasing more CO2 and methane.
Tens of thousands of homes in the Bay of Bengal will be flooded.
Hurricanes will occur in the South Atlantic (off South America).
Storm intensity will increase, including cyclones (hurricanes).
England will be growing things like grapes that normally do not grow there.
The lands experiencing severe drought will increase from 3% to 30% of the planet.
Species will go extinct at an even faster rate than now.
Most of the coral will experience bleaching and eventually die.
Tuvalu, Kiribati, the Marshall Islands, Tokelau, and the Maldives will sink under water.

I think it is now too late to avoid this. I read about a year ago that there is another 0.6 degree C rise already “in the pipeline”, meaning it would occur even if we immediately and completely stopped producing excess green house gases (GHG). Plus the albedo feedback means another 0.3 degree rise is inevitable. And there may be another full degree that will happen as we stop putting particulate matter into the atmosphere when we finally do close down the coal plants. But we can survive this much. We should not give up, because things could get much, much worse than this. We need to reduce GHG emissions as much and as soon as possible and at the same time remove as much CO2 from the atmosphere as possible. Here is an article where scientists are finally speaking up about this subject:
http://www.msnbc.msn.com/id/28874983/

The article below, about the same study, sounds even more ominous. They are saying that the effects of global warming, however bad they get, will last about 1000 years after we bring our emissions down:
http://www.npr.org/templates/story/story.php?storyId=99888903

"The Long Thaw" by David Archer, a leading climate scientist, says the effects will last much longer than 1000 years after we severely reduce our emissions. The worst effects might last 100 to 1000 years, but CO2 levels won't fully return to preindustrial levels for hundreds of thousands of years.

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