While slogging through the backlog of good blogs that I haven't read in two months, I saw that Mike over at Opinion8 noticed a UK Telegraph headline:
"The truth about global warming - it's the Sun that's to blame"
The link is broken - the article was from the middle of last month - but we'll take Mike's word for it. It got me thinking about some things that I've read recently in regard to global warming. Here's the deal in a nutshell:
There are a few things that I think everyone will agree on:
- Climate has varied over time, and varied significantly before the last 200 years, when industrial civilization started taking off.
- If natural processes produce vastly larger quantities of greenhouse gases, we have to believe that natural processes have a larger effect on the biosphere. (Not to mention the effect of the sun.)
- If we took a poll, and large numbers of climate scientists (not just scientist in general) thought that there is no consensus on global warming, then we'd have to agree that there is no consensus.
- If current temperatures are somewhere in the middle of the historical highs and lows, and the ecosystem didn't crash before, we have a buffer zone before any conceivable human activity causes the ecosystem to crash.
When we look at historical climate records, we notice some interesting things. Over the last two millennia, temperatures were both much higher, and much lower than the average for the twentieth century. Temperatures were at a peak around 1000 a.d., a period referred to as the Medieval Climate Optimum 2-3 degrees centigrade warmer than now. Later, around 1350, temperatures began to drop, culminating in the Little Ice Age, when temperatures were significantly lower than currently. The warming trend of the last 200 years has put us well above the lows of the Little Ice Age, but we have not yet reached the highs of the Medieval Climate Optimum.
Four thousand years ago, the climate was even nicer than during the medieval climate optimum. Temperatures were warmer still, as high above todays as the Little Ice Age was below so cold that trees exploded in England in the winter. Many areas now covered by desert were lush savannah and forest notably the Sahara. Millions of years before that before the ice ages, temperatures were even higher. At none of these points did the ecosystem collapse rather the opposite, in fact. Higher temperatures led to increased CO2 levels, and both of these factors are like crack for plant life. More plant life meant more animal life. Among the benefits we could see now are much like those experienced a thousand years ago: longer growing seasons, increased crop yields, sunnier weather, and vineyards in Ontario.
Given that the planet has successfully endured many periods of global warming, panic over a current episode seems, well, overwrought. Especially since it is not established that human activity is a major or even significant contributor to the process. People release about 30 billion metric tons of CO2 into the atmosphere every year. That eems like a lot, until you realize that natural processes such as volcanoes, the outgassing from the oceans, and the natural functioning of the biosphere add up to 1800 billion tons. The sum of human activity adds less than two percent to the preexisting total. And further, water vapor is present in concentrations averaging at least ten times higher; and water vapor is a much more efficient greenhouse gas because it is active across the entire infrared, where CO2 is only active on two narrow bands.
The total greenhouse effect necessary for life on earth adds about 33 degrees to the Earths temperature. Without it, wed have permanent ice at the equator. Water vapor is responsible for somewhere between 95 and 99% of this, or about 32 degrees. Human activity is responsible perhaps for 2% of the remaining degree. When you factor in the effects of variations in the Suns output due to the sunspot and other cycles, variations in water vapor levels, natural changes in the climate, that percentage is likely even smaller.
The idea that humans could single handedly wreck the biosphere is hubris, really. Wed have to try a lot harder than we are now; yet throughout the industrialized world emissions and pollution are on the decline. (The Kyoto accords would only effect the one region of the world where pollution is declining, at great economic cost, while leaving India China, Brazil and all the other industrializing nations free to pollute at will. Mike Patton calls that economic self immolation. Oprah calls it empowerment.) Panic is perhaps counterindicated.
And another thing about CO2 emissions the bulk of the .5 degree raise in temperature in the twentieth century happened before 1940, while 80% of the increase in CO2 didnt happen until after. Youd expect some correlation there. But the strongest correlation with temperature is for sunspot activity, which tracks almost exactly from 1800 to the present. The sun might have something to do with the weather, after all.
And yet another thing: historically, CO2 levels rise about fifty years after a temperature rise. Just as we experienced recently temps start to rise around 1890, and CO2 starts up in 1940. While the burning of fossil fuels in the conventional explanation, before we do something drastic we should be aware that the Earth has enormous reservoirs of carbon in various forms. Some large percentage of the CO2 increases weve seen might still be the result of natural causes.
And one more thing: as I mentioned earlier, plants dig CO2. 100 million years ago, CO2 concentrations were on the order of ten times higher than now. Most plants cant survive below levels of 50-100ppm. During the coldest parts of the Little Ice Age, CO2 levels dropped to around 180ppm. Crop failures may not have been due solely to the cold weather. If you double a plants supply of CO2, it increases yield by a third while reducing evaporation and doubling the efficiency of water use. Tests have shown that improvements continue at least out to CO2 concentrations of 1000ppm, nearly three times the current total. Increasing the amount of CO2 could bring enormous benefits, not just higher crop yields but even possibly reclaiming desert regions, and increased biodiversity.
And one last thing: the warm periods between periods of glaciations typically last 11,000 years. Its been 10,800. Global warming could be a very good thing, and a noble goal.
As to the idea that all scientists agree that global warming is a real and present danger, check this out:
- After the 92 Earth Summit, 218 leading scientists including 27 nobel prize winners signed the Heidelberg Appeal condemning the irrational science and ideology behind that event. Since then, the numbers have grown to 4,000 and 70 nobel prize winners.
- After a 1995 international symposium in Germany, the Leipzig Declaration was issued, saying, there does not exist today a general scientific consensus about the importance of Greenhouse Warming and we cannot subscribe to the politically inspired worldview that envisages climate catastrophes and calls for hasty actions. The declaration was reissued on the eve of the Kyoto conference in 97, signed by an additional 100 atmospheric researchers and with the added statement, we consider drastic emission control policies likely to be endorsed by the Kyoto conference lacking credible support from the underlying science to be ill-advised and premature.
- Climate specialists, atmospheric researchers and other specialist 17,000 of them signed a petition declaring that there was no evidence that greenhouse gases were or were likely to cause disruption of the climate.
- The German Meteorological Institute of the University of Hamburg conducted a survey of climate researchers. 67% of Canadians rejected the notion that any warming was the result of human activity. For Germans, 87%, Americans, 97%.
- Then of course, theres the scandal of the IPCC (Intergovernmental Panel on Climate Change) executive summary which was widely reported in the media, and which systematically misrepresented the findings of the actual report, to the disgust of many of the contributors.
This is not to dismiss any solid research that supports or indicates global warming, but I think it demonstrates that we dont have a consensus, or in fact anything close to it. Think about it for a minute when, in your experience, has the media gotten right anything that you know something about? Whether its rose gardening or military history, the media screws it up, distorts and misrepresents the facts and in general gives anyone who doesnt know what you know a completely inaccurate picture of whats going on. Why should we imagine that they got this right?
Given all of the above, I think its safe for us to do the wise thing, which is to say nothing beyond what were already doing. We are getting better at being cleaner, and we will continue to get better. The third world will eventually (hopefully) become cleaner as they get richer, just as we did. Assuming that we get no worse at polluting (a conservative prediction, I think) we are not going to press the ecology destruct button anytime soon. The world can take a five degree centigrade change in either direction, and has done both within the last five thousand years and yet survive. That gives us a comfortable margin of error, and breathing space to do some careful research to see whether anything really needs to be done.
And who knows, given the timing of Ice Ages, the answer might come back to give up the clean burning sissy cars and start using coal fired dragsters to keep the glaciers off your lawn.
August 2004
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