It is quite a paradox. After the decade of the 1990s, in which each year was "one of the five hottest of the past century!", the first decade of the 21st Century has been disappointingly cool. A recalculation of some data indicated that 2007 may—just maybe—have been ever-so-slightly hotter than 1998, but 2008 is on track to be the "least warm" year so far since about 1992.
Climate gurus of all stripes are predicting that 2009 will be warmer. Will they have better success with their predictions than Jeanne Dixon, the famously inaccurate 'psychic' of my youth? She made a comfortable living from being right only a quarter of the time.
Climate modelers and other researchers are faced with the fact that climate is in continual flux for many reasons, most of which we are wholly ignorant. Milankovich cycles that span tens of thousands of years, Bond events of unknown cause that span a thousand or two (most recently the Medieval Optimum followed by the Little Ice Age), shorter cycles perhaps mediated by the 22-year Sunspot cycle, and trends both shorter and much longer than any of these that may relate to varying fluxes of cosmic rays: these are things we know a little about, but how many influences are as yet wholly unknown?
To those who'll react, "Isn't the Sunspot cycle 11 years?": one 11-year series has the Sun's magnetic field aligned the same direction as Earth's, while the following series it is in the opposite direction. The effects of solar flares on earth systems during a "same" series differ from flares during an "opposed" series.
My observation of the climate change debate for more than forty years is that as the (emotional) heat increases the light vanishes. I despair of pundits from any "side" of this many-faceted debate showing any reasoned restraint in my lifetime. But perhaps there is a ray of hope. Nigel Lawson (Lord Lawson, former Chancellor of the Exchequer), safely ensconced in retirement, strives to inject a rational note with his little book An Appeal to Reason: A Cool Look at Global Warming.
There is no sense pulling punches. Let's begin with his conclusion:
"...a lurch into protectionism, and a rolling back of globalization, would do far more damage to the world economy, and in particular to living standards in developing countries, than could conceivably result from the projected continuation of global warming...[It] is clear that the would-be saviors of the planet are, in practice, the enemies of poverty reduction in the developing world." (p. 106)Though he has more than one central point, I think this is the most telling: The IPCC reports of recent years are based on various projections of the economic progress of developed and developing nations. The "hotter" cases, those that predict greater greenhouse heating of earth, are based on greater economic growth, and the "cooler" cases are based on various amounts of throttling of economic growth. Thus, the IPCC "worst case" scenario predicts that people in the developed nations will be 2.5-3 times better off 100 years from now than their great-grandparents (us) are today; for the developing nations, the figure is between 8 and 10. Their intermediate cases are based on people being perhaps "only" 75% as well off—and require cutting back our own prosperity a similar amount. So our efforts to reduce the greenhouse heating experienced by our unbelievably rich great-grandchildren entail rolling back twenty or more years of economic progress!
Looked at carefully, the IPCC predictions for the least warming ("best case") require reducing not just growth, but actually contracting the economic structure of all countries, so as to reduce greenhouse gas emissions by 70%. Think about that. It is, effectively, a rollback of Western lifestyles to the those of the 1920s or earlier, certainly before any kind of air conditioning became widespread and before most people traveled by auto rather than carriage or tram. It requires China and India, home to almost half of humanity, to halt their progress in its tracks. Precisely how likely are these things? My conclusion: ZERO.
Lord Lawson take a look at the very real reports of heat-related deaths during those hotter years in the 1990s. In one year, 2,000 people, mostly elderly, died in France. News reports that year failed to mention that the prior winter, 20,000 people, mostly elderly, died due to the cold...and that was a bit less than usual. Is the point clear? Winter is still a bigger killer than summer. At what point will they become equivalent? Perhaps that is the optimum temperature!
For those who worry that heating will truly get out of hand, the author introduces us to a few folks in the relatively new field of Geoengineering. They are working on methods to cool the planet, whether we reduce CO2 emissions or not. Certain aerosols, for example, result in significant cooling without harming the Ozone layer (a worry that still comes up at times). So, fire a few million tons thereof into the stratosphere! With research, and luck, maybe they'll come up with something more effective and more benign than the sulfates that volcanoes routinely spread, but which come down as acids over a few years' time.
We find buried in the IPCC reports the prediction that warming is bad for some and good for others. They even phase it: a degree or two seems to do more good than harm, while four or five degrees (Celsius, of course) is expected to be mostly bad. Lawson writes, "...is it really plausible that there is an ideal average world temperature, which by some happy chance has recently been visited on us, from which small departures in either direction would spell disaster?" (p. 27). I don't think so either.
The age of Dinosaurs, which ended 65 million years ago, experienced CO2 levels four or five times today's level, and global average temperatures as much as 18°C (32°F) greater than today. That doesn't mean the tropics baked at 50+°C, but that the poles were almost as warm as the tropics, which were only slightly warmer than they are today. All computer climate models predict 5 or more degrees of warming in the Arctic and Antarctic for each degree of equatorial warming. Canada, Siberia, and southern South America will likely be the grain belt of such a future!
Secondary threats such as rising sea level are much touted. Yet they aren't really panning out. Even the IPCC's worst case predicts at most a fifth of a meter (roughly a cubit, or 1.5 feet) of sea level rise by 2100, and then only if a goodly portion of Greenland's ice cap melts. That ice is receding a bit at the edges, but its center is thickening! Perhaps that is why, in thirty years, the sea level at the Maldives has not risen, but fallen slightly! (See N. Morner et al 2004, 'New perspectives for the future of the Maldives', Global and Planetary Change, v40, Jan 2004, pp. 177-182.)
I've been particularly bemused by the idea of carbon trading. What can it accomplish? When Al Gore pays a "carbon offset" to get a few hundred trees planted somewhere so he can feel OK about having a huge mansion and fly about in a private jet, is anything genuine actually happening? Lawson thinks not, saying, "[Buying carbon offsets] resembles nothing so much as the sale of indulgences by the medieval church." (p. 78).
He prefers we do things that might really help. Geoengineering is one possibility. Another is to learn all the climatic influences so we can make our computer models actually meaningful. Today's state of the art is miserable: "The earth's climate is determined by hugely complex systems, many aspects of which are not at all well understood. Reliable prediction is impossible." (p. 91). He favors greatly increasing research spending to bolster our understanding in hopes that this "miserable" situation will be better in the future. Yet we must remember that climate is the quintessential chaotic system. Doing something twice in a row won't always produce the same results. Too much depends on what else happened between time one and time two.
So I am heartened by his effort, but it is bittersweet. His appeal will only resonate with those who really don't need it, and be ignored by those who do.
Posts
No comments:
Post a Comment