Back to the Green house
By Michael Hailstone
Are we to look on the Greenhouse Effect as a matter of concern?
Our authorities are of course aware of the dreadful things our world civilization is likely to do to the Earth. Two depressing dooms (must I apologize for using that word? What word would you have me use instead? Besides, the original meaning of the word was judgment , so you can take it in that sense here) lately named on the media are the ozone layer and the greenhouse effect, nothing new of course, but the scientists seem to be getting sure about them. Alistair Cooke recently talked of a steady depletion of the ozone and an increase of deadly ultraviolet on the ground, leading to a present “epidemic” of skin cancer. Surely, with my sensitive skin, I would know if the sun were getting more burning every summer, but no, the experts tell us, we need the experts to tell us everything like that. More accurately, what the REAL experts (of whom Cooke is one) are telling us is that there is a big hole in the ozone over Antarctica , and they're worried and puzzled about it. They're keeping their collective eye on it, in case it gets bigger. But, if fluorocarbons from spray cans and so on are destroying the ozone, why should it happen in Antarctica , of all places, where nobody dwells? Of course the funny thing is, the ozone shouldn't be there at all, were it not for the solar ultraviolet it's shielding us from, and the Antarctic doesn't get much sun, but enough said about that.
More serious is the greenhouse effect. Our Commonwealth Scientific and Industrial Research Organization has just published a book that makes dire forecasts for our climate. Now it seems, it's not only carbon dioxide we need to worry about but also methane from flatulating cattle, as well as fluorocarbons. They expect mean temperatures to rise by about three degrees in the next twenty years and five degrees in the next fifty. Now, I presume they are using the Celsius scale (I can hardly imagine them still using Fahrenheit), yet they say that the snowline will rise 100 meters for every degree rise in temperature. That doesn't sound right to me, presumptuous as it might be of me to doubt the word of so august a body as the CSIRO. The average lapse rate of the lower atmosphere is one degree F for every 300 feet or six degrees C per kilometer, thus back in the ice age, when mean temperatures were nine degrees or ten degrees C lower, snowlines were about 1500 m lower than now.
That aside, assuming they are right, think of what it really means. A three degree rise in temperature may not seem much, but indeed such a change would make Canberra as warm as Wagga Wagga now is. If that still doesn't seem very much, then think of it as making Hobart, Melbourne, Sydney and Brisbane about as warm as Melbourne, Sydney, Brisbane and Rockhampton in turn now are. Then think of this happening within the next twenty years! This would mean an AVERAGE rise in mean yearly temperature of fifteen hundredths of a degree C per year, which is not at all a steep rise and would be drowned at first in the noise of the natural climatic variability (meaning, to put it less technically, that the mean temperature can vary by more than that from year to year with no climatic change taking place). Indeed such a steep rise took place in parts of Australia over the seven years from 1967 to 1973, when temperatures rose by as much as two degrees C in the northwest (which is already not only the hottest part of Australia but also one of the hottest parts of the world), though the rise here in the east was only about half a degree C. The year 1973 was Sydney's warmest on record, but it was not much warmer than 1922, the second warmest year, and even then Sydney was still about two degrees C cooler in 1973 than Brisbane normally is.
But the warming trend did not continue but peaked that year. The CSIRO's dire forecast is by no means new; even before 1970 climatologists foresaw temperatures rising by about two degrees C by the year 2000, which is now only one year further from us than l973. Along with the temperatures we can expect the sea level to rise by one and a half meters owing not to melting ice but rather to thermal expansion of the oceans. This reads more like Herzog's novel HEAT rather than real life. Carbon dioxide and methane have been building up in the air for years at an ever-quickening rate, but can there be a time when bang!—a climate change sets in? Surely there must be a slight long-term warming before such a drastic change takes place? Well, indeed the Earth has been warmer this century than for hundreds of years, but the cause could be natural. I could go on here about natural cycles, but perhaps I'd better not.
What would this hotter climate be like? Much of Australia would be wetter owing to the southward penetration of the summer monsoon. Indeed it would seem like an extreme version of 1973-74. We could expect a narrower seasonal range, as the cloud and rain would temper the summer heat, but it would also be a lot more humid. (In 1973 such normally brisk climes as Canberra and Goulburn got just as humid as Sydney.) Owing to the southward shift of weather systems, mild south-easterlies off the Tasman would replace the cold westerlies in winter. But we would get some exciting storms, and Sydney could expect the odd tropical cyclone. (Indeed, it seems that Australia , as a whole, would benefit from either a warmer or cooler climate, since in the present climate it lies right athwart the subtropical high pressure belt, which makes the continent two-thirds desert, but the Mediterranean climates of western Victoria , South Australia and southern Western Australia would dry out. While a warming would bring tropical rains to the interior in summer, a cooler climate would bring the winter rains further north and lessen evaporation.) Indeed, in 1973-4 sea temperatures around Australia were up to three degrees C above normal. The pacific aberration known as el Nino was blamed for our peculiar wet weather then; oddly enough this same phenomenon has also been blamed for our droughts in the eighties. I think there's something funny going on there.
The little bit of good news about the greenhouse effect is that a higher level of carbon dioxide would heighten plant growth. So maybe we should get busy planting lots of trees. But then we should be doing a lot of things but aren't.
By the way, another odd phenomenon of 1974 was the unusually high tides, which largely contributed to the damage caused by the freakish storms which struck the central coast of New South Wales in the late autumn of that year. These were put down to something to do with the Moon called “perigee syzygy,” though it's quite beyond me how there could have been anything unusual with the Moon's orbit that year. (Okay, I guess it means when the Moon comes closest to Earth when new, in line with the Sun, but surely that happens every year?)
However, a possible comfort could be taken in the fact that the Sun has been lessening in brightness at least since 1978. This could just be part of the 11- or 22-year solar cycle; as yet nobody knows how long this dimming will go on for. Since the rate is less than two hundredths of a percent per year, it would take about sixty years for this to drop temperatures on Earth by one degree C, thus putting us back in the “little ice age” that gripped Europe from about 1500 to 1850. There is, of course, the hope that this could change and the solar dimming and greenhouse effect could cancel each other out.
But, before leaving this subject, I must quote from THE RESTLESS ATMOSPHERE by F.R. Hare, professor of geography at McGill University (Hutchinson University Library, London, 1958). In the chapter “Moisture in the Atmosphere,” he gives a table of the gases making up the atmosphere, grouping them into two main classes, the fixed and variable gases. He says, “The second class…contains gases or vapors which vary widely and rapidly in quantity in the air. Of these we may dismiss carbon dioxide…As far as we know, it plays little part in atmospheric processes. ” (My stress.)
So. Are you now going to try to tell me, “Oh, they didn't know about the greenhouse effect back then?” As recently as the 1950s? If that's the case, when did they suddenly find out? And, by the way, the writer knew quite well about the greenhouse effect we already have of water vapor and clouds. There really seems to be some kind of tendency, if not conspiracy, to change history in such little ways like “back in the forties or fifties they didn't know about the effect of nuclear radiation,” which is b.s., as anyone who does a little reading on the matter will soon see. Shadows of Orwell's 1984! Capitalizing on the herd's short memories.