Global warming, the prospect of a slow but consistent increase in average world temperatures, is one of the most frequently talked-of ecological problems. It has wide-ranging implications for climatic and other conditions during the next century, and is linked to capitalism's reckless exploitation of cheap energy sources.
It is now generally accepted that global warming is a real phenomenon, and that the 1980s were around one degree Celsius warmer than the 1880s, and contained the six warmest years of the century. It must be said, however, that some scientists cast doubt on the figures, on the grounds that earlier temperature records are unreliable, and that too many weather stations are sited near cities, which produce their own heat. Moreover, some places, including Britain, probably got a little cooler between the mid-1970s and mid-1980s. On the whole, though, it does seem likely that global warming is genuine, and certainly it will not do to ignore the warnings.
Predictions about the future course of world temperatures must be treated skeptically, if only because not too long ago there were widespread claims of global cooling, often by the same scientists who predict global warming! For instance, it was argued that there would be a cooling period for up to 100 years before the warming trend set in. Nowadays, though, even the most optimistic of those who accept global warming believe that temperatures will increase by 1.5 degrees by 2050 (and pessimistic views at least double this figure). These rises may seem very small, but the last Ice Age was only four to five degrees colder than now, and small changes in temperature can have very large consequences.
Greenhouse gases
The basic cause of global warming is the Greenhouse Effect, which means that a number of greenhouse gases in the Earth’s atmosphere allow sunlight to enter but do not allow the heat reflected back from the ground to escape. So the heat is trapped in the atmosphere and the planet becomes warmer. Without the Greenhouse Effect, Earth would be about 35 degrees colder than it in fact is, and life would be impossible (as it is on the Moon, which has no atmosphere at all). The Greenhouse Effect itself, then, has played, and continues to play, an essential part in the development of life on Earth. However, over the last couple of centuries, the amount of greenhouse gases in the atmosphere has increased quite dramatically, leading to even more heat being trapped and the temperature rising to give what is now recognised as global warming.
The main greenhouse gas is carbon dioxide; it is estimated that since the late eighteenth century the concentration of carbon dioxide in the atmosphere has increased by around 25 percent. This increase is partly due to the chopping-down of forests, but mostly to the burning of fossil fuels (i.e. coal, oil, gas and lignite, which release carbon dioxide when burned). These carbon dioxide emissions are responsible for about half of the Greenhouse Effect, but there are other important greenhouse gases too: methane, nitrous oxide, chlorofluorocarbons (CFCs). CFCs contribute to global warming quite separately from their effect in weakening the ozone layer, which is responsible for increased skin cancers and cataracts. Deforestation, the destruction of trees in such places as the Amazon rain forest, is relevant in that trees absorb carbon, and fewer trees means more carbon is around to form carbon dioxide and so add to the Greenhouse Effect.
Climatic changes
The consequences of warming are many and varied, and some may be here already: droughts in the US and north Africa may well be due to temperature increases, though it is impossible to isolate a single cause. Overall, however, a rise in temperature is likely to mean more rainfall, though many places will indeed get less rain. Some areas may benefit from the longer growing seasons caused by warming, but in others drought will lead to a drastic fall in crop yields. Water expands when it warms, and the sea level is likely to rise by at least 30 centimetres (maybe far more) by 2030, flooding many coastal areas such as the Nile delta. The rise in sea-level could also mean contamination of drinking water and the spread of waterborne diseases. Hurricanes are likely to become both stronger and more frequent. Forests in temperate zones may be partially destroyed, thus leading to more warming. The general alteration in the world’s climate will be too fast for many forms of vegetation to cope with, causing them to die out—crops can adapt to changes in rainfall and temperature, but not if the changes are too rapid. If people move in large numbers to cooler, wetter areas, there will be vast social changes to cope with. So global warming means not just sultrier summers but droughts, alterations in the pattern of agricultural production, loss of vegetation, rise in sea-level, increased pollution, and possibly big population movements. There have been some claims that global warming is a good thing, but the balance of evidence is very much against this notion.
The Greenhouse Effect is permanent, and cannot be done away with, but we can ask whether it is possible to stop or reverse the current global warming trend. Clearly the answer is to drastically reduce the emission of greenhouse gases, but this is easier said than done. Unlike CFCs, for which substitutes are readily available (even if not profitable to introduce), processes which produce most of the greenhouse gases cannot be simply abandoned or drastically modified. One claim is that carbon dioxide emissions must be cut by at least 50 percent in order to lessen the rate of warming to 0.1 degree per decade, which will be more manageable as far as natural ecosystems are concerned.
Capitalism tinkers
There are plenty of renewable energy sources which can be tapped, and which have minimal environmental impact. Wind turbines, tidal barrages, solar heating, the burning of biomass (various kinds of vegetation), and geothermal energy (using heat stored inside the Earth) all have great potential for supplying energy needs. Under capitalism, few resources are put into developing them, so they remain economically unviable. But there are many alternative sources of energy besides the burning of fossil fuels, and a socialist society, untrammelled by considerations of profit, could give priority to developing existing sources and discovering new ones.
Capitalism can do no more than tinker with the problem. The British government recently announced the aim of cutting back carbon dioxide emissions to 1990 levels by the year 2000. But this is an astonishingly modest target, and makes little contribution to reducing emissions to an ecologically-acceptable level, even if it were to be achieved. Moreover, it leaves out the other greenhouse gases.
Of all the ways in which capitalism has interfered with the environment, the processes which lead to global warming are potentially the most disastrous. The very unpredictability of the consequences makes it vital to bring the situation under human control. But capitalism is the worst possible social system for the kind of rational, integrated action which is needed. Socialism, in contrast, will provide the kind of framework within which global warming, and other ecological problems can be tackled and solved by that marvellous resource—human ingenuity.
Paul Bennett
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