Back to Global Warming
For an updated account please refer to:
The Rape of the Planet and Genetic Holocaust
in our 2006 work Sexual Paradox
At first sight, changes of a degree or two not seem very much, but apparently small changes have dramatic effects. An increase of 2 deg C will produce temperatures last seen 125,000 years ago. A rise of 3 deg C would make the world hotter than it has been for the last 2 million years.
Past changes of this size took thousands of years and species could adapt. The greenhouse effect threatens to produce them in decades leaving plant species no time to set seed fast enough to move their habitats to compensate for climatic change. In the past, as conditions grew harsher, people moved to more congenial areas. On a crowded planet, divided by national frontiers, this is not possible and whole populations are likely to suffer.
Sea levels will rise as the world gets warmer because the heat will melt ice and expand the water in the oceans. Over the next century, levels could increase by a meter or more. Historical changes of sea levels have been vast. Only 400,000 years ago changes in ocean levels accompanied by the formation of coral reefs caused an ocean rise of 20 metres when the deposition of vast quantities of calcium carbonate caused the ocean to release CO2 because although carbonate was deposited, the loss of calcium reduced the buffering capacity of the oceans (New Scientist 31 May 97). Such non-linear feedbacks illustrate the danger of assuming one can set off a global bifurcation and not expect significant changes. Although our polluted warmer oceans with frequent epidemics of starfish may not do likewise there is continuing debate about how significant the signs of warming are in the polar regions.
Both the Arctic and Antarctic have shown signs of heat stress, although there is debate as to whether this is global warming or part of a natural oscillatory fluctuation. Local variations can occur as the result of a variety of local and global conditions, from El Nino to Mt. Pinatubo, whose eruption caused two years of temperature decline in the early 1990s, as well as fine sunsets from the atmospheric contaminants.
Sinking islands and deltas
A 1-metre rise in sea level could make 200 million people homeless.
At particular risk are islands. Many of the people of Polynesia face a real threat of rising oceans because they are island nations with many low-lying coasts already ravaged by tropical cyclones. Global warming is likely to both raise the oceans and increase the severity of storms. "Almost all the 1,196 islands of the Maldives are less than 3 meters high, and most people there live less than 2 meters above the waves. Six other coral atoll countries - the Cocos Islands, Tuvalu, Tokelau, Kiribati, the Marshall Islands and the Line Islands - face a similar crisis. In all, 300 Pacific atolls are expected to disappear, but will become uninhabitable long before as storms wash over them more frequently and freshwater supplies become salt: (Lean 93).
Many more people are at risk from the flooding of deltas and other low-lying coastal areas. Some areas are already subsiding, making them doubly vulnerable to the rising sea. "Four fifths of Bangladesh is made up of the delta of the Ganges, Brahmaputra and Meghna rivers: half is less than 4.5 meters above sea level. The land is already sinking, partly because some 120,000 wells have been drilled to extract drinking water. Studies suggest that up to 18 per cent of Bangladesh could be under water by the year 2050: by 2100 this could rise to 34 per cent and affect 35 per cent of the population. The Nile Delta - twice as densely populated as Bangladesh - is sinking rapidly, because the Aswan High dam traps the silt that used to replenish the land. By 2050, up to 19 per cent of Egypt's cultivable land, home to 16 per cent of the population, could disappear - rising to a quarter of both cultivable land and population by 2100" (Lean 96).
Productive croplands on the move
But the effect of rising oceans is likely to be overshadowed by the impact of global warming on harvests. For, as the world heats up, the local patterns of rainfall and climate will both change and be subject to increased fluctuation, severely disrupting food production. Computer programs modelling the warmer world of around 2030 have come up with some tentative predictions.
"The American Midwest, which helps to feed 100 nations, may see its harvests cut by about a third. The United States, it is thought, will still be able to feed itself, but exports to the rest of the world could fall by up to 70 per cent. New land will open up in Canada as the weather warms, but the soils are too poor to make up the loss. The Soviet Union may be luckier: Its breadbasket, the Ukraine, may not be hit so badly and the land that opens up in Siberia is better than in Canada. Greece and Italy are expected to be very badly hit and harvests may decline less seriously in France and Germany. Britain, the Netherlands and Denmark should benefit, at least initially; harvests will increase greatly in Sweden, Norway and Finland, while improved grassland in Iceland may be able to carry two and a half times as many sheep as at present. Developing countries will be hardest hit. Areas that are already dry - like Tunisia, Algeria, Morocco, Ethiopia, Somalia, Botswana, eastern Brazil and parts of Asia - will probably dry out even further. Some relatively wet regions, including Central America and Southeast Asia, are also likely to suffer. Third World farmers are desperately vulnerable, dependent both on the quality and the timing of the rains" (Lean 96).
All these forecasts are based on a snapshot prediction of the world at around 2030. However this is still relatively early in global warming. As the world heats up further, the effects could become more widespread and pervasive.
The Loss of the Temperate and Tropical Forests
A sinister example of deleterious effects occurring later in the next century is the loss of temperate and tropical forests and their carbon storage.
Global warming will cause a massive "dying-off " of tropical vegetation after 2050, warns a new study - the most sophisticated study yet carried out into the impact of climate change on vegetation. The devastation will mean that the 2 billion tonnes of carbon that are currently soaked up by rainforests every year will remain in the atmosphere, further accelerating global warming (New Scientist Dec 97). It has also been reported that insect species may become extinct because increasing CO2 levels reduce the nutritive value of the leaves they eat (NS 15 Aug 98 10).
The loss of temperate forests has been described as a very serious potential threat to further runaway global warming as the carbon they represent becomes released through decomposition - the boreal carbon bomb. The possible loss of temperate forest species from whole regions of the globe is an area of major concern because they are likely to be carried into too warm a climate too fast to remain viable and have too little time to spread their seeds an adequate distance to survive elsewhere.
With every rise of 1 deg C, plant and tree species will have to move about 90 kilometers polewards to survive, many will simply not be able to spread fast enough. The strain will be greatest in the higher latitudes because they will heat up fastest; winter temperatures in latitudes between 60 deg and 90 deg are expected to warm up more than twice as fast as the global average, and the Arctic tundra may disappear altogether. Some species of beech (Nothofagus) can still be located on the portions of Gondwanaland which later separated to form the southern continents. These only move their habitat by about a metre a season. Such species cannot possibly keep up with the pace of change which is over 1000 times faster than during the onset of natural periods of global warming or cooling.
Changing rainfall patterns will compound the ecological disaster, while rises in sea levels will swamp coastal habitats. As trees and plants die out and habitats disappear, so will the animals that depend on them. As the world's wilderness areas shrink and are increasingly hemmed in by agriculture and development, species will find it ever harder to move. And as the world continues to get warmer there will be nowhere for habitats to re-establish themselves" (Lean 96).
The discovery of chaos was first elucidated in Lorenz's 1960s meteorological example modelling atmospheric circulation. The butterfly catastrophe of Lorenz - that a butterfly in Hawaii could become the nucleus of a subsequent tropical cyclone in Tahiti - remains the quintessence of the sensitive dependence on initial conditions that characterizes chaos. We thus do not have to look further than the weather to understand how chaotic climate change may occur in unpredictable oscillations and abrupt changes in the frequency of events such as El Nino.
El Nino, the Southern Oscillation with an intermittent frequency of some 4 to 7 years, is associated with the excessive warming of water in the Eastern Pacific just south of the equator. It is associated with an atmospheric pressure inversion between Tahiti and Darwin Australia which peaks at Christmas, giving El Nino the name of the Christ child. Although El Nino has been with us for centuries and previous droughts in the Amazon believed to be associated with the Southern Oscillation have been described in the archaeological record, the end of the century has been associated with an increasing series of severe El Ninos, the last of which in 1997 triggered widespread forest fire damage in the Amazon and Indonesia, disrupting ecosystems from Africa to the Galapagos. Although it is debated whether accentuated El Nino is a direct consequence of global warming, its association with warm bodies of water and increasing severity are both consistent with the predicted effects of global warming in simulations which indicate anomalous changes in global weather patterns.
A second coupling between ocean and atmosphere, the North Atlantic conveyor which moves warm water up to the Arctic from the tropics is essential in moderating European weather from the severe effects of the wind flows off the Arctic ice sheets. Model predictions suggest that global warming could move the limit of the conveyor south, which would precipitate severe winters as were sometimes seen in the middle ages.
The overall prediction for moisture and precipitation can be ascertained from the maps of the predicted global distribution of global warming and precipitation and the simulations of global warming precipitation changes. Generally these lead to a wetter more stormy world overall, but one in which precipitation moves regionally in such a way that some large productive areas with marginal rainfall including significant areas of the US could become arid while other places will becomes wetter. Some of these predictions fail to completely model the concomitant effects of the Southern and North Atlantic oscillations which may fluctuate in such a way as to drop more precipitation on areas of low rainfall such as the Atacama desert, while leaving current rainforest areas, such as the Amazon in a state of drought. Disrupting existing ecosystems and productive areas alike is likely to be of great harm both to biodiversity and to the world economy.
Facing the climate crisis
Global warming from the greenhouse effect is now inevitable: the build-up of pollution that has already taken place ensures it. The best the world can do is to slow down the rate, in the hope that it will become manageable. This is a major problem for industrial society because of its current dependence on fossil fuels for the very foundation of all its activity and productivity. This makes for an insoluble situation unless a real attempt is made at rapid and effective conversion to renewable energy sources.
"Action has to start at once if it is to be effective. Delays will ensure that the greenhouse effect accelerates beyond all control. Carbon dioxide emissions can best be controlled by conserving energy, halting deforestation and planting more trees. These measures require an unprecedented degree of cooperation, because very few nations, acting alone, can make much of an impact on global emissions. The world will have to cooperate both in cutting pollution in rich countries and in striking a new deal with the Third World to enable it to develop faster, but without relying too much on fossil fuels" (Lean 96).
Lean (96) comments wryly from history in the light of Kyoto 1997: "From 1988 onwards, the magnitude of the climatic crisis and the need for action began to penetrate the consciousness of national leaders in many countries. The world began preparations for a World Treaty on the Climate. But by early 1990, though the evidence of climatic change continued to mount, little concrete action had been taken."