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 I cambiamenti climatici sono, con ogni probabilità, il peggior disastro della storia per la nostra specie. Il rischio più grave è che i cambiamenti climatici portino a un deficit di produzione alimentare, creando un'emergenza umanitaria permanente.
L'unica maniera in cui possiamo prevenire questi problemi è quella di ridurre la quantità di combustibili fossili che bruciamo. Le emissioni globali possono essere stabilizzate e poi ridotte. I paesi industrializzati devono prendere l'iniziativa, riducendo le emissioni in maniera considerevole nel giro di qualche decade. Ma bisogna iniziare fin d'ora. E questo non potrà accadere se non ci sarà nel pubblico una consapevolezza di gran lunga maggiore del fatto che bisogna agire al più presto.
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| Devastating Storms |
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Warmer sea water provides more energy to power hurricanes, and the predicted increase in such "extreme events" with the onset of global warming appears to be coming true. These storms are becoming increasingly violent and numerous. A sobering glimpse of the future was given by the example of Hurricane Mitch in 1998 which killed 11,000 people and left three million homeless in Honduras, and by Hurricane Katrina in 2005 which wreaked enormous damage on the major US city of New Orleans. |
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| Heatwaves |
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Although many of the effects of global warming will be felt by developing nations, rich countries can not escape. Acute heatwaves will become frequent and kill many. In the heatwave of August 2003 in Western Europe (confidently attributed by scientists to climate change) 35,000 old people died, more than 18,000 in France. |
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| Disease |
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The World Health Organisation fears that global warming, with its heavier rainfall, could lead to a major increase in insect-borne diseases in Europe such as malaria, Lyme disease and encephalitis, and has called for urgent government action to prevent it. |
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| Rising Sea Levels |
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In the coming century, global sea levels are predicted to rise by up to three feet, threatening regions at or below sea level, such as Pacific islands, much of Bangladesh, the Nile delta in Egypt, the Netherlands, and even East Anglia and the Thames estuary in Britain. Storm surges (like that which drowned more than 300 people in eastern England and 1,800 people in the Netherlands in January 1953) are likely to be much more frequent and catastrophic. The population of Bangladesh is projected to double as its land surface halves. |
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| Endangered Wildlife |
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Polar bears may be the first spectacular casualties as the ice of the Arctic Ocean, on which they depend to hunt seals, is rapidly melting and will probably all be gone by mid-century. But Britain itself is already feeling the problem: we are losing to rising temperatures not only the cod in the seas around our coasts, but also the small fish such as Sand Eels on which seabirds depend to feed their young. Last year in the Northern Isles, Orkney and Shetland, hundreds of thousands of birds such as guillemots and arctic terns failed to breed for lack of food. |
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| Water Shortages |
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Drought will be much more common. In the drylands, rain will be even less frequent, while some parts of the world that are temperate will become arid; Central Spain may be desert-like by the mid-century. And it is not only rain that will fail. Glaciers are shrinking. Lima, with seven million people, depends for half the year on water from the Sullcon glacier in the Andes, which has retreated by 30 per cent. Himalayan glaciers which feed the river Indus, the source of much of Pakistan's water, are also shrinking. |
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| Agricultural Turmoil |
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The hundreds of millions of people living in the world's marginal agricultural lands, such as the countries of the Sahel region, already face a desperate daily struggle to grow food. All their energies are consumed in the effort to produce a harvest of a stable crop such as millet. As global temperatures rise, this struggle is likely to become impossible as more frequent and longer droughts make crop-growing unviable. In poor tropical regions, the increased storms predicted from climate change will be an added threat. The terrifying images of African famine are as nothing to what will come. |
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| Tipping Points and Feedbacks |
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One of the most truly frightening scenarios is the idea of our civilization pushing the boundaries of nature too far, and a tipping point occurring wherein positive, or reinforcing feedback loops are created. For example, the reduction in sun-reflecting snow and ice cover in the poles allows more heat to be absorbed by the land and oceans. This in turn increases temperature, melting more snow, ice and permafrost. The Siberian permafrost traps frozen methane, a greenhouse gas twenty times as potent as carbon dioxide, which if released, would further boost rising temperatures. The seabed also contains stored methane, and rising ocean temperatures would trigger the release of this.
Desertification, or the process of semi-arid lands turning into desert, is increasing, and where this takes place, plant matter can die from lack of water, which in turn removes the anchoring of the soil that the roots provide. In addition, the absence of plants reduces the ability of the area to absorb carbon dioxide, and upsets the hydrological cycle, further drying out the area. The loose surface soil blows away, exposing the land to further erosion, and without plants to anchor soil, and regulate and contain moisture in the area, the spread of the desertification process continues. |
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| The Unknown Factor |
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What's already beginning and what is predicted is terrible enough. But it is what's not even on the radar that some scientists fear most of all, the possibility that global warming might bring about some sudden, extreme and devastating climatic phenomenon that we cannot yet even imagine. The climate is a complex system, and we know that complex systems, when subject to stress, can collapse (it happens on your office desk when your computer crashes) and the global climate is now being subjected to stresses that have never been put on it before. The global warming disaster movie "The Day After Tomorrow" tried to show this with the northern hemisphere freezing solid in a matter of weeks. Most people dismissed it as far-fetched, but something just as catastrophic may be out there, not far in the future. |
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