Last week, a report supported by 1,360 scientists from 95 countriessome of them tops in their fieldswarned humankind it is living beyond its means. The group warns that nearly two-thirds of the natural systems that support life on this planet are being disabled by human pressure.
The study says that wetlands, forests, estuaries, savannas, coastal fisheries and other places that recycle air, water and nutrients for all living creatures, including man, are being irreversibly damaged.
Human activity is putting such a strain on the natural functions of Earth that the ability of the planets ecosystems to sustain future generations can no longer be taken for granted, the report said.
It further states that because of human demand for food, fresh water, timber, fiber and fuel, more land has been taken for agriculture in the last 60 years than in the 18th and 19th centuries combined. An estimated 24 percent of the Earths land surface is under cultivation.
Water withdrawals from lakes and rivers have doubled in the past 40 years. Humans now use between 40 and 50 percent of all available fresh water runoff. At least one-quarter of all fish stocks are over harvested. In some areas, the catch is less than a hundredth of what it was before industrial fishing.
Some other symptoms: since 1980 about 35 percent of the mangroves have been lost, 20 percent of the worlds coral reefs have been destroyed and another 20 percent badly damaged. Deforestation and other changes could raise the risks of malaria and cholera, and could open the way for new and unknown diseases to emerge.
A team of biologists and economists in 1997 attempted to place a value on the services provided by nature, such as the free pollination of crops, the air conditioning furnished by wild plants, and the recycling of nutrients by the oceans.
They arrived at an estimate of $33 trillion, nearly twice the gross global national product for that year. But after this report, titled Millenium Ecosystem Assessment, spoke of an unprecedented period of spending Earths natural bounty, it was time for a reassessment.
In many cases, said the scientists, it is literally a matter of living on borrowed time. By using up supplies of fresh groundwater faster than they can be recharged, for example, we are depleting assets at the expense of our children.
Flow from rivers has declined sharply. An estimated 90 percent of the total weight of large predators such as tuna, swordfish and sharks, has vanished in recent years. Additionally, an estimated 12 percent of bird species, 25 percent of mammals and more than 30 percent of amphibians are threatened with extinction in the next century.
More and more of the planets population lives in cities, exploiting our advanced technology. Scientists warn, however, that nature is not something merely to be enjoyed on weekends. Conservation is not just a nice practice if you have time and inclination.
These are dangerous illusions that ignore the vast benefits of nature to the lives of 6 billion people on the planet. We may have distanced ourselves from nature, but we rely completely on the services it delivers, they said.
Meantime, as the supply of hydrocarbon fuels begins to dwindle, attention has focused on the Gulf of Mexico and a few other locations. More than a mile below the surface of the Gulf lies a vast untapped energy field containing what are called methane hydrates.
These are crystals containing the gases that are in the sediment beneath the seabed. Geologists say there is enough natural gas there to service U.S. consumption for decades, or to bring about a catastrophic climate change powerful enough to melt the glaciers and cause devastating flooding.
Scientists say there may be more energy down there than in all the known reserves of oil, gas and coal put together. Besides the Gulf, the methane crystals are found under the Arctic permafrost and at the bottom of most of the oceans.
The amount of energy there is just too big to ignore, said Bahman Tohidi, who heads the Centre for Gas Hydrate Research at Heriot Watt University in Edinburgh, Scotland. Its not easy (to get), but its not something we can say we cant do, so lets forget about it.
The Bush administration is sending a drilling vessel into the Gulf on a mission to find ways to bring this huge new energy source to power stations within a decade.
Ray Boswell, of the U.S. Department of Energys national energy technology laboratory, said the U.S. is determined to be the first to mine this resource. Commercially viable production is definitely realistic within a decade, he said. The world is investing in hydrates, and one reason for us to do this is to maintain our leadership position in this emerging technology.
Whether the exploration will produce benefit or disaster depends on how the crystals are foundin thick layers or scatteredand how the methane is released, in one big rush or under a gradual, controlled acquisition.
Environmental groups are against disturbing the seabed in search of hydrates. Paul Johnston, a scientist with the Greenpeace laboratory at Exeter University, said such exploration is very risky.
There are legitimate concerns that attempts to tap into these reserves could cause very widespread destabilization of the seabed and damage to ecosystems, Johnston said. He noted methane is a much more potent greenhouse gas than carbon dioxide, and any that gets released during production would only aggravate global warming.
Boswell takes another tack. The prudent approach is to address all the avenues for supplying future energy. People who say it has to be one or the other, I think, are putting too many eggs in one basket, he said.
The overall question now is, do we have 10 years to accomplish this before the oil flow dries up? (guardian.co.uk).
From the April 6-12, 2005, issue