f ice in the Greenland Sea and cut off the process." (Independent on Sunday) The consequences are uncertain but it is thought that the failure of the Ogden Feature may weaken the Gulf Stream which keeps northern Europe much warmer than other regions at the same latitude; violent switches in the climate may be triggered as a result.
Paul Brown of The Guardian reports (July 6, 1996) that ice which has held the Swiss Alps together for 10,000 years is now melting at the rate of 30 meters per year in some places: "Scientists who advise politicians believe that countries like Switzerland are suffering irreversible damage," Brown writes, with villages threatened by the prospect of "tidal waves" of "melt-water descending on their homes" bearing "an avalanche of rocks" and "the collapse of cliffs that flank their valleys."
Alongside what we know, scientists also regularly warn us that there is plenty that remains unknown. During the early 1990s, the aim of the Joint Global Ocean Flux Study was to evaluate how much atmospheric carbon dioxide is absorbed into the oceans and how much is released from them. Previously, only general patterns were known. For example, warm, tropical waters tend to release carbon dioxide, while cold, high-latitude waters tend to absorb and store carbon dioxide. For this reason, oceanographers fear that in a warming world warmer seas may strongly amplify warming by releasing stored carbon dioxide. The problem is that the Ocean Flux study found astonishing variations in the carbon dioxide content of the North Atlantic over even short distances.
"The variations observed," concluded the authors of a paper in Nature, "suggests that estimates of the oceanic storage or release of carbon dioxide calculated from existing data will be subject to significant error."
Similarly, summarizing their results in a paper in Science magazine (August 23, 1991), 17 climate modelling teams from around the world found that, depending on the behaviour of clouds above melting snowy areas, the role of snow in global warming varied from strongly-positive to weakly-negative.
More recently, Martin Perry of Oxford University has said that "Unexpected changes cannot be ruled out. There are potential surprises out there, both in time and in place. This ignorance is a risk in itself. We don’t know when these unexpected impacts could occur, or where." Nobel prize-winner Paul Crutzen suggests, ominously, that global climate change will bring "unpleasant surprises."
The threat of global warming, then, is real. The response to it, as yet, however, is not. At the 1992 Rio Earth Summit, the world’s governments signed a treaty agreeing to combat global warming. Industrialised nations promised to "aim" (the crucial word) to level off their emissions at 1990 levels by the year 2000.
The United States signed this treaty in the full knowledge that its carbon dioxide emissions were projected to rise by 13 percent by the year 2000, with its multinationals providing the lion’s share of $1,000 billion investment in the search for oil over 10 years. George Bush once said he would use the "White House effect to counter the greenhouse effect: and then, when elected, adopted the "wait and see strategy" favored by big business, despite the fact that, as the Ocean Flux and other studies have shown, the environmental systems under investigation are of such complexity that certainty is impossible and waiting never ends.
Four years later, we know that almost no Western countries will meet the modest targets set at the Earth Summit. The International Energy Agency estimates that by the year 2000 global greenhouse gasses will be 17 percent higher than in 1990; by 2010 they will have risen by 49 percent. Similarly, the World Energy Council reports that combined emissions of Western countries have actually increased by 4 percent between 1990 and 1995. Only Britain and Germany are on track: Britain, because it happened to change from coal to gas for political reasons (the destruction of the coal industry was not motivated by a desire to protect the environment); Ger