The projected effects of rising greenhouse gas levels are based on the amount of fossil fuels burned, methane liberated from landfills, chlorofluorocarbons (CFCS) released, and so on. But it is known that there are massive deposits of methane, a much more potent greenhouse gas than carbon dioxide, frozen beneath the permafrost in the Arctic and on the ocean floor. Inuit people in the circumpolar countries have been warning for years that permafrost is melting, something even the rabidly anti-climate-change senator from Alaska, Ted Stevens, has finally acknowledged is happening in his state as dozens of villages report their buildings are sinking. As permafrost melts, it will liberate massive amounts of methane into the atmosphere, accelerating the warming process far beyond the predictions of current computer models in what is called a positive feedback loop: rising levels of greenhouse gases induce warming, which melts permafrost, which in turn releases more greenhouse gas, which accelerates the warming even more.
In addition, the well-documented melting of polar ice sheets may have catastrophic effects on the movement of heat through ocean currents. There are enormous movements of water masses through the Atlantic and Pacific oceans. In the North Atlantic, water from the equator absorbs heat, which is moved by currents northward along the coast of Europe, raising the winter temperature above the levels expected for that latitude. As that water mass releases its heat and cools on its passage along the coast of Europe, it curves around and sinks at its northernmost point, slowly making its way south deep in the ocean. It is like a continuous stream of water through the ocean.
As ice sheets and glaciers melt more rapidly, fresh water floods the ocean and interferes with the current. This flooding can happen rapidly and has occurred in the past, shutting down the ocean currents and thereby bringing about a colder period or ice age in Europe. It seems counterintuitive that global warming might shut down the “heat engine” of this current and cause a catastrophic cooling of Europe, but in November 2005, scientists reported in Nature that currents appear to have slowed by 30 percent.
EVEN AS THE SKEPTICS persist in their claim that the IPCC scientists are missing or ignoring bits of evidence that “disprove” climate change, there are two types of evidence I find overwhelming. One comes from nature itself. If warming occurs, animals and plants that live within a certain temperature range will be forced to move to stay within that range. For organisms on mountainsides, that can be achieved by moving up. In a Nature of Things program entitled “Warnings from Nature,” scientists documented that very kind of movement. In another case, a bird-watcher in the American Midwest has carefully recorded the comings and goings of birds through the seasons for fifty years. Her records clearly show that migratory birds are now arriving in her backyard up to two weeks earlier and leaving up to two weeks later. It's hard to believe that observational biases could be responsible for these results.
For me, the most powerful data are the annual atmospheric carbon dioxide levels extracted from the Antarctic ice sheets. In the topmost layers recording the most recent years, the carbon dioxide signature inflects sharply upward, rises steeply over the past decade and a half out of the background “noise,” and now reaches a height beyond anything ever seen.
BY 1997, GLOBAL CONCERN about climate change had grown enough to warrant a gathering of delegates from most countries in the world at Kyoto, Japan. They were meeting to discuss a protocol for reducing emissions, with a goal of reaching a balance between emissions and the absorptive capacity of the biosphere. Collectively, humans were producing twice as much greenhouse gas, especially carbon dioxide from burning fossil fuels, as Earth could reabsorb, so overall emissions had to be reduced by 50 percent. But since countries like Canada, Australia, and the United States were disproportionately high emitters, our targets would eventually have to be reduced by 85 to 90 percent.
I found myself reluctantly attending this conference along with staff of the David Suzuki Foundation. I say reluctantly because, at these massive international affairs, much of the decision making goes on behind closed doors while groups such as ours merely buzz around like annoying gnats.
Kyoto is the cultural hub of Japan, and stepping out of the Shinkansen (bullet train), we were confronted with that strange contradiction of Japan, the traditional domes and pagoda shapes of its temples and the garish signs and monuments in plastic. After dropping off our luggage in our tiny hotel rooms, we walked through a light rain past the many shops and malls packed with Japanese shoppers. We were in a hurry, with little time to sightsee or shop or even seek out some good restaurants. When we reached the meeting halls, we were greeted by Green-peace's large blowup of Godzilla, the fire-breathing monster, created by garbage, a perfect metaphor for humanity's effects on the planet.
The halls were filled with the babble of people, official delegates from dozens of countries, environmentalists and other NGOs, lobbyists for the fossil-fuels industry, and the media. Altogether, it was a mélange of perspectives and priorities. At the meetings, leading scientists talked about the latest evidence for climate change, environmental groups called for serious cuts in emissions, and government delegates wrestled with lobbyists working to sabotage the process by driving it off the rails. The Australian delegation complained bitterly that their country was special, a big country with a sparse population that had few rivers for hydroelectric power and therefore was dependent on highly polluting coal-fired plants.
The insurance industry was the one large group in the business community that took climate change very seriously. Their actuarial data were dramatic — claims for climate-related damage like fires, floods, droughts, and storms were rising dramatically, as were the number of insurance companies going out of business.
The European Union (EU) was very concerned about climate change and wanted serious cuts in the range of 15 percent below 1990 emission levels. Aligned against them were the JUSCANZ countries (Japan, United States, Canada, Australia, and New Zealand), which formed a bloc working to water down the target. There were enormous debates about whether to allow Canada, and similar countries, to be given credit for the fact that its boreal forest absorbed carbon dioxide, therefore acting as a “carbon sink”; others wanted “emissions credits” to be traded so that polluting countries or industries could avoid reducing their emissions by paying for someone else's “share” of the atmosphere.
In such surroundings, the cynics could suggest the final decisions and targets were far too shallow to be effective and far too expensive for what would be achieved. But I believe the final outcome of the Kyoto deliberations was extremely important for what it signified. Kyoto signaled the recognition that the atmosphere is finite, that human activity has saturated it with emissions from fossil-fuel-burning vehicles and industries, and that we are adding more carbon dioxide and other greenhouse gases than the biosphere can handle. For the first time, governments and industries had to acknowledge that there can't be endless growth.
The atmosphere is not confined within national boundaries; it is a single entity shared by all people and organisms on Earth. The industrialized nations created the problem with their highly productive fossil-fuel-dependent economies. As an illustration of the disparity between the industrialized and nonindustrialized nations, Canada's 30 million people use as much energy as the entire African population of 900 million. In 1976, when I first visited China, which had thirty times Canada's population, it was using the same amount of oil and gas as Canada. I wrote at the time that if every Chinese wanted a motorbike, the results would be devastating. Now, a quarter of a century later, most Chinese aren't interested in bikes; they want cars, and with a booming economy and a growing middle class, more and more can afford them.