Since the mid-1980s, I had known that the buildup of greenhouse gases such as carbon dioxide might be on a scale sufficient to affect our climate. But I thought there were far more pressing immediate issues, like toxic pollution, deforestation, and species extinction, and that climate change was a slow-motion disaster that would not really kick in for generations. It was only in 1988, when I first visited Australia, that Phil Noyce, my host, convinced me it was an urgent issue that needed action now. In the autumn of that year, climate experts from all parts of the world, who were gathered in Toronto for a major conference on the atmosphere, warned that the threat of global warming was real and called for a reduction in greenhouse gas emissions of 20 percent in fifteen years.
That year, the World Meteorological Organization and the United Nations Environment Program established the Intergovernmental Panel on Climate Change (IPCC), made up of hundreds of climatologists from many countries, to monitor the state of global climate. Sadly, hindsight reveals that had governments responded and met that challenge beginning in 1988, the air today would be cleaner, people healthier, and fossil fuels more plentiful, and we would be saving hundreds of billions of dollars and be well along the path to achieving an emission level that could be absorbed by the biosphere.
At the height of global concern about the environment, governments and nongovernmental organizations planned the 1992 Earth Summit in Rio de Janeiro. The countries attending the summit agreed to stabilize greenhouse gas emissions at the 1990 levels by 2000, but most countries, including Canada, merely called for “voluntary compliance” with the targets. In the meantime, the fossil fuel industry launched an aggressive campaign to discredit the very idea that human activity was influencing climate, and the use of fossil fuels and thus greenhouse gas emissions continued to rise.
In 1995, to film for The Nature of Things, I attended a conference on climate organized by the Intergovernmental Panel on Climate Change in Geneva. Hundreds of IPCC climatologists from more than seventy nations had painstakingly assessed thousands of scientific papers on weather and climate, and they concluded in 1990 in their first major assessment that global climate was warming, and that the change was not part of a natural cycle. In 1995, the IPCC's second assessment concluded that “the balance of evidence suggests a discernible human influence on global climate.” Though it seemed to me a pretty tepid conclusion — in the global arena, delegates are under enormous scrutiny and pressure from groups like governments and industries — this was a powerful warning. The IPCC's third assessment, released in 2001, was even stronger.
In Geneva, I was deeply moved by two delegates I met there. One was a Kenyan farmer who said traditional farmers used the cyclical appearance and disappearance of different plants as the cues to start plowing, planting, and harvesting, but they were having difficulty because these wild indicator plants seemed to be out of phase. Here was a scientifically uneducated farmer, dependent on external signals for his livelihood, reporting signs that climate was changing. I also encountered a South American Indian who told me that even on the equator, where there are not the traditional seasons that we know, plants were behaving in strange, never-before-seen ways.
Unfortunately, these traditional people did not have PhDs and were not fluent in the jargon of science, and like the people living on tropical coral atolls threatened by rising waters and the Inuit of the Arctic reporting on melting permafrost, they were paid little heed.
The IPCC continues its work, especially refining computer models and carefully refuting the arcane objections (satellite readings fail to confirm ground level measurements, sunspots are the primary cause of warming, models have no basis in reality, et cetera) of a handful of nay-sayers, most of whom are funded by the fossil fuel industry. Overall, the enormous undertaking by the IPCC has merely made the warnings of 1988 stronger and more urgent.
Most climatologists believe the evidence is overwhelming that the atmosphere is warming unnaturally, that humans are the major contributor to this warming, and that immediate action is needed to counter the effects. Sadly, the renowned science-fiction writer Michael Crichton, author of The Andromeda Strain and Jurassic Park, has recently published a sci-fi thriller, State of Fear, based on the premise that environmental extremists are creating ecological crises to frighten people into supporting them. It is a preposterous thesis that seems to legitimate the idea that climate change is not real and does not require action.
There have been other books that purport to disprove climate change, many of them written by ideologues who dismiss environ-mentalists out of hand or who have a vested interest in industry. Gregg Easterbrook was an environmental writer for Newsweek and other publications, so his suggestion that environmentalists had been so successful that they had achieved most of their goals was taken very seriously, though it was refuted by many eminent ecologists and experts. Academic Bjørn Lomborg's book The Skeptical Environmentalist has been embraced by right-wing think tanks like the Fraser Institute in Vancouver and business organizations. Again, a great deal of effort has had to be made to counter Lomborg's claim that the state of the environment is far better than environmentalists acknowledge.
One of the remarkable aspects of the IPCC work is the consensus of all but a handful of climatologists. Very few new ideas in science achieve such agreement among the overwhelming majority of experts. Consider biology — evolution is the fundamental basis on which our interpretation of life on Earth rests, yet there are hundreds of people with PhDs in biology who believe in the biblical version of Creation and deny evolution. Complete, 100 percent agreement is seldom achieved in science, so when most climatologists agree about something, their conclusions must be considered compelling.
Crichton ends his novel with a rant of his personal opinions, complete with references and footnotes that give the illusion he is writing a scientific treatise. He argues from examples in the history of medicine where consensus has proved to be wrong to discredit the IPCC conclusions. For example, doctors once universally believed that pellagra was the result of bacterial infection when it was actually a dietary deficiency. Physicians used to believe that deliberate bleeding cured a variety of problems and that ulcers could not be caused by bacteria. But in the world of medicine, as Harvard Medical School director Eric Chivian points out, doctors are trained to intervene when the evidence may not be absolute but where the dangers of not acting become too perilous. For example, one cannot be absolutely sure of a diagnosis of appendicitis before operating, because the risks of peritonitis and fatal septicemia from a ruptured appendix are too great. This is comparable to the need to act on global warming — except that here, as Chivian says, “we're dealing with the lives of billions of people.”
Some opponents of reducing greenhouse gas emissions accept that the climate is changing, but they argue that we need a higher level of certainty that we are the cause, and that until we are completely convinced, we can't afford to act. The Stanford University climatologist Stephen Schneider asks how much certainty is necessary to act. He believes the evidence of human-induced climate change is at least 70 percent certain, a figure that skeptics pounce on as far too uncertain for action. Schneider responds by asking rhetorically, if we were told a sandwich had a 70 percent chance of containing a deadly poison, would we eat it? Of course not. So if we are performing an experiment on the only home we have, planet Earth, what level of certainty do we require, especially if the warnings of scientists are accurate and the consequences of not doing anything will be catastrophic? Even if those scientists are wrong, taking action will lead to enormous benefits in health, greater energy supplies, cleaner environment, and vast economic savings.