A Consensus on Crisis
A U.N. panel details the distress that global climate change might cause human societies.
GETTING DISPARATE world governments to agree is like herding cats. Getting disparate world governments to agree on the effects of climate change is like teaching cats to sit, shake hands and roll over. That is why the new report from the U.N. Intergovernmental Panel on Climate Change (IPCC) is noteworthy — and sobering. After heavy review from government representatives, it is not a radical document. But it represents a fundamental international consensus on climate change that has developed in the past few years. And its conclusions are more than worrying.
Droughts. Rising seas. Overflowing rivers. Mass extinction. Malnutrition. Disease. The report, which focuses on “changes in the natural and human environment,” predicts all of these effects with high confidence if world temperatures rise even a few degrees and world governments do little to mitigate the consequences. Citizens of developed countries with the capabilities to adapt to the possibly devastating environmental changes won’t have it as bad, of course, and some areas might even prosper under warmer conditions, the report noted. But every region will face negative consequences, especially if warming continues unabated and the effects magnify. An increase of 4 degrees Celsius (7 degrees Fahrenheit), the report projects, could result in a decrease of up to 5 percent of average global gross domestic product.
By 2020, water shortages might harm as many as 250 million people in Africa, and certain agriculture yields on the continent might fall by 50 percent. In Asia, decreased availability of fresh water might effect more than a billion people by the 2050s. Some areas of Europe are projected to lose up to 60 percent of their species by 2080. The report predicts reduced snowpacks in the American West, leading to even worse water supply problems in Southwestern states, while “pests, diseases and fires” will plague American forests.
It is tempting to read the IPCC’s document and conclude that all world governments need to do is prepare for heat waves, water shortages, flooding, or increased incidence of diarrheal and cardiorespiratory disease. But the report makes clear that although preparation will be key to decreasing the burden of global warming on human societies, an unmitigated increase in world temperature would “be likely to exceed the capacity of natural, managed and human systems to adapt.” The report is also not exhaustive in detailing the possible effects of global warming, only listing those that scientists now know have a high probability of occurring.
All of which should persuade American policymakers to begin regulating carbon emissions, major agents of global warming. Last week, the Supreme Court all but ordered the Environmental Protection Agency to do so, indicating that it could decline to regulate greenhouse gases (as it has done so far) only if the agency shows that they do not contribute to climate change or if the EPA gives a good reason for not making that determination. Given the strength of the international consensus on the science of climate change, the Bush EPA will have a hard time doing either. Meanwhile, California has already proposed deep cuts in permissible vehicle emissions that require, and should promptly receive, an EPA waiver. Other states are signing on. These efforts should continue in statehouses across the country.