Scientific concerns about the impacts and risks of global climate change are scarcely new. In 1988, those concerns became sufficiently widespread in the scientific community that the United Nations established the Intergovernmental Panel on Climate Change (IPCC), a committee that included hundreds of the world’s most distinguished climate scientists, to study the emerging climate problem and its implications. Since its creation, this panel has issued five full extensive reports. These assessments were soundly criticized by some independent climate scientists as understating the significance and dangers of climate change. However, earlier this month, the IPCC seems to have rectified that purported problem.
In the first segment of its Sixth Assessment, issued earlier this month, the IPCC report states that it "provides a full and comprehensive assessment of the physical science basis of climate change that builds upon the previous assessments ... and considers new information and knowledge from the recent scientific literature, including longer observational data sets, new scenarios and model results." This authoritative document draws conclusions that are deeply alarming. While (like all prior assessments) the report does not recommend specific remedial actions, the latest report implicitly suggests an urgent need for collective action to avoid natural devastation and massive future human catastrophes.
The report notes recent advances in climate science. Climate modeling has become more sophisticated and precise, and much helpful new data has been collected through the deployment of additional satellites and ocean buoys and recent robust analyses of ice cores and peat bogs.
New data demonstrates that current climate changes have had little precedent. Atmospheric carbon levels have not been this high for at least 2 million years, and the past five years are "the hottest five-year period in the instrumental record since at least 1850." Moreover, human activities have "unequivocally" warmed our planet. Without question, the rapid rise in global temperatures since the 19th century has been driven by massive human atmospheric emissions of carbon dioxide, methane and nitrous oxide.
According to the IPCC, major alterations in natural global systems are already well underway; and without major changes in human behaviors the future will be bleak. There is evidence that, over the past 40 years, tropical cyclones and become more intense, a result that cannot be explained by natural variability alone. There are also ominous signs that a crucial ocean circulation system that helps to stabilize the climate of Europe is beginning to shift and slow down. And the rapid melting of polar ice and the calving of glaciers, has been widely noted.
Sadly, the IPCC report indicates that nothing can stop global warming from intensifying over the next 20 years. Average surface temperatures will continue to rise over this period. The inevitable result will be life-threatening heatwaves, severe droughts, inland and coastal floods, melting glaciers, decreased mountain snowfalls, the extinction of many plant and animal species, as well as massive die-offs of many of the coral reef systems that sustain fisheries. Nonetheless, the latest IPCC assessment does contain a measure of hopefulness. According to the IPCC, a rapid shift away from fossil fuels — and toward solar, wind, geothermal and other benign techniques for generating energy — can still cause global warming to level off and decrease by 2050. Thus, if humankind acts promptly and responsibly, it remains possible to avert the most catastrophic climate outcomes.
Given this, how should we proceed? As I have suggested previously, under current circumstances many individuals and institutions can play constructive roles. By way of example and quiet diplomacy, the United States must use its influence to encourage other nations to meet their climate responsibilities. Federal climate legislation to curb the release of greenhouse gases and prepare to address future climate impacts is urgently needed. So, too, are constructive steps at the state and local level, as well as voluntary measures by private enterprises, NGOs and individual citizens.
At the international level, the world's national leaders are scheduled to meet in Glasgow in November for a critical summit regarding climate matters. Given the IPCC's recent findings, these leaders must squarely confront the urgency of the climate crisis, and firmly commit to crucially needed actions to protect humankind, other living species and scarce and precious natural resources.
The forthcoming Glasgow summit provides remarkable opportunity to do what is needed. It may also be our species' last chance to prevent many tragic, self-created, disasters.
Joel A. Mintz is a professor emeritus and the C. William Trout Senior fellow at the Nova Southeastern University College of Law in Fort Lauderdale, Florida, and a member-scholar and board member of the Center for Progressive Reform. A former EPA attorney and chief attorney, he has published numerous books and articles regarding environmental issues.