The United Nations created Intergovernmental Panel on Climate Change (IPCC) has issued a landmark report claiming that climate change is real and human beings are the culprits. The report called the existence of Global Warming, a point of contention in Congress, “unequivocal.” And noted that “human influence has been the dominant cause of the observed warming.”
“Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes,” the report says.
The IPCC also published a summary for policymakers with a more digestible breakdown of the results for those without a scientific background. The summary includes other information besides the conclusion that Global Warming is real and man-made such as:
• The atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions.
• There is “high confidence” that the rate of sea-level rise since the mid-19th century has been larger than the mean rate during the previous two millennia. Over the period 1901-2010, global mean sea level rose by about 7.4 inches. Global mean sea level will continue to rise during the 21st century.
• There is “high confidence” that over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent.
• Global surface temperatures are “likely” to be at least 2.7 degrees above pre-industrial levels by the year 2100, and will likely range from 4.7 to 8.6 degrees above the levels seen in 1986-2005.
Whether this report has any influence on the debate in Congress or American politics generally is an open question. If the drivers of the debate (or lack thereof) on Global Warming in America are business interests who would lose under a more regulated energy environment then this report is unlikely to matter as the calculus will not have changed. But if those opposing environmental regulation of carbon emissions in Congress were really conflicted due to lack of evidence and clarity from scientists – this report should help alleviate fears of a “hoax.”