IPCC says it’s “extremely likely” that humans are causing climate change
The UN’s Intergovernmental Panel on Climate Change (IPCC) is more certain than ever that human activity is the primary cause of global warming. In a leaked copy of an upcoming report, the group designates the probability that human activity is causing global warming to be “extremely likely” and with a statistical certainty of “95 percent.”
They are also state certainty of severe consequences for our species if we do not make dramatic halts to carbon emissions in the near future. Sea levels could rise by more than a meter by the century’s end, enough to inflict severe damage to coastal communities everywhere.
The IPCC has been meeting since 1988 and has been periodically releasing an Assessment Report every few years in which it documents the sum conclusions of existing knowledge on climate change and the extent to which human activity is behind it.
There have been four reports thus far, the last two having been released in 2001 and 2007. In the six years between them, the evidence for human-caused climate change grew, and the wording in the reports reflected it: The 2001 report said that it is “66 percent certain” that human activity is causing climate change,” while the 2007 report upped the likelihood to “90 percent,” a statistical figure that it said equated to “very likely.” This fifth report carries the certainty and the urgency forward by a few more notches.
The fifth report is still in the review phase. Scientists and government officials are to discuss its findings and language, and institute revisions when they deem it necessary, before its slated release date at the end of September.
The conclusion will hardly be news to a solid majority of Earth scientists, most of whom have been of a consensus for many years that global warming is real, is caused by humans, and holds serious consequences for life on this planet. A National Academy of Sciences survey of peer-reviewed studies found that 97% of the climate-related studies decisively tied human activity to climate change.
A small but persistent and very outspoken minority of scientists in various disciplines have been questioning the climate science and the evidence for humanity’s role in it. The 2007 IPCC report suffered some rough going in the public-relations arena when its authors retracted their initial estimates on the pace at which glaciers in the Himalayas would melt. Critics have not shown, however, that glaciers are not melting. And if these leaked findings are any indicator, then the skeptics are not winning the battle of scientific debate, any gains they may make in the public-relations arena notwithstanding.