A United Nations climate panel has released its latest report on the state of our planet, and is now ready to declare it a virtual certainty that human activity has led to a rise in global temperatures. The report, which is released every six years by the Intergovernmental Panel on Climate Change, is an attempt to compile and synthesize all the relevant research being done in climate science into one comprehensive document. It contains the work over 800 contributing authors and 50 editors from 39 different countries, and the level of agreement among their work is overwhelming.
The bottom line finding in the report is that global temperatures are on the rise over the last century (an indisputable fact) and that "anthropogenic" [caused by human activity] factors are to blame:
It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.
The report also explains that "extremely likely," in this case, means a 95-to-100 percent confidence level, which in scientific terms is pretty much a lock. That's also a substantial increase over the same report from 12 years ago, which expressed only a 66-percent confidence level of the same finding.
They also said (with slightly less confidence, but still classified as "likely") that "1983–2012 was likely the warmest 30-year period of the last 1400 years."
Despite the dire warnings, there are some scientists who say the panel didn't go far enough. The New York Times quotes one researcher who believes the panel is too conservative in its estimates of future increases in temperatures and ocean levels. Meanwhile, that five-percent window is enough for climate change denialists to fight back, which they are already doing.
The report does say that it's not too late to undo some of the damage, but the world is not moving in the right direction. In order to keep warming below the target level of 3.6 degrees Fahrenheit, humans would have limit the total amount of carbon burned into the atmosphere to one trillion tons. The world has already burned half a trillion tons since the beginning of the Industrial Revolution, and at its current pace, will reach one trillion in the year 2040.
The full report will be released on Monday morning, but you can read the detailed summary at the IPCC website.