A UN panel has released part one of its six-yearly update on the current state of Earth's climate. The much-anticipated report by the Intergovernmental Panel on Climate Change (IPCC) says that with 95 percent certainty, humans are the dominant cause of global warming since the 1950s.
In the air, in the oceans, and on the ground, global warming is "unequivocal," the report states. Taking aim at the skeptics who tout the apparent recent pause in warming, the report adds that the delayed warming over the past 15 years is too short to reflect long-term trends.
According to the IPCC, each of the last three decades has been successively warmer at the Earth's surface, not to mention warmer than any period since 1850, and likely warmer than any time in the past 1,400 years.
“Climate change is the greatest challenge of our time,” said Thomas F. Stocker, IPCC co-chairman. “It challenges the two primary resources of humans and ecosystems, land and water. In short, it threatens our planet, our only home.”
Going beyond its four previous climate reports, the panel endorsed a “carbon budget” for humanity -- a limit on the amount of carbon dioxide that can be produced. No more than one trillion metric tons of carbon could be burned and the resulting gases released into the atmosphere, the panel found, if planetary warming is to be kept below 3.6 degrees Fahrenheit (2 degrees Celsius) above the level of preindustrial times.