When it comes to climate, more than ever humanity is at a crossroads, the United Nations reemphasized on November 2. The world could very well become uninhabitable if we keep spewing greenhouse gases into the atmosphere, the international body said in its latest assessment of global climate science.
“Our assessment finds that the atmosphere and oceans have warmed, the amount of snow and ice has diminished, sea level has risen and the concentration of carbon dioxide has increased to a level unprecedented in at least the last 800,000 years,” said Thomas Stocker, co-chair of the UN Intergovernmental Panel on Climate Change (IPCC) Working Group I, one of three groups that compiled the report, in a statement.
The evidence is stronger than ever before that human activity is the root cause of these changes, and that the effect is compounded rather than progressing in a linear fashion, the IPCC said. Moreover, time is running out to change it.
“With this latest report, science has spoken yet again and with much more clarity,” said United Nations Secretary General Ban Ki-moon in a statement, launching the final installment Fifth Assessment Report of the IPCC in Copenhagen. “Time is not on our side…leaders must act.”
This was the fifth in a series of reports put out by the IPCC, which was created in 1988 by the World Meteorological Organization and the UN Environment Programme to evaluate published scientific papers related to climate change and compile the findings into a digestible form of information for policy makers.
Nuggets such as the following abound.
“Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850,” the scientists said in their summary Synthesis Report. “The period from 1983 to 2012 was likely the warmest 30-year period of the last 1,400 years in the Northern Hemisphere, where such assessment is possible (medium confidence).”
“Medium confidence” is the degree of consensus among the scientists in evaluating the literature, and “likely” is a 66 percent probability, according to a UN translation of the terms. But the degree of certainty ranges all the way up to “virtually certain,” which is 99 percent probability.
More than spouting dire warnings, though, the scientists emphasized that the human race does have the power—and, for now, a limited window of opportunity—to change the planet’s fate for the better. The news is only all-bad if nothing is done about the findings, they said.
“We have the means to limit climate change,” said IPCC Chairman R. K. Pachauri in the statement. “The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change.”
The question is, will we? Ban Ki-moon called on world leaders to act, reminding those assembled at a November 2 press conference that the technology to adopt more sustainable energy options, for instance, is within our grasp. He also said the cost of inaction would be much, much, higher than an investment in renewable energy and other constructive changes would be.
“I have seen for myself those rapidly melting glaciers, most recently in Greenland together with the Prime Minister of Denmark,” said the secretary-general, who participated in the People’s Climate March of September 21 in New York City and has traveled the world, as he put it, “to see the impact for myself and…add to the voices of scientists in a political way, as a common man.”
Later this year governmental leaders will gather in Peru for the annual meeting of the UN Framework Convention on Climate Change, which will set the framework for Paris meetings in 2015, when emissions targets are scheduled to be finalized.