As the 2015 UN Climate Conference approaches, new studies indicate its necessity. Studies released last week indicated that both greenhouse gas concentrations and global temperature have reached new milestones since the Anthropocene began with the industrial revolution.
The first study, coming from the World Meteorological Organization (W.M.O.), confirmed that the average global CO2 concentration topped 400 parts per million (as a monthly average) in the opening months of this year. The number represents an increase of 43 percent from pre-1750 levels of 278 parts per million.
The second study, coming from the Met Office and Climatic Research Unit at the University of East Anglia in Britain, reported that Earth’s average temperature has crossed the anticipated 1 degree Celsius mark. Temperature data from January to September indicates that global averages over those nine months exceeded historical averages by 1.02 degrees Celsius.
“This evidence shows us that the concentrations are increasing, and they are increasing with increasing rates,” Oksana Tarasova, chief of the W.M.O.’s Atmospheric Environment Research Division, told The New York Times. “This calls for urgent and very strong actions to limit the emission of those greenhouse gases.”
Tarasova added that the number was “symbolic,” since “there is nothing magic about 400 — it’s nothing better than 399 or 401. This is like our obligation to ourselves; we’d like to not go over 400.”
The reason 400 has become the threshold number is because it is tied to commitments made by a number of nations — and the fact that it has now been surpassed is indicative that “our commitments are not there,” Tarasova said.
A somewhat less symbolic (and more significant) figure is 560 (double the pre-industrial levels): should greenhouse gas concentrations exceed that, according to Tarasova and The New York Times, then the combination of water vapor and anthropogenic greenhouse gases will increase warming by a rate of triple the capabilities of the latter factor alone.
“We can’t see CO2. It is an invisible threat, but a very real one,” Michel Jarraud, head of the United Nations weather agency, said. “It means hotter global temperatures, more extreme weather events like heatwaves and floods, melting ice, rising sea levels and increased acidity of the oceans. This is happening now and we are moving into unchartered territory at a frightening speed.”
According to Joby Warrick of Washington Post, this year is likely to top 2014 as the warmest year on record.
This month’s studies come on the heels of one published last month in the journal Nature Climate Change, which predicted that parts of the Persian Gulf could be in danger — by the end of this century — of occasional temperatures high enough to cause hyperthermia after six hours of exposure. And this “even for the fittest of humans,” reads the paper, by Jeremy S. Pal of Loyola Marymount University in Los Angeles and Elfatih A. B. Elthahir of the Massachusetts Institute of Technology.
“Our results,” they wrote, “expose a regional hotspot where climate change, in the absence of significant mitigation, is likely to severely impact human habitability in the future.”
