Monthly Archives: June 2016

Earth crosses a historic threshold

Antarctica has become the last place on earth to reach atmospheric carbon dioxide levels of 400 parts per million.  The level was breached in New Zealand a few weeks ago.

The pole has shown the same, relentless upward trend in CO2 as the rest of world, but its remote location means it’s the last to register the impacts of increasing emissions from fossil fuel consumption, the primary driver of greenhouse gas pollution.

The level was recorded for the first time in New Zealand just a few weeks ago at NIWA’s Clean Air Monitoring Station at Baring Head, and in Australia shortly before in Cape Grim, Tasmania.

“The far Southern Hemisphere was the last place on earth where CO2 had not yet reached this mark,” said Pieter Tans, the lead scientist of the National Oceanic and Atmospheric Administration (NOAA) Global Greenhouse Gas Reference Network.

“Global CO2 levels will not return to values below 400 ppm in our lifetimes, and almost certainly for much longer.”

The annual growth rate of atmospheric carbon dioxide measured at NOAA’s Mauna Loa Observatory in Hawaii jumped 3.05 ppm during 2015, the largest year-to-year increase in 56 years of monitoring.

Part of last year’s jump was attributable to El Nino, the cyclical Pacific Ocean warming that produces extreme weather across the globe, causing terrestrial ecosystems to lose stored CO2 through wildfire, drought and heat waves.

Last year was the fourth consecutive year that CO2 grew more than 2 ppm — which set another record.

This year promises to be the fifth.

“We know from abundant and solid evidence that the CO2 increase is caused entirely by human activities,” Dr Tans said…”

 

 

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