“This may not be our climate rubicon, but we’re certainly standing on the shores of disaster, 400 ppm is well past the point of safety which many scientists put at 350 ppm.” Jamie Henn, co-founder and communications director of 350.org in an interview to Huffington Post on May 6.
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New reports out from NOAA today showed that in March of this year global average CO2 levels broke the 400 parts per million monthly average for the first time in the climate record. These levels, which include a measure of all global readings, are the highest seen by the inhabitants of Earth in at least three million years.
(Global average CO2 levels exceed 400 parts per million for the first time in March. Image source: NOAA.)
The Mauna Loa measure, which we’ve been using for record keeping here, first exceeded the 400 ppm threshold back in 2013, with monthly averages hitting 401.8 ppm in May of 2014. This year, Mauna Loa daily measures began exceeding 400 parts per million in January and have hit as high as 404.8 parts per million in recent weeks.
Southern Hemisphere averages lag those in the Northern Hemisphere, which accounts for the global average delay.
This inauspicious milestone comes with a massive burning of fossil fuels that now dumps more than 10 billion tons of carbon (37 billion tons of CO2 equivalent) into the atmosphere every year. It’s a ridiculous rate of burning — likely one that is six times faster than at any time in the deep history of Earth.
“This marks the fact that humans burning fossil fuels have caused global carbon dioxide concentrations to rise more than 120ppm since pre-industrial times,” Pieter Tans, lead scientist of NOAA’s greenhouse gas network, said in an interview to The Guardian Wednesday. “Half of that rise has occurred since 1980.”
This is a level far exceeding the 350 parts per million safe limit recommended by scientists. A level that, if maintained, is enough to warm the world by 2-3 degrees Celsius long term and cause enough ice to destabilize and slide into the ocean to raise sea levels by 60 feet or more. And if you add in all the other greenhouse gasses, the problem looks even worse — with about 484 parts per million of CO2 equivalent gasses circulating and trapping heat in the Earth atmosphere.
The problem is that once the CO2 is in the atmosphere and oceans, it takes a long time to become sequestered. It generates extra heat for decades, centuries and millennia. Tackling this issue not only involves rapidly moving to a zero carbon civilization. It involves changing the way we do business in a manner that is less disruptive to Earth systems. In a way that allows for the carbon sinks to vitalize and take up a portion of the massive volumes of carbon we’ve emitted.
But we’re nowhere near achieving that goal. Though carbon emissions stabilized in 2014 due to rapid adoption of renewable energy sources, continuing to emit at current rates is a recipe for disaster. What we need is a very rapid draw down to zero emissions.
Hat Tip to Greg