From USA Today – May 2, 2014:
For the first time in human history and likely for the first time in at least 800,000 years, the average level of carbon dioxide (CO2) in Earth’s atmosphere topped 400 parts per million for an entire month. …
Scientists at the Scripps Institution of Oceanography in San Diego reported that April’s average CO2 value was 401.33 parts per million (ppm). Each day in April had a reading above 400 ppm.
The “Keeling curve,” overseen by Scripps, is the longest continuous record of CO2 measurements. The measurements were started in the late 1950s by Charles David Keeling on the Mauna Loa volcano on the Big Island of Hawaii.
Late last month, officials at California’s Scripps Institution of Oceanography turned to Twitter seeking donations to maintain the iconic ‘Keeling curve’, a 55-year record of rising atmospheric carbon dioxide levels. An appeal for funds launched in July had attracted only a few small contributions, not nearly enough to keep the programme going. …
Scripps geochemist Ralph Keeling … with his funds running dry, wonders about the future. “Things have never been this dire before,” he says.