The iconic ‘Keeling curve’, a 56-year record of rising atmospheric carbon dioxide levels, will continue with support from American philanthropists Eric and Wendy Schmidt. A five-year, US$500,000 grant, announced on 3 September, will help ease funding pressure on the greenhouse-gas monitoring effort run by researchers at the Scripps Institution of Oceanography in La Jolla, California.
The measurements were started at Mauna Loa, Hawaii, in 1958 by Charles Keeling. His son, Ralph, a geochemist at Scripps, now runs an expanded monitoring programme that tracks atmospheric CO2 and oxygen. In July 2013, when Keeling’s funding from US government agencies was in doubt, the scientist launched a ‘crowdfunding’ campaign to support his work.
That raised about $20,000, Keeling says, enough to keep programme staff on his payroll during lean months earlier this year. The new Schmidt grant will allow the Scripps team to chip away at a years-long backlog of air samples to measure changes in the ratio of carbon isotopes, which provides information about manmade sources of CO2. And Keeling’s pioneering oxygen-monitoring programme, which helps researchers to calculate how much CO2 is being absorbed by oceans and plants, has received roughly $400,000 from the US National Oceanic and Atmospheric Administration (NOAA).
“The [financial] need now is not the same as it was eight months ago,” Keeling says.
Keeling has documented a decrease in oxygen levels that is due to fossil-fuel combustion, which uses up oxygen and releases CO2. By accounting for both CO2 and oxygen levels in the atmosphere, scientists have calculated that oceans and plants each absorb roughly one-quarter of humanity’s CO2 emissions, leaving half to build up in the atmosphere.
While NOAA maintains its own atmospheric CO2 record, it does not track atmospheric oxygen, says Jim Butler, director of the agency’s Global Monitoring Division in Boulder, Colorado. “Ralph is one of the few people in the world who do this,” he says. “He has the longest ongoing record. We intend to continue funding this programme.”