There was all kinds of news about CO2 level reaching 400 ppm.
Climate Change and CO2 400 ppm
Energy Collective-by -May 11, 2013Climate Change and CO2 400 ppm ... on 400ppm, which is to say, an amount of CO2 in the atmosphere that's 400 parts per million, by volume.
Out of all the hype, National Geographic and The Economist tell the story behind the 50+ years of measurement started by Charles David Keeling.
Here is the National Geographic post.
Climate Milestone: Earth’s CO2 Level Passes 400 ppm
Greenhouse gas highest since the Pliocene, when sea levels were higher and the Earth was warmer.
Two teams of scientists at the Mauna Loa Observatory in Hawaii have been measuring carbon dioxide concentration there for decades, and have watched the level inch toward a new milestone.
Photograph by Jonathan Kingston, National Geographic
Published May 9, 2013
An instrument near the summit of Mauna Loa in Hawaii has recorded a long-awaited climate milestone: the amount of carbon dioxide in the atmosphere there has exceeded 400 parts per million (ppm) for the first time in 55 years of measurement—and probably more than 3 million years of Earth history.
And here is The Economist post.
Environmental monitoring
Four hundred parts per million
The only good news about the Earth’s record greenhouse-gas levels is that they have been well measured
May 11th 2013 |From the print edition
CHARLES D. KEELING, mostly known as Dave, was a soft-spoken, somewhat courtly man who changed the way people and governments see the world. A slightly aimless chemistry graduate with an interest in projects that took him out into the wild, in 1956 he started to build instruments that could measure the proportion of carbon dioxide in the atmosphere, a scientific topic which, back then, was barely even a backwater. In 1958, looking for a place where the level of carbon dioxide would not be too severely influenced by local plants or industry, he installed some instruments high up on Mauna Loa, a Hawaiian volcano. He found that the level fluctuated markedly with the seasons, falling in northern summer as plants took up carbon dioxide and rising in northern winter as dead foliage rotted. And he found that the annual average was 315 parts per million (ppm).
The Economist honors the effort by Dave.
Scientists involved in other measurements of the Earth, and those who pay for their work, need to build on his legacy. So does anyone taking a position on global-warming, where numbers as clear as Keeling’s are a rarity. Measurements of the temperature of the ocean depths and the acidity of its surface waters, of the volume of the planet’s forests and the mass of its ice sheets (see article), need to be made not just for the few years of a specific research project. Their ceaseless continuance needs to be built into the planet’s infrastructure. A world in which governments claim to be committed to spending trillions of dollars to change the shape of the Keeling curve decades hence, but do not find the funds to produce consistent records of the change going on today, is one that still has lessons to learn from the patient chemist.
And National Geographyic as well.
When the elder Keeling started at Mauna Loa, the CO2 level was at 315 ppm. When he died in June 2005, it was at 382. Why did he keep at it for 47 years, fighting off periodic efforts to cut his funding? His father, he once wrote, had passed onto him a "faith that the world could be made better by devotion to just causes." Now his son and the NOAA team have taken over a measurement that captures, more than any other single number, the extent to which we are changing the world—for better or worse.