During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well.
Earth-size planet discovered orbiting Alpha Centauri B
An Earth-sized planet has been discovered orbiting Alpha Centauri B. The Alpha Centauri system, which includes three stars, is the star system nearest Earth - only 4.4 light years away. The discovery was made by a team of European astronomers. The planet is likely to be a rocky planet, but is not habitable, with surface temperatures of 1,200 degrees.
For more information, see http://earthsky.org/space/whoa-earthlike-planet-in-alpha-centauri-system and http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?_r=1&ref=science.
