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.
Here Comes the Solar Maximum
What we know - and don't know - about solar storms and their hazards. Sometime in the next few months - summer or fall of 2013 - the sun will reach the solar maximum, the peak of sunspot counts during its roughly 11-year cycle.
To get all the details, check out the Earth Magazine article http://www.earthmagazine.com/article/here-comes-solar-maximum-what-we-know-and-dont-know-about-solar-storms-and-their-hazards
