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.
Researchers find that unusual volcanic episode rapidly triggered Little Ice Age
30 January 2012
AGU Release No. 12-05
For Immediate Release
WASHINGTON, DC—New evidence from northern ice sheets suggests that volcanic eruptions triggered the multiple-century cool spell known as the Little Ice Age, and pinpoints the start of the climate shift to the final decades of the 13th century.
According to the new study, the Little Ice Age began abruptly between 1275 and 1300 A.D., triggered by repeated, explosive volcanism and sustained by a self-perpetuating sea ice-ocean feedback in the North Atlantic Ocean.
For more information, see the full press release from AGU at http://www.agu.org/news/press/pr_archives/2012/2012-05.shtml.
