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.
Ice Age Field Reversal, Abrupt Climate Change, and Supervolcanoes!
In a recent report in Earth and Planetary Science Letters, researchers from the GFZ German Research Centre for Geosciences found that around 41,000 years ago there was an abrupt and complete reversal of the Earth's dipole field which lasted only 440 years. During this period, the Earth's magnetic field was significantly weaker, with only 5% of the current field intensity, which would significantly reduce the protection provided the surface from radiation exposure.
Their study of Black Sea sediment cores also revealed evidence of multiple abrupt climatic changes, as well as the eruption of a supervolcano in the Phlegraean Fields area near Naples, Italy 39,400 years ago.
For more information, see the report in Science Daily, or the article in EPS at http://www.sciencedirect.com/science/article/pii/S0012821X12003421.
