NASA researchers report that much of the atmospheric warming observed in the Arctic since 1976 may be due to changes in tiny airborne particles called aerosols. Though greenhouse gases are invariably blamed for global climate change, and the shrinking Arctic ice cover in particular, this new research indicates that as much as half the warming in the Arctic can be attributed to sort lived particulate pollution—basically soot. Unlike the dreaded gas, CO2, aerosols do not stay in the atmosphere very long, suggesting that the effects of any warming caused by aerosols would quickly be reversed if their emissions ceased.
A recent article in the journal Science has provided a new, detailed climate record for the Medieval Climate Anomaly (MCA), also know as the Medieval Warm Period. It was the most recent pre-industrial warm period, noted in Europe and elsewhere around the globe. The researchers present a 947-year-long multi-decadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. The interesting thing is that the MCA had basically been removed from the climate record by Michael Mann's infamous “hockey stick” history graph that was adopted by the IPCC a decade ago.
Eclipsed by the pageantry of the 2008 Beijing Olympics and Russian attempts to start WWIII by invading their former client states, is a noticeable downward trend in global temperatures. Data from the UK Meteorology Office shows that temperatures in the first half of the year have been cooler than any year since 2000. The reason given for the cooler temperatures is the natural cycle of La Nina and El Nino periods, which affect climate world wide.