If you have been worried about global warming the latest news will give you some comfort.
Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The signals that these microwave radiometers measure at different microwave frequencies are directly proportional to the temperature of different, deep layers of the atmosphere. Every month, John Christy and I update global temperature datasets (see here and here)that represent the piecing together of the temperature data from a total of eleven instruments flying on eleven different satellites over the years. As of early 2011, our most stable instrument for this monitoring is the Advanced Microwave Sounding Unit (AMSU-A) flying on NASA’s Aqua satellite and providing data since late 2002.So what does the graph show? Global temperatures are falling like a rock and are now .02 degrees C below the baseline. Of course if the coming of an Ice Age (or even a Little Ice Age) worries you this is bad news. I have reliable reports that it is rather difficult to grow food crops under ice.