This thread is started to record global temperature changes March 2008 to March 2009 and significant climatic change observations in the same period.
Based on the solar magnetic field modulation of cloud hypothesize, the planet should cool to roughly 1880 temperatures by March 2009, if the change matches the largest estimate of the cloud forcing function (Svensmark’s) and if the solar magnetic cycle moves to a Dalton minimum. (Based on the slope of past abrupt climate changes and assuming past abrupt climate changes were driven by solar magnetic field changes. See comments, for caveat. The solar magnetic cycle modulation of clouds hypothesis is still being evaluated, by the scientific community.)
The following is a graph that shows how global temperature has increased in the 20th century. Also included is a monthly global temperature deviation table that shows the first indication of global cooling (2008 February, cooling of about 0.35C to about 0.12C.)
The Baud thread “solar cycle 24” outlines how changes to the solar magnetic field are hypothesized to modulate planetary cloud cover. The paleoclimatic data shows that there are periodic abrupt drops in planetary temperature which correlate with solar magnetic field changes, but there has not been until the 21th century a hypothesized mechanism as to how solar magnetic cycle changes could possibly affect the earth’s temperature.
As noted in the Baud solar cycle 24 thread there are also a minority of solar physics that are predicting that cycle 24 will be move to a Dalton minimum (period of low solar magnetic cycle activity.) As noted in the same thread, there is observational evidence that supports the assertion that the solar magnetic cycle has been interrupted.
There are a minority of scientists (Svensmark, Shiva, and so forth) who have stated that a significant portion of the 20th century warming is due to solar magnetic field changes that increase or decrease the total amount of planetary cloud cover. (A link to Svensmark’s paper is provided below. See comments, for caveat.)
The following is Svensmark’s paper “Cosmoclimatology”. (The Baud thread solar cycle 24 is a better summary.)
1) Although papers have been written to support the solar magnetic modulation of cloud hypothesis and there is data to support that hypothesis, this subject is not resolved and there have been critical papers written that challenge the solar cloud modulation papers.
2) There are historic observations from the turn of the 19th century that can be used to predict how the climate in different regions would change if the planetary temperatures drop to 1880 levels by March 2009.