How do we know how warm or cold it was in the past?

A frequently asked question is about changes in temperatures in the past.  This short article in The Guardian provides a quick introduction to the science  and the  sources of evidence that are used to piece together past climates.  The record from weather stations goes back 200 years at best.  Before that there are a range of proxies that can be used to assemble a picture of climate change in historical and geological time. 

Follow this link for the full article:

http://www.guardian.co.uk/environment/2012/mar/07/past-climate-temperature-proxies

Valentine's Day destroyed by climate change?

According to the activist group Climate Nexus as reported in the Los Angeles Times

Research from the International Center for Tropical Agriculture found last year that as temperatures rise, the principal growing regions for cocoa could shrink, especially in Ghana and Ivory Coast, the sources of half the world’s supply. Production could fall off dramatically by 2050, making cocoa less available and more expensive.

Peter Gleick, a MacArthur fellow and chief executive of the Pacific Institute, bemoaned the potential decline of the sweet treat last week in an open letter to climate change skeptics in Forbes.

Full story here.

Link to the original research (PDF file).