They also describe the new map as much more sophisticated than the 1990 version, which was based on a data set covering only 13 years (1974 through 1986 for the U.S.). The revised map draws on 30 years of data and uses a complex algorithm to factor in other variables that affect local temperatures, such as altitude and the presence of water bodies.
"All we could really do earlier was draw a straight line between data points, but now we're trying to input a lot of other information," says USDA spokeswoman Kim Kaplan. "We'll pick up more heat islands and cold zones, and the edges of zones will be defined more clearly."
The new map is being developed by Oregon State University's PRISM Group, a team of modelers that also produces climate maps for other state and federal agencies. Unlike past versions, the 2009 map will be GIS-compatible, storing and linking layers of information in a digital version that can be read with widely available GIS (geographic information system) viewing programs. It will have a resolution of 800 square meters, so users will be able to zoom in on their hometowns or zip codes and see where they lie within zones.
This last quote sounds like a t-shirt waiting to be made: "All gardeners are in zone denial."
2. From Duncan Green: food prices for the poor aren't coming down. The Senate Foreign Relations Committee was hearing much the same thing today.