Efforts to anticipate how climate change will affect future food availability can benefit from understanding the impacts of changes to date. Here we show that in the cropping regions and growing seasons of most countries, with the important exception of the United States, temperature trends for 1980-2008 exceeded one standard deviation of historic year-to-year variability.
One way of understanding how climate change is likely to affect global food production and food security is to better understand the recent past. That is, how have changes already influenced agricultural activities and production? For example, considerable debate has taken place on whether
