Africa: Summer frost blamed on global warming

allAfrica.com: Africa: Link Between Crop Failure And Climate Change Often Missed (Page 1 of 1)

Another consequence of climate change that affects food security in Africa is the increasing frequency of extreme weather events such as floods, droughts, hail and heat waves. These can be fatal to crops.

"A couple of years ago, I was in Lesotho during December. A sudden spell of frost destroyed much of the country's maize harvest," Ziervogel told delegates. "This is unusual for summer."

This Google search turns up a few more things blamed on global warming.