Slide 10: Global features, Last Glacial Maximum (21-18 kbp)
The world looked considerably different over the last glacial maximum. The extent of icefields (dark blue) and permafrost (green) in the northern hemisphere is considerably larger than today. The tropical forests are considerably reduced in extent, and, much of what is now tropical forest was then savanna grasslands. These dramatic differences were caused by as little a change as 5 degrees less than present.