1. climate models
1.1. agree
1.1.1. the polar and subpolar
1.1.1.1. recevie more
1.1.2. the subtropics
1.1.2.1. receive less
1.2. disagree
1.3. arid
1.3.1. the mediterranean
1.3.2. mexico
1.3.3. the southwestern us
1.4. grow damper
1.4.1. canada
1.4.2. thr northen europe
2. rainfall amout change
2.1. green house gas
2.1.1. warm air holds more vapor
2.1.2. hotter world
2.1.2.1. more moisture
2.1.3. water vapour
2.1.3.1. increase every degree celsius
2.2. moist air
2.2.1. rise
2.2.2. drop
2.2.2.1. rain snow
2.3. temperature
2.3.1. higher
2.3.1.1. increased evaporation
2.3.1.1.1. drought
2.3.1.2. risk
2.3.1.2.1. regions that subsist on minimal rainfall
2.4. ipcc
2.4.1. heavy precipitation events
2.4.1.1. disaster
2.5. global warming
2.5.1. the area bet. 40 and 70 degrees north latitude
2.5.1.1. grew rainier
2.5.2. the area bet. zero and 30 degrees north
2.5.2.1. grew drier
3. isaac held
3.1. about him
3.1.1. scientist at the national oceanic
3.2. explain
3.2.1. transfers of water
3.3. say
3.3.1. wet areas are getting to get wet
3.3.2. dry areas dries
4. akkad
4.1. location
4.1.1. the tigris and the euphrates rivers
4.2. ruled from
4.2.1. city known as akkad
4.3. country resources
4.3.1. well armed , organized , wealthy , woods
4.4. collapsed
4.4.1. four men claimed to be emperor
4.5. empire's fall
4.5.1. politics
4.5.2. change in rainfall
5. sandra postel
5.1. about her
5.1.1. expert on freshwater resources
5.1.2. director of the global water policy project
5.2. explain
5.2.1. the irrigated lands of africa