Correlation: Failed States Index and climate

[Hierophant]

Malaria risk: http://en.wikipedia.org/wiki/File:Malaria_...Y_-_WHO2004.svg

Thats one, and the other is the fact that growing season in aggriculture in limited by temperature in the higher latitudes, while it's limted by rainfall near the equator.

In high latitudes, the rainfall is more or less stable and abundant, sometimes there are droughts, but not very often. The temperature is what limits the length of the growing season most of the time. Temperature is very easy to predict. Cold in winter and hot in summer. Very easy to make plans based on that.

Near the equaor, temperature is always high enough to grow stuff. Whethere is 10 degrees or 40, the plants dont really care. What they care about it water. There is a steady seasonal cycle in rainy/dry season(s). The problem with rainfall is that its much harder to predict, and much more variable. Mean temperature from one year to the next may vary by 2 degrees. THe plants dont care. Mean rainfall, how ever, can be 2 to 5 times more or less what fell last year, espicially when you go down to the local scale (not continental or region scale) which is relevant for a farmer. It's much, much harder to plan your growing season, and relatively small anomalies in rainfall can have disastrous consequences for a farmer.

2 reasons the equatorial countries got it harder: diseases and rainfall variability. One is directly dependant on temperature, one indirectly.

Hierophant, researcher in climate and hydrology IRL:D