Is literacy the most effective means of reducing global warming?

In the graph below, we have plotted literacy in India against fertility by state.
We need to do some proper calculations of the deviations, but it looks very much like a very high inverse correlation between fertility rates and literacy rates.

Therefore one of the following is true:
1. Higher literacy rates cause lower birthrates;
2. Lower birthrates cause higher literacy rates (highly unlikely);
3. Something else causes lower birthrates, and higher literacy rates as well.

Our next step is to find out if #1 is true.

It has been suggested that lowering birthrate is probably the most effective method of reducing global warming. (See http://www.optimumpopulation.org/reducingemissions.pdf)
Therefore if we can lower birthrate cheaply by making people literate, we can reduce global warming by making people literate.

To see a full-size version of the graph, please click here.