I was wondering if anyone could offer some advice in pursuing a PhD in Climate or Earth Science. More specifically, I was wondering (a) what sort of topics in climate research would be likely to ensure a better chance of job security (post-Phd in consutancy or Post Doc in academia), (b) which universities would be more willing to offer financial support to student from LEDC's like India or Africa and (c) what age do most student begin working towards a PhD.

Any advice would be appreciated. Thanks very much !