The parents contention is that climate change will prevent these countries becoming first world/that it will interrupt their growth. I'm saying even without climate change they won't become first world. Certainly not on the timescale suggested. Now I agree, climate change won't help. But the reason CAR isn't (now or in 50 years) a first world country is not down to climate change, its because they don't have any of the myriad things needed to support that type of economy.
economists think in curves - starting from a low base it's very easy to improve fast, but the rate of improvement drops off as it nears the global average.
ecologists think in straight lines - the rate of improvement is x/year, so in 50 years the improvement will be 50x and they'll be richer than Sweden, who are only improving at (x/10)/year.
The reason isn't climate change.
The Central African Republic has just come out of a civil war. Of course things are going to improve rapidly, because that farmer that was in a refugee camp can now go home and grow enough to barely feed his family.
You can't extrapolate that out to the CAR overtaking first world countries in a generation simply because that farmer hasn't been educated to do the jobs that the economy would require, neither probably will his children.
That's before getting into things like infrastructure, rule of law, etc, etc, etc.
Edit: To clarify, I don't disagree that climate change will probably hurt the poorest countries disproportionately though.