I suppose the first thing to ask is "What can go wrong?"
Our planet maintains a balance so far and if you start to upset that balance then you are going to have two possibilities. 1) The planet goes through a runaway greenhouse effect and effectively gets far too hot, although probably not as hot as Venus. 2) The planet goes into deep freeze and this has happened before. We can actually thank volcanic action for reversing this process.
I can understand concern over potential global warming and am in favour of reducing green house gas build up or better still to have a balance between consuming liquid fuels (example: practical bio-fuels without the hype) and growing them. Burning fossil fuels without some sort of balance is asking for trouble. Solar energy in all its forms should be seriously considered and the most suitable for each region implemented if possible and practical by all nations, although IMO that is basically asking the impossible but at least first world countries should set the example.
Another area to look at is the design and building of housing that is energy efficient in that there would be less need for heating and cooling. Practical solar solutions should also be considered here as well.
The things I have just mentioned are easily achievable with our current technology and would go a very long way in stabilising the climate of our planet. Of course this is but a pipe dream since we are a short lived species but if our life potential could be made to say 200 or more healthy years then most people in power would realise that they and not just their children are going have to put up with radical changes if they make stupid decisions. Of course human greed and fanaticism can still blind some even in the face of imminent disaster.