Planet was much hotter, much colder etc. So as a species we need to learn to cope and tackle this anyway, why not start now?
No that only shows we can change the climate, not engineer it to best suit humanity.
"Stop doing what broke it in the first place" (e.g. stopping CO2 emissions) sounds like the sanest option.
Also, few of our changes to the environment have an impact as great as the greenhouse gases.
The idea is to mitigate our impact on ourselves and the environment by reducing consumption. We already have widespread understanding that reduction of resource usage is the most environmentally beneficial change we can make.
I am proposing that this perspective has run its course. It is clear that human behavior can have a very broad impact, so we should aim to learn to work with the environment for the better.
This means learning how to intervene on "natural" (whatever that means) environmental processes such that they tip in our favor (ecological engineering).