First of all:
1) Climate Change is a natural response to the Earth's ability to support life.To thwart the Earths ability to prevent or adapt either through increasing the surface area of the oceans as compared to land, or through geoengineering projects more than likely will destroy the biosphere.
Contrary to what these scientists will tell you, shining a heat lamp on a beaker filled with CO2, although a useful experiment, is not exactly the same as a 4 billion year old Biosphere, created through wholly unknown means and unknown processes.
So predicting a outcome through any purposeful change would be highly reckless and it is beyond our ability now, and more than likely a thousand years from now.
Yes, the earth really is that complicated I am afraid than that beaker of CO2.
So what can we do in the mean time?
2) One thing we CAN do is divorce ourselves gradually over time from the environment. We would do that by building structures in orbit in the future, but right now, we have all the tools to do something far more practical: Create and build archologies on the surface or underwater.
Since human beings are sort of picky about their environments anyway, to provide our own air, recycling and power systems to grow food in a closed loop from outside the environment is something which our current engineering systems can solve.
No need to experiment with the environment outside, and much more useful than carbon taxes which do absolutely nothing but make problems worse by removing the financial benefits of climate change for building real solutions like the above.
A great way to test this out would be to build an archology on the island and move everyone into it. Depending on what the culture produces or decides, they could allow the archology to float or stay fixed.
It would represent a really valuable experiment to see what the details we would need to solve to make that happen.
It would also produce and refine the timelines on some technology we desperately need like Thorium reactor technology and Hydroponic farming on large scales.
And of course most of the industrial automation of the systems would be a HUGE project to make a distro of LINUX to handle. :-)
Call it Archology LINUX. All the software you need to run a archology! :-)