We would need to cover the world in material made by photosynthesis and leave it there. Millions of square kilometers. No eating it or using it, just leave it behind. Apart from the shit that dies, then we would need to make sure that was quickly replaced.The greenhouse house effect happened on a human scale, not a a geological scale. To reverse the damage done, we don't have to dig holes to bury the carbon in it, just storing material made by photosynthesis will do the trick.
So where are all the veges going to be grown (meat being a no no) and the people live. Or do we just insist that countries like Brazil keep the forests in place. Plus how long will it take to grow all this stuff to sequester the co2, according to Grets we have a very small time frame and her childhood has gone. Of course she is a teenager so not surprised really. If we are looking at a minimum of 30 years to get this stuff organised, in the ground and big enough to make a difference it is all over rover. The science is settled, go down this route and we are extinct. Much like the beloved parrot. Next theory?