If my house is "chilly" I turn up the heat. If it's too warm, I either cut off the furnace, or turn it down. We can't "adjust" earth's furnace as you correctly pointed out, and the "blanket" we can use to keep warmer is inadequate.
My own personal belief is that it's the height of human arrogance to suggest we can alter how the planet heats and cools. It is not within our human capability....no more than we can make a simple molecule of hydrogen or oxygen or "water" which more than 70% percent of this planet's surface consists of.
We cannot make one of these. Impossible
If we can't even make the most simple basic component of the planet's surface, how is it we can actually adjust how rapidly or slowly the planet heats and cools?
We simply do not have that type of providence over the planet.