I highly doubt that the amount of interaction that humans have contributed to the climate has had any truly significant effect on the climate.
...why?
Search: ruddiman early anthropogenic hypothesis
You don't even need to select any of the search results, but just browse ...to get the idea.
[
such as:
http://www.nature.com/news/2011/110325/full/news.2011.184.html ]
"...
new evidence in support of the controversial idea that humanity's influence on climate began not during the industrial revolution, but thousands of years ago. Proposed by palaeoclimatologist William Ruddiman in 2003, the theory says...."
Ruddiman was an early researcher, and is widely cited in old climatology research; but he's now moved beyond the mainstream IPCC dogma, and he sees a more comprehensive, big-picture, perspective ...imho.
http://www.evsc.virginia.edu/ruddiman-william-f/His "...earliest research was on orbital-scale changes in North Atlantic sediments to reconstruct past sea-surface temperatures and to quantify the deposition of ice-rafted debris."
A few years ago I met with a local climate science professor to ask him about my ideas of soil, and soil's influence on climate. He told me about Ruddiman's ideas, which were along similar lines, and he suggested I read "
Plows, Plagues and Petroleum: How Humans Took Control of Climate" by William Ruddiman.
Have you not heard of this? His book was "Winner of the 2006 Book Award in Science..."
in case that makes any difference for you. Have you also not read
1491, by Mann ...or not read
Vestal Fire, by Pyne?
===
As you noted, the planet is "highly capable and really very stubborn about cooling itself down all by itself...." But Humans have been fighting the planet's natural trends, for millennia, as Ruddiman, Mann, Pyne, and others show.
...of course recently we've gone a bit overboard,
with that 'industrial age' phase, but we can still moderate things.
~
