your assertion 100% true. in the history of mankind, we have hit mucher higher points on the y-axis if you are only charting the average temps.
not only that, i will also assert that (almost) nothing humans can do to the earth, including nuclear apocalypse, will injure the earth itself beyond the point of recovery. the earth always recovers (historically).
us humans occupy and depend on a very (extremely) specific niche to survive as we do. even the most minor shift in either direction will cause economic (at least) and humanatarian (conceivably) disaster. the shift is suddenly happening at an extremely accelerated rate, possibly (and statistically likely) due to activities of humans.
the cause of all this seems to be clear (scientifically)...and moving towards sustainable energies as fast as possible is the right thing to do anyway (economically and politically). should we go full speed ahead towards the possible iceberg, or try to avoid it, even if it might not be an iceberg?