#environment "There isn't one tipping point. There isn't one cliff that we go off. It's more like we're stepping out onto a minefield and we don't know exactly where those mines are, but the farther we step out into the minefield — the more we warm the planet — the more likely it is that we do set off these mines, that we do encounter devastating tipping point-like changes in the climate.”
Mann's hockey stick would be valid if you deny the MWP, the little ice age, natural climate variation, and history.
The hockey stick graph is invalid because it had predicted 4 or 5 degrees rise in temp by now. Since the warming did not happen as predicted they changed the name to "climate change" and are now claiming that 2 more degrees by the end of THIS century will be catastrophic.
The worldwide average temp is 4/100s of one degree warmer than last year making it the "hottest year in history."
https://www.pri.org/stories/2017-11-04/humanity-has-entered-global-warming-minefield-climate-scientists-say