@No-Quarter Hah yeah that was me, one of the funner moments on the Fern over the years, if only for the "wait a minute...!" factor.
@Rembrandt Well, the climate is definitely getting warmer, and atmospheric CO2 concentration is definitely going up. Historically we know those two things are linked from sampling the temperature vs CO2 relationship going back millions of years via drilling ice cores in the Arctic. So we're on fairly solid footing so far, scientifically.
Whether or not human activity is a) totally responsible for this, or b) just helping it along, or c) has had no impact whatsoever, is up for debate. But given the amount of fossil fuels burnt since the industrial revolution (that took millions of years worth of stored CO2 and whacked it into the atmosphere in very short order, geologically speaking), it's highly probably somewhere between a) and b).
The extent to which people are responsible is sort of a side issue, as the change is happening regardless. The debate then becomes how much effect a massive societal change to curb emissions would have on the entire climate system. If we ban flying, redistribute all the wealth, halt economic growth etc, and we still get 80% of the warming we would've got anyway, then it's probably not worth it. Instead we should crack on as we are with capitalism / economic growth and bet on technology allowing us to innovate our way out of the negative effects of climate change. That it the ideological/political fork in the road, and the left wing vs right wing solutions are obviously dramatically different. This is why it's such a politically charged issue (and why we're discussing it in the TSF politics forum).
Clearly it also depends on the extent of the damaging effects. No one has a definitive answer to that either, as the system is so ridiculously complex to model accurately. But most would agree it makes sense to err on the side of caution, as huge sea level rises / more frequent catastrophic natural disasters will have a big negative affect on society. 50cm sea level rises versus 20m is quite a big difference etc. The presence of possible feedback loops in climate, e.g. the melting of Arctic permafrost releasing methane and runaway warming, makes this even more unpredictable. That example is just one thing that we know might happen, there will also be "unknown unknowns" that (by definition) no one's considered.
Whatever happens, the poor will be affected more than the rich, developing world more than developed, East more than West etc. Which again makes it very political, especially as developed countries got to grow fast in the 20th century without caring about emissions, but now the developing world can't, or shouldn't, do the same? Again, you can take the view of making everyone more wealthy via economic growth, and using that to fuel development of technology to mitigate the effects is better than making everyone poorer by throwing human progress into reverse, but that's a political debate. You can probably tell which side I am on, and it's not Extinction Rebellion's.
Extinction Rebellion are a political / religious movement more than environmental. The idea "humanity has sinned and must repent or be destroyed" is an ancient, powerful story that has deep psychological appeal to humans, as any theologian could tell you. The whole shouty concept of "this is SUCH an emergency there is no time for nuance or debate and you must do as WE say" is really damaging and insidious, particularly the way it is being indoctrinated to children/adolescents. It is causing deep rooted psychological issues in young people, and doesn't help the above logical debates that need to take place in a rational society.
Whatever happens, people aren't going to "extinct", billions almost certainly won't die. But mass migration / hardening of borders is already happening, and will probably get worse. It will be the biggest challenge that humanity will face for decades/centuries to come IMO. NZ is very fortunate in its isolation, in this regard.
