It's tragic that only the threat of a deadly disease could compel such a change, but perhaps we may find other levers to help us achieve such widespread beneficial changes in the future?
I am willing to bet that come 2022 or so, emissions will rebound and exceed peaks as people 'catch up' on travel, including simply visiting near and dear ones, that they have missed out on.
Climate change has untold cost too, so what you’re saying doesn’t have much weight.
The foregone economic activity in just one year of lockdowns in the US is a significant fraction of cumulative worldwide damages anticipated from climate change through 2050.
We're on the path to a 4C world by something like 2100. An increase by that much might possibly wipe out the species. If it fall short of that forecast the damage will be far greater.
Not to mention that pandemic shares the same root cause as climate change. Destroying our ecosystem has increased the incident of zoonotic spillover. We'll see more pandemics as we continue on this path. And the costs of these are not separate from the costs of climate change.
That is absolutely not what scientists and economists are predicting. An RCP 8.5 scenario (which is considered on the worse side of what's likely in a "do nothing" world) is expected to knock 6.7-14.3% of US GDP by 2100: https://www.brookings.edu/wp-content/uploads/2019/10/2019102... (p. 7). That would be about half as bad as the COVID lockdowns (but permanent): https://www.cnbc.com/2020/07/30/us-gdp-q2-2020-first-reading....
Note that's a 14.3% hit compared to what GDP would be in 2100. That's a big impact. It's equivalent to going from 3% annual GDP growth between then and now to 2.7% annual GDP growth.
Now, the numbers hide some really terrible costs. The Florida and Gulf coast will become uninhabitable, destroying half the economy in those areas. To put it into perspective the 2018 California wildfires cost 0.75% of GDP. So this is like 20 times worse. It's bad! But it's not an "untold cost." It's not an outcome worth spending any amount to avoid.
Scientists don't think mitigation will cost more than the damages from climate change, because scientists aren't proposing to mitigate climate change by shutting down the economy the way we did during the COIVD lockdown. That's an insanely inefficient way to achieve mitigation. I mentioned the economic loss from COVID lockdown not to suggest that is actually how we would reduce emissions, but to put into perspective what the expected costs of climate change are.
Saying that climate change will have "untold cost" is problematic because it makes you believe that mitigation strategies that will have massive costs will be justified to avoid climate change damages. It's worth the U.S. spending hundreds of billions of dollars a year on climate-change mitigation. The EU is planning on spending 260 billion euro annually by 2030. That's roughly the scale of Biden's plan.
But the "World War II-style" mobilization of the economy that Green New Deal advocates want will hurt economic growth by more than climate change will. If we go from 3% annual GDP growth to 2% annually we'll shoot ourselves in the foot.
None of the RCP scenarios consider potential positive feed back loops. This is understandable because from a climate modeling perspective these are complex and involve a lot of uncertainty/unknowns. However historical evidence suggests that in all mass extinction events involving rapid increase in atmospheric CO2 there is a point at which CO2 concentrations appear to start to dramatically increase due to some systemic trigger. We don’t know what exactly that may be, but many climate change concerns are happing “faster than expected”.
Events that cause positive feedback include things like increased CO2 emissions from wild fire, destruction of the amazon rainforest, increased albedo from melt arctic sea ice, methane release from melting permafrost, etc. We really don’t know how to account for all of these but past climate/co2 events suggest there is a “tipping point” for radical climate change.
It is also worth pointing out that climate change is only one of the ways in which our current system is completely unsustainable.
Our current economy demands perpetual growth. We are already living unsustainably. The consequences for this are obvious, and if we were remotely capable of surviving in a way remotely resembling our current standard of living we would have to immediately start scaling back production and consumption. The green new deal is a joke, and we clearly are incapable of changing our path.