I believe that carbon emissions should be reduced just enough to stop environmental disaster. Most people are not explicit about this, but I think it’s a view almost everyone shares if they think about it: the climate can absorb some carbon without disruption, so there’s no problem in that amount of emissions. Besides, eliminating all emissions would require the end of civilization if not the end of mammals.
I would go further and say that some climate change is probably acceptable. The problem right now is that since carbon emissions are an externality, there’s no decision process over how much is acceptable. If carbon were properly priced, the market could weigh the trade-off between carbon-emitting activities and climate change. Will economic growth now be enough to make up for environmental consequences later?
This long, self-reflective essay gives a good counter-argument:
[Sustainability] means sustaining human civilization at the comfort level that the world’s rich people—us—feel is their right, without destroying the “natural capital” or the “resource base” that is needed to do so…The success of environmentalism has been total—at the price of its soul…This is business-as-usual: the expansive, colonizing, progressive human narrative, shorn only of the carbon.
The environmental movement used to be about protecting the environment for the environment’s sake, but then it became co-opted by capitalism into this utilitarian economic thinking that I presented above: the environment is a big truck you can dump a certain amount of shit in before the tubes get clogged.
In Canada this is expressed by the tension between the Green Party, which sometimes acknowledges the trade-off between social justice and environmental justice (but mostly just promises all the justice!), and the NDP, which is a social justice party that added some sustainability policies. And the BC Liberals introduced a carbon tax because sustainability is just good business.
It doesn’t really matter because ecocentrism failed and now even sustainability is failing because the majority have decided (if subconsciously) that economic growth now is worth any amount of environmental pain later.