"deep ice surveys have revealed long term variable climate changes over long periods of time" - the key bit here is "long periods of time". The climate is changing far faster now than has ever happened in the past from any form of "natural variability" - this is a major problem for animals and plants, because they can't adjust or adapt fast enough.The climate can't adjust quickly, too. Yes, the planet will 'recover' and find a new stable state eventually, but you're talking there about thousands of years, not months!Plus it's not just air pollution, it's micro-plastics and in particular CO2 which we don't see or smell because there's a small amount in the air anyway. As for the volcano thing, that's a popular semi-myth. I say semi, because yes, they can spew a lot of SO2 (sulphur dioxide), which is problematic and can cause weather changes.However, the amount of CO2 they put out is tiny compared to human production. Here's a couple of interesting articles on exactly this topic:https://www.thenakedscientists.com/articles/questions/how-much-pollution-does-volcano-producehttps://www.scientificamerican.com/article/earthtalks-volcanoes-or-humans/
Bryan Betts ● 2125d