This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.
Objection:
The Earth has had much warmer climates in the past, what is so special about the current climate? It seems like a generally warmer world will be better.
Answer:
I don’t know if there is a meaningful way to define an "optimum" average temperature for planet Earth. Surely it is better now for all of us than it was 20,000 years ago when so much land was trapped beneath ice sheets. But anywhere between the recent climate and the most extreme one we may be heading for with tropical forests inside the arctic circle, one global mean temperature seems just as good as any other. Maybe it is even better with no ice caps anywhere.
But the critical issue with what is going on today is not where the temperature is or would be and not with what it may end up being. The critical issue is how fast it is moving.
Rapid change is the real danger. Human habits and infrastructure are suited to particular weather patterns and sea levels, as are ecosystems and animal behaviors. The rate at which the global temperature is rising today is very likely unique in the history of our species.
This kind of sudden change is even very rare in geological history, though perhaps not unprecedented. So the planet may have been through similar things before, that sounds reassuring, right? Well, once you look at the impact similar changes had on biodiversity at the time, the existence of some historical precedent or another actually becomes anything but reassuring. Rapid climate change is the prime suspect in most of the mass extinction events, including the Great Dying some 250 million years ago, in which 90% of all life went extinct.
What we know about ecosystems and what geologic history demonstrates is that dramatic climate changes – up or down or sideways – are a tremendous shock to the biosphere and cause mass extinction events. And that, all in all, is not likely to be a good thing.
This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.
“What’s Wrong With Warm Weather” was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.