Yeah, but they've been doing so for millions of years without any measurable effect upon global climate.

You sure about that? Most likely they are having an extremely measurable effect, it's just the effect is maintaining the status quo. Do you really think that the climate in Africa wouldn't change if forests were permitted to grow? Remember that climate is a complex dynamical process full of feedback loops. If anything, given the size of the landmass, allowing the savannahs to become dense forest would be a huge source of carbon capture.

Also I deny the premise that all climate change is bad prima facie, although again because complex dynamical system it can be impossible to predict the eventual outcomes. Nevertheless, a climate change like greening the Sahara could at least potentially be a net positive for humanity.

The point is that a sudden change in climate can't be blamed on them continuing to do what they've been doing for millions of years.

Now I highly doubt that an elephant occasionally knocking over a tree is the only thing holding back the continent from being forested, especially given that many elephants live in densely forested areas, but if for the sake of argument we assume that their behavior is a major factor, you still need to explain why their behavior, and thus that forcing function acting on the environment, would suddenly change.

> Now I highly doubt that an elephant occasionally knocking over a tree is the only thing holding back the continent from being forested, especially given that many elephants live in densely forested areas

Indian and African elephants are quite different ecologically speaking.

> but if for the sake of argument we assume that their behavior is a major factor, you still need to explain why their behavior, and thus that forcing function acting on the environment, would suddenly change

I never claimed it would suddenly change, I claimed that it's been consistent and has maintained a status quo.

Am I misunderstanding you?