Is there an economic case for tackling climate change?

What is the economic case for tackling climate change? And if that case can be made, what's the best way of going about it?

And, yes, this is all based on the assumptions that policy makers are taking with them to the Paris conference: that the climate is warming due at least partly to human activity and it is possible to slow or halt that process.

Economists have been wrestling with the question since at least the early 1980s.