Dear Evil Engineer: How many leopards do I need to heat my home?

The Evil Engineer weighs up the environmental credentials of carnivorous domestic heating systems.

Dear Evil Engineer,

I am frustrated by the lack of leadership on climate action, particularly regarding low-hanging fruit such as boosting the energy efficiency of housing stock. I ask myself: what can I do to prevent the Earth becoming uninhabitable through climate change?

Before anyone makes any snide comments; it goes without saying that I want the Earth to become a hostile wasteland scattered with the remnants of the humanity. But I want to do it myself and not let the fossil fuel industry claim the greatest honour in villainy since someone threw a meteorite at Mexico 66 million years ago. I want to be evil and green, like the Grinch before his heart grew three sizes.

This leads me to my query: I have two fearsome pet leopards and I was already considering buying more. How many would I need if I wanted to heat my pleasant two-bed semi entirely with leopards?

Yours,
A conscientious villain