The other night I watched the David Attenborough film and it made me think. First I tried to persuade my wife that we should buy a Tesla but it looks like it might end up being more at the, not so smart, Smart car end of the market. Anyway, I was wondering if the real problem is energy consumption rather than just burning fossil fuels. All the enrgy we use ends up as heat and that has to be radiated which leads to an increase in temperature, maybe buying a Tesla isn't the answer.

I looked up how much heat we would need to produce to give a 1℃ rise in temperature. I found Mother Earth News 5 x 10¹⁸J. That didn't tell me much. The Earth recieves 1.8 x 10¹⁷ W from the sun, This is all radiated out at the present temperature of about 290K (simple model). The power radiated is proportional to T⁴ (Planck) so an increaseof 1K would mean an increase of power to 1.82 x 10¹⁷ W, an increase of 2 x 10¹⁵ W. So how much power do we use?

yearbook.enerdata.net about 15,000 Mtoe per year. what's an Mtoe? Million tonnes of oil energy = 4 x 10¹⁶ J, that's an average power of 1.9 x 10¹³ W. For the Earth to radiate this it would have to be about 0.01 K hotter and that's not enough.

What about all the people each producing 100 W? That's only 7.8 x 10¹¹W. All the farm animals? 15 billion cows, let's say 500 W each, that's 7.5 x 10¹² W, still not enough but it all adds up. Well at least all the wild animals we are forcing into extinction will not be producing any heat.

Conclusion: It's CO₂ not energy use that is the problem, order the Tesla.