I just exchanged email with a climate scientist at the University Of Washington. I was curious as to how much global energy production impacts global temperature rise. All energy eventually shows up as heat.
He said relative to greenhouse gases total energy production accounts for about 2%.
I wasn't sure of this and felt like trying to check it on the back of an envelope.
I don't think it's true that ALL energy becomes heat, at least in the near-term. What about energy used to create high-enthalpy substances? What percent of man-produced energy does end up as heat? Call it 60% for now.
Earlier in the thread I noted that the oceans warm by about 10 Zettajoules per year; a large majority of global warming's heat ends up in the oceans. Elsewhere I read that humans consume about 90 million barrels of petroleum per day; round that off to 0.2 Zettajoules per year. Petroleum supplies about one-third of man-used energy (most of the remaining two-thirds is also carbon-based); call it 0.6 Zettajoules total, or about 5% of global warming. If only 60% ends up as heat, that would be 3% — much closer to the professor's number than I'd hoped for, given my back-of-the-envelope and with only one-sig-fig numbers.
What percent of man-made energy DOES finish as heat in the near-term, ignoring plastics etc. that won't degrade for many centuries? Is it indeed close to 100%?