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Comment by throwaway5752 | Hacker News Reader

You can mock this, but the data doesn't care what either of us think.

Current Mediterranean water temps are +6C above normal, as observed over peak human civilization in the 20th century. That is 6kWh per cubic meter, in just the Mediterranean. The article briefly mentions this extending 30m down.

To give the order of magnitude of the energy involved, the Mediterranean surface area is 2,500,000,000,000 sq m. At 6kWh cu m and 18m deep, that is the energy equivalent of about 390,000 megatons. Or about 8,000 Tsar Bombas. The Mediterranean is small, about 0.7% of ocean surface area.

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I still have no clue at all how much a Tsar Bomba is in the context of the climate.

270Trillion kWh is about 1.5 × the total energy from the sun that hits the earth in one hour. I'm not sure if that helps, and the trillion-kilo is kinda gross.

50 megatons is more on the order of 270 trillion kilojoules, not kilowatt-hours (factor of 3600 difference).

1 Tsar Bomba (50 MT = 2e17J) is about 1/28,000,000 of the total solar power delivered to Earth annually, so about 1.4 seconds of top-of-atmosphere solar power (~1.5 million PWh / year).

On the other hand, it roughly equals 1/2000 to 1/3000 of annual global energy consumption (~175 PWh / year) so about 4 hours of human energy.

The energy of those 8000 Tsar Bombas in the Mediterranean then is the same as all of human energy, electrical and fossil and otherwise, going to heating up that sea for a little over 2 years straight, or focussing all sunlight over the disc of the Earth on it for 3 hours.

(All these figures depend on who you ask as all the figures are a little bit fuzzy).

It also shows that any key to climate change revolves around adjusting the modulation of insolation and/or retention - the actual energy used by humans is, for the forseeable future, completely irrelevant except on local scales like warm water outflows into rivers and seas.

Plants and any organisms in photosynthesis-dependent food chains may have issues with modifying the degree of insolation.

Also, again, the Mediterranian is 1/100-1/200th of global ocean surface area. And we have melted a lot of ice cap/glacier mass. The latent heat of fusion of water is very large, also.

Long term, insolation and retention are important, but short term we are reaching the limits of the "Free Ride" portion of climate change where energy sinks absorb the additional delta created by the CO2 induced greenhouse effect.

edit: the tsar bomba was to try to make it tangible, as people don't understand these orders of magnitudes well.

The point is not that "we're not fucked" (we probably are pretty fucked). Just that Tsar Bomba yield, like basically any amount of energy directly generated by human endeavour, is a pretty irrelevant unit of energy when talking about the climate because they are on a completely different scale.

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