Comment by 300bps | Hacker News Reader

Comment by 300bps | Hacker News Reader

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Cool visualization.

I agree, but I have to say their imagination on what other things might be causing warming is not very robust. For just one example, there are at least two major effects of burning:

1. Release of chemicals into the atmosphere (ex: carbon dioxide)

2. Directly heating the atmosphere

There are literally billions of air conditioners, heaters, cars, factories, etc that all generate heat. The effect of these billions of heaters throughout the world definitely increases global temperatures. After all, this effect is a reason why cities are warmer than their surrounding rural areas (1). This is relevant because direct heating should be temporary while greenhouse gas increases are cumulative.

Honest question - has anyone calculated the effect of the direct heating on the atmosphere from the billions of heaters we use vs greenhouse gas increase?

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(1) http://www.smithsonianmag.com/science-nature/city-hotter-cou...

The primary yearly energy consumption is about 155,000 TWh and the volume of the ocean is around 1.33e9 km^3, so back of the envelop, the heat dissipated by energy consumption yearly is enough to raise the temperature of the ocean by 0.0001 C. Doesn't seem very substantial.

> this effect is the reason why cities are warmer than their surrounding rural areas.

Anthropologically produced heat is certainly a contributor, but as the article itself says, I believe the majority of the difference is more accurately attributed to the large amount of concrete in cities which takes much longer to dissipate heat.

They did the math already. The amount of directly released human heat is a drop in the bucket.

I would love to see it if you have a source.

EDIT Thank you.

http://www.skepticalscience.com/Waste-heat-vs-greenhouse-war...

This doesn't add much to what earlier respondents have said, but it was five minutes of fun to do.

The mass of Earth's atmosphere is about 5e18kg. Specific heat of dry air is about 1kJ/kg-°K. Total human energy consumption in 1990 (just to pick a year) was about 102,000 TWhr (3.6e20 J/TWhr. Wikipedia for most of the numbers.

Assuming all the energy consumed resolved into heat and only heated the atmosphere, then I get the one-year temperature increase due to human energy use during 1990 as about 0.073°K.

Less than I would have guessed, and probably wrong by at least a couple orders of magnitude due to simplifying away 99% of what's really happening.

What about the heating caused by ~7.5 billion humans? Collectively, we consume ~13 trillion calories, or (IIRC) enough heat to vaporize a 4-cubic mile block of ice, every day.

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