[thedoc (OP)]

Maria Davey asked the Naked Scientists:
   I want to know how much we are contributing to global warming and extreme weather by producing electricity heating water to steam, as opposed to solar and wind generation.

Electricity generated by fossil fuel or nuclear plants also generates heat.  Solar generation presumably involves absorbing heat, while wind turbines presumably absorb kinetic energy.


What do you think?

[chris]

It is certainly true that heat-generating processes, whether that's industry, transport, domestic or commercial activity, will have a warming effect - this is why cities are always a few degrees warmer than the suburbs or rural settings. These are dubbed "urban heat islands". That the energy powering the process also leads to an atmospheric CO2 increase delivers a double whammy, because that CO2 will also exert a greenhouse effect and trap more heat.

[chiralSPO]

Yes, but barely.

The sun supplies us with almost 10,000 TW of power. In contrast, of our entire civilization currently uses less than 20 TW. Even if all of it ends up as heat it would only heat the Earth at 1/500th the rate as the sunlight does.

The real root of climate change is the difference in the rate that energy can leave the Earth.