greg's Comments

Do we understand the long-term impacts of using geothermal energy? Will development at huge scales interfere with planetary processes? If this sounds like a nutty thing to even ask, imagine telling a British industrialist 170 years ago not to burn coal because he might change the weather.

I think using geothermal energy may be a necessary response to climate change. I would like to see more discussion of potential effects of massive scale geothermal energy extraction, and I would like to have it stop being referred to as "renewable."

Our system of interest is Earth. Any energy source restricted to that system (the planet) is locally finite and, by definition, not renewable. Renewable energy is, therefore, energy whose source is extraterrestrial, including the sun and its derivatives (wind, waves, hydro-dams...).

It may seem a semantic distraction, but I think the language matters.