The answer has the sign wrong. It would be a source of energy.<p><a href="https://www.theworldcounts.com/challenges/climate-change/energy/global-energy-consumption" rel="nofollow noreferrer">https://www.theworldcounts.com/challenges/climate-change/ene...</a> says “The annual global energy consumption is estimated to 580 million terajoules”, so that’s about 6E20 joules.<p>So, there’s enough energy there to power the world for 400 million years.<p>(<a href="https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)</a> has 5×10^20 J, respectively 2.1×10^29 J, agreeing with that)<p>Now, about extracting it…