That only works for a limited amount of time though. E.g. the London tube has warmed the rock around it by a very considerable amount. https://www.citymetric.c

That only works for a limited amount of time though. E.g. the London tube has warmed the rock around it by a very considerable amount. https://www.citymetric.com/transport/londons-tube-has-been-running-so-long-its-literally-raising-temperature-earth-around-it https://www.citymetric.com/transport/londons-tube-has-been-r...