It occurred to me to wonder – given the Second Law of Thermodynamics (‘there’s no such thing as a free lunch’) whether the notion of renewable energy resources vis a vis wind power, wave power, solar might be a myth. The earth’s energy cycle is not exactly a closed system: it’s fed by the sun – energy comes in and some of it is radiated out again – less than used to be because of the greenhouse gases which trap more of it than used to be trapped. OK. But nothing humans can do will alter the amount that comes in. We can only alter the amount we trap. So suppose we aim to trap more via wind power and wave power and solar arrays. That means we are extracting more energy from the climate system than we used to do. The question is – what effect does that have on the climate? And, at what point would the effect become noticeable? I’ve only come across one paper which attempts to address this issue: Climate Impact of Surface Roughness Anomalies – the synopsis of which is far from clear to a non-specialist like me… But I can’t help wondering whether we might not be facing some unintended consequences by extracting energy on a large scale from our climate system.
OK – so looking at a few links from the bottom of the link above – I note that large scale wind farms on land or sea are likely to affect the local weather. How important this might be locally, and how significant it might be for global climate if large wind farms were widely deployed on a global scale, together with, say, wave power, is not apparent from the synopses of the papers. I repeat – unintended consequences anyone?