Monday, May 14, 2012

Energy use

So this is a graph of per capita energy use in several countries. Fairly consistent over the last 40(!) years and the US is fairly consistenly twice the height of the other countries. I'm having trouble getting good per capita breakdowns of US energy consumption, but I can find it for the UK (who consume about half as much energy as the US) here: Sustainability Without the Hot Air.

85% of the energy in the US (90% in the UK) is from fossil fuels. I think perhaps the US figures need to be taken with a grain of salt because I don't know of any compelling reason the US numbers would be twice that of those other countries (though roughly on par with Canadians - not shown on graph). A good guess might be energy-intensive industries plus more travel plus more HVAC. Here is an estimate of how an affluent UKian spends their energy: Energy Expenditures. I have seen a couple actual charts at times for the US and UK - I can't find them now - which have about the same breakdown - but empirical rather than estimated. If you want something that's not per capita, the entire system can be seen here: http://en.wikipedia.org/wiki/File:LLNL_US_Energy_Flow_2009.png

And then there's a broad discussion of US energy use on the wikipedia page: Energy in the United States. Residential use and transportation are the two things we can directly change. The lion's share of residential energy consumption is HVAC.

I bring this up because it's important. We need to significantly curtail energy consumption and aggressively invest in "green" energy. Fossil fuels, which provide 85% of our current energy, are a finite dwindling resource with a significant environmental cost and abundant replacements are far on the horizon - almost too far. Merely replacing current capacity will be difficult, much less keeping up with population growth and growing energy demands (both in the US and in developing countries). Meanwhile, climate change is real and will be catastrophic: there may not be enough time to wean ourselves off fossil fuels in time to prevent severe economic and environmental catastrophes.

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