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Limits On Growth of Energy Use and Economies

snoop.daub writes "Dr. Tom Murphy, professor of astrophysics at UCSD, has a new blog called 'Do The Math,' and the first few posts are doozies. In the first, he shows the impossibility of continued exponential growth in energy use. Even if a new, 'free' energy source is developed, thermodynamic limits on efficiency mean that the heat associated with converting this energy into useful work will increase the temperature of the earth to unbearable levels within 300 years. In the second, he extends the argument to economic growth. The timescales there are faster, only 50-100 years. Fascinating stuff. Time to stop breeding, folks, or to get our butts into space."

11 of 482 comments (clear)

  1. Simple by LoRdTAW · · Score: 4, Funny

    Since we have an abundance of energy we can simply turn our air conditioners backwards and cool the earth back down.

  2. Re: I love this by Dunbal · · Score: 4, Insightful

    Denial is a powerful instinct. You can tell them the ship went aground a long time ago, and they still won't believe it.

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    Seven puppies were harmed during the making of this post.
  3. Endless growth is impossible by MpVpRb · · Score: 4, Insightful

    You don't need a PHD or a complex study, just common sense.

    Why do so many people in finance continue to insist on growth?

    We should be focusing on steady state sustainability.

  4. Read "The Party's Over" (Heinberg) by stereoroid · · Score: 4, Interesting

    I'm almost all the way through it. Very sobering stuff, only a few bits I have quibbles with. Or, if you don't have the time, read the synopsis.

    The point about the assumption of growth is an important one. The world's financial systems are built on that assumption i.e. anyone who lends money expects to make a profit on the loan, after inflation if applicable. That's true of all loans, from the smallest micro-loan to the trillions in sovereign debt owed by the USA.

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    (this is not a .sig)
  5. Re:He misses one HUGE assumption by Dunbal · · Score: 4, Insightful

    No, you're simply claiming perpetual technological growth to compensate for physical limits. At some point you hit diminishing returns - even with technology. Compare a Pentium III from 10 years ago to a Quad Core i7 from today. Yeah today's machines are faster and have more memory - but not stunningly so. In fact, there's not so much difference between the machines as a 1977 XT with 128k, a tape drive and a monochrome monitor and a 1987 80386 with megabytes of memory, megabytes of hard disk space, a VGA monitor, sound card, multitasking, etc. Now leap forwards to 1997 and your Pentium II... better but only incrementally so.

    You could argue that this scenario is specific to computers but it's not. This is why you don't have your flying car. This is why life expectancy has shot up from 50-odd years to the seventies and is hovering there. This is why cancer patients live longer free of the symptoms of their disease, but the overall mortality of their disease hasn't changed much. There are hard limits to technology, too. It would be foolish to ignore them.

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    Seven puppies were harmed during the making of this post.
  6. Re:No One by turing_m · · Score: 5, Insightful

    The yeast in the bottle of grape juice said the same thing too.

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    If I have seen further it is by stealing the Intellectual Property of giants.
  7. Re:He misses one HUGE assumption by artor3 · · Score: 5, Insightful

    The difference is that his statement is based on natural laws, rather than assumptions about the source of the energy. Unless the fundamental laws of thermodynamics turn out to be wildly incorrect, his statement will stand.

    Denying this by claiming that technology will always improve is like denying that there's an end to Moore's law. Yes, we've been able to find ways to keep it going so far. But by 2150, some quick math says that transistors would need to be smaller than the Planck length. It requires some serious magical thinking to believe that not only will we reach that target, but that we'll be able to keep making them even smaller than that!

  8. Club of Rome (1972, 2004) by Anonymous Coward · · Score: 5, Informative

    MIT was commissioned decades ago to study the 'Limits to Growth' by the Club of Rome. The created a simulation and published a description of their efforts in 1972. Then updated the program and its parameters 30 years later and published again. It's very interesting. The authors made it accessible and understandable. The conclusions are not what you might expect, especially if you are just itching for an argument like so many here seem to be.

    Man has become the dominate actor in the natural global system, and we have choices to make regarding our future. We can seek to understand our cumulative effect or we can bungle in what's left of jungle, fiddle while home burns or just party like it's 1999. If you're interested enough to read a grown up book, here's a chance.

    Limits to Growth: The 30-Year Update

  9. Re:He misses one HUGE assumption by AthanasiusKircher · · Score: 4, Informative

    No, exponential means that the advances would be getting greater and greater over time. You're confusing the popular expression of "exponential" with the real one.

    Um, no. You're the one who's confusing meanings. A number of elements of computer technology actually show true exponential growth (according to the mathematical definition), and have been for decades.

    Now, whether or not our generally inaccurate human perceptions sense that growth accurately, or whether the technology advances in ways that make that growth visible are different questions. But the growth pattern in a number of aspects of computing hardware actually has been exponential.

  10. Re:No One by wrook · · Score: 5, Informative

    I wonder if anybody on Easter Island ever said, "Hey guys. Do you think we might be running out of trees?" But you know, after the fact I'm sure they were all like, "Oh man. Yeah, you were right. Now that we're all dead I can see that putting up idols for the gods was not as effective as managing our forests would have been."

    The funny thing is that Japan was heading in the same direction. By the beginning of the Edo period, the people there were at very high risk due to deforestation. A general ban on logging was put in place and it literally saved Japan from destruction.

    If you bother to look, there is quite a large list of civilisations that have wiped themselves out due to exhausting their resources and degrading their environment. The list of civilisations which understood their predicament and did something in time to save themselves is pathetically small.

    I often wonder what list we'll be on.

  11. Re: I love this by magarity · · Score: 4, Informative

    "As it currently exists, if we were to take 100% of the income from every American today, it would not pay off the national debt. "

    False. but hey, I don't really except anyone to understand what the national debt actual is.

    OTOH, that line did spare me from reading the rest of your post, since It is probably as accurate.

    Which part did you think was false about those numbers?
    Federal debt (not to mention state debt) is 14 T
    Total personal income in 2010 was 12 T