• Sustainability and Humanity’s Footprint

    This week’s Science is all about sustainability and I wanted to bring on particular article to your attention.

    The article is “Humanity’s unsustainable environmental footprint. To being, let’s run through an analogy. We all have (I hope) retirement accounts of some kind, at the very least, social security. The amount of money you put into that account and take out after retirement is greatly dependent on two things. How long you live after retirement and how much money you need after retirement. Sadly, these things are very, very difficult to estimate.

    One woman, whom I worked with for several years, finally retired at the age of 69. She didn’t live out the rest of the year. My dad, rather foolishly, spent more of his retirement and is now living off of social security and medicare. My mom has saved very wisely (at the expense of some of my teenage years) and now has a VERY nice house, a new car, and money to do whatever she wants, whenever she wants. Not to mention very good health.

    So, there’s no real way to tell just how much you’re going to need when you retire. My 401k company tells me I’m on track to make just a little less during retirement than I make now, which should be OK for me. Of course, if I chose to, I could withdraw more money than my current salary and hope that I die before the money runs out. Or, in anticipation of a longer life, I could withdraw less, life more frugally, and hope for either a longer life or that my children will have more money when I die.

    That sounds like a strange way to talk about sustainability. But it’s pretty close. We have a supply of resources on Earth and we have a budget. Unfortunately, it’s very difficult to determine what those values are, but here are the numbers estimated in this paper (generally by other papers).

    The use of blue water, the surface and ground water resources, exceeds the maximum sustainable values for at least part of the year for half the world’s rivers. Gray water, referring to water pollution, exceeds the maximum sustainable amount in 2/3s of the world’s rivers. Dynamic environments can handle some waste naturally. Wetlands, for example, are excellent sinks for some forms of waste. But we’re over budget.

    We have to talk about global warming here. The current carbon production of 46-55 gigatons per year must be reduced to less than 25 gigatons per year just to keep the Earth from getting two degrees Celsius warmer.

    Material resources are much, much worse. We’re using 70 gigatons per year of natural resources. The estimated sustainable value is between 8 and 10 gigatons per year.

    Land use is another area of concern. We’re using 18 billion hectares, but 12 billion is the sustainable level. At this level we need one and half planets for our population.

    The situation is poised to get worse. As developing countries see the wealth of countries like the US, they want that wealth for themselves. And, honestly, it’s really hard to jump far out into the lead in terms of individual wealth and then declare the race over and no, you may not even catch up. If the rest of the world used resources at the same rate that industrialized nations do, then we would need four or five planets to support all of us.

    Something like 80% of the world’s population lives on less than $10 US dollars per day. That’s less than I pay for my cell phone and internet/TV bills. How’s that for some perspective?

    The ecological footprint (that is how much land it takes to support something) of the average global citizen is 2.7 hectares. The average US citizen needs 7.2 hectares.

    from Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Human_welfare_and_ecological_footprint.jpg
    from Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Human_welfare_and_ecological_footprint.jpg

    Note that this graph shows US citizens at 10 hectares. I also found graphs that show us at 6 hectares. This goes to the point I made about how difficult this is to estimate.

    Another chart by the World Business Council for Sustainable Development shows something else that I want to mention.


    Notice how the bio-capacity for 1961 is almost twice what is for 2007? Going back to the analogy of my retirement. If I take out roughly my present salary from my various retirement accounts, then I can do that for about 20 years. If I take out about half my salary, then I could that almost indefinitely. If I take out more, then the time I can withdraw that amount of money falls rapidly.

    If we were had started using resources at a sustainable level  in 1961, then the world could have supported everyone at an average of 3.8 or so hectares per person. But instead, between 1961 and 2008, resource use more than doubled. Now, having used a big chunk of our nest egg, even if we move to total sustainable levels of everything, the Earth can’t support us at the level from 1961.  Now, it’s much lower, according to this chart 1.9 hectares per person.

    Yes, these charts and the paper have different values for all of this. They aren’t that different though. And the one thing that they all show is that we (and I mean all humans on the planet) are using way too many resources.

    The solution is going to be unpleasant. It means that we can’t live like we do now. We can’t bring the developing nations up to our level of resource use and we have to bring our own levels of use down considerably.

    The paper suggests some things

    —include replacing animal with crop products (40, 41), reducing food and other waste (40), saving energy at home  and in transport (42), and buying second-hand, recycled products and low-footprint, dematerialized “services” rather than primary-material–based goods (39). However, such behavioral changes are difficult to
    achieve in reality because of social constraints and lock-ins (43).

    Of course, even doing all of those things, we will probably fall into the trap that we have historically fallen into. We get more and more efficient, but instead of keeping at the same level, we use that efficiency to give ourselves more.  Instead of consumption levels decreasing, they increase. Electricity costs 5 cents instead of ten cents, run that AC all day and all night, instead of leaving it at 79 all the time.

    The authors say it best here

    Profound, effective, socially accepted, and long-lasting changes as required for a truly sustainable transition have yet to occur.

    I do think that we are getting better. The reality of global warming seems to have reached the majority of the US, even if our so-called leaders try to ignore it. People are trying to be more efficient. Most cities have recycling programs now where even ten years ago, most did not. There is a larger push for electronics recycling instead of just tossing it in the trash*.

    Communities are coming together to reduce water usage and support renewable, non-polluting energy. The costs and efficiencies of renewable energy are roughly equivalent to the fossil fuels they are trying to replace.

    Once we get a national movement to more sustainable forms of electricity and accept that GMOs are about the only way we’re going to be able to feed everyone on the planet (especially as we get closer to that 2 degree C temperature increase), then we’ll begin to make real progress.

    Of course, there is the possibility that science and technology can come to our rescue. Perhaps we can find a way to easily and cheaply remove carbon dioxide from the atmosphere (as can be done with nitrogen oxides, which cause smog).

    Perhaps we can add resources from asteroids. The Earth is not a completely closed system (as solar energy proves), but there are additional sources of metals and elements out there in our solar system. It will be some time before we can move and extract them, but that time (I hope) is coming.

    And, as I mentioned, using our knowledge of genetics to craft food crops that are suited to the environment (as we have been doing through artificial selection for millenia) in order to make the best use of available land. Keeping in mind that we’re going to lose a big chunk of that land over the next 100 years.

    This is a good paper and I think it should be much more widely circulated. (So please share this.) There are people that we just will not be able to get to understand that they can’t just buy a new car every two years. But, 50 years ago, there wasn’t anyone willing to let homosexuals marry. Today about half the states allow it and all the rest of them are being challenged in court.

    We can do this. We have to do this. I have a kid and I want him to have something left.


    Hoekstra, A. & Wiedmann, T. Humanity’s unsustainable environmental footprint.Science 344, 11141117 (2014).

    * Man, if I could figure out a way to extract useful metals from landfills, I’d be a bajillionaire.

    Category: CultureEvironmentfeaturedScienceSociety


    Article by: Smilodon's Retreat