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How to Survive a Climate Catastrophe

The views expressed are those of the author and are not necessarily those of Scientific American.


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It happened before. Well, not quite this rapidly, but about 55 million years ago (to geologists, the recent past), Earth experienced an explosive rise in temperature. Through the investigative science of paleontology, we can reconstruct a world where tropical flora flourish at the poles and the world is rocked by mass die-offs – that is, the world that the Intergovernmental Panel on Climate Change predicts as the “worst-case scenario” by 2100.

Six degrees Celsius may not sound like a catastrophe, but that only tells part of the story. Most of the world can at least apportion its heat, but warmer currents converge on the poles with a particularly vicious effect. Normally, the white icecaps reflect much of the sun’s energy (objects appear to be a certain color because of the wavelength of light they reflect back at us, and white light is what we see when every color is reflected back). However, as they melt, there is less white and less reflection of solar energy back to space, resulting in accelerating melting.

All this warmer, fresh water floods into the global ocean and helps to heat it up even more than the sun beating down on it could do alone. At this point, the temperature rise can be tracked in the type of oxygen that microscopic marine drifting organisms use to build their chalky exoskeletons. Elements like oxygen come in multiple versions, called isotopes, which are the same element but are sometimes heavier or lighter, and this can be examined in the fossil record.

Normally, the drifters ‘prefer’ the heavier version of oxygen, but when the ocean heats up, the lighter version is more accessible because it gets moved around more easily. Fossil drifters show that around 55 million years ago, there was a spike in light oxygen being taken up by drifters, and thus a spike in temperature.

Foraminifera like this one are at the base of the ocean's food chains — and are highly susceptible to climate change. Photomicrograph by Scott Fay.

Foraminifera like this one are at the base of the ocean's food chains — and are highly susceptible to climate change. Photomicrograph by Scott Fay.

The Paleocene-Eocene Thermal Maximum (PETM), as scientists call it, was a shocker to the Earth. Up to one-half of all species of foraminifera (a kind of drifter that makes its skeleton of chalk and usually lives on the seafloor) went extinct, triggering a probable collapse of the marine food chain. In parts of rural Montana you can still clearly see a sudden layer of red clay in the sedimentary record. That clay is important because it shows what’s missing: usually, the skeletons of foraminifera blanket the sediment, but in their absence, the clay is all that’s left.

A lot of these effects are not in fact due to the rising temperatures, but instead are another side effect of the injection of carbon dioxide, or CO2, into the atmosphere. When plants are exposed to heightened CO2 levels, they are much more productive – but they lose out in protein payoff per kilogram! Land animals shrank in size, because when protein is hard to come by, natural selection favors an animal that can survive on less. The fossil record attests to everything from dwarf condylarths (strange mix-‘n’-match mammals that have been called “sheep in wolves’ clothing”) to even insect burrows getting skinnier. Meanwhile, nutritionally deficient tropical plants expanded their range, pushing out local competition and disrupting ecosystems around the world.

The exact cause of the PETM is still a mystery, although several very knowledgeable fingers have been pointed at a release of methane locked up in ice at the bottom of the sea. Methane, like carbon dioxide, is a greenhouse gas that traps heat in the Earth’s atmosphere and helps to keep the Earth hotter. Both of these gases are currently being emitted at record levels by human activity, and correspondingly the Earth has been heating up, as a global average, to a record high. It’s happened before, and it might happen again – but this time it would be our fault, and our problem.

Some might have noticed that the Earth seems to have gotten over the last event pretty much fine. Why should this be any different, the hecklers in the audience demand. Last time, organisms moved and populations adapted. The Earth’s inhabitants are usually good at that. Not us. As a species, we humans want to live wherever we want, eat whatever we want, and live our lives however we want. That just won’t work. We must react or die. According to the latest data, the concentration of CO2 in the atmosphere hit almost 400 parts per million. The Intergovernmental Panel on Climate Change has endorsed 350 parts per million as a sensible upper limit. If we want to avoid an apocalyptic scenario, emissions must be reduced and minds shifted toward the ultimate goal of saving everything we know and love on this planet for both ourselves and future generations.

Luckily, there is still hope. That hope is you. That hope is in lessening our dependence on burning fossil fuels for energy. That hope is in conserving our resources and ensuring that there is enough to go around. That hope is in lobbying our governments and standing up to our corporations. That hope is in human resilience and ingenuity that I trust will manifest itself, but that hope is also the little things we do every day. Our little choices – the decision to turn off that light or forgo that hamburger or save that plastic bag – constitute a sum greater than their parts. They constitute the solution. Now that we understand the past and can more clearly see the possibilities for the future, there is one part left: to take the present into our hands.

Zev Brook About the Author: Zev Brook is a student entering the 12th grade at Lowell High School in San Francisco whose passion for science has not flagged since he learned the word paleontology at age 5. He intends to pursue a career in paleosciences, which includes his interests in the evolution of extinct organisms and the world they lived in. Contact him at z (at) brook (dot) com.

The views expressed are those of the author and are not necessarily those of Scientific American.






Comments 14 Comments

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  1. 1. Asteroid Miner 4:00 pm 07/17/2013

    Sorry, Zev Brook. Hope is not the little things we do every day. Hope is getting a positive attitude toward nuclear energy. The decision to turn off that light or forgo that hamburger or save that plastic bag will never shut down a single coal fired power plant. Neither will wind or solar power; they are too intermittent. Natural gas fired power plants don’t help either. The only one that actually works is nuclear. We can shut down fossil fueled power plants by converting to nuclear.

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  2. 2. jonhuie 4:24 pm 07/17/2013

    1. Saving plastic bags isn’t going to save us. Ever increasing overpopulation is the fundamental problem. Until we cap population worldwide, and begin to reduce population, the our environmental catastrophes will only get worse.

    2. It is already too late to prevent human-caused climate change. Our grandchildren will need to migrate 3 billion people away from low-lying areas.

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  3. 3. Zev Brook 4:36 pm 07/17/2013

    Asteroid Miner, my opinions on nuclear energy match the conclusions of the IPCC’s Fourth Assessment Report. I’ll quote the relevant passage: “Nuclear energy, already at about 7% of total primary energy, could make an increasing contribution to carbon-free electricity and heat in the future. The major barriers are: long-term fuel resource constraints without recycling; economics; safety; waste management; security; proliferation, and adverse public opinion.”

    Jonhuie, your first point is basically accurate. Population is the underlying problem, but using less resources per person will still help mitigate the effects. As for your second point, we don’t know if that’s true. If it is true, nothing we do will have much of an impact, but if it isn’t true, the future is in our hands. The logical choice is to do what we can within reason to save our planet, just in case it might make a difference.

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  4. 4. Owl905 10:19 pm 07/17/2013

    The PETM disruption, 6dC and acidification strong enough to wipe out a layer of the food web, is smaller than the disruption from human GHG pollution. The PETM transpired over a 20,000 year period. Like the Permian extinction’s 10,000 year aftermath, conditions on Earth worked against life and the biosphere shriveled. But it was a pressure and a process, not an event.
    Today’s disruption is happening at a pace 50 to 100 faster than the PETM. The few hundred years it will take to cause near-permanent carbonization of the biosphere is a pace that is closer to the meteor event that sealed the fate of the Mesozoic World.

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  5. 5. stargene 11:41 pm 07/17/2013

    Good article. I just want to point out the seldom
    noted fact that when good science papers (popular
    and professional both) say things like, “probable”
    “may” or “might” and other such qualifications, they
    reflect the ongoing attempt by scientists and science
    writers to be honest and forthright about existing
    uncertainties in both data and interpretation of that
    data. Scientists know exactly what is meant by this
    reference to uncertainty and that it is crucial in
    good science. However, it puts real science and scientists at an extreme disadvantage in the larger public conversation, where politicians and industry
    feel gleefully under no obligation to temper their counter-claims whatsoever.

    When the public arena is dominated by these latter
    agencies and their media, words like “uncertainty”
    “perhaps” and so on, lend themselves to the lay
    person’s conclusion that “they don’t know anything
    for sure, so why should we worry when we are already
    on overload just trying to bring home the bacon?!”

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  6. 6. sault 12:34 am 07/18/2013

    Owl, don’t forget that it took 30 MILLION YEARS for the Earth to get back to the biodiversity it had before the End Permian Mass Extinction. When we mention our species’ name, we need to start putting quotation marks around the “sapiens” part!

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  7. 7. moss boss 1:26 am 07/18/2013

    Where are Carlyle and Sisko?

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  8. 8. vittoriotomasi 3:50 am 07/18/2013

    The precautionary principle although not easy to define , includes considerations based on our experience and on what reported by others which limit or change our actions. This principle can be correctly applied to nuclear energy. Can we forget what happened at Cernobyl ,then at Fukushima and more recently even in the most controlled state as Swirtzerland? When applied to fracking the principle works also well. If fracking side effects are limited to the increase in methane emission and to problems of water contamination ,I think the enormous economical advantages creating also milions of jobs , should overcome precautionary Principle. But when scientists on Science tell us that fracking can be connected to earthquakes , the principle stars to gain momentum. I think that this connection is so difficult to accept that many more investigations have to be presented to us.

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  9. 9. jonno 4:27 am 07/18/2013

    Did radiation from a nuclear power plant kill somebody in Switzerland? It didn’t at Fukushima. Consider that our current CO2 levels are liable to flood all the areas inundated by the Japanese tsunami, not just for a short time but for ever, and every other coastal area as well. Compared to that, a Chernobyl every month would be nothing, and fossil fuel smoke is killing more people than that already.

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  10. 10. lemonchiffon 9:35 am 07/18/2013

    Zev, this article is very well-written. I look forward to hearing more from you in the future.

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  11. 11. Zev Brook 7:09 pm 07/18/2013

    Thank you, stargene and lemonchiffon. I certainly hope that you’ll be hearing more from me as well!

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  12. 12. Dr. Strangelove 10:56 pm 07/18/2013

    It wasn’t an explosive rise in temperature. From 100 to 55 millions yrs ago, global temperature was pretty stable at 20 C. It’s hard to compare the biodiversity millions of yrs ago vs. today. In the past, tropical flora flourished at the poles. They disappeared in the ice age. Does it mean warm climate is good for life? BTW we are still in an ice age. 550 million yrs ago, global temperature was 22 C and atmospheric CO2 was at 7,000 ppm. Surely that would be catastrophic by today’s standard (IPCC recommends 350 ppm). But, on the contrary, life flourished. It was the greatest explosion of life in earth’s history – the Cambrian explosion.

    Warm climate and CO2 good for life? Well, we know plants need CO2; we put plants in greenhouses to grow; the greatest biodiversity is found in the Amazon rainforest – a tropical warm climate; less biodiversity in the cold polar region – Antarctica, Greenland, Siberia, Iceland. Of course humans are not plants and we don’t inhale CO2.

    Yes let’s conserve energy. Ride a bicycle, put solar panel, use LED light, I don’t understand the hamburger. I like hearing from 12th graders. The article is good.

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  13. 13. Dr. Strangelove 2:57 am 07/19/2013

    BTW the methane hydrate hypothesis cause of PETM has been discredited by Thomas et al. The carbon isotope anomaly happened too fast compared to the 10,000 yrs predicted by the hypothesis.

    PETM was not a mass extinction event, defined as extinction of over 50% of animal species. PETM was an extinction of forams, which are not even classified as animals. They belong to the kingdom of protist.

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  14. 14. Dr. Strangelove 3:42 am 07/19/2013

    During the PETM global temperature increased by 6 C over 20,000 yrs and atmospheric CO2 was 1,000 ppm. Very rapid warming indeed. This ought to be catastrophic. Instead, planktons and mammals bloomed consistent with previous correlations in geologic history between warm climate, CO2 and life. Primates appeared and spread throughout the world. One can argue, if not for PETM and rapid warming, humans will not be here today debating global warming.

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