Wednesday, April 16, 2014

Near-Term Human Extinction

Global Warming and Feedbacks

Is there a mechanism that could make humanity go extinct in the not-too-distant future, i.e. within a handful of decades?

Most people will be aware that emissions due to human activity are causing global warming, as illustrated by the arrow marked 1 in the image on the left. Global warming can cause changes to the land, to vegetation and to the weather. This can result in wildfires that can in turn cause emissions, thus closing the loop and forming a self-reinforcing cycle that progressively makes things worse.

Furthermore, less forests and soil carbon also constitute a decrease in carbon sinks, resulting in carbon that would otherwise have been absorbed by such sinks to instead remain in the atmosphere, thus causing more global warming, as illustrated by the additional downward arrow in the image on the right. In conclusion, there are a number of processes at work that can all reinforce the impact of global warming.

Emissions can also contribute more directly to land degradation, to changes in vegetation and to more extreme weather, as indicated by the additional arrow pointing upward in the image on the right. A recent study by Yuan Wang et al. found that aerosols formed by human activities from fast-growing Asian economies can cause more extreme weather, making storms along the Pacific storm track deeper, stronger, and more intense, while increasing precipitation and poleward heat transport.

Accelerated Warming in the Arctic

Similar developments appear to be taking place over the North Atlantic. Huge pollution clouds from North America are moving over the North Atlantic as the Earth spins. In addition, the Gulf Stream carries ever warmer water into the Arctic Ocean. As the image below shows, sea surface temperature anomalies at the highest end of the scale (8 degrees Celsius) are visible off the coast of North America, streching out all the way into the Arctic Ocean.

As said, feedbacks as are making the situation progressively worse. Feedback loops are causing warming in the Arctic to accelerate. Warming in the Arctic is accelerating with the demise of the snow and ice cover in the Arctic, and this is only feedback #1 out out many feedbacks that are hitting the Arctic, as described in an earlier post. As the temperature difference between the equator and the Arctic decreases, the Jet Stream is changing, making it easier for cold air to move out of the Arctic and for warm air from lower latitudes to move in (feedback #10).

Abrupt Climate Change leading to Extinction at Massive Scale

The danger is that, as temperatures over the Arctic Ocean warm up further and as the Gulf Stream carries ever warmer water into the Arctic Ocean, large quantitities of methane will erupt abruptly from the seafloor of the Arctic Ocean, adding a third kind of warming, runaway warming resulting in abrupt climate change, and leading to mass death, destruction and extiction of species including humans.

Persistence of such a progression makes it inevitable that the rest of Earth will follow the huge temperature rises in the Arctic. Massive wildfires will first ignite across higher latitudes, adding further greenhouse gas emissions and causing large deposits of soot on the remaining snow and ice on Earth, with a huge veil of methane eventually spreading around the globe. The poster below, from an earlier post, illustrates the danger.

[ click on image to enlarge - note that this is a 1.8 MB file that may take some time to fully load ]
Views by Contributors

How likely is it that the above mechanism will cause human extinction within the next few decades? What views do the various contributors to the Arctic-news blog have on this?

Guy McPherson has long argued that, given the strengths of the combined feedbacks and given the lack of political will to take action, near-term human extinction is virtually inevitable.

In the video below, Paul Beckwith responds to the question: Can climate change cause human extinction?

Further contributors are invited to have their views added to this post as well. While many contributors may largely share Paul Beckwith's comments, it's important to highlight that contributors each have their own views, and this extends to their preference for a specific plan of action.


One of the more controversial issues is the use of geo-engineering. Guy McPherson doesn't believe geo-engineering will be successful. In the video below, Paul Beckwith gives his (more positive) views on this.

I must admit that the lack of political will to act is rather depressing, especially given the huge challenges ahead. So, I can understand that this can make some of us pessimistic at times. Nonetheless, I am an optimist at heart and I am convinced that we can get it right by giving more support to a Climate Plan that is both comprehensive and effective, as discussed at


  1. (Submitted in two parts as too long for one)

    The idea that geoengineering will spare humanity from climate change-induced extinction is not merely a bad idea because it relies on untried magic technologies…it also exemplifies the massive failure of climate change scientists and activists who are missing the forest for the trees in a much more fundamental way.

    Climate change is only ONE symptom of human overshoot. It is a very serious one, perhaps even the most serious, but it is not the only problem or even the root problem. If climate change did not exist as an issue, humanity would still be on a collision course with catastrophe - ecopocalypse so extreme that even if there are a few straggling survivors, they will envy the dead.

    A prime example of this myopia is the total neglect, by both climate scientists and environmentalists, of the premature death of trees from air pollution. It is even being ignored by those who should be most directly concerned, foresters and nurserymen. The damage caused by highly toxic tropospheric ozone to vegetation when it enters through leaves and needles has been well understood for decades. The effects of shrinking roots - making plants more vulnerable to drought and wind - and the increased vulnerability to biotic attacks from insects, disease and fungus (all of which are epidemics around the globe) have been documented and replicated in countless research papers, fumigation experiments, and reports from government agencies. The loss of critical annual crop yield and quality from air pollution is well into the billions of dollars and worsening every year.

    Clearly, the ultimate loss of trees will ripple throughout the ecosystem, leading to the loss of countless species that depend on them for habitat, food, shade, and precipitation. Wildfires and landslides and finally desertification will result. The only disaster that compares with this is the parallel collapse of the food chain in the oceans, from pollution, overfishing, acidification and warming. The web of life is unravelling on land and in the sea.

    Climate scientists, rather than accounting for the loss of vegetation as a crucial CO2 sink in the models that predict warming, have actually promoted planting more trees to combat climate change. And it's not that they don't know - I have personally told Hansen, Solomon, Mann and numerous others, and they have chosen to ignore what is patently obvious in a cursory inventory of trees around the earth, requiring only a rudimentary understanding of the mechanisms of ozone injury to plants. It is exactly as simple as smoking causes cancer.

    Prominent activists have decided to be similarly complacent even though, again, I have personally alerted people like Bill McKibben, George Monbiot, Naomi Klein and Chris Hedges to this ongoing, accelerating disaster. Even Guy hasn't added it to his list of amplifying feedback loops!

    Encountering this deliberate obtuseness has taught me to understand (after much reading and thinking) the fundamental reason humanity will not pull back from the brink, despite our very normal desire to believe we can and will make a rational choice to do so.

  2. Part Deux:

    Delusional thinking is hard-wired into our brains as are other behavioral traits, like the need to bond with other humans - a herd instinct to fit in, which is an often unfortunate incentive towards group think. Others are the craving for status (we all seek it even if we label it as something else), and the tendency to use tools to maximize our access to energy. Pattern seeking and the power of the mind to enable us to believe in overoptimistic illusions are basic building blocks of our brains - universal inherent abilities - that haven't changed. Self-delusion enables us to think of ourselves as "good" no matter how violent we are towards others. These properties enabled our species to grow and be tremendously successful.

    Evolution just doesn't happen because a few people can intellectually realize that we're in big trouble. Even those people - climate scientists and activists among them - continue to engage in the same self-destructive behavior that brought us to this point. They can't help themselves.

    There obviously is a huge range in individual behavior, which can clearly be influenced by many things. But when you are talking about the behavior of a species, cultural evolution doesn't matter. The cultures of China and the US are very different. And yet both societies are exploiting the natural environment as fast as possible. In fact they are in a race to see who can commandeer more.

    There is an old adage that the leopard cannot change its spots. I would add that for the most part, it doesn't even know it HAS spots. And so humans will insist they have free will, despite the fact that they all behave, essentially, just the same.

    Links to published research about ozone and plants can be found here:

    1. Excellent article, Gail, as said before, I agree that ground-level ozone should be reduced and the Climate Plan that I propose can most rapidly and effectively accomplish such necessary shifts by imposing fees on polluting products (and facilities), and then using the revenues to fund rebates on local sales of the better products.

    2. I like this discussion. But I have a different view than both Sam and Gail. I can't agree with Gail that we are hard-wired for delusional thinking. If that were so, then how can we be having this discussion about it? We should be looking at the system - the current imperialist/capitalist/electoral system of representative government mistakenly called "democracy" - that leaves people so powerless even when they think that they are exercising some control over their environment. Somehow "scientists" have become the only category that is sanctioned to pronounce on the environment, including the climate, even though they all - necessarily - must then speak beyond their specialization. However, as far as history, politics, society, and culture go, they can be incredibly naive.

  3. By the end of this summer we will know how much time time we have left.

  4. Wow, that was quick, I find a study one night and Sam has a piece written on it the next day! Good work Sam! I tried to spread it and this topic here around a little myself today too.

    I wrote this earlier today on a Mother Jones Facebook topic on the water supposedly wasted growing marijuana in California, as I have done extensive academic work on water supply sustainability across the greater Southwestern US and Mexico.


    It takes thousands of gallons of water to produce a pound of beef and 250 gallons to grow a pound of broccoli.

    It takes 12-15 acre feet (4-5 million gallons) to drill a single frack well, water that is permanently lost to the hydrologic cycle, and another study has found that the average golf course in Palm Springs uses over one million gallons of water per day too.

    So, if it takes 250 gallons of water to grow a pound of broccoli, 2000 gallons to grow a pound of beef (including water for livestock feed), and a couple thousand more gallons to produce a quart of milk, how many gallons of water does greater Los Angeles use considering that the average person in LA uses about 300 gallons of water on a daily basis for other uses?

    Now add the water used to produce natural gas for heating and hot water, 12-15 gallons per cubic foot, as well as the 10-13 gallons of water used to produce every gallon of oil too.

    After you get a result, now figure-in a current decline of 5-8% per decade in annual runoff that has been going-on for 3-4 decades already, and the fact that southern and central California is currently overdrawing its aquifers by more than 2-1 over the natural recharge rate too.

    Also figure-in that every surface source of water within 1000 miles of southern California is already severely over-appropriated.

    Add to this the fact that ocean desalinization uses a tremendous amount of energy and costs $2600-$2700 per acre-foot (326,000 gallons) to produce fresh water.

    Now, let's add-in the effect of climate change which is rapidly worsening, which will mean an advanced surface water evaporation rate, and an advance in the decline rate on annual runoff, (plus an ever-greater loss of humidity as well as loss of vegetation, desertification, and salinization of soils, especially agricultural soils).

    Worse yet, there is no city within a 500-mile radius of LA that is in any better shape from a water supply sustainability perspective either, in-fact, most are in even worse shape.

    I wonder if the Canadians would be willing to sell water out of Lake Winnipeg, as public opinion surrounding the Great Lakes says that their water isn’t for sale?

    Why not let those of us in the Great Lakes States grow and supply your marijuana as there isn’t nearly the water shortage there as exists anywhere west of I-35 and south of I-70 either?

    [end quote]

  5. Part Two

    Paul asks what is going to kill us and here is my take on that question. We are going to lose an ever-larger amount of habitable space and viable farmland, as well as lose an ever-larger amount of fresh water too. The end result will be an ever-increasing number of refugees which will overwhelm the possible sustainability of adjacent regions.

    Today here across the entire affected region, from Mexico City up to our northern Rocky Mountain and west coast States, there are many water resource managers and sustainability planners watching annual runoff and declining aquifer depths like they are measuring liquid gold. Today numerous urban areas across the affected region have had to make draconian water service cuts and farmers are losing their shirts too.

    For the last 3-4 decades the Colorado and Rio Grande basins have experienced an ongoing decline in annual runoff which started further south and has been moving northward, as snow levels have risen in elevation and winter temperatures have warmed, which has caused the pine and spruce beetles to also move northward too.

    Most of Mexico's major urban areas are struggling today to supply their average resident 40-50 gallons of water per day and all are facing a fairly rapid population growth rate too. El Paso and Juarez have been growing at over 5% per year since NAFTA passed, to a population of about 2.5 million now, and they are down to 75 gallons of water per day in El Paso and 50 in Juarez too.

    Last summer Elephant Butte Reservoir in New Mexico was down to 3% of capacity and farmers there dependent on the reservoir only got 3 acre-inches rather than their normal 3 acre-feet, which resulted in the aquifer being drawn dry around Hatch, NM. Meanwhile east of the river ranchers have sold their water rights to the fracking industry as they haven't received enough rainfall or runoff for several years to maintain livestock herds.

    Guadalajara and Puebla are both down to into the 30-gallon per day range, Monterrey is at about 45 gallons per day, and Laredo/Nuevo Laredo are completely dependent on Rio Grande and Rio Conchos runoff as is Chihuahua and a large amount of northern Mexico's and south Texas farmland too, even though the river was dry for the majority of last year. Mexico City was in deep trouble until they found a mile-deep aquifer that might last them another 30 years if global temperatures keep rising on their present rate, combined with the current growth rate too. In 30 years greater Mexico City could see a population of 40 million people too.

    On the US side of the border Austin and San Antonio are struggling with Stage 3 and 4 drought restrictions as is Wichita Falls, and Dallas/Fort Worth is almost as bad too. San Angelo ran completely out of water last summer as did 30 other towns in Texas and Las Cruces, NM too.

    Amarillo and Lubbock are running out of water, as is Albuquerque, and Phoenix, Tucson, and Yuma are also facing a grave threat as the Colorado continues to lose annual runoff and their aquifers have dropped by hundreds of feet already, in-fact Tucson is injecting treated wastewater hoping to resell it later too. Las Vegas is hoping to build a 350-mile pipeline to try to steal groundwater from northern Nevada farmers but that has been tied-up in court for 25 years, and now they want to drain Lake Powell to try to partially fill up Lake Mead. Southern Utah is running out of water too.

  6. Part Three

    The end result if climate change continues on its present path will force these urban areas to shed population as their water supply falls off. Indoor hydroponic climate-controlled agriculture could in theory produce a yield of 8 times that of crops grown in dirt but even so, the amount of greenhouse capacity required would be immense.

    In my senior seminar I reverse-engineered a model to ascertain required irrigated farmland to supply population using USDA ERS food availability and loss rate charts combined with historical State crop yields, and to meet the USDA 2500-calorie daily diet including 30% crop loss is almost 1000 lbs of food per person per year.

    If we take average crop yield per acre we find that each acre only supplies 5-10 people so how many acres are required to feed 10, 20, or even 50 million? Let's say 10 million acres for 50 million people divided by 640 = 15,625 square miles of irrigated crop land, just to grow enough broccoli at average yield, using 3 acre-feet of water per acre (or almost one million gallons). Now what do you do when millions of desperate climate change refugees start flooding into town?

    How large can a sustainable city be if there is a requirement to locally grow food using a minimum amount of fossil fuels for farm equipment and transportation, central warehousing and processing, and distribution to retail stores small-enough to walk to? Remember, 1000 lbs. per person including a 30% loss rate, 5-10 people per acre at average crop yield, God what a nightmare, as even a city of 100,000 people requires 10,000-20,000 acres of farmland times 3-4 acre-feet of water just to supply its food needs locally on an annual basis.

    All of the States and cities in the greater US Southwest and Mexico are running out of water even now, There are several sources that I have worked with that forecast a 40% water supply shortage just to continue world population growth through 2030-2035. Ackerman and Stanton are one of the sources, Patricia Pina wrote a study of the water supply shortfall in Mexico City, Chaidaz wrote a study on Monterrey, and the US Office of National Intelligence wrote their Global Trends 2030 study.

    Siemens produced their Green Cities Index, Lester Brown has written extensively on food and water supply issues, and the US Bureau of Reclamation produced their Colorado Basin demand study, all of which forecast a major and growing water supply shortage affecting 200 million people just in North America or more. Ackerman and Stanton forecast a shortage of 2.4 billion acre-feet through 2100, with 1.4 billion acre feet of that just in California alone on their high growth scenario.

  7. Part Four

    And now we want to add 4-5, maybe 6 degrees Celsius of temperature rise over a few decades to what is already a massive water supply disaster? I can tell you how the story ends right now Paul. Just here in North America by ourselves we will see an 8 to 9-figure sum of increasingly desperate water and food scarcity refugees flooding northward and eastward in search of their survival, while rising sea levels cause the same issue away from low-lying coastal regions.

    The end result if we take a figure of only 5 degrees Celsius by 2060 will see 400-500 million people pushed up against the Canadian border rapidly running out of water and food, a large part of them clustered around the Great Lakes and northern New England, which in either case can't possibly grow enough food locally to provide more than starvation rations.

    To this giant mass of desperate humanity we add the current sustainability protocol of various Asian governments that says that better-off nations will have to absorb hundreds of millions if not billions of Asian climate change refugees too. Most Africans will end-up being forced to their south as will most residents of South America, and who knows what will happen in Australia and Tasmania as their residents run out of viable real estate?

    Have any you seen this Dutch degree-by-degree warming impacts piece? I found the actual source of it but it is on my other computer, which is laid-up in the shop right now. It came from some European conference on climate change back around the early part of the last decade, and it goes into great detail as to what will happen as global temperatures rise. It has been translated from Dutch so the English is not always correct. Just concentrate on the 4-6 degree Celsius range as that is where we are headed.

  8. Rather than give my own take on how climate change will cause our extinction, I want to report that here, in Australia, news of our impending demise is making a timid appearance in our mainstream media.

    If you read those pieces below you will notice that release of methane held in clathrates is mentioned as a central threat. For this I am quite sure we have to thank the indefatigable work of Sam Carana and the people mentioned in this article.
    Please keep on with your essential work Sam. Even though your site is rarely if ever quoted by others, it is widely read and contributes to the rising awareness of the seriousness and immediacy of the danger to the whole biosphere of our current inaction and increasing reliance on fossil fuels.

    On the ABC (Australian Broadcasting Corporation - Federal state radio and TV broadcaster) web site:
    Act and adapt or face a bleak future -

    On the Canberra Times (part of the Fairfax News Network. Canberra is our capital city):
    Human Extinction: is it possible?