Tuesday, 18 August 2009

The World at 4 degrees of global warming

"In 2010, 50 million people will be trying to escape the effects of environmental deterioration" (The Planet Documentary)

On the 25th of February 2009, New Scientist published a map of the world at 4 degrees of global warming. This map can be found here: http://www.ecochanges.co.uk/educational/education/tables_pictures_and_maps.pdf

It is shocking as it shows the bulk of the inhabitable world becomes uninhabitable due to droughts, flooding and extreme weather. I suppose that in order to create the map, they used Mark Lynas's excellent book 6 degrees which describes the impact of each degree of global warming on the world's ecosystems and land. Although the book seemed to emphasize the bulk of the changes would take place in the second half of the century. The idea that the world could be 4 degrees warmer as soon as 2050 didn't seem to be included.

Last week, I finally got round to simplifying the map to show the areas that were inhabitable and those that weren't. Then I added up the populations currently living in the uninhabitable areas and factored in a 35% growth rate corresponding to the expectation that the world population will grow from 6.7 to 9 billion people by 2050 (calculations available here). The total number of people living in uninhabitable areas adds up to a little over 8 billion people, 95% of the 2050 human population. I'm making the map public domain and it can be used for commercial purposes. Email me at info@ecochanges.co.uk if you want a map with no comments.

MAP 1: Geographical area affected

Map 2: Impact on populations

One fact that has long bothered me is James Lovelock's assessment that 8 billion people will die by 2100 ( watch: too little too late?). He believes it is already too late. I long wondered how he got to his 8 billion figure as I had not found it anywhere else. The answer's in the map: if 8 billion people live in uninhabitable areas, James Lovelock assumes that they will die. That's not an unreasonable assumption. It is reminiscent of a quote from The Planet Documentary: "An environmental refugee has to leave, has no options whatsoever to remain in the area where he or she is coming from because of a lack of opportunities, lack of a viable environment, lack of ecological services" James Bogardi, United Nations University.

What would be the consequences of 8 billion people being displaced? I can only picture flows of refugees to inhabitable areas. I have often heard people complaining that they lost their job to a polish immigrant and that they felt like voting for the BNP. A flow of immigrants will likely cause those countries accepting refugees to close their borders but that won't stop refugees from trying to get in. Eventually the refugee's frustration will be reflected in their governments who will have no choice but to go to war to secure a livelihood for their inhabitants. What will happen then? What's already happened in the past and is described in the book Collapse by Jared Diamond. The best example was Easter Island. The population peaked at 7000 people around 1300. When they'd finished deforesting and could no longer build boats to fish, they ate and killed each other. A few centuries later, less than a thousand people remained. Nuclear bomb technology wasn't available at that time. Unfortunately, the countries that will become uninhabitable have it.


I found the map visually striking and it stuck with me. I was however surprised by the fact that instead of trying to establish the populations affected the map focuses on how the new lifeless areas can be exploited for renewable energy. This view it seems, is the one that got us in trouble in the first place. By over-exploiting our ecosystems, we've brought them to the brink of the limits they can tolerate.

I found the idea that we had a future in a globally warmed world disturbing. New Scientist and Mark Lynas didn't explore the consequences of the world warming beyond 4 or 6 degrees. There is no doubt that it will. Mark Lynas was content with his assessment that if the world does indeed warm by 6 degrees, it is unlikely that mankind will survive. Nobody knows how much the world could warm by but it has warmed by up to 20 degrees in the past. With all the world's ecosystems as a whole capable of creating far larger amounts of global warming than us humans can, it's not the impact caused by humans we need to be concerned about beyond 2 degrees, it's the impact caused by the world's ecosystems. Two degrees is the point of no return. Once we move past it, we're doomed.

The greatest concern of our time is the fact that we live at a time when we may still be able to avoid disaster yet the world's culture hasn't caught up with this truth. Evidence of this is most easily seen on television where the topic isn't covered enough, the programming is still mainly focused on trivial entertainment and news bulletins focus on the return to growth. I saw one news bulletin at the week-end where a presenter interviewing a French government representative appeared to praise her for their good management and the return of their country to growth. The mood was focused on assessing when our country would return to the "rosy path". Growth in economies 80% dependent on fossil fuel for energy is catastrophic. It's not something to look forwards to.

It seems at this point in time, that the only thing that will make us wake up to the threat of global warming, is the world warming beyond 2 degrees, at which point it will be impossible to avoid runaway global warming.

You can do something to avoid this: visit www.ecochanges.co.uk to find out how to reduce your own carbon footprint, how to set up a green business or charity, how to volunteer and how to sign petitions to ask for change.


  1. Hi,

    I know this is an old post but I wanted to point out that the green areas in Western Africa and Western Australia are marked as "potential for reforestation" on the New Scientist map, in other words, uninhabitable but valuable oxygen-producing jungle.

    The New Scientist map also marks several spots for renewable energy generation, but If the world is busy fighting over scarce resources, it seems unlikely that renewable energy generation will reach the scale that is portrayed by the map.

    All populations which exceed the carrying capacity of their environment experience a die-off, usually in the range of 90-99%. It would be foolish to think that humans are any different in this respect.

  2. Nice post with great details. I really appreciate your info. Thanks for sharing. world population

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