Global Warming 101
Like many other concerned citizens who are not specialists in climatology, I have regularly looked for some helpful keys to understand and assess the many controverted claims about global warming. How fast is it happening? How urgent is it that we act now? At what level of parts per million can we tolerate increases in greenhouse gasses? Presently standing at 385ppm (an increase from around 280ppm at the start of the industrial revolution), can we tolerate increases to 550ppm (as some climate watchers, such as Nicholas Stern, claim) or would we best aim for capping increased carbon dioxide particles at 400 to 450ppm ? Projected increases in warming during the next century or so range from 1 degree Celsius (almost certain to occur) to 6 Celsius (which was the amount the earth was warmer than today, during the end of the Permian period 251 million years ago, when almost 95 percent of life-forms went extinct). Would sustainability be better reached at a 2 degree Celsius cap or can we safely risk even higher warming ?
I welcomed my read of Mark Lynas’ recent book, Six Degrees: Our Future on a Hotter Planet, which won, last June, the prestigious British Royal Society science book of the year award. Lynas’ authored an earlier 2004 book, High Tide: The Truth About Our Climate Crisis. One image from that earlier book remains firmly etched in my memory. Lynas juxtaposed two photos of an Andean glacier in Peru. One was taken by Lynas’ father in 1932; the other by Lynas in 2002. The loss of ice was truly startling.
Lynas is a journalist, environmental activist and a National Geographic Emerging Explorer. He is, thus, parti pri for firm action to turn around global warming now. No climate skeptic he! Still, he has scoured and mined, carefully, the various complex computer models for projected global warming and tries to lay out their divergences and convergences. He signals the uncertainties (some more favorable than others) in the models. Basically, the book is organized, as the title suggests, into six main chapters, outlining the likely prospects for the world at each degree level of warming, from 1 degree Celsius to 6.
One degree is basically and clearly the trajectory we are on now. Already, the world is seeing new kinds of glacier melting (Kilimanjaro has lost 80% of its ice in the last century and will be ice free some time between 2015-2020). The world has seen earlier springs and threats, downstream, for water supplies, dependent on glacier melt offs in the Alps, the Himalayas and the high Andes. Water supplies to Beijing, Lima and the western United States are under severe threat (it will not likely be sufficient for current population densities, let alone increased ones).Coral reefs (which feed one-third of life in the ocean) are becoming bleached and the deep sea shows the highest temperatures in 1,300 years. Projected cyclone and hurricane patterns foresee higher levels of storm activity.
At 2 degree increases, the oceans become more acidic, with deleterious effects on plankton (which helps absorb, as a carbon sink, half of all C02). At two degrees most of Australia enters a permanent drought, as does most of the western United States. Global warming and its earlier springs will have devastating impact on many species which will not be able to migrate fast enough to climates suitable to them. Crop declines will have impact on world food supplies. While there will be some winners and losers in global warming (Russia and Canada might be net winners), there are more areas of the world which will suffer from drought (most of South America and Africa). While the 2007 report of the International Panel on Climate Change showed some uncertainty about ice sheet melting in the Arctic and Antarctic, in fact, the melting of ice in Greenland and the Arctic has been faster than projected in the 2001 IPCC report. Ice declines are currently 30 years ahead of the IPCC projected models.
At 3 degrees and beyond, there is severe danger of a kind of “tipping point” which could make global warming beyond human control or ability to impact. The world was once (during the Pliocene period) 3 degrees warmer than today. Sea levels were 25 meters higher than today. At 3 degrees, coastal cities become severely threatened, tropical forests could burn, monsoons could intensify, leading to severe flooding. Most ominous of all will be literally millions of climate refugees. As Lynas notes, “All of human history shows that given the choice between starving in situ and moving, people move.” Much beyond a 3 degree increase, civilization, food cultivation, the contours of land and sea simply shift from what humans have known.
In a final chapter, entitled “ Choosing Our Future”, Lynas notes that all of our efforts to this point—carbon trading, switching to more energy efficient lights, some gentle moves toward wind and solar power—have had less than a zero impact in stemming global warming . Some of the warming is already in the process of occurring because of what we have already put into the atmosphere, even if we were to drastically reduce carbon emissions today. Clearly, there is no one quick fix to address global warming. Policy should not be based on wishful thinking. If it was easy to move away from fossil fuels we would have done so by now. Fatally, with the growth of China and India, world energy demand is on course to rise by more than half by 2030. As the International Energy Agency notes, this is not sustainable.
Lynas addresses, forthrightly, the various states of denial ( blame others, willed ignorance, denial of responsibility) and notes, citing Al Gore, that it is difficult to accept something if your salary depends on not understanding it. Lynas turns, for some hope, to the work of Princeton scholars, Robert Socolow and Steve Pecala: “ Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies”, Science , 305-968-72 to argue for a series of important wedges to turn back global warming or cap it at 2 degrees increase. These wedges include increased fuel economy in vehicles from 30-60 miles; halving the distance travelled at present; a four fold increase in gas fuelled power stations; 700 new nuclear power stations; an increase of wind power by 50 times and of solar power by a factor of 700; carbon capture and storage at 80 coal plants. Re-forestation is central (since 20% of all greenhouse emissions comes from de-forestation in the tropics). Energy efficiencies in homes and offices would also cut down greenhouse gasses.
I am not sure I come away from Lynas’ six-fold descent into a kind of hell terribly optimistic. But the threats are real and potentially catastrophic. The time line for action is roughly a decade. The possibilities of keeping global warming at 2 degrees are also real and technologically possible (if there is the human will). The costs of not acting, as Lord Stern noted in his famous report to the British Parliament will far outweigh any costs or sacrifices in acting now. For us, too, as ethical actors: the heat is on!
John Coleman, S.J.