The Magnitude of Risk

UPDATE: See a special follow-up to this entry, our "Memo to Barack Obama."

Some say that once exponential general-purpose molecular manufacturing (MM) is achieved, our worries about global warming and climate change will be over. A relatively simple solution like tiny balloons fitted with adjustable mirrors could give us all the control we need to moderate warming and create preferred climate conditions.

CRN and those with whom we share a similar technological outlook expect that MM is likely no further than twenty years away at most, and perhaps could be here within ten years or even less. If it does arrive within that time frame, and if it can be applied to our growing climate problems as suggested above, then indeed at least some of our fears will be assuaged.

Of course, there are many other risks of MM that will still have to be faced, including severe economic disruption and the prospect of a new arms race.

But let's leave those aside for now and stay with the issue of global warming.

Assume for the moment that there are unforeseen technological challenges that prevent MM from being achieved as we and others envision; or that some variety of political and social objections disallow its development within the next twenty years; or that even if it is achieved, all attempts to install simple solutions for climate change fail -- they don't work as hoped, because the problem is too complex and too big.

Then what?

If any of these plausible conditions come to pass, the looming disasters associated with global warming will not be so easy to avert. And those disasters could be very disastrous indeed. In this extended post, we'll do two things: 1) review the magnitude of the danger; and 2) propose an appropriate way forward from here.

How Bad is Bad

A terrifying leap in average global temperatures of 6.4C ­with higher figures nearer the poles ­could occur over the next century, according to the most authoritative report yet on global warming. The rise, which would make agriculture, even life, almost impossible over much of the Earth, was the worst-case scenario envisaged by hundreds of scientists on the UN's Intergovernmental Panel on Climate Change (IPCC).

The "six-degree world" might come about by 2100, the scientists said, if human society carries on with rapid economic growth and high levels of burning fossil fuels ­ coal, oil and gas ­ which emit the carbon dioxide causing the atmosphere to warm. Their worst case was worse than that suggested in the previous IPCC report, published in 2001, when the highest rise envisaged by the end of the century was 5.8C.

Yesterday was the first time the figure of six degrees has been mentioned in UN predictions. The scientists added that, as it was a global average, it would mean higher rises in high latitudes, with consequently severer droughts, increased storms and melting of ice and glaciers.

It was the most extreme of a range of predictions by the group of 600 researchers from 40 countries, whose consensus report, using 14 supercomputer models of the global atmosphere, has been peer-reviewed by 600 more meteorologists.

These figures came from the most recent comprehensive IPCC report, issued in 2007, their fourth such report. It should be noted that with each subsequent report, which have been spaced five or six years apart, their findings have been more dire and their warnings more urgent.

Concentrations of carbon dioxide in the atmosphere are at their highest levels for at least 650,000 years and this rise began with the birth of the Industrial Revolution 250 years ago, according to the Intergovernmental Panel on Climate Change.

Carbon dioxide is the principal greenhouse gas responsible for global warming and, in 2005, concentrations stood at 379 parts per million (ppm). This compares to a pre-industrial level of 278 ppm, and a range over the previous 650,000 years of between 180 and 300 ppm, the report says.

Present levels of carbon dioxide -- which continue to rise inexorably each year -- are unprecedented for the long period of geological history that scientists are able to analyse from gas samples trapped in the frozen bubbles of deep ice cores.

However, the IPCC points to a potentially more sinister development: the rate of increase of carbon dioxide in the atmosphere is beginning to accelerate. Between 1960 and 2005 the average rate at which carbon dioxide concentrations increased was 1.4 ppm per year. But when the figures are analysed more closely, it becomes apparent that there has been a recent rise in this rate of increase to 1.9 ppm per year between 1995 and 2005.

It is too early to explain this accelerating increase but one fear is that it may indicate a change in the way the Earth is responding to global warming. In other words, climate feedbacks that accelerate the rate of change may have kicked in.

Those carbon cycle feedbacks, which are still poorly understood, could trigger the release of millions of tons of long-buried methane deposits that have remained in stasis for tens of thousands of years, held in Siberian permafrost and beneath the Arctic seabed. Since methane is 20 times more potent than carbon dioxide as a greenhouse gas, this development, if and when it happens, will almost certainly accelerate global warming.

Here is even more bad news...

It's a pretty grim conclusion: greenhouse gas reduction targets being talked about to stop climate change will not now avoid potentially catastrophic rises in global average temperatures, [a recent] report from the UN Intergovernmental Panel on Climate Change makes clear.

The target for stabilising CO2 levels in the atmosphere which some scientists and politicians increasingly hope to aim for -- an upper limit of 550 parts per million -- would probably involve a rise of 3C, perhaps one as high as 4.5C, and almost certainly no lower than 1.5C, the report says.

But a 3C rise would bring about enormous damage to agriculture, weather patterns and ecosystems across the world with catastrophic effects on human society.

As we and others have said before, aiming for a CO2 stabilization level of 550 ppm is not a good idea. The target should be 450 ppm at most, with an eventual aim of lowering the level to 350 ppm. Will that be easy? Hardly. But the consequences of allowing CO2 to reach 550 ppm are far too risky to allow.

Although 550 ppm is seen as far too lax by environmentalists, other observers see it as an ambitious target for a world so wedded to carbon use. Yet yesterday's report makes clear that even in the 550 ppm target were attained, the future looks bleak.

The report says that for the next two decades a warming of about 0.2C per decade is predicted. It says that even if CO2 emissions had been halted completely in 2000, the world would still be committed to a rise of about 0.6C, because of the time the climate system takes to react.

The best estimate for the low scenario, known as B1, is a 1.8C rise (on a range of 1.1C to 2.9C) and the best estimate for the high scenario (known as A1FI) is 4C, with a lower range limit of 2.4C, and the upper range limit of 6.4C -- up substantially from the worst-case figure of 5.8C given in the IPCC Third Assessment Report, known as the TAR, published in 2001.

What has informed these new projections is the increase over the past six years in knowledge of climate "feedback" mechanisms -- by which a warming world becomes less able to absorb CO2, which further increases the warming, which further slows the CO2 uptake, and so on. The report says: "The new assessment of the likely ranges now relies on a larger number of climate models of increasing complexity and realism, as well as new information regarding the nature of feedbacks from the carbon cycle."

I'll go out on a limb and predict that the next IPCC report, due around 2012, will project yet more extreme scenarios for greenhouse gas levels, climate warming, and subsequent cataclysms. If you've followed the trend over the past twenty years or so, each succeeding report, from them and others, offers more and more worrisome outlooks.

And how bad could things actually get? Pretty bad.

Buried within the [2007] IPCC report is an apocalyptic warning: if greenhouse gas emissions continue to rise at current rates, global warming by the end of the century could total 6.4C. The scientists don't say so explicitly, but a rise in temperatures of this magnitude would catapult the planet into an extreme greenhouse state not seen for nearly 100 million years, when dinosaurs grazed on polar rainforests and deserts reached into the heart of Europe. It would cause a mass extinction of almost all life and probably reduce humanity to a few struggling groups of embattled survivors clinging to life near the poles.

An eco-alarmist fantasy? Unfortunately not -- having spent the past three years combing the scientific literature for clues to how life will change as the planet heats up, I know that life on a 6C-warmer globe would be almost unimaginably hellish. A clue to just how unpleasant things can get is contained within a narrow layer of strata recently exposed at a rock quarry in China, dating from the end of the Permian period, 251 million years ago. For reasons that are still not properly understood, temperatures rose by 6C over just a few thousand years, dramatically changing the climate and wiping out up to 95 per cent of species alive at the time. The end-Permian mass extinction was the worst ever: the closest that this planet has ever come to becoming just another lifeless rock orbiting the sun.

That's Mark Lynas, author of Six Degrees: Our Future on a Hotter Planet.

If what you've read above is not enough to make you queasy, take a look at these brief descriptions of what we can expect this century with increased temperatures:

+2.4°: Coral reefs almost extinct

+3.4°: Rainforest turns to desert

+4.4°: Melting ice caps displace millions

+5.4°: Sea levels rise by five meters

+6.4°: Most of life is exterminated

Remember that those temperature numbers are in Celsius; readers in the United States should understand that rises in Fahrenheit will be higher in absolute numbers.

UPDATE: National Geographic's website for their "Six Degrees Could Change the World" program includes an interesting multimedia presentation on various scenarios as temperatures climb, degree by degree, during this century. Click on the Interactive tab.

What Should Be Done 

Nearly all of the world's most informed scientists agree that catastrophic global warming is a real and worsening phenomenon. Those who know most about it seem the most alarmed by what they see ahead.

So, what should we do now?

1. Move as quickly as possible in developing molecular manufacturing. Apply targeted government funds to support a variety of promising private sector and academic research efforts. Assuming that this long-sought goal can be realized within the next decade or two, it may offer a short-cut to help us avoid the worst results of climate change.
2. Commit an equal amount of funding to study the implications of advanced nanotechnology. Not just 5%, as the NNI has set aside, or 10%, as Environmental Defense and DuPont have proposed, but 50% of all public nanotechnology financing should be devoted to gaining a thorough understanding of both the risks and benefits, and strategies to maximize the former while avoiding the latter.
3. Begin a strong and sustained program of energy conservation in the nations of the developed world, going well beyond the goals set in the Kyoto Protocol. As Bill Clinton has suggested, we should lead with the power of our example, not just the example of our power.
4. Undertake urgent and sincere negotiations with the largest developing nations -- especially China, India, Russia, Brazil, and Indonesia -- to achieve agreements on target CO2 levels, phase out of coal use, and possibly carbon trading strategies.
5. Mount a crash program, on the level of US World War II mobilization, to develop and implement alternative energies, including wind power, concentrated solar thermal power, and more. The required approach in order to avoid the worst climate change scenarios, also would include nuclear power, cellulosic biofuels, carbon capture and storage, and more.
6. Prepare for disaster mitigation. Given that time is rapidly growing shorter for us to slow global warming before irreversible carbon cycle feedbacks kick in, it is essential that we begin preparing soon for the likely impacts of climate change. Sea level rises, increased storm frequency and intensity, droughts, floods, agricultural damage from shifts in growing regions and invasion of unfamilar pests and diseases, and much more are in the offing unless we change direction very quickly. We may have a decade or two to make ready for what's coming -- how well we use that time to prevent and/or alleviate suffering of our fellow humans (and other species) will show just how humane we truly are.
7. Explore geoengineering as a last resort. CRN believes that some geoengineering approaches may have merit, but that they should be studied in great detail before being attempted, and should be modeled extensively and, if possible, trial tested before broad implementation. The risk of unanticipated consequences is just too great for us to act precipitously.

This series of seven steps takes into account all that we now know about global warming and all that we hope will be possible with molecular manufacturing. It calls for rapid development of advanced nanotechnology and simultaneous exploration of the risks and benefits of that potentially disruptive technology. At the same time, it includes the urgent changes that climate experts and other serious commentators define as essential.

If we had our way, steps 1 through 5 above would get underway in 2009, with step 6 to follow between 2010 and 2015, and step 7 after 2020 and only if shown to be absolutely necessary.

Mike Treder