Science – Page 67 – a sibilant intake of breath

Morton on the end of the carbon cycle

Among many other things, Oliver Morton’s Eating the Sun discusses the carbon cycle across extremely long timespans. It highlights the existence of positive and negative feedbacks, which have historically constrained atmospheric concentrations of carbon dioxide to a particular range: with a high point established though increased emissions from volcanoes, and a low point established through the absorption of atmospheric carbon dioxide through the weathering of rocks.

The book predicts that, on the basis of astronomical and geological factors, this see-saw will eventually come to rest about a billion years from now: with the victory of erosion, and the permanent elimination of carbon dioxide from the atmosphere. As a consequence, photosynthesis will cease – for lack of building material – and the energy system that supports all complex life will collapse. Morton dubs this ‘the end of plants’ and the explanation of why it is to occur is difficult to compress into a blog post. It’s one of many reasons for which the book is worthwhile reading.

It’s a sobering perspective: akin to the knowledge that our sun will eventually fail, or that the Second Law of Thermodynamics and a universe expanding without end would combine to produce ‘heat death’ and an end to all chemical reactions everywhere.

That being said, it is essentially impossible for our minds to appreciate the meaning of a billion years, or anticipate how life (and humanity) would change across that span. Long, long before this final descent in the carbon cycle could be approached, we would have ceased to resemble our present forms; indeed, our current forms and future forms might not even be able to comprehend one another. After all, the Cambrian explosion, in which complex life forms like molluscs and crustaceans emerged, happened ‘only’ 530 million years ago.

Of course, even starting to approach that post-human future requires surviving the all-too-human threats we have created for ourselves, with climate change foremost among them. The billion-year carbon bust offers no prospect of avoiding the warming we are creating at the level of years and centuries. What Morton’s long-term perspective does offer, however, is a fairly strong assurance that life can adapt to most any set of climatic circumstances we might be able to create. Of course, ‘life’ writ large is far more adaptable and resilient than our present form of civilization, which may be quite impossible to propagate in a world where temperatures are more than 5˚C higher, on average, glaciers and icecaps are gone, the oceans are acid, and precipitation patterns have changed dramatically.

It is both startling and entirely possible that human civilization, for all its accomplishments, will prove less adept at responding to large-scale changes in climate than ancient sharks or turtles have done.

Climate change on the Globe and Mail wiki

The Globe and Mail has an initiative called Policy Wiki, in which they are trying to foster web discussions on public policy issues of interest to Canadians. The third topic they have selected is climate change. The site includes a briefing note by Mark Jaccard, of the Pembina Institute, and an analysis and proposal by David Suzuki.

Some of the sub-questions to be discussed include:

How closely should Canada’s policies be linked to the US?
Should our focus be bilateral or multilateral?
What position should Canada adopt at the Copenhagen conference?
How does the economic crisis impact actions on climate change?
How will this impact Canadian industry?
How many green jobs can Canada create?
What added responsibility does Canada have as an energy superpower?

Most frequent commenters on this site are quite concerned with Canadian climate policy. As such, this might be an opportunity to discuss the issue with a broader audience. I personally plan to contribute, and would be pleased to see readers doing so as well.

The Man Who Loved China

Simon Winchester’s The Man Who Loved China is a competent and sometimes compelling biography of the scientist and sinologist Joseph Needham: a man who started off as a Cambridge biochemist and later devoted his life to documenting the scientific history of China. While it contains a lot of interesting narrative and information, it does sometimes feel more like a catalogue of achievements, written by an admirer, than a substantive examination of either Chinese scientific history or Needham’s own work.

The book is essentially divided into two phases: one describing Needham’s life and explorations within China, in the period of the Second World War, and a second describing the process of writing his masterwork: Science and Civilization in China. More accurately, it must be said that he began his masterwork, as he was only able to produce the overall plan and the first few volumes before dying as an elderly man. During the first section, Needham is serving as a kind of official scientific liaison between the British government and the Chinese nationalist government during the period of Japanese occupation. During the second, he is principally installed in Cambridge as an academic, though he did return to China to lead an easily-duped team of weapons inspectors, investigating claims that the United States had used biological weapons during the Korean War.

The book is a somewhat odd one to read at this point in history. Needham’s work was published long enough ago to have become the mainstream understanding: namely, that a great many critical inventions and discoveries happened earlier in China than elsewhere. Most members of the public are probably able to identify gunpowder and the compass as Chinese inventions. Those with knowledge in other fields – from engineering to nautics – are probably similarly familiar with early Chinese contributions. By not providing much evidence about the prevailing view beforehand, the book makes it a bit awkward to assess Needham’s own contribution, aside from the indirect evidence provided by all of his subsequent academic recognition.

The book does a fairly comprehensive job of expressing Needham’s curious personal characteristics: his polyamory (spending most of his life within reach of both wife and mistress, both well aware of one another), his socialism, his love of trains and boats, and his overwhelming dedication to China. The strength of the latter is revealed through his inability to appreciate the problems with Mao’s revolution, at least, nor until the man himself had been dead for some time. Needham is portrayed as quite a dashing figure: scientist, activist, diplomat, and adventurer. In terms of the sheer number and variety of experiences, his life is one that must be envied by anyone who is curious about the world.

The so-called ‘Needham question’ of why scientific innovation in China stalled, prior to exploding in the West, gets surprisingly brief and superficial treatment in this volume – just a few pages in the epilogue. This is a curious way for a biographer to treat the central subject of his subject’s fascination. It would have been interesting to see various hypotheses discussed more thoroughly, with a focus on the evidence supporting and challenging them that arose from Needham’s investigations and subsequent scholarship.

For me, this book didn’t manage to be as compelling as Winchester’s history of the Oxford English Dictionary. Nonetheless, it would probably be of interest to those who enjoy reading about people who lived notable and unusual lives. It certainly tends towards inspiring a person to wonder what more exotic and worthwhile things they might be doing themselves.

Business-as-usual estimates from MIT

Researchers at MIT have updated their climatic models and reached conclusions generally in line with the Hadley Centre in the UK, in terms of the amount of warming that would occur by 2100 under a business-as-usual case, in which no significant emissions reductions are achieved:

[T]here is now a nine percent chance (about one in 11 odds) that the global average surface temperature would increase by more than 7°C (12.6°F) by the end of this century, compared with only a less than one percent chance (one in 100 odds) that warming would be limited to below 3°C (5.4°F).

It is difficult to express how enormous a change 7°C would be. Conservative estimates of the point at which anthropogenic climate change should be considered ‘dangerous’ tend to cluster around the 2°C target adopted by the European Union, and others. As the MIT model suggests, a world that does not mitigate emissions may face a 99% probability of experiencing average warming a full degree above that target.

When politicians talking about climate change say that they ‘accept the science,’ people should be asking them if these kinds of projections are part of the science they accept. If so, they ought to be asked why they are treating climate change with such an utter lack of seriousness, concentrating far more on matters of fleeting political concern. In retrospect, it seems that people three or four generations from now will judge our current leaders largely on the basis of their failure to respond effectively to this threat.

Tropical forest carbon sinks

A recent Nature article discusses the status of forest-based carbon sinks in general, with special emphasis on an African sink that is estimated to be absorbing 1.2 billion tonnes of carbon dioxide per year: nearly twice the level of Canada’s 2006 emissions.

Today’s launch of the Orbital Carbon Observatory should help scientists to gain a better sense of how carbon dioxide is moving through and between the atmosphere, hydrosphere, and biosphere.

All told, the article estimates that 18% of human carbon dioxide emissions are being absorbed by tropical forests. The article highlights the uncertainties involved in the future trajectory of absorption by this sink. It may be that additional atmospheric CO2 causes it to maintain or even increase its absorption in the medium term. Conversely, it may be that the trees will reach a maximum size and cease to absorb further carbon, or that temperature and precipitation changes caused by global warming will restrict growth.

In any event, humanity will be in a better position to plan for the future once we have a deeper understanding of the nature of existing carbon sinks, and better projections for how they will respond to future conditions. In the mean time, working to avert further tropical deforestation is an important precautionary step.

Cool Tools on The Deniers

I was disappointed by a recent entry in the Cool Tools blog – a place that normally highlights useful stuff like little tripods. Their post on the 16th, which got re-posted on Boing Boing, was about Lawrence Solomon’s book: The Deniers: The World Renowned Scientists Who Stood Up Against Global Warming Hysteria, Political Persecution, and Fraud – And those who are too fearful to do so. The post argued that since science is advanced by those who question current beliefs, we should encourage those who question the reality of anthropogenic climate change.

It is regrettable that the mistaken impression endures that the key tenets of climatic science are still disputed by the scientific community as a whole. Greenhouse gasses unambiguously cause warming, and humanity is unambiguously releasing those gasses. While we certainly need critical thinking to advance climatic science (there is much left to learn about feedbacks and the internal dynamics of the climate system) the kind of people who deny the existence or seriousness of climate change are not engaged usefully with the scientific discussion. In most cases, they tell stories that contradict one another (it’s not happening, it’s not caused by greenhouse gasses, it is likely to be beneficial, it is all China’s fault, etc). In most cases, I also don’t think they are genuine in their approach: they are united by the desire to avoid government regulation of greenhouse gasses, not by a substantive disagreement about what is happening in the world.

Given the strength of entrenched interests opposed to climate change regulation, people willing to add confusion to the debate will always be able to find financial support. That is, at least, until society as a whole finally appreciates that their arguments are self-serving and wrong.

Plants and infrared light

If you have ever seen plants photographed using infrared film, you will know that they have a weird glowing quality when viewed at those wavelengths.

Apparently, the reason behind this has to do with quantum mechanics and photosynthesis. Photons with shorter wavelengths (violet and beyond) have higher energy than those with longer wavelengths (red and beyond, in the other direction). Since only photons with a certain level of energy can be used by photosystems I and II in chloroplasts, plants reflect insufficiently energetic photons, rather than absorbing them. This keeps them from taking in uselessly low energy photons which would simply turn into heat, rather than powering their photosynthetic machinery.

Climate change and Australia’s brushfires

Scientists frequently condemn journalists for being too quick to assert that particular events either support or call into question anthropogenic climate change. Indeed, reporting responsibly on the issue can be challenging. One the one hand, one cannot ignore the long-term contribution climate change makes to the frequency and severity of events; on the other, one doesn’t want to propagate the false idea that the accuracy or inaccuracy of climatic science hinges on a small number of extreme events of local weather trends.

A recent RealClimate post considers the case of Australia’s terrible recent brushfires. It considers a century worth of evidence on Australian brushfires, examining the importance of maximum temperatures, relative humidity, wind speed, and drought factors. Climate change trends are pushing in the direction of higher average temperatures and reduced rainfall. In the end, it comes to a measured by sobering conclusion:

While it is difficult to separate the influences of climate variability, climate change, and changes in fire management strategies on the observed increases in fire activity, it is clear that climate change is increasing the likelihood of environmental conditions associated with extreme fire danger in south-east Australia and a number of other parts of the world.

That may not be the kind of conclusion that translates easily into a headline for a popular newspaper, but it is the sort that we need to consider when making public policy on both climate change mitigation and adaptation.

The fourth report of the Intergovernmental Panel on Climate Change (IPCC) concluded back in 2007 that:

An increase in fire danger in Australia is likely to be associated with a reduced interval between fires, increased fire intensity, a decrease in fire extinguishments and faster fire spread. In south-east Australia, the frequency of very high and extreme fire danger days is likely to rise 4-25% by 2020 and 15-70% by 2050.

Those fires will naturally contribute to positive feedbacks within the climate system, as heat-induced dryness prompts the fire-induced emission of greenhouse gasses previously bound up in forests and grasslands.

A responsible position on carbon capture

People reading this blog might get the mistaken impression that I am fiercely opposed to carbon capture and storage (CCS) technology. That is definitely untrue. There are few things that would be more helpful than safe, cheap, and effective CCS. It would ease the transition to a zero-carbon global economy, and it would allow for the actual removal of CO2 from the atmosphere, through the growing and burning of biomass.

All that said, it is deeply inappropriate for planners to count emissions reductions from anticipated future CCS in their plans, as the government of Alberta has done to an extreme extent. The technology is in its infancy. Indications to date suggest that it will not be as cheap as its biggest boosters hope. It may not be able to store carbon permanently or safely. Carbon capture certainly cannot do anything to mitigate emissions from mobile sources, making fossil fuel operations that generate fuels for them problematic.

On the basis of these concerns, I suggest that the following elements are important in any responsible consideration of CCS, from a public policy standpoint:

Emissions reductions from CCS should not be estimated until information on the costs and effectiveness of commercial operations are known.
It should not be assumed that CCS will allow high carbon activities such as burning coal or harvesting the oil sands to continue.
While some public funding for CCS may be justifiable (especially investigations into using it with biomass fuels), industry groups that are predicting heavy usage of the technology should bear most of the development and implementation costs.
CCS doesn’t make coal ‘clean.’ Even if it reduces CO2 emissions by 80-90%, coal will still be a climatically unsustainable technology. There are also a large number of environmental hazards associated with coal mining, coal ash, and so forth. Coal will probably never be clean, and will certainly never be clean just because it has CCS bolted on.
Likewise, CCS cannot redeem the oil sands.
We must develop alternative plans, in case CCS proves to be ineffective, unsafe, or unacceptably expensive.

As I have said before, we are in the Wright Brothers era of CCS technology, and it is far too soon to project whether it will be an important stabilization wedge or an expensive flop. It is definitely too early to be estimating the specific quantities of emissions that will be averted by as-yet-nonexistent technologies at unknown future dates.

If emissions are going to peak and descend to safe levels, we are going to need a lot of stabilization wedges: efficiency, protected and enhanced forests, zero-carbon electricity and fuels, and more. If we want to have a strategy that can survive the failure of a few major initiatives, that means we need extra wedges for contingency. As such, we probably can’t reject technologies like CCS and the increased use of nuclear fission out of hand.

Hiding Nobel Prize medals

Recently, I came across an interesting anecdote about the history of Nobel prizes: specifically, those that were awarded to James Franck (for work on quantum physics) and Max von Laue (for discovering x-ray crystal diffraction). Fearful of confiscation by the Nazis, both scientists illegally sent their medals to Niels Bohr in Copenhagen, for safe keeping. Franck then fled from Germany to America, prior to the Nazi invasion of Denmark in 1940.

At the time, sending the medals out of Germany was a very serious crime and, since they were engraved with the names of their recipients, Bohr feared what would happen to them if the medals were found by the occupying army. Fearful that the invaders would find and confiscate the medals, Bohr eventually passed the medals to the chemist George de Hevesy, who subsequently dissolved both Franck and von Laue’s medals in acid (aqua regia, specifically). He was able to hide the resulting black solution from the Nazi invaders and, after the war, the gold was precipitated out of the solution and sent to Stockholm to be re-forged into medals by the Swedish Academy. Bohr had previously sold his own medal at a charitable auction earlier that year.

In 1943, de Hevesy himself won a Nobel Prize in Chemistry, for work on using isotopes to trace chemical processes.