Science – Page 104 – a sibilant intake of breath

Five gigatonne globe

[Update: 22 January 2009] Some of the information in the post below is inaccurate. Namely, it implies that some level of continuous emissions is compatible with climate stabilization. In fact, stabilizing climate required humanity to have zero net emissions in the long term. For more about this, see this post.

As discussed before, credible estimates of the carbon absorbing capacity of the biosphere are around five billion tonnes (five trillion kilograms) per year of carbon dioxide equivalent.

The graphic above is probably far too nerdy to have popular appeal – and it is possible the numerical figure will need revision – but it does strike me as a concise expression of what needs to be tackled.

Knowledge brokers get the Nobel

The hot news today is that the Intergovernmental Panel on Climate Change and Al Gore (though not Sheila Watt-Cloutier) have been awarded the Nobel Peace Prize. While some have questioned the appropriateness of awarding the prize on the basis of achievements not directly related to armed conflict, it does seem that the conflict potential connected with migration, water scarcity, and so forth makes this less of a stretch than some previous awards.

What is most notable about all this, for me, is that neither Gore nor the IPCC have actually contributed to climatic science. The IPCC exists to review the published academic literature on climatic science and agree upon a consensus position; Gore has acted as an effective advocate and representative, though his overall contribution has been far more in the area of information transmission than the area of information generation.

What this shows is how vitally important the layer between scientists and policy-makers or the general public is. Scientists are looking (with great skill and detail) at the individual elements that make up the climatic system. Translating that into a comprehensive understanding of relationships and risks – of the sort that can guide policy development – is critical and challenging. As such, these Nobel prizes are well earned.

Previous related entries:

The World Without Us

Around the globe, every natural system is being affected by human behaviour: from the composition of deep oceanic sediments to mountaintop glaciers. As such, the concept behind Alan Weisman’s extraordinary book The World Without Us is both ambitious and illuminating. Using a combination of research, expert consultation, and imagination, he projects what would happen to the Earth if all 6.7 billion human inhabitants suddenly vanished. Within weeks and months, all the nuclear power plants will melt down; the massive petroleum refinery and chemical production complexes will burn, corrode, and explode; and nature will begin the slow process of reclaiming everything. Over the course of decades and centuries, the composition of all ecosystems will change as farmland is retaken and once-isolated patches of wildlife become reconnected. Cities will fall apart as bridges stretch and compress with the seasons and foundations fail on account of flooding. In the end, only bronze sculpture and ceramics are likely to endure until our red giant sun singes or engulfs the planet in about five billion years. More broadly, there is reason to hope that radio waves and some interstellar space probes will endure for billions of years.

Weisman uses his central idea as a platform from which to explore everything from material science to palaeontology and ecology. The book is packed with fascinating tidbits of information – a number of which have been shamelessly plagiarized in recent entries on this blog. A few examples of especially interesting topics discussed are the former megafauna of North America, human evolution and migration, coral reef ecology, lots of organic chemistry, and the history of the Panama Canal.

In the end, Weisman concludes that the human impact upon the world is intimately linked with population size and ultimately determines our ability to endure as a species. As such, he concludes with the concise suggestion that limiting human reproduction to one child per woman would cut human numbers from to 3.43 billion by 2050 and 1.6 billion by 2100. That might give us a chance to actually understand how the world works – and how human activity affects it – before we risk being overwhelmed by the half-glimpsed or entirely surprising consequences of our energetic cleverness.

Whether you accept Weisman’s prescription or not, this book seems certain to deepen your thinking about the nature of our world and our place within it. So rarely these days do I have time to re-read things. Nevertheless, I am confident that I will pick up this volume again at some point. Readers of this blog would be well rewarded for doing likewise.

[4 November 2007] I remain impressed by what Weisman wrote about the durability of bronze. If I ever have a gravestone or other monument, I want the written portion to be cast in bronze. Such a thing would far, far outlast marble or even steel.

Hot Air

Hot Air: Meeting Canada’s Climate Change Challenge is a concise and virtually up-to-the-minute examination of Canadian climate change policy: past, present, and future. Jeffrey Simpson, Mark Jaccard, and Nic Rivers do a good job of laying out the technical and political issues involved and, while one cannot help taking issue with some aspects of their analysis, this book is definitely a good place to start, when seeking to evaluate Canada’s climate options.

Emission pathways

Hot Air presents two possible emissions pathways: an aggressive scenario that cuts Canadian emissions from 750 Mt of CO2 equivalent in 2005 to about 400 Mt in 2050, and a less aggressive scenario that cuts them to about 600 Mt. For the sake of contrast, Canada’s Kyoto commitment (about which the authors are highly critical) is to cut Canadian emissions to 6% below 1990 levels by 2012, which would mean emissions of 563 Mt five years from now. The present government has promised to cut emissions to 20% below 2006 levels by 2020 (600 Mt) and by 60 to 70% by 2050 (225 to 300 Mt). George Monbiot’s extremely ambitious plan calls for a 90% reduction in greenhouse gas emissions by 2030 (75 Mt for Canada, though he is primarily writing about Britain).

While Monbiot’s plan aims to reach stabilization by 2030, a much more conventional target date is around 2100. It is as though the book presents a five-decade plan to slow the rate at which water is leaking into the boat (greenhouse gasses accumulating in the atmosphere), but doesn’t actually specify how to plug the hole before it the boat sinks (greenhouse gas concentrations overwhelm the ability of human and natural systems to adapt). While having the hole half-plugged at a set date is a big improvement, a plan that focuses only on that phase seems to lack an ultimate purpose. While Hot Air does not continue its projections that far into the future, it is plausible that the extension of the policies therein for a further 50 years would achieve that outcome, though at an unknown stabilization concentration. (See this prior discussion)

Policy prescriptions

Simpson, Jaccard, and Rivers envision the largest reductions being achieved through fuel switching (for instance, from coal to natural gas) and carbon capture and storage. Together, these account for well over 80% of the anticipated reductions in both scenarios, with energy efficiency improvements, agricultural changes, waste treatment changes, and other efforts making up the difference. As policy mechanisms, the authors support carbon pricing (through either a cap-and-trade scheme or the establishment of a carbon tax) as well as command-and-control measures including tightened mandatory efficiency standards for vehicles, renewable portfolio standards (requiring a larger proportion of energy to be renewable), carbon management standards (requiring a larger proportion of CO2 to be sequestered), and tougher building standards. They stress that information and subsidy programs are inadequate to create significant reductions in emissions. Instead, they explain that an eventual carbon price of $100 to $150 a tonne will make “zero-emissions technologies… frequently the most economic option for business and consumers.” This price would be reached by means of a gradual rise ($20 in 2015 and $60 in 2020), encouraging medium and long-term investment in low carbon technologies and capital.

Just 250 pages long, with very few references, Hot Air takes a decidedly journalistic approach. It is very optimistic about the viability and affordability of carbon capture and storage, as well as about the transition to zero emission automobiles. Air travel is completely ignored, while the potential of improved urban planning and public transportation is rather harshly derided. The plan described doesn’t extend beyond 2050 and doesn’t reach a level of Canadian emissions consistent with global stabilization of greenhouse gas concentrations (though it would put Canada on a good footing to achieve that by 2100). While the book’s overall level of detail may not satisfy the requirements of those who want extensive technical and scientific analysis, it is likely to serve admirably as an introduction for those bewildered by the whole ecosystem of past and present plans and concerned with understanding the future course of policy.

Geologic time

While the Earth is about 4.54 billion years old, all of human civilization has been compressed into a single geological epoch: the Holocene. This has been ongoing for about 11,500 years, predating the first Mesopotamian civilizations for which we have any evidence. Prior to the Holocene was the Pleistocene, which ended with the Younger Dryas cold spell. Actually, the Holocene exists more as a demarcation for the period of geologic time that has included human civilization than as an epoch with an independent definition.

Our best ice core samples extend back 650,000 years: about a third of the way into the Pleistocene, but just a tiny foray into geologic time. Pollen from Lake Tanganyika might take us through the Pliocene (Greek for ‘more new’) and into the Miocene (‘less new’). Perhaps some yet-unanticipated data source will be able to take us further still.

It is amazing what scientists are able to determine from inference and the meticulous collection of data: from the age of the universe to the evolutionary history of the planet.

Heat, bacteria, and evolution

For those who are unfamiliar, capsaicin is one of the most interesting molecules out there. This is the chemical that makes chili peppers spicy; it is also the active ingredient in pepper spray. Pure capsaicin is rated at about 15 million Scoville heat units: a scale where Tabasco sauce is scored at about 2,500.

Capsaicin is quite an amazing adaptation, actually. Plants developed it to deter animals from eating them. Eventually, animals realized that capsaicin was painful to them, but not actually harmful. By contrast, it is very harmful to some of the species of bacteria that spoil food. As such, spicy foods emerged in hot climates as a defence against nasty prokaryotes. A direct descendent of that realization are the veggie vindaloos I enjoy so much.

Spices have been mentioned here before.

Polymers in the Pacific

In addition to nuclear waste, there are other very long lived forms of human detritus accumulating in the world. Most pervasive among those may be plastics. Virtually non-existent before the Second World War, they are now produced in staggering quantities. So far, none of those artificial polymers have broken down chemically; instead, they just break into smaller and smaller pieces, float down rivers to the sea, and end up in places like the North Pacific Gyre. It is also discussed on MetaFilter.

As with vulcanized rubber, these materials will endure in the world until microorganisms evolve the ability to metabolize them. Apparently, when plants first evolved lignin and cellulose, bacteria were unable to digest them. Until that changed, wood would have been as enduring as the plastic wrap currently swirling and collecting persistent organic pollutants in the world’s oceanic gyres, quite probably for millions of years.

The true price of nuclear power

Several times this blog has discussed whether climate change is making nuclear power a more acceptable option (1, 2, 3). One element of the debate that bears consideration is the legacy of contamination at sites that form part of the nuclear fuel cycle: from uranium mines to post-reactor fuel processing facilities. The Rocky Flats Plant in the United States is an especially sobering example.

Insiders at the plant started “tipping” the FBI about the unsafe conditions sometime in 1988. Late that year the FBI started clandestinely flying light aircraft over the area and noticed that the incinerator was apparently being used late into the night. After several months of collecting evidence both from workers and by direct measurement, they informed the DOE on June 6, 1989 that they wanted to meet about a potential terrorist threat. When the DOE officers arrived, they were served with papers. Simultaneously, the FBI raided the facilities and ordered everyone out. They found numerous violations of federal anti-pollution laws including massive contamination of water and soil, though none of the original charges that led to the raid were substantiated.

In 1992, Rockwell was charged with minor environmental crimes and paid an $18.5 million fine.

Accidents and contamination have been a feature of facilities handling nuclear materials worldwide. Of course, this does not suffice to show that nuclear energy is a bad option. Coal mines certainly produce more than their share of industrial accidents and environmental contamination.

The trickiest thing, when it comes to evaluating the viability of nuclear power, is disentangling exactly what sort of governmental subsidies do, have, and will exist. These subsidies are both direct (paid straight to operators) and more indirect (soft loans for construction, funding for research and development). They also include guarantees that the nuclear industry is only responsible for a set amount of money in the result of a catastrophic accident, as well as the implicit cost that any contamination that corporations cannot be legally forced to correct after the fact will either fester or be fixed at taxpayer expense. Plenty of sources claim to have a comprehensive reckoning of these costs and risks, but the various analyses seem to be both contradictory and self-serving.

Before states make comprehensive plans to embrace or reject nuclear power as a climate change mitigation option, some kind of extensive, comprehensive, and impartial study of the caliber of the Stern Review would be wise.

Jeffersonian trivia

Little known facts:

Former American President Thomas Jefferson was an avid amateur palaeontologist.
In an attempt to mock him, his political opponents gave him the nickname “Mr. Mammoth” during the 1808 election.
He is credited with the discovery of an enormous ground sloth, larger than an elephant, that inhabited North America during the late Pleistocene.
The creature now bears his name: Megalonyx jeffersonii.

These and many other entertaining facts come from the marvellous recent book The World Without Us, which has leapt to the top of my reading pile. I will post a full review when I finish it.

Seafood harm reduction

For those who haven’t taken the plunge into vegetarianism or veganism, but who are concerned about the ecological consequences of fish consumption, there are some good resources online. The Monterey Bay Aquarium has printable pocket-sized seafood guides, highlighting which species are harvested in relatively sustainable ways and which should definitely be avoided. The Blue Ocean Institute also has a number of resources, including a website for looking up species and a guide that can be downloaded.

Species that are particularly threatened (as well as often caught in highly unsustainable ways) include:

Bluefin tuna
Chilean Sea Bass (this is an industry name for Patagonian Toothfish)
Groupers
Orange Roughy
Atlantic Cod
Atlantic Halibut
Oreos (the fish, not the cookies)
Rockfish
Sturgeon Caviar
Snappers
Atlantic Salmon (note, all Atlantic salmon in the U.S. is farmed)
Sharks

While it is inadequate to think about marine conservation in terms of single species, such lists do provide a reasonably accessible way for consumers to scrutinize their actions. In the long run, however, marine resources need to be thought about in terms of whole ecosystems that need to be protected from threats including over-exploitation, toxins, and climatic changes.