Using Geoengineering to Control the Climate

Let me say at the outset that geoengineering to control Earth's climate is not the wisest path which Homo sapiens ("Wise Man") could travel down. Because of the large scales involved, future geoengineering may turn out to be the dumbest thing our dumb (albeit clever) species has ever done.

On Tuesday Jim Kunstler spoke of the unintended consequences of applying technology willy-nilly to solve all our problems. As global warming really gets going in the coming decades, the temptation to geoengineer the climate will become stronger and stronger.

Indeed, I think we can make a bolder prediction than that implied by mere temptation. If I am correct in my view, expressed on Monday in The Assumption Of Technological Progress, that an irresistible orientation toward technological thinking is built right into human cognition, it follows that geoengineering will necessarily be applied on large scales to control the climate. That's the way the future must look. Heroic technology will be deployed because that's just what Homo sapiens does, as opposed to making fundamental changes in its behaviour to curb population and economic growth, and scale back modern civilizations to a size commensurate with sustainable living on the Earth.

Every once in a while geoengineering stories surface in the mainstream press, and then, at least at this juncture, these stories disappear as quickly as they arose. The latest go-round can be found in the Christian Science Monitor's Dumping iron in the ocean could slow global warming, say scientists. I'll quote that story, and then show you the abstract of the Nature study it was based upon.

Dumping iron in the seas can help transfer carbon from the atmosphere and bury it on the ocean floor for centuries, helping to fight climate change, according to a study released on Wednesday.

The report, by an international team of experts, provided a boost for the disputed use of such ocean fertilisation for combating global warming. But it failed to answer questions over possible damage to marine life.

When dumped into the ocean, the iron can spur growth of tiny plants that carry heat-trapping carbon to the ocean floor when they die, the study said.

Scientists dumped seven tonnes of iron sulphate, a vital nutrient for marine plants, into the southern ocean in 2004. At least half of the heat-trapping carbon in the resulting bloom of diatoms, a type of algae, sank below 1,000 metres (3,300 ft).

"Iron-fertilised diatom blooms may sequester carbon for timescales of centuries in ocean bottom water and for longer in the sediments," the team from more than a dozen nations wrote in the journalNature.

Burying carbon in the oceans would help the fight against climate change, caused by a build-up of carbon dioxide in the atmosphere that scientists say is raising temperatures and causing more floods, mudslides, droughts and higher sea levels.

The study was the first convincing evidence that carbon, absorbed by algae, can sink to the ocean bed. One doubt about ocean fertilisation has been whether the carbon stays in the upper ocean layers, where it can mix back into the air.

A dozen previous studies have shown that iron dust can help provoke blooms of algae but were inconclusive about whether it sank.

Large-scale experiments with ocean fertilisation using iron are currently banned by the international London Convention on dumping at sea because of fears about side-effects.

Heroic Technology - various geoengineering solutions have been put forward to control the climate.

Here's the Nature abstract.

Fertilization of the ocean by adding iron compounds has induced diatom-dominated phytoplankton blooms accompanied by considerable carbon dioxide drawdown in the ocean surface layer. However, because the fate of bloom biomass could not be adequately resolved in these experiments, the timescales of carbon sequestration from the atmosphere are uncertain. Here we report the results of a five-week experiment carried out in the closed core of a vertically coherent, mesoscale eddy of the Antarctic Circumpolar Current, during which we tracked sinking particles from the surface to the deep-sea floor. A large diatom bloom peaked in the fourth week after fertilization. This was followed by mass mortality of several diatom species that formed rapidly sinking, mucilaginous aggregates of entangled cells and chains.

Taken together, multiple lines of evidence-although each with important uncertainties-lead us to conclude that at least half the bloom biomass sank far below a depth of 1,000 metres and that a substantial portion is likely to have reached the sea floor. Thus, iron-fertilized diatom blooms may sequester carbon for timescales of centuries in ocean bottom water and for longer in the sediments.

The stimulated algae bloom sucks CO2 out of the air, ingesting it by conversion to sugars (glucose) through photosynthesis, the algae dies off after a while, and then (hopefully) sinks to the ocean bottom, where the carbon remains buried for centuries. That's a pretty fancy carbon sequestration scheme, and a very slim reed to place your hopes upon. Yet hope is the vaporous quality which makes the world go round, and knowledgeable people can agree that global warming is making the future look more and more hopeless.

There is little doubt in my mind that very-large-scale heroic technology will be applied to control the climate in the future. After all, what else can people do? They can't change their fundamental behaviours. They won't stop having babies and trying to increase the material comfort (and fitness) of those offspring. So iron filings in the oceans it is! Or something else. For example, Columbia professor Klaus Lackner wants to suck the carbon right out of the air.

To address the exponential rise of atmospheric carbon dioxide concentrations since the Industrial Revolution, Professor Klaus S. Lackner, director of the Lenfest Center for Sustainable Energy at the Earth Institute, is working on ambitious carbon capture and sequestration strategies.

"Our goal is to take a process that takes 100,000 years and compress it into 30 minutes," says Lackner.

Lackner and his team are developing a device they have dubbed an air extractor, modelled after one of the most abundant but most complicated devices in nature: the leaf of a tree.  Leaves are significant absorbers of carbon dioxide from the atmosphere, but planting enough trees to absorb the current overabundance of carbon dioxide in the world would leave no fertile land left for other uses.

The lack of humility before Nature displayed here takes my breath away. There's also a video you can watch. I wonder where we would put the carbon after we've sucked it out of the atmosphere. Bury it in the backyard? Store it in the basement? (We're talking about gigatons here-billions of tons.) I'm sure Klaus has an answer for that too.

I also have little doubt that heroic geoengineering will (eventually) constitute an egregious (but inevitable) Error In Judgment. People are starting to think the unthinkable. It is only a matter of time before such thinking becomes commonplace.

By. Dave Cohen