Earth Hour tonight, 8:30 PM your time

March 28, 2009

Tonight is Earth Hour. Last year, more than 50 million people in 400 cities turned out their lights for one hour to show political leaders that they wanted real action on climate change. This year, let’s make it even bigger.

All you have to do is turn off your lights at 8:30 PM your local time and leave them off for 60 minutes. I’ll even be turning off my beloved laptop for some grantwriting with…paper and pencil!!!

I’m perfectly aware that Earth Hour is just a minuscule drop in the giant ocean of worldwide energy use. But even for something as trivial as turning out the lights, seeing the entire world taking collective positive action warms the cockles of my cold dark heart.

Here’s the official Earth hour video if you want something all inspirational. But if I’m going to sit alone in the dark contemplating climate change, I’m going to do it to the dark beats of VNV Nation:

Iron fertilization in the Southern Ocean doesn’t sequester carbon

March 24, 2009
I can haz ur carbon sequestration? NOM NOM NOM.

I can haz carbon sequestration? NOM NOM NOM.

The results of the latest iron fertilization experiment in the Southern Ocean are in – and it doesn’t look good as a solution for climate change. The Lohafex project, a collaboration between Indian and German scientists, found that merely stimulating a plankton bloom with iron did not lead to carbon sequestration.

What they were hoping would happen was this:

  1. Iron input
  2. Diatom bloom – diatoms have fast-sinking silica shells
  3. Diatoms die & sink to bottom
  4. Silica shells buried for all eternity
  5. Carbon sequestration WIN!

What actually happened was this:

  1. Iron input
  2. Yummy Phaeocystis algae bloom – no silica shells
  3. Copepods (tiny crustaceans) eat delicious soft algae.
  4. Amphipods (small crustaceans) eat delicious crunchy copepods.
  5. Copepods and amphipods respire, turning the algae right back into carbon dioxide.
  6. Carbon sequestration LOSE.

Previous studies have shown that only 1-2% of sinking carbon (and that’s a generous estimate)  gets sequestered. There’s life in the deep midwater and life in the deep sea and all life is HUNGRY. (Personally, I blame the deep-sea sea cucumbers – those gluttons are major consumers of what little detritus makes it down there.)

Though the iron fertilization part of this cruise didn’t work out as desired, understanding nutrient cycling and plankton dynamics in the Southern Ocean is really important. As the polar ice melts it could cause nutrients to fluctuate, affecting the whales and squid and birds that all depend on Antarctic food sources. So please count me in for any future collaborations with Indian scientists! From the press release:

Spicy Indian curries were prepared at each meal by a Goan cook specially engaged for this cruise and contributed to the good atmosphere.

Will dumping cornstalks into the ocean sequester carbon?

February 11, 2009

There a new ocean carbon sequestration scheme in town – dumping crop waste. A study published in Environmental Science and Technology last month proposes baling up corn husks and wheat stalks, weighting them with rocks, and tossing them into the deep sea. (Here’s the NYT blurb.)

The authors claim that marine creatures will be unable to digest chewy terrestrial plants chock-full of lignin and cellulose, so the sea will keep that carbon down for thousands of years. If this worked, they calculate it would reduce carbon accumulation in the atmosphere by 15%.

Unfortunately, their entire premise might be wrong. The deep sea is not a lifeless cold dark empty place – it is filled with animals that are evolved to take advantage of whatever food drifts down from above, terrestrial or not. For example, wood that falls into the deep sea gets eaten. There’s even a deep-sea bivalve that specializes in drilling into wood.

Since wood is a lot harder on the digestion than grass stems, I doubt that all that crop waste would just sit there bereft and alone for thousands of years. It’s going to get munched upon and decomposed, and the carbon will go back into global circulation. I wish that controlling climate change were as simple as dumping some stuff nobody wants anyway into the ocean, but I just don’t think it’s going to be that easy.

Stuart E. Strand, Gregory Benford (2009). Ocean Sequestration of Crop Residue Carbon: Recycling Fossil Fuel Carbon Back to Deep Sediments. Environmental Science & Technology, 43 (4), 1000-1007.

The risks & benefits of geoengineering

January 9, 2009

ResearchBlogging.orgGeoengineering – the deliberate manipulation of the earth’s atmosphere in order to mitigate global warming – seems to be gaining more credibility worldwide. Just today, Wired reports that an iron fertilization experiment is being conducted in the Southern Ocean by Indian and German scientists.

Though iron fertilization is the best-known geoengineering proposal (thanks to Planktos’ shenanigans), there are several other serious methods under discussion. In a commentary published in Nature Geoscience in November, Philip Boyd summarized current geoengineering proposals and ranked them based on effectiveness, cost, risk, and time.

Here are the proposals Boyd ranked:

  • Iron fertilization. Deliberately stimulating plant growth in the ocean with the aim that the excess material will be permanently sequestered in the deep sea. This would remove carbon from the atmosphere.
  • Stratospheric aerosols. Injecting sulfer particles into the upper atmosphere to mimic a volcanic explosion and physically deflect sunlight. This would not remove carbon from the atmosphere, but would lower the overall amount of  heat reaching Earth.
  • Cloud whitening. Spraying seawater droplets into marine clouds in order to increase their reflectance of sunlight. Like the stratospheric aerosols, this would not remove carbon from the atmosphere, but would lower the overall amount of  heat reaching Earth.
  • Atmospheric carbon capture. Removing carbon from the atmosphere with a chemical absorbent (“scrubbers”) and then sequestering it.
  • Geochemical carbon capture. Removing carbon from the atmosphere by using brine pools to transform it to a dissolved or solid state.

Boyd provides an handy, color-coded guide to the risks and benefits of each type of geoengineering. The more colored blocks a scheme has, the “better” it is.

Ranking geoengineering schemesBased on Boyd’s work, the highest-ranked proposal is cloud whitening. It has a reasonably solid rationale based on observations of ship tracks, it is reasonably affordable & safe, it would rapidly lower the Earth’s temperature if it worked (“mitigation rate”), and can be quickly stopped if there are unintended side effects (“emergency stop”).

The lowest-ranked proposal is (SHOCK!) iron fertilization. Though it has a relatively solid rationale based on experimental data, it has many unpredictable side effects and cannot easily be stopped in an emergency. Oh, and it probably won’t actually work.

Though Boyd’s ranking is certainly oversimplified – for example, cloud whitening, even if it worked, would do nothing to halt ocean acidification – that’s intentional. Boyd intends his system to be used as a logical starting point to figure out which geoengineering schemes deserve more research, and which should be trashed. He writes:

A transparent assessment should strive to increase public confidence in any selected tools, a prerequisite for tackling the difficult questions and complex issues raised by geopolitical, social and economic risks. Such an assessment of all of the
well-established proposals is urgently needed but so far entirely lacking.

Right now, I don’t feel confident in any of these proposals. I am dubious that we understand the ocean and atmosphere well enough to tinker with them. But since the nasty consequences of climate change are already coming fast and furious, I’m willing to listen to sober assessments of geoengineering risks and rewards. Just hold the pseudo-scientific hubris.

Thanks to Hao for the Wired article and Geoff for the geoengineering paper!

Philip W. Boyd (2008). Ranking geo-engineering schemes Nature Geoscience, 1 (11), 722-724 DOI: 10.1038/ngeo348

A quick & dirty guide to ocean acidification

January 4, 2009

Are you confused about this whole ocean acidification thing? As a followup to my guide to nearshore drilling, I’ve written a guide to ocean acidification. It’s up as a guest post over at The Reef Tank, an online community of aquarium hobbyists. Here’s the beginning:

Ocean acidification will make off with your children! It will come after you in the night! It’s not safe until its head is mounted on my wall! KILL THE BEAST!

Ooops. Wrong movie. But ocean acidification has received a lot of high-profile attention lately, most notably with an editorial in the New York Times. The claims are flying every which way – ocean acidification will kill all the coral reefs, ocean acidification will make the oceans a barren wasteland of jellyfish, ocean acidification will even level the blood-thirsty Humboldt squid.

So here’s your handy guide to ocean acidification, and how it might affect coral reefs in particular.

Click here for the rest.

Thanks to Ava at the Reef Tank for the opportunity!

Breaking: High prices more persuasive than insistent nagging

July 17, 2008

For years, environmentalists have employed what might best be called the Nudge Model of persuasion. The conversation went like this:

Enviro: C’mon guys! Global warming! Stop driving those big cars. Pleaaaaaaase? C’Mon.”

American: Uh, right. Look, could you get that clipboard out of my face? I have people coming over, and I need to set the table with my plastic plates, take a 30-minute shower, and crank up the  air conditioner.

[Gets into Dodge Durango. Revs engine for Indy 500 effect, and screeches out of parking lot].

Enviro: But… but… C’MON!

Now, though, with gas prices over $4 a gallon, and with $5 and $6 well in sight, well! Now we’re seeing some changes  (quotes below taken from the articles linked):

• “Car Buyers Downsize, spend big on options“, NYT, 7/17/08, “I’ve never seen anything like it,” Mr. Smith said. “You don’t have too many people saying, ‘It has to be white with a power package and it has to have Michelin tires.’ Instead it’s, ‘What do you have and can I get it by the end of the month? Just get me out of my Tahoe.’”

• “With Gas Over $4, Cities Explore Whether It’s Smart to Be Dense“, WSJ, 7/7/08, “Expensive oil is going to transform the American culture as radically as cheap oil did,” predicts David Mogavero, a Sacramento-based architect and smart-growth proponent.”

• “Wal-Mart goes local“, Clean Tech Group, 7/2/08, “Through better logistics planning, better packing of trucks and local sourcing, the company expects to save millions of “food miles” each year, which it said is the distance food travels from farm to fork.”

• “Field Poll finds high gas prices change Californians habits, views“, Press-Enterprise, 7/17/08, “We do no weekend driving — we don’t go out,” said Charley Stillwagon, a truck driver and single father of five from Rancho Cucamonga. “If we feel like a movie, we rent one.”

• “Gas Prices Drive  Students to Online Courses“, Chronicle of Higher Education, 7/8/08, “It’s getting to the point of either gas or class,” says Robbie K. Melton, associate vice chancellor for the Tennessee Board of Regents.”

Not that any of it’s at all surprising that people respond more quickly to money than moral arguments. But with the policy question of how best to address CO2 emissions and water conservation still raging, environmentalists would do well to think about how economic tools can best alter behavior, rather than imply moralizing. Al Gore has done his work for us,  raising awareness on the issue. Now we have to fix it.

The Managed World: Tidal power in the UK

June 24, 2008

There is no place on earth, no matter how remote, untouched by humans. We are mighty: we can trawl the deep, explore the South Pole, and fish every single island in the South Pacific. But as every young nerdling knows, with great power comes great responsibility. “The Managed World” series in the Oyster’s Garter explores the hard choices that come from a human-dominated world.

Science Magazine reports that the UK is pondering the world’s biggest tidal power generator. The Severn estuary, which separates southwest England from south Wales, has the second-biggest tidal flux in the world – the water rises and falls 45 feet (15 meters) between high tide and low tide. That’s a huge amount of power, and Britain wants to builf a tidal dam, or “barrage”,  to capture it.

A barrage is a huge dam, similar to a hydroelectric dam, built across an estuary. The Severn barrage is designed to let water freely flow into the estuary through sluice gates, which would then close to impound water in the estuary. The water would then slowly be let out through turbines.  Locks can be built to let ships through, but there’s no channel for water critters except through the turbines.

The ecological impacts could be vast and devastating. Over 68,000 birds overwinter in the Severn estuary, feeding from mudflats at low tide and sheltering in marshes. The barrage would essentially eliminate low tide, flooding these habitats and making them unavailable to birds. Also, many species of fish and invertebrates migrate into estuaries to breed, and the barrage could either prevent adults from migrating in or trap the larvae inside. Because of these vast negative impacts, it’s not surprising that Britain’s largest environmental groups have rejected the Severn barrage plan.

However, there’s no way the UK will be able to meet the EU’s goal of 15% renewable energy by 2020 without some drastic changes. Currently, only 5% of the UK’s current power is renewable. The Severn barrage alone would provide another 5% of the UK’s total energy, in reliable, carbon-free, and low-maintenance form. The only comparable barrage, the La Rance Tidal Power Plant in France, has been in operation for 40 years without a breakdown. This type of cheap, reliable, carbon-free power is pretty tantalizing, even at a hefty construction cost of £15 billion and the abovementioned environmental costs.

So again, well-intentioned people have to choose – carbon-free energy, or giant critical habitat estuary? This is the that we must reduce emissions – we are already surpassing the IPCC worst case scenario. But estuaries are critical habitat for hundreds of thousands of species and provide important ecosystem services such as flood control and pollution filtration.

One potential angle that I did not see discussed in my uncomprehensive readup on the Severn barrage is the potential for estuaries to act as carbon sinks. Because estuaries (and mud flats) have little oxygen in their soil, plant matter gets buried and doesn’t decompose for a long, long time. How much carbon is buried in the Severn estuary, and would the barrage release it? This might be one way to decide whether the energy generated by the Severn barrage would be worth the ecological damage.


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