Tech fixes to tackle acidifying seas

Can technological advances help acidifying seas?

MANY scientists are increasingly acknowledging that we can no longer afford to dismiss some gee-whiz technological fixes outright. We need to understand what, if any of it, could help.

In 2012, a controversial California entrepreneur motored off the coast of British Columbia and dumped 100 tonnes of iron dust into the Pacific Ocean, hoping to spark a 360sqkm plankton bloom. Scientists around the world were outraged. The broad-scale move to scrub carbon dioxide from a patch of water by stimulating plant growth took place with no input from the international community.

There was little evidence to suggest the businessman even carried the right tools to test his results. Experts dubbed him a rogue and dismissed his plan for so-called iron fertilisation as “disastrous”, “madness” and “insane.”

But reaction to the risky, unsanctioned experiment masked a new reality: once largely panned as cuckoo, the idea that geo-engineering or technological tinkering may someday play a role in tackling the world’s CO2 problem is no longer dismissed by mainstream scientists. In the last few years, researchers have even worked on setting global protocols to guide research.

These scientists insist that reducing CO2 is still a must to avoid global climate and ocean disruption. But with progress stalled on scaling back fossil fuel emissions, many scientists concede the time could come when massive technological solutions are necessary. Some even argue that we need to better understand the options because a frustrated nation one day may attempt to unilaterally deploy an untested technique as happened in British Columbia – but on a far larger, more dangerous scale.

“I’m really surprised in the last few years how quickly some of these ideas have gone from being ‘thought experiments’ to being the kind of thing people are considering seriously and that some think might ultimately even happen,” said Ken Caldeira, a climate scientist with Carnegie Institution for Science at Stanford, who has studied geo-engineering proposals. Caldeira and others see the value of massive technological fixes as an “in-case-of-emergency-break-glass kind of thing.”

Jeremy Mathis, an oceanographer with the National Oceanic and Atmospheric Administration (NOAA) who studies chemistry changes in the Arctic, said he would never endorse manipulating sea chemistry or global CO2 in lieu of reducing emissions. “But at this point it makes sense to pursue all possibilities … just in case,” he said.

Brad Warren, with the non-profit Sustainable Fisheries Partnership, said it’s time to figure out what’s feasible and what’s not.

“We’ve reached the stage where we can’t afford to be snooty about this stuff,” he said. “I don’t want to rely on this. I doubt many of the ideas are workable on a global scale. And I think there is real peril in believing we can engineer our way out of everything. We can manage far better through prevention. Nonetheless, we need to be looking at the whole tool kit, whether we like it or not.”

Certainly, there is no shortage of ideas. And many have no shortage of problems. On a global scale, no option “has yet been demonstrated to be effective at an affordable cost, with acceptable side effects,” according to a major 2009 study by the Royal Society, the United Kingdom’s academy of sciences.

For starters, most plans are designed to deal exclusively with temperature increases – not the changing chemistry of the sea. That includes inventor Nathan Myhrvold’s idea to shoot sulphur dioxide 24km into the sky through a hose to scatter sunlight and cool the planet, and proposals to seed ocean clouds to reflect back sunlight.

Meanwhile, iron fertilisation, such as the type attempted in British Columbia, could reduce some amount of acidification in surface waters as algae grows and sucks up CO2. But research suggests it may promote souring seas near the bottom as plant life dies, sinks and decays. Efforts to grind up limestone, barge it out to sea and dump it to increase ocean alkalinity would require incredible amounts of material and the energy to transport it.

“I always wanted to do a calculation to show how many of the White Cliffs of Dover you would have to grind up to get enough material to really make a difference,” said Michael O’Donnell, an acidification expert with California Ocean Science Trust, which helps incorporate the best marine science in policy-making.

Yet CO2 lasts so long in the atmosphere that some computer models suggest even if emissions begin declining within a decade, some engineered fix could still be needed just to get oceans to maintain their current chemical balance. For the moment, the most promise seems to be on smaller scales.

“I wouldn’t call what I’m working on geo-engineering,” said Greg Rau, a marine chemist with Lawrence Livermore National Laboratory. “That’s misleading.”

Rau has experimented with using seawater and limestone to transform the CO2 waste in power plants into a new by-product: calcium bicarbonate. In lab tests, he has successfully eliminated 97% of CO2, and believes the alkaline waste – if tests show it’s free from impurities – could be dumped into the sea, reducing the water’s acidity. It’s the same process some seawater aquariums use to reduce acidity.

Rau suspects it would be most useful in a select few situations – such as a natural-gas-fired power plant operating near marine waters, where seawater already is used as coolant. The CO2 from coal is filled with too many other contaminants, he said.

“We’re probably not going to solve the global problem using this method,” he said. “But it could be beneficial in, say, helping some oyster beds, or in a bay or helping some coral reefs.”

Some scientists and policy-makers fear that focusing too much on technological fixes could draw emphasis away from reducing CO2.

“If a scheme gets deployed and it basically works even just a little, people might relax and allow us to wind up with even higher CO2 emissions,” said Caldeira. But he also dismisses criticism for contemplating such fixes at all.

“I get a lot of people thinking I’m an advocate of deploying these things just because I want to understand them,” he said. “I’m not. But if the models say you can reduce the environmental damage, it would be irresponsible to not investigate it.”

Craig Welch, The Star Online, 17 February 2014. Article.

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