Technological fixes can have serious consequences | Science Matters | David Suzuki Foundation
Photo: Technological fixes can have serious consequences

Putting carbon into the oceans to induce algal blooms and absorb carbon dioxide can cause the blooming of plants that produce deadly neurotoxins (Credit: heathzib via Flickr).

By David Suzuki with Faisal Moola

In 1962, Rachel Carson galvanized a global environmental movement with her book Silent Spring. Before she wrote about the unexpected consequences of pesticides — including bioaccumulation of toxic molecules up the food chain — scientific innovations such as DDT dazzled us with their promise of greater control over the forces impinging on our lives.

We often look to technological fixes without acknowledging our ignorance about how the world works, and then we end up trying to correct the unexpected problems that result. When we began to use CFCs in large amounts, scientists had no idea they might affect the ozone layer. Salmon farms seemed like a good idea, but no one anticipated parasitic sea-lice outbreaks that would harm wild salmon.

Scientists find clever ways to tease out information about our world. And everywhere we look, we discover new challenges because our knowledge is so primitive. Accumulating toxic pollutants in air, water, soil, and our bodies; vanishing species; loss of nutrients in topsoil; ocean degradation — all these provide warnings that human numbers, consumption, and activity are undermining the very things that keep us alive.

Climatologists have accumulated a powerful set of observations and models pointing to fossil-fuel use as the cause of global warming. Obviously, the solution is to reduce the amount of greenhouse gases we create so the biosphere can sop up the rest.

Some imaginative suggestions would allow us to continue to burn fossil fuels without reduction: giant umbrellas in space to shield the Earth from the sun, aerosols of sulphide to mimic volcanic emissions that reflect sunlight, and so on. Two that have attracted attention are carbon seeding in oceans and carbon capture and sequestration on land.

The first involves putting iron into the oceans to fertilize waters where the lack of carbon limits algae growth. In the lab, it has been shown that adding this carbon to Antarctic Ocean water, for example, leads to massive increases in the algal populations. Companies have been formed on the promise that putting carbon into oceans to induce algal blooms will help absorb carbon dioxide from the atmosphere. Now, in a paper in the prestigious journal Proceedings of the National Academy of Sciences USA, scientists report that this process can cause the blooming of plants that produce deadly neurotoxins. Oops.

The second suggestion is carbon capture and sequestration. Prime Minister Stephen Harper has avoided discussion about the serious impacts of climate change on Canada and the economic implications of failing to reduce emissions. Instead, government policy is based on the fear that reducing emissions will be economically destructive, so we will wait instead for the development of methods to pump carbon dioxide into the ground.

This technique is based on an observation that when carbon dioxide is pumped into depleted wells so that more oil can be recovered, the CO2 doesn't come back out. This has led to a hope that we can capture much of the CO2 from smokestacks, coal plants, and the tar sands and simply inject it into the ground — out of sight, out of mind.

But wait. While we once thought that life petered out at bedrock, we now know that life exists up to three kilometres underground. Bacteria from deep underground are so different from anything we know aboveground that we need entire new categories to describe them. Scientists estimate that the weight of all the organisms underground is greater than the weight of all life above it, including whales, trees, and people! Scientists know very little about the role these organisms play in transfer of heat from magma or the flow of nutrients and water in the subterranean world, yet we are contemplating pumping millions of tonnes of CO2 into that mysterious world.

I once asked Tullis Onstott of Princeton University, one of the world's top experts on underground life, what effect CCS might have on them. His reply? "I don't know, but the methanogens will love it."

"What are methanogens?" I asked. He said they take up carbon dioxide and produce methane, a greenhouse gas 22 times more potent than carbon dioxide!

We have so many ways to reduce our emissions and to save money and resources by becoming more efficient. Yet we avoid doing them on the hope of a totally untried technological promise that could have enormous negative consequences. Does this make sense?

March 26, 2010