Thu, Feb 21, 2019 - Page 9 News List

Geoengineering is a dangerous distraction

Some climate change deniers are pushing tactics that were once considered unthinkable, such as carbon-dioxide removal and solar radiation modification, which are not only environmentally risky, but are more likely to accelerate the climate crisis than to reverse it

By Carroll Muffett

Illustration: Mountain People

As concentrations of atmospheric carbon dioxide surpass 400 parts per million, the costs of the climate crisis — in terms of economic losses, environmental impacts, and human lives — continue to rise.

In October last year, the Intergovernmental Panel on Climate Change (IPCC) said that global temperatures approaching 1.5°C above pre-industrial levels would have serious consequences for humanity and biodiversity. Anything beyond that level will be catastrophic.

To avoid crossing the 1.5°C threshold, the world must nearly halve its carbon-dioxide emissions by 2030 and reach net zero emissions by 2050.

This is going to be possible only if we completely eliminate fossil fuels from the economy within the next few decades. Attempts to circumvent that reality will only make matters worse.

We are at risk of doing just that. A growing number of people are now considering the once-unthinkable strategy of geoengineering our way out of the climate crisis.

Proposed approaches vary widely, but all share a few key features: they are technologically uncertain, environmentally risky and more likely to accelerate the climate crisis than to reverse it.

Proponents advocate two main geoengineering strategies: carbon-dioxide removal (CDR) and solar radiation modification (SRM). Both — along with most other geoengineering strategies — would depend on the widespread deployment of so-called carbon capture, utilization and storage (CCUS), in which a suite of technologies captures carbon-dioxide from industrial waste streams and stores it underground, in the oceans, or in materials.

On its own, this would raise serious environmental and social risks, but economically, CCUS is viable only if captured carbon is pumped into old oil wells to force out more oil, into abandoned coal mines to produce natural gas, or into refineries to produce yet more plastic.

This would benefit the fossil-fuel industry — and hurt everyone else.

The specifics of each strategy only reinforce the dangers of geoengineering. Consider CDR, which aims to absorb carbon from the atmosphere after it has been emitted. The most widely discussed approach — bioenergy with carbon capture and storage (BECCS) — would mean clearing large stretches of intact forest, displacing food crops, or both, to produce more burnable fuels.

This would not only threaten food security and land rights; the clearing of forests could cause more carbon to be released than BECCS ever absorbs.

Another major CDR technology — direct air capture (DAC) — would suck carbon dioxide from the air by installing what are essentially huge air filters around the planet. To pay for this extremely energy-intensive process, proponents want to use the captured carbon-dioxide to produce diesel and jet fuels, which would then be burned and re-emitted in an endless cycle.

Put simply, DAC is a very expensive means of turning renewable energy into gas.

The other major geoengineering strategy, SRM, seeks to mask rather than reduce atmospheric carbon dioxide. The most widely discussed approach involves injecting sulfur dioxide into the upper atmosphere, producing a temporary cooling effect.

However, burning coal, oil, and gas — which also produce large amounts of sulfur dioxide — has the same effect, while also causing acid rain and depleting the ozone layer.

Proponents of SRM thus argue, perversely, that we should protect the planet by producing more of the pollutants that are already destroying it.

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