Not enough to slash carbon emissions, vital to deplete stock of emitted CO2

The latest climate report from the United Nations is a scary document, but also provides clarity on the action to be taken and who is best placed to take it. The developed world has to immediately get down to sucking carbon dioxide out of the atmosphere, even at a relatively high cost: it is just not enough to bring down emissions, however drastically.

The existing stock of greenhouse gases in the atmosphere is enough to do significant damage. The air must be scrubbed clean of the gases that trap heat on the planet, instead of letting it radiate out of it. The primary culprits for the stock of manmade CO₂ in the atmosphere are the developed countries, and they must accept the responsibility to remove carbon dioxide from the air.

All doubting Thomases sceptical about climate change only need to wear that other hat Tom has traditionally been made to wear, and take a peep at the forest fires in Australia, Northwestern United States, Turkey and Greece, the extraordinary floods in Europe and China, in addition to the ones that we in India have come to accept as ordinary ones, as well as at the heat waves that have pushed up temperatures in Canada’s British Columbia to 49.6 per cent, made Sicily sizzle at 48.8 per cent and warm the Arctic. The world is already warmer than pre-industrial levels by 1.09^oC, finds the Sixth Assessment Report by the Intergovernmental Panel on Climate Change.

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Extreme weather events, cloud bursts, floods, heat waves that dry once-green forests into tinder waiting for the least incendiary provocation to turn into a raging, fiery mass of mobile destruction reaching for nearby farms and human settlements, have caught on earlier than rising sea levels have submerged tiny islands in the Pacific or the coasts of Bangladesh or Kerala. This helps concentrate minds in developed country capitals, on the plus side.

Atmospheric concentrations of CO_2­ above 400 parts per million have existed in the past, too — three million years ago, it has been estimated. Clearly, the planet can survive high levels of greenhouse gases in the air and concomitant high temperatures. There is a minor inconvenience, however. The sea level then was 15-25 m above today’s. So, all fervent cries to Save the Planet or Save Earth are so much hypocrisy. The cry ought to be, Save Humanity or, more honestly, ‘Somebody Stop Me’.

Calls will intensify for all countries, including developing ones, to accelerate their pace of emission reduction. India will be expected to announce a deadline for reaching net zero carbon emissions — China has announced its deadline to be 2060. This, of course, is important. But that will not prevent global average temperature rising 1.5^oC above pre-industrial levels by 2030. To prevent that nasty eventuality, carbon dioxide had to be removed from the atmosphere at a phenomenal rate.

Geoengineering methods, to reflect light and heat off the planet, could have unpredictable effects on the weather, often in the poorest parts of the world. These are too risky to be deployed on any large scale at the moment.

The world emits upwards of 40 billion tonnes of carbon a year now. Suppose 10 years’ worth of emissions are sucked out, it might be possible to slow down the rise in global temperatures and the momentum of climate change, although some sorts of changes are on autopilot and will continue for some time.

Carbon Dioxide Removal (CDR) goes beyond the traditional carbon capture and storage/sequestration (CCS) used for scrubbing CO₂ from the exhaust gases of power plants and the like. The technology for capturing carbon from gases where levels of CO₂ concentration are high is different from the technologies that have to be deployed to capture the offending gas at concentrations of 400 parts per million, of the kind that is found in the air we breathe.

Of course, nature has its own ways of absorbing CO₂ from the air. Plants do it in their normal process of synthesizing food using carbon dioxide as feedstock and sunlight as energy. The seas absorb atmospheric CO₂. When the concentration of the gas in the sea water rises, its ability to absorb additional amounts comes down. Carbon dioxide dissolved in water is an acid, carbonic acid, the sour stuff in soda. Ocean acidity is already up by 30 per cent. There are limits to how much afforestation and other forms of greenery can take surplus CO2 from the air. You would need to plant new forests to an extent that leaves little room for human habitation and agriculture. Of course, research is underway to increase carbon absorption by plants: deeper, larger roots with robust wanderlust underground is one idea that is, well, taking root. But that will only make a marginal difference. We need to adopt new, manmade methods to scrub CO₂ from the air.

Interesting kinds of technologies are being developed. The Lawrence Livermore National Laboratory has developed a method of 3D printing porous graphene electrodes that absorb CO₂ while being charged and release the gas when discharging. Some startups and universities are working on a range of possibilities, from encouraging phytoplankton growth in desert oases to absorb the gas and release water, to a chain of enzyme-triggered reactions that begin with CO₂ and end up with carbon fiber and hydrogen. Conversion of the captured CO₂ into other useful materials promises to offset the cost of carbon reduction.

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One goal is to use the captured gas to produce synthetic hydrocarbon fuel (this would later release the carbon into the atmosphere, and so, at best, only succeed in preventing further rise in atmospheric CO₂ rather than in reducing the stock of the gas).

At an optimistically realistic level, it is estimated that CO2 can be captured for use at a cost of some $35 per tonne (see the Columbia University site for a better idea of the costs involved – http://bit.do/Columbia-climate). That would put the cost of taking out 400 billion tonnes of the gas at $14,400 billion over 10 years, or $1.44 trillion a year. That is some 4 per cent of the combined GDP of the G7 and 2 per cent of that of the G20.

As technology matures and CO₂ becomes a profitable feedstock for producing value added products, this cost will come down drastically, and could even turn a profit.

India should press for such a proposal and Indian startups should take vigorous part in creating carbon capture and use businesses.