In July 2012, a Canadian ecologist called Russ George took out a small fishing boat some 200 km out into the Pacific and dumped a hundred tonnes of iron — in the form of soluble iron sulphate — into the waters.

His intentions were noble — he wanted to enrich the waters so as to create a plankton bloom to increase the salmon population to save a dying fishing village nearby. But he was roundly criticised as a “rogue geoengineer”, who did all this to earn carbon credits without a care about the unintended consequences of his action.

That was eight years back, when geoengineering was an idea just being dusted off the shelves, where it had lain for over half a century. There were few takers for technologies meant to manipulate the environment towards fighting global warming.

However, the world has since got locked on a course to climate emergency and there is a realisation that we must hit it with all that we have. And so, slowly but steadily, geoengineering is gaining narrative space, and support.

It is still early days, but there are more heads nodding in approval than ever before. There is no better evidence for this than the fact that the world’s leading universities — Harvard, Oxford, Cambridge, to name three — have stepped up work in this area, with climate change at the back of their minds.

What is geoengineering?

Geoengineering simply refers to all human interventions to manipulate the environment so that the rise in temperature is checked. Basically, geoengineering is divided into two broad approaches — carbon dioxide removal (CDR) and solar radiation management (SRM).

There are a bunch of CDR measures, some well-known, such as afforestation and carbon capture and sequestration and some less understood, such as adding nutrients in select locations in the oceans so as to increase the biota and thereby enhance oceans’ ability to absorb carbon dioxide and adding alkalinity to oceans for the same effect. Russ George’s efforts were in this direction, because increasing fish population creates carbon sinks — when the fish die, their carbon-containing bones sediment to the ocean floor and remain there forever.

SRM fundamentally takes the approach of spraying aerosols in the stratosphere so that the particles reflect back some of the sunlight. This is a proven technology and hence most talked about, but the concerns are about the as yet unknown side-effects.

However, there are other and even more fanciful approaches — such as spraying sea water through fine nozzles in high masts in the polar regions so that salt particles reflect sunlight back into the space, thinning of greenhouse effect producing cirrus clouds, and marine cloud brightening, which is to thicken the cloud cover to enhance its sunlight reflectivity.

Of all these, afforestation and carbon capture and sequestration under CDR and aerosol spraying are technologies that are ready for use; the rest are still in the labs. When experts speak of geoengineering, they basically have aerosol spraying in mind.

Slowly, the ayes are increasing in number. SRM through aerosol spraying has many mouth-watering advantages.

First, it is known that it works, and works quickly — it will bring about a cooling effect. To a world in the pincers of climate emergency, this technology is like applying ice to the head of a person suffering from very high fever. Second, it is inexpensive.

A fact sheet produced by the Belfer Center for Science and International Affairs of the Harvard Kennedy School says: “In economic terms, the potential long-term benefits likely exceed $1 trillion. This is quite large, particularly when compared to the direct costs of deploying stratospheric solar geoengineering, which are about $2 to $10 billion per year.”

Well then, what is keeping us back? The answer is: fear. Fear of the unknown.

The fear of what else aerosol spraying will do, such as deplete the ozone layer, is why the antagonists call for returning geoengineering to the shelves. You don’t want to solve one problem but end up with another bigger one. Secondly, who knows where the thin line between use and overuse lies? What happens if you overdo it? Over-cool the planet? What will be the impact on rainfall? Aerosol spraying happens when volcanoes throw up dust into the atmosphere; it is known to affect rainfall.

Aerosol-armed stratosphere will reflect back sunlight, fine, but in the process, it will get hotter too. What wil be the consequence of a hotter stratosphere?

More importantly, SRM could become a ruse to the world, particularly the developed countries, to turn their backs on climate action. This is particularly significant because SRM is only like ‘ice to high fever’ and doesn’t cure the underlying disease, which is emission of greenhouse gases. SRM at best can buy you time, but emission reduction has to happen. The real fear is that it will retard climate action.

Thus, the risks fall under the heads of ‘science’ and ‘moral hazard’ and have to be dealt with separately.

For the technical risks, scientists are sketching out solutions. For example, the Belfer fact sheet notes that “early studies suggest that calcium carbonate might actually increase the ozone layer and reduce the amount of stratospheric heating compared with sulfate aerosol,” but it also cautions that “much more research needs to be done to better understand if it holds true under real stratospheric conditions.” The moral hazards can only be politically tackled.

The proponents see all this from a different standpoint. To them, these risks, no matter how real, are acceptable against the bigger risk of climate change.

In this debate, one sees the needle slowly shifting towards an ‘aye’, though all proponents call for extreme caution and due research. For example, the Union of Concerned Scientists, which opposes solar geoengineering, says also that “society must consider the potential escalation of solar geoengineering research and possible future deployment with great care and with substantial leadership from nations and communities most vulnerable to climate change.” It also insists that geoengineering researchers must accept funding “only from governments and other entities who unequivocally support mitigation and adaptation as the first-line solutions to climate change.”

A similar stance is taken by the Environmental Defense Fund, a New York-headquartered environmental advocacy group. EDF said in a statement that it opposes solar geoengineering, stressing that “it would be criminally negligent to count on geoengineering to save the day” and that “geoengineering won’t put the genie back in the bottle.”

However, it also subsequently made its stand clearer. “That said, we also think it makes sense to explore and understand this issue. As the world warms, somebody is bound to propose use of geoengineering technologies, or even deploy one of them. We need to understand the potential consequences before that happens," it said.

This ties in well with what Russ George said in an interview to Scientific American — that to understand something you need data, and you can’t get data unless you do an experiment first.

Funding low but rising

Funding for solar geoengineering is abysmally low, amounting to practically nothing, but showing a rising trend. A group of Harvard experts noted in their blog in November 2018 that global funding supporting solar geoengineering research and advocacy has been “rather minimal” since 2008. But there is a rising trend. “For example, in 2008, there was a little more than $1 million in solar geoengineering funding, and in 2018 there was a little more than $8 million in funding.” The message is clear. People are more willing to look at this technology as a means to fighting climate change. Geoengineering is an idea whose time has not yet come, but for sure, is coming.