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Climate Avengers, Time To End Your Games


Marvel’s ‘Avengers: Endgame’ is the biggest grossing film of the 21st century, ending the long story of several main characters in a climactic battle to save the universe from destruction. Superheroes abound, from Iron Man to Falcon to Thor.

So too, grandiose ‘geo-engineering’ schemes are attempting to save us from our own destruction, with ideas to intervene in the Earth’s natural systems on a large enough scale to counteract the effects of our unwanted emissions and waste. Geo-engineering avengers abound, from Iron Spam to Falcon Jet to Thaw.

Iron Spam

Earth is really an ocean planet, so one geo-engineering scheme to remove more atmospheric carbon is to increase the capacity of the oceans to absorb our emissions, by ‘fertilising’ the oceans with tons of iron or other nutrients to stimulate plankton blooms. These organisms pull carbon out of the atmosphere and become deposited in the deep ocean when they die. Researchers worldwide conducted thirteen major iron-fertilisation experiments in the open ocean since 1990, until the UN Convention on Biological Diversity put in place a moratorium on all ocean-fertilisation projects. This moratorium was in response to adverse effects of these experiments, such as the massive toxic algal blooms they generated. The unintended impacts of ocean fertilisation are so far removed in distance and time from the initial sites of the iron that it is very difficult to quantify the amount of carbon removed with any acceptable accuracy.

Falcon Jet

The subject of hundreds of research papers by scientists, another big idea to fight global warming is ‘solar radiation management’ whereby we inject sulphide gases into the atmosphere to block sunlight. The plan is relatively straightforward: spray a mist of sulphuric acid into the lower stratosphere from jet planes flying above typical cruising altitudes; the sulphate aerosols formed are swept upwards by natural wind patterns and dispersed over the globe including the poles; once spread across the stratosphere, these aerosols will reflect about one percent of the sunlight back into space and offset some of the warming effects below. Unfortunately, some of consequences include depletion of ozone that acts as our natural atmospheric protection against the sun’s ultra-violet radiation; reduction in water precipitation around the world; and potential side effects to our health from tons of sulphate particles returning into the lower atmosphere.


The melting of the ice sheets means more than just a dramatic rise in sea levels as the lack of ice at the poles would also change the ocean’s water currents, the jet streams and how weather forms across the planet. The polar ice is thawing fast, so we need a plan to ‘refreeze’ the ice caps. In one scheme, around ten million wind pumps covering ten percent of Arctic Ocean would spray seawater onto the icy surface where it would freeze and thicken the ice cap. Other scheming to halt the thaw involves reflecting solar radiation back into space, either by artificially whitening the ice cap by scattering light-coloured aerosol particles over the ice, or by spraying seawater into the atmosphere above it to create reflective clouds. Even if there were an effective way of restoring ice in the Arctic, it would not solve the carbon dioxide problem, or the acidification of the oceans, or fully decrease temperatures.

Taking ourselves seriously

Geo-engineering avengers are defective and dangerous. When it comes to the deployment of such technology, technical considerations are no more important than social, legal and moral concerns. There are significant ethical and political consequences, for example, of injecting sulphide gases into the stratosphere that become unevenly dispersed and hence disproportionately impact some countries more than others. Such concerns may yet be our best form of defence against such reckless experimentation.

Unlike the Marvel storylines, we are not innocent victims of some extra-terrestrial threat but are the very agents who have created this endgame. We don’t need our brightest minds to invent new-fangled geo-engineering technologies: we want them to find amazing ways for technology to help all of us change our behaviour. Together, we must regenerate our natural resources instead of depleting them; bend our economies from straight lines into circles; find common cause through greater fairness.

The smartest and cheapest way to reduce carbon emissions is not to emit them in the first place. Applying innovative technology closer to home and work can reduce greenhouse gases at source, but it’s our will to change that makes the real difference.

Photo by Erik Mclean on Unsplash

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