Hacking the earth: the last thing we will ever do?

Bill McGuire, Professor Emeritus of Geophysical & Climate Hazards at UCL and a regular guest blogger for Operation Noah, has just published his eco-thriller, Skyseed. It explores what could go wrong if we use climate engineering to try to solve the climate crisis.

It beggars belief that as the climate crisis deepens, calls to try technological tinkering to get us out of the mess grow ever louder. Remember, we are where we are, because we have been conducting an experiment with the composition of our planet’s atmosphere ever since the wheels of the industrial revolution began to turn. Launching another experiment to try and solve the problems brought about by the first is exactly what we don’t need. But that is what the supporters of so-called geoengineering –intentional, large-scale, interference with the environment – want to do.

In the footsteps of Dr. Strangelove

The belief that we can apply a techno-fix to stop global heating in its tracks has been around for quite a while. None other than Edward Teller – father of the H-bomb and putative inspiration for Dr. Strangelove – was keen on the idea. Wild and wacky as ever, Teller toyed with such notions as giant sunshades in space, or deluging the stratosphere with billions of tiny reflective spheres, to block out part of the sun’s heat. Today’s schemes are perhaps less freaky, but no less risky for that. Broadly-speaking, they can be grouped into plans – like Teller’s – for reducing the sun’s input (Solar Radiation Management), for easing the passage of heat from the Earth into space (Earth Radiation Management), and for sucking carbon dioxide from the air (Carbon Dioxide Removal).

Mimicking a volcano

Amongst the many geoengineering schemes proposed to put global heating in its place, one seems to have gained significant support in the last couple of years. Following in Teller’s footsteps, the plan is to mimic a large volcanic eruption by pumping millions of tonnes of sulphur dioxide into the stratosphere. As happens after a major volcanic blast, the gas would form an aerosol veil of tiny sulphuric acid droplets, conjuring up a planetary shroud to manage incoming solar radiation. In fact, the tiny droplets are especially effective at reflecting the sun’s heat back into space, so cooling the troposphere (the lower atmosphere) and the surface beneath. This is why a significant fall in global temperature follows very large volcanic eruptions.

Global cooling

In the years immediately after the 1991 eruption of Pinatubo (Philippines), the global average temperature fell by around 0.6°. Looking back further, the 1783 Laki (Iceland) outburst caused severe cooling across Europe and North America the following year, and even weakened the African and Asian monsoons. Most famous of all, the colossal 1815 blast of Tambora (Indonesia) is held responsible for the so-called ‘Year Without a Summer’ in 1816, which drove widespread harvest failure, famine, and the last, great, subsistence crisis in the western world.

Wishful thinking

But geoengineers are nothing if not optimists, which is why they poo-poo the mass of evidence for the manifold and unpredictable ways in which stratospheric sulphur veils can affect the climate system and, ultimately, society and economy. In fact, some insist that their modelling shows that everyone will be a winner. Generating and maintaining an artificial volcanic shroud, they say, will have positive benefits for all. A significant reduction in global temperatures without any nasty side effects. This touching confidence in technology has always smelled to me of a conspiracy of scientistic hubris and a particularly naïve confidence in modelling. Others say it is just pie-in-the-sky.

What could possibly go wrong

There are so many potential problems associated with such attempts to artificially block the sun’s input that it is difficult to know where to start. Studies have shown that plant photosynthesis would slow, resulting in falling crop yields. Solar power installations would become less efficient, while the sulphur gases could damage the ozone layer. Regional rainfall patterns could bring drought to some places and floods to others.

Tackling the symptoms, not the cause

At the same time, the oceans would keep on getting more acidic, as the scheme does nothing to reduce atmospheric carbon levels. And this is the nub of the problem. By seeking to reduce temperatures while doing nothing about carbon emissions, nor carbon dioxide levels in the atmosphere, such a solar radiation management techno-fix simply addresses (one of) the symptoms of global heating and accompanying climate breakdown, not the cause.

What we need are urgent measures to slash carbon emissions at a rate that is in line with keeping the global average temperature rise (compared to pre-industrial times) below the 1.5° dangerous climate change guardrail. What we don’t need are harebrained techie schemes that are costly, dangerous, and detract from efforts to tackle global heating by conventional means. Such dubious plans should stay where they are most at home, in the pages of a science fiction book.

Skyseed is here

Speaking of which, if you want to find out what happens when a climate engineering programme goes pear-shaped, you could do worse than read my just-published eco-thriller, Skyseed. Hacking the Earth could be the last thing we ever do.

Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.

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