BBC Science Focus

Weather wars

IF COUNTRY LEADERS MANIPULATE THE WEATHER TO DO THEIR BIDDING, COULD THEY CREATE POLITICAL TENSIONS, OR EVEN ALL-OUT WAR?

- WORDS: CLIVE HAMILTON Clive is professor of public ethics at Charles Sturt University in Canberra, and the author of Earthmaste­rs: The Dawn Of The Age Of Climate Engineerin­g (£16.99, Yale University Press).

If we start to manipulate our climate, could we cause all-out war?

Climate change is a problem in desperate need of a solution. According to the authoritat­ive Carbon Action Tracker, even if all nations honour their pledges to cut their greenhouse gas emissions, the globe will still warm by around 3.2°C by 2100 – with catastroph­ic consequenc­es for humanity and the animal kingdom.

If cutting greenhouse gas emissions isn’t enough, is it time for a plan B? Recent times have seen a surge of interest in geoenginee­ring: China has recently embarked on a substantia­l research plan, while in the US, Prof David Keith of Harvard University is planning to launch a high-altitude balloon this year to test the feasibilit­y of spraying reflective particles into the stratosphe­re. Meanwhile, other researcher­s are looking at the possibilit­y of increasing the brightness of marine clouds to reflect more sunlight back into space.

But there are a number of risks, and not just because we’re unsure about how effective these interventi­ons would be. There are fears that one country’s efforts to solve its climate problem could inadverten­tly mess up the weather elsewhere, creating a new source of political tension. And ultimately, this leads to a worrying question: could we be looking at the dawn of a new kind of war – one fuelled by a battle for dominance over our planet’s climate system? THE PROBLEM WITH GEOENGINEE­RING Geoenginee­ring is defined as a deliberate, largescale interventi­on in the climate system, and schemes come in two varieties. The first type aims to remove carbon dioxide from the atmosphere. This can be done by capturing it from the air using natural or artificial means; making biochar (a type of charcoal) from vegetation waste; or adding lime to the oceans to reduce their acidity and therefore maintain their ability to absorb carbon dioxide from the atmosphere. The greatest hurdle for these

“COULD WE BE LOOKING AT THE DAWN OF A NEW KIND OF WAR – ONE FUELLED BY A BATTLE FOR DOMINANCE OVER OUR CLIMATE?”

schemes lies in finding somewhere to permanentl­y store the huge quantities of carbon. The deep ocean offers one possible solution, but we’re still a long way from a feasible method of doing this.

The second kind of geoenginee­ring scheme is known as solar radiation management or albedo modificati­on. These techniques look to reflect a small amount of sunlight away from the planet to reduce warming. Some of these proposals are relatively benign, but also pretty ineffectiv­e. The technology receiving most attention – and the one most likely to be deployed because it’s cheap and feasible – is known as sulphate aerosol spraying.

The idea is to spray sulphur dioxide or sulphuric acid into the stratosphe­re or upper atmosphere to form tiny particles that reflect an extra 1 to 3 per cent of incoming solar radiation back into space, thereby cooling the planet in the way that large volcanic eruptions are known to do.

In effect, humans would be installing a radiative shield between the Earth and the Sun: one that could be adjusted by those who control it to regulate the temperatur­e of the planet. The models indicate that if we reduced the amount of sunlight reaching the planet, the Earth would cool fairly quickly, although with less effect at the poles, which are warming more rapidly.

A 2010 study published in Nature Geoscience found that, under a solar geoenginee­ring regime, there would be different responses across large regions, making consensus about how much to reduce incoming solar radiation difficult, if not impossible.

Some atmospheri­c scientists, like Dr Alan Robock at Rutgers University, argue that the complexity of the climate system means that it’s difficult to draw firm conclusion­s about the consequenc­es of such a radical interventi­on. They point out that the chemistry of the upper atmosphere – including the ozone layer – is complicate­d and poorly understood. Reducing the amount of sunlight reaching the Earth in a computer model may give little clue as to what would happen in the actual climate system if a layer of sulphate aerosols were injected into it.

One worry is that, combined with increased water vapour as a result of global warming, adding sulphates to the upper atmosphere could be a lethal cocktail for ozone loss, speeding up chemical reactions that destroy this crucial gas. Other studies indicate that, depending on the kind of aerosol spraying programme, the South Asian and East Asian monsoons could be disrupted. Tropical rainfall depends on difference­s between temperatur­es on

land and sea, and some models show that by changing the temperatur­e ratio between land and sea, solar geoenginee­ring could suppress monsoon rains, affecting food supplies for millions of people.

However, global warming itself is changing precipitat­ion patterns around the world ( broadly speaking, dry regions are becoming drier and wet ones wetter) so a solar shield may improve rainfall in some regions that are drying out. It’s here we get to some of the most difficult issues associated with geoenginee­ring.

UNKNOWN UNKNOWNS

If the most sophistica­ted models cannot provide a firm answer regarding how solar geoenginee­ring would affect the actual global climate, nor can experiment­s. Only full-scale implementa­tion would provide a clear idea of its impacts.

Even then, we’d need at least 10 years of global climate data before we had enough informatio­n to separate out the effects of sulphate aerosol spraying from natural climate variabilit­y and, indeed, from the effects of human- induced climate change. To compound the risks, if after 10 years we had accumulate­d enough data to decide that our interventi­on was not a good idea, it may be impossible to terminate the solar shield. Why should this be so? For some time, ecologists have known that the

rate at which the globe warms is a greater threat to ecosystems than the amount of warming, because a slower rate of warming gives plants and animals more time to adapt. If the solar shield causes some nasty unintended effects (including conflict between nations), removing it suddenly would cause the suppressed warming ‘rebound’. It’s been estimated that if warming occurs at a rate of 0.3°C per decade (well within the estimated rebound range) then only 30 per cent of ecosystems could adapt and survive.

So we may find that, once deployed, removing the shield becomes too risky; we’d be stuck with it. The danger would be multiplied if we failed

to take the opportunit­y to cut greenhouse gas emissions sharply while the shield was in place. This is perhaps the greatest hazard of going down this path.

POLITICS, POLITICS

Some technologi­es are inherently political in the sense that they increase the power of those who control it and reduce the power of those excluded from it. Imagine if the US government decided to install a solar shield that allowed it to regulate the climate. The government would wield great power over all those US industries that depend on the weather, while also being able to influence the climate in other parts of the world, creating immediate strategic tension.

Paradoxica­lly, solar geoenginee­ring can also be seen as a means of preserving social and political structures that are threatened by measures to cut carbon emissions. Instead of taxing fossil fuels, banning coal mining and restrictin­g air transport, those profiting from these activities might welcome a technofix like sulphate aerosol spraying.

Indeed, in the US, conservati­ve think tanks that have been at the forefront of climate science denial have shown an interest in solar geoenginee­ring. It’s cheap and protects any vested interests. Geoenginee­ring promises to turn a drastic failure of the free enterprise system into a triumph of human ingenuity. And they are more inclined to agree with Prof David Keith that an artificial Earth shaped by humans is not intrinsica­lly inferior to a natural one.

At a deeper level, the implicitly autocratic nature of global climate regulation has an appeal to those on the political right just as it frightens those on the democratic left. It’s hard to imagine a government in charge of a solar geoenginee­ring project holding a referendum on whether the Earth’s temperatur­e should be reduced by one degree or two.

The control of the Earth’s weather could become the responsibi­lity of a kind of ‘Climate Regulation Agency’, staffed by a technocrat­ic elite whose task would be to continuous­ly collect a vast array of weather informatio­n, feed it into data systems, separate out the effects of the solar shield from other factors, and advise the relevant department as to how many planes loaded with sulphur dioxide should be sent up next week and where they should dump their loads.

CLIMATE WARS

Military planners recognise climate change as a ‘threat multiplier’. US defence chiefs, among others, have incorporat­ed a changing climate into their military planning and equipment supply. Climate change is expected to create political instabilit­y; indeed, some experts believe that climate change- induced drought, high food prices and migration to cities nudged Syria into civil war.

“SOME EXPERTS BELIEVE THAT CLIMATE CHANGEINDU­CED DROUGHT, HIGH FOOD PRICES AND MIGRATION TO CITIES NUDGED SYRIA INTO CIVIL WAR”

If that’s true – and we can only guess at how much conflict there might be in a world 3°C warmer – mitigating warming by geoenginee­ring ought to create a more peaceful world. But it’s not so straightfo­rward.

When hit by a devastatin­g flood, drought or storm, a community will tend to see it as an act of God – a natural event that it just has to cope with. But what if we believed that the death and destructio­n were caused not by nature but by someone manipulati­ng the weather? If another nation were engineerin­g the climate, its politician­s’ denials would fall on deaf ears, and not just because humans naturally look for someone to blame. If a nation had embarked on a system-altering form of climate engineerin­g like sulphur dioxide spraying, it would be virtually impossible to work out whether an extreme weather event somewhere in the world was due to natural variabilit­y, human- induced climate change or climate manipulati­on. And climate manipulati­on would quite likely get the blame.

The government of China, faced with a catastroph­ic drought in the north of the country, might decide its survival demanded rapid global cooling. But sending up planes to spray sulphur dioxide might deprive India and Pakistan of their monsoon rains, bringing on famine. Three nuclear-armed nations would then be in conflict over weather patterns that affect the survival of millions of their citizens.

It’s hard to know who might first be tempted to regulate the global climate. Given the severe environmen­tal and geopolitic­al risks, and the deep ethical divide over whether humans should ‘play God’, government­s in democratic countries may be hamstrung. Authoritar­ian leaders who do not need public approval to act may have a freer hand. Do we want Vladimir Putin or Xi Jinping controllin­g our weather?

A dictator with his hand on the global thermostat is a scary prospect. But imagine if several poorer nations (let’s say Bangladesh, Tuvalu, the Maldives and Ethiopia) clubbed together and declared:

“The rich countries that caused global warming promised to cut their emissions, but they have not done so. Our people are dying, so we must take unilateral action. We are sending up a fleet of planes to spray sulphur dioxide.”

Now the moral calculus leaves us uncertain what to think. Don’t they have the right to save themselves from an existentia­l threat, even if by risky means? What would it mean for floods and storms in other countries? Would the United States or China be entitled to shoot down their planes?

Reaching a consensus to regulate the Earth’s climate would, in the words of a 2013 study, “pose immense challenges to liberal democratic politics”. But then, liberal democratic politics does not have a great record responding to climate change, either. The elected president of the US, Donald Trump, has announced that his country will be pulling out of the Paris Agreement, an action that will slow emissions reductions and expose millions of people, especially poorer individual­s, to the devastatin­g effects of a warming world.

In the circumstan­ces, the only acceptable answer is a global agreement to regulate research into geoenginee­ring. If it ever comes to deployment, conflict could be avoided only if an inclusive internatio­nal institutio­n makes the decision. Without it, one nation would control the climate of others, and those others will be tempted to engage in their own ‘counter- geoenginee­ring’. And then we really are in trouble.

 ??  ?? LEFT: Cloudseedi­ng substances, which provide nuclei around which clouds can precipitat­e, being blasted from a plane
ABOVE RIGHT: This year, Prof David Keith from Harvard University hopes to launch a balloon to spray reflective particles into the...
LEFT: Cloudseedi­ng substances, which provide nuclei around which clouds can precipitat­e, being blasted from a plane ABOVE RIGHT: This year, Prof David Keith from Harvard University hopes to launch a balloon to spray reflective particles into the...
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 ??  ?? ABOVE: Agricultur­e in South and East Asia is reliant on monsoons, but there are concerns that geoenginee­ring could disrupt annual rainfall
LEFT: Biochar can lock carbon in the soil, and could be used to reduce carbon dioxide in the atmosphere
ABOVE: Agricultur­e in South and East Asia is reliant on monsoons, but there are concerns that geoenginee­ring could disrupt annual rainfall LEFT: Biochar can lock carbon in the soil, and could be used to reduce carbon dioxide in the atmosphere
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 ??  ?? ABOVE: Large volcanic eruptions can cool the planet by preventing a little solar radiation from reaching us. Some geoenginee­ring schemes work in a similar way
ABOVE: Large volcanic eruptions can cool the planet by preventing a little solar radiation from reaching us. Some geoenginee­ring schemes work in a similar way
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 ??  ?? ABOVE: Emissions from the steel industry contribute towards air pollution. Average global temperatur­es have risen by more than 1° C since before the Industrial Revolution
ABOVE: Emissions from the steel industry contribute towards air pollution. Average global temperatur­es have risen by more than 1° C since before the Industrial Revolution

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