It could be worse than global heating to try to cool the Earth using dimming sun.

A group of 60 scientists demanded a MoratoriumOn solar geoengineeringLast month, including technologies like stratospheric aerosol injection (SAI). This involves a fleet of aeroplanes releasing aerosol particles – which reflect sunlight back to outer space – into the atmosphere, cooling down the Earth.

SAI may make the sky a better place A little whiter. This is not the only concern. SAI could pose grave risks, possibly worse than the warming that it seeks to reduce. To understand the risks, we’ve undertaken a risk assessmentThis is a controversial technology.

Cooler Earth would mean less water evaporating from its surface into the atmosphere, which would lead to climate change rainfall patterns. This could produce ripple Effects across the world’s ecosystems – but the exact nature of these effectsIt all depends on how SAI was used. Poor coordination of aerosol releases could lead to extreme rain in certain places and blistering drought elsewhere, further triggering the spread Diseases.

SAI could also cause natural catastrophes to get worse than they already are. A volcanic eruption, like that of Iceland’s EyjafjallajökullVolcano in 2010 could naturally cool Earth as plumes ash block sunlight from reaching the planet’s surface. It would be necessary to immediately take action if this happens while SAI is deployed. adjustedIt is difficult to avoid overcooling one hemisphere, resulting in extreme weather patterns.

Similar, but Nuclear warAlthough it might seem unlikely, global nukes capabilities continue to grow. Bad political decisions are also not uncommon. A “Nuclear winter”, during which global temperatures drop for years due to soot clouds from nuclear-triggered fires, could be deepened by SAI.

Termination shock

SAI would likely be dependent on aerosols being continuously sprayed in the atmosphere by a fleet aircraft. Because the particles have an approximate half life, it is unlikely that they will be able to survive for very long. Eight months. Satellites would be required to coordinate these efforts and monitor any changes in the atmosphere.

Any disaster severe enough to permanently disable these systems could trigger a “Termination shock”. If an SAI system effectively “hiding” global warming were suddenly removed for an extended period, the Earth could heat up by multiple degrees in a matter of decades. If we’re already seeing fires, heatwaves, and flash floods All over the globeWith around 1.1°C of warming since 1850, just imagine what warming of 3-4°C would do.

There are many ways an SAI system could be hacked. A record-breaking explosion in solar matter, related with a solar flare, could knock out the world’s Electrical systems by smashing into the Earth’s magnetic field. This could be a possibility. DamageThe aviation and satellite systems required for SAI.

A mistake would be to believe that catastrophes won’t happen in the next century. One model estimates that nuclear war between Russia or the USA is likely at a probability of 5%. 0.9% per Year. Estimates of large-scale Weather in spaceEvents rangeAnnually, 0.46% to 20.3%

Cyberattacks could also target SAI. DarkSide hackers took control of the US oil company Colonial Pipeline in 2019 HostageRansomware was used to attack their computer systems. Fearing widespread fuel shortages across the US, operators were forced to pay £3.7 million to DarkSide in exchange for reactivating their systems.

In 2000, hundreds of thousands of gallons sewage were released into the ocean by the Maroochy automated sewage system. These “leaks” were actually caused by a single disgruntled ex-employeeThe name of the company that installed it. An international infrastructural system to mask global warming would attract more controversy, have a larger workforce and could fetch an even higher return.

Political chaos?

Of course, it’s possible that SAI will end up being used responsibly. But if one thing goes sufficiently wrong – such as one unpredictable solar storm taking place – the hidden risks of SAI could be unleashed. Predictions of SAI’s average or “most likely” outcomes are generally fine. But although far less likely, SAI’s worst case scenarios could be calamitous.

SAI should be used sparingly to offset a smaller amountAny negative effects from warming would be minimized. Most SAI modelsTake it as a given Ideal conditionsA cooperative group of countries that rationally and carefully deploy SAI. Unfortunately, international politics has become a problem. It can get messy.

Without international agreement, SAI could be used by a small number of countries that favor a cooler Earth. However, little research has been done on the potential effects of SAI’s more disorganized use.

In an ideal world those who manage SAI would ensure that the infrastructure is resilient to disasters, operates cooperatively among countries, and is closely supervised for the duration of SAI deployment (likely many decades or possibly over a hundred years). And to ensure we don’t get trapped into relying on SAI indefinitely, we’ll still have to reduce greenhouse gas emissions to net zeroAlso, Eliminating excess emissionsThe atmosphere.

This kind of governance would be foolish. Take the pandemic as an example. From UnderinvestingIn COVID testing and in vaccine development to placing misguided faith in Herd immunityPolicymakers are not reliable decision-makers. Imagine the conflict over putting a Chemical maskAll over the Earth

SAI could become a highly politicised topic, with changes to SAI driven more by political swings than sound science. The fossil fuel industry and its associated supportersYou may be able to use SAI to delay the adoption of renewables.

Is SAI more dangerous than climate change? We’re still uncertain. What we can say is this: in a world where things don’t go wrong, SAI is a prudent response to the climate crisis. We live in a world full of complexity and chaos. Relying on SAI is a poor decision. SAI would enable us to create a planetary system by tightly coupling our climate system to the global political and economic system. Sword of Damocles.