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  • The record-number of fires burning across Brazil's Amazon rainforest has

  • prompted renewed global outcry over climate change and big spending.

  • Five million dollars from Leonardo DiCaprio, 10 million pounds from the

  • U.K. Meanwhile, Bill Gates is backing the first high-altitude experiment

  • of one radical climate change solution, creating a massive chemical cloud

  • that could cool the earth. It's called solar geoengineering, and it's

  • highly controversial.

  • How long will it be that countries keep experiencing these climate impacts

  • before someone gets desperate and says, hey, we need to cool the planet

  • with solar geoengineering?

  • It would look something like this: thousands of planes would fly very high

  • and use nozzles to inject millions of tons of light-reflecting particles

  • into the stratosphere. It would create a thin chemical cloud of those

  • particles around the whole planet, blocking some sunlight from reaching

  • the surface. It would mimic a giant volcanic eruption, which we know cools

  • the earth. Back in 1991, Mount Pinatubo erupted in the Philippines.

  • It was the largest eruption to affect a densely populated area, creating

  • avalanches and giant mud flows that left more than 700 dead and 30,000

  • homeless. It also spewed a cloud of 20 million tons of sulfur dioxide

  • particles into the stratosphere.

  • That chemical cloud was hundreds of miles across and reflected about 2% of

  • sunlight back to space.

  • And in 1992, the earth was cooler than in 1991.

  • That is part of the mechanism.

  • But you do this in a controlled way.

  • Modeling studies have found that it could reduce the intensity of heat

  • waves, for instance.

  • Apparently it could reduce the rate of sea level rise.

  • It could reduce the intensity of tropical storms.

  • But it also comes with significant risks and uncertainties.

  • Things like mass famine, mass flooding, drought of kinds that will affect

  • very large populations.

  • It could weaken monsoons in India, China and Africa enough to affect

  • crops. It could eradicate blue sky.

  • You start increasing the amount of diffused light and you have less direct

  • light, which is the same thing as saying it looks hazy and white.

  • And if the global community decides it should stop?

  • So you stop injecting it and after a year, the cloud is gone and you get

  • this rapid warming at a rate much faster than you would get if we had done

  • nothing. If you've taken out the greenhouse gases that are adding to the

  • warming, then the temperature won't go up and stay what it is.

  • So if we don't stop emitting greenhouse gases into the atmosphere, we

  • don't try as hard as we can to do that, then there's no point in doing

  • solar geoengineering.

  • A 2016 opinion poll conducted by the Harvard group doing solar

  • geoengineering research found that 67 % of subjects support its use.

  • One reason this technology is appealing it's cheap.

  • One study estimates it would cost an average of $2.25

  • billion globally every year for the first 15 years of deployment.

  • Compare that to the half a trillion dollars the U.S.

  • government estimates it will cost just the U.S.

  • by 2100 if no action is taken against climate change, or the $1.6

  • to $3.8 trillion projected global spending by 2050 on low-carbon energy

  • production. You can also compare it to direct air carbon capturing,

  • another climate change solution backed by Bill Gates and by big oil.

  • It involves sucking billions of tons of carbon out of the air and at

  • $100-$200 a ton, it could be big business.

  • Solar geoengineering, on the other hand, is so cheap that nobody currently

  • stands to make money from the process.

  • But just because a solution is cheap doesn't make it make it a good one.

  • It's cheap and dangerous.

  • It doesn't require a lot of materials.

  • It doesn't require a big innovation.

  • It basically affects the whole planet with one project.

  • So that is not necessarily a situation that has a lot of profit

  • opportunity, right?

  • Because there's not gonna be a lot of different people that can do it and

  • compete in a marketplace.

  • Bill Gates is among a dozen individual donors and 14 foundations backing

  • the first stratospheric solar geoengineering experiment out of Harvard.

  • It's called Stratospheric Controlled Perturbation Experiment, or SCoPEx.

  • A high-altitude balloon will lift instruments about 20 kilometers into the

  • stratosphere, where it will release less than two kilograms of different

  • naturally occurring chemicals like calcium carbonate and sulfates, and

  • then measure the change in atmospheric chemistry and light scattering.

  • The Harvard group that runs SCoPEx and other experiments has raised more

  • than 16 million dollars, more than double any other solar geoengineering

  • effort. And annual global funding has gone up from $1 million in 2008 to

  • $8 million in 2018, with the majority of that funding coming from the U.S.

  • The first phase of SCoPEx will cost around $3 million, with much more

  • needed for wider research on solar geoengineering.

  • To this point, stratosphere injections have only been tested with climate

  • modeling. In the U.K.,

  • a government-funded solar radiation management test called SPICE was

  • cancelled in 2012 because of issues with patents.

  • And we're not trying to develop any technology that is patented or where

  • we want to make money with this later on.

  • A study last year found that no existing aircraft can inject the

  • stratosphere at a high enough altitude.

  • But developing a new high-altitude tanker would not be technologically

  • difficult or prohibitively expensive.

  • Nozzles still need to be designed that can continuously blast out

  • trillions of particles. And scientists still need to decide what chemicals

  • those particles should be made of.

  • But unlike cloud brightening, which is another solar reflection technique,

  • the tech needed for stratospheric injections is not far off.

  • The technology is not the main thing that's holding this back.

  • The main thing that's holding it back is the uncertainty about what the

  • exact effects would be and the positives and negatives of its effects and

  • the governance and decision making process for implementing it.

  • Other radical attempts to control climate change have been tested in the

  • past. Like when one California businessman dumped 100 tons of iron dust in

  • the Pacific to spawn the growth of carbon-absorbing plankton.

  • But unlike small, sometimes rogue experiments, planet-wide solar

  • geoengineering will require buy-in from the international community.

  • You know, in our simulations, we found China got warmer and drier relative

  • to the past when you stabilize global temperature and India was now cooler

  • and wetter. So you can see there how, you know, international relations

  • around using this technology could become complicated.

  • I mean, we can't even decide on what to do about emissions of greenhouse

  • gases. And so how are we going to decide on setting the planetary

  • thermostat?

  • There's this real concern that we won't be able to reach agreement, we

  • being the entire planet.

  • And so there's the prospect that countries just go ahead and do solar

  • geoengineering. And that causes disagreement, conflict, tension, even

  • possibly war.

  • Three years ago, the international community did come together when almost

  • 200 countries signed the Paris Agreement on climate change, agreeing to

  • limit global temperature rise to less than two degrees Celsius.

  • Since then, President Trump has stated his intent to withdraw from the

  • agreement.

  • The Paris Climate accord is simply the latest example of Washington

  • entering into an agreement that disadvantages the United States.

  • And global emissions are not being reduced fast enough to reach these

  • goals.

  • We know what we should be doing.

  • What we should be doing is reducing carbon emissions.

  • So we're creating a moral hazard.

  • We are providing an out for you where you can say, well, I'm going to fix

  • this technologically instead of doing the ethically right thing to do.

  • It's way too early to give up on much more ethical approaches to climate

  • change. If future generations were literally in the room to question us on

  • our dubious arguments, we wouldn't get far with some of the kinds of

  • arguments we're trying to offer for neglecting conventional climate policy

  • and going down this path.

  • For now, the failure to rapidly reduce emissions has prompted more

  • exploration of alternative solutions like carbon dioxide removal and solar

  • geoengineering. But scientists warn we will still need to reduce

  • emissions, too.

  • If we're not cutting CO2 emissions at the same time, from my perspective,

  • there is little point in doing this because you would have to start using

  • ever increasing amounts.

  • No responsible scientist says that it's a silver bullet.

  • All the responsible scientists say this is something that we deploy if we

  • had to, alongside all the other stuff that we already have to do.

  • The U.S. Academies of Sciences is holding a series of meetings to study

  • solar geoengineering, including one at Stanford this month.

  • The committee will issue a report next year with recommendations for how

  • or if solar geoengineering research should continue.

  • Some scientists say the research is necessary in order to arm future

  • generations with the ability to enact this backup plan, even though it

  • seems nearly impossible now.

  • We ought to start working on this solar climate engineering problem right

  • now with as much urgency as we can so that if we want to deploy it in a

  • decade or so, we understand what we have to do.

  • This is a real moral horror, especially in a situation where we're not

  • doing all the things that we could be doing to minimize the risks of

  • climate catastrophe now.

  • But experts do agree that more public awareness is needed around solar

  • geoengineering, because within a couple decades, for better or worse, it

  • could be part of the solution helping return the planet to pre-industrial

  • temperatures.

  • Modeling evidence gathered over the last decade has pretty consistently

  • found that a moderate amount of solar geoengineering could significantly

  • reduce many of the impacts of climate change.

  • But it can't be a solution because it doesn't return the climate system

  • back to how it was. It doesn't do anything about things like ocean

  • acidification. So whatever happens, we've got to cut our CO2 to zero.

  • So right now, we need more research to understand this better and a

  • broader conversation so that all of the world's nations have a seat at the

  • table when this is discussed.

The record-number of fires burning across Brazil's Amazon rainforest has

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Why Bill Gates Is Funding Solar Geoengineering Research

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    joey joey に公開 2021 年 06 月 08 日
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