Why band-aid-like, simulated volcano eruptions (a.k.a. Stratospheric Aerosol Injections) will probably be the most cost-effective way to lower global temperatures while our civilization phases out the use of fossil fuels over the course of the next several decades.
When a large volcanic eruption occurs, a few years of cooling in global temperatures follow. Recently, a team of climate researchers and aerospace engineers estimated that it would cost about $2-2.5 billion per year to operate a global program that would spray volcanic-like particles into the upper atmosphere. The particles would reflect part of solar radiation into space, which would have a cooling effect large enough to offset the heating caused by greenhouse gasses.
While this may seem like meddling with the Earth’s ecosystem, consider that volcanoes have already been doing such meddling, albeit in an uncontrolled fashion, periodically during recorded human history. And while the particle injections would not address other issues related to increased CO2 pollution, consider the immediate costs we are already incurring from wildfires and hurricanes, and the massive changes required to our culture and economy to reduce/eliminate greenhouse gas emissions.
Compare the $2.5 billion spraying program figure to the $3.2 billion it cost to suppress this year’s wildfires in California , and about $13 billion in insurance losses from last year’s wildfires .
This year’s hurricanes Florence (in NC) and Michael (in FL) cost approximately $13 and $10 billion respectively [3, 4].
The above losses are just in the US alone and due to disasters widely covered in US media and thus underestimate of the true costs.
The fossil fuel industry, collectively, could easily cover the costs of the atmospheric particle spraying program. Last year, the world’s largest six oil companies made a combined $78 billion in profit. The $2.5 billion cost to fund the atmospheric spraying program would be less than 4% of the top six oil company profits. If other fossil fuel companies contributed to the program, the overall effect on their profits would be even smaller.
PetroChina: $23 billion net income (2017)
Exxon Mobil: $19
While the oil and fossil fuel companies are easy to scapegoat for our climate problems, the companies would not exist if we, the consumers, did not buy and depend on their products. However, eliminating or greatly reducing the greenhouse gas emissions to pre-Industrial Revolution levels within a decade or so seem ridiculous, even absurd.
To see why consider what it would take to change the following popular greenhouse gas emitting activities:
Cars. Most cars and trucks are gasoline or diesel powered. While electric vehicles are making inroads, look around and count the fraction of fully-electric cars during your next commute. Then estimate how long before most people will be able to find a used fully electric vehicle, powered by electricity produced only from renewable or nuclear sources for $5-10K on Craigslist.
Airplanes. Have you even heard of an electric passenger jet airplane?  Consider what it would take for you and everyone else to forgo jet-fueled airplane travel for family holidays, vacations, business trips, and conferences. While remote desktop software and improved VR technology could certainly help reduce both air and road travel, could you get used to not seeing your out-of-town family for years and favoring in-town vacations? The biggest barrier to electric airplanes is the 5-10X improvement needed in battery energy storage density to be able to compete with jet fuel.
Air-conditioning. Global warming makes summers hotter and longer. Some cities in US are nearly uninhabitable during the summer without AC. Consider how long it will take to build a massive number of fully functioning solar, wind, and nuclear power plants to replace those coal and oil burning electric plants?
Meat. Steaks, burgers, and chicken wings are delicious. But animal farming produces a lot of methane, which is even better than CO2 at trapping heat in the atmosphere. To address this, our culture would have to shift to favor vegetarian or vegan diets, and while some of that is startinf to take place, it’s not going to happen overnight.
Population. Even if someone reduces their greenhouse gas footprint by 50%, the addition of another human, just-as-judicious, offsets the savings. While you personally might be able to have fewer or no children at all, look around and estimate how many of your neighbors would be willing to do the same?
In summary, while the costs of greenhouse gas pollution are starting to rise, transitioning to a greenhouse-gas-free culture and economy will require a large number of difficult changes. These changes will likely take many decades and we will not be able to afford to delay responding to the immediate effects of climate change. As climate-change-caused disasters continue to intensify in frequency and magnitude, relatively inexpensive, stop-gap geoengineering measures like a stratospheric aerosol injection program will look more and more favorable.