Cost Per Life

It feels crazy to think of "lives saved per  dollar spent"... but it's even crazier not to. This is (~) the root of many varieties of utilitarianism. Effective Altruism, The Life You Can Save, 80,000 Hours, Give Well: there's no shortage of groups trying to evaluate how to effectively spend time and money on Improving The World. 

Unsurprisingly, issues arise. Some of the biggest boil down to a cold, hard question: how much are future lives worth compared to our own? Your gut reaction may be that all lives are of equal value. This is far from what the insurance industry thinks, and truly believing this would mean we have to invest ~all global resources into preventing climate change as well as reducing other existential risks. You could reasonably argue for a universal basic income as well as prioritizing becoming an interplanetary species. Things get complicated quickly. 

It's a lot simpler if we instead focus on a narrower set of concerns. Let's look at just one aspect of climate harms: heat deaths between now and 2100. "adding 4,434 metric tons of carbon dioxide in 2020... causes one excess death globally in expectation between 2020 and 2100." The reverse is also true: if we remove this quantity of carbon carbon or offset its temperature impact, we can prevent a death. Let's look at 3 ways we can do that. 

Direct Air Capture: $6,651,000 Per Life

If cost is no object, do this. Assuming no leakage of gas or dishonesty, you're actually removing co2 from the atmosphere permanently. Unfortunately, cost is quite an issue:

$1500 per ton * 4,434 metric tons = $6,651,000. Ouch.

Voluntary Carbon Credits: $1,100,000 Per Life

Plant trees! Everybody loves trees. Pretty websites let you quickly buy promises to plant trees and do other good stuff too. The price is better:

Saving a life for $110k = good... not great. And, a big caveat: many carbon credits are fake. The Guardian says 90%+! With a 10% chance of being real, that 110k becomes $1,100,000... and, even if real, those trees will eventually get cut down. It's common to (at least pretend) to evaluate carbon credits on 100-year impacts... which is a hell of a long time to assume a tree will be protected. My advice: skip the fake tress and pull carbon out directly... or Cool Earth:)

Cooling Credits: $354,720 Per Life (And Falling!)

We deploy Cooling Credits to directly reduce earth's temperature. 1 Cooling Credit offsets the warming effect of 1 ton of CO2 for 1 year. We've got 80 years between our 2020 emissions and 2100, so we've got to deploy Cooling Credits *every year*:

Cost per Cooling Credit (subscription): $1 * 4,434 tons CO2 * 80 years = $354,720

So, a third of a million dollars' worth of Cooling Credits cools earth enough to save one life between now and 2100. This isn't quite malaria nets; at first glance, it's ~188x less lives saved per dollar. So, why should you care?

Novelty

Call it Propaganda of the Deed or The Overton Window or any of many other things: demonstrating that something new is not only acceptable but desirable can move the world.  This is where we are at with solar geoengineering: we sell Cooling Credits partly to show the world that we can. Every Cooling Credit we sell makes it a little less risque for a company or country to buy a million of them.

Scale

And, when someone buys a gigantic quantity, we scale. Sulfur is our main required input, and it's the sixth most abundant element. Our costs will drop substantially when we deliver greater quantities of Cooling Credits with zero reliance on technological breakthroughs to get there.

Time

Technology got us into this climate mess, and it will get us out of it. Unlike theoretical reductions in cost for direct air capture if deep tech breakthroughs occur or slow, yearly growth of largely-theoretical trees, we create actual cooling impact this year. Within 3 months of your order (usually less), we deploy your Cooling Credits. They create reflectivity this year.  We need to use the best technology available to create as much cooling as possible NOW. As we learn more, we'll add better technology and continue to bumble along... kinda like people have done forever at ~everything;)

In conclusion: Act!

Whether by purchasing Cooling Credits or putting your body on the line to risk arrest for direct action, we must escalate our tactics. Earth's getting hotter, and we need to act differently. Regardless of what discount rate you place on future lives, we need to Cool Earth.