Carbon rationing versus breakthrough tech

We are all wondering what our carbon future will look like.  I must admit that I anticipate the years ahead with a mixture of excitement at what new technologies could bring, nervousness at what disruptions we might face and fear that we could still fail in our bid to recover the global environment in time.

Will we all be issued carbon ration cards and be expected to live within our means, or will technology emerge that enables us to thrive in a world of boundless opportunity?

Having spent my career looking at technology transformation in many industries, I want to understand whether this is about a portfolio of small changes, combined with major shifts in culture, or a few substantial disruptive technologies.  Or, of course, it could be both!

Green technologies are emerging almost every day as alternatives to their emitting predecessors, including green energy, green materials and green transport.  Renewable energy is approaching scale, new steelmaking processes could enable construction with a much lighter footprint and hydrogen made entirely without carbon is approaching a price point that could enable transportation which displaces fossil fuels.

But the direct extraction of carbon from the atmosphere has really started to capture the imagination of many in the tech community.  Direct air capture from companies like Climeworks, Carbon Engineering and Global Thermostat show real promise while start-ups such as Carbon Collect and Heirloom Carbon are exploring even more innovative approaches.  At the same time, there is serious money being raised to enable these and other technology breakthroughs.

To help me understand the mix of individual behaviour changes, use of replacement technologies and the role of removing carbon from the atmosphere, I figured I needed to understand the scale of the problem by doing some “back of the envelope” estimates!

Today CO₂ makes up 0.04% of the atmosphere which doesn’t sound like much, but it has an outsized impact on the global temperature through the greenhouse effect.  We’ve been accurately measuring the concentration of CO₂ since the middle of the twentieth century when it made up 0.03% of the atmosphere (25% less than today).  Ice core measurements suggest that before the industrial revolution, CO₂ was even lower at 0.028% of the air that our ancestors breathed.

Most measures that we see of carbon emissions are described in terms of mass.  The total mass of the atmosphere is approximately 5×10¹⁸kg (that is 5 followed by 18 zeros).  The total increase in the mass of CO₂ as a result of human activity is 0.012% of 5×10¹⁸kg which is 6×10¹⁴kg or 600 billion metric tons.

With increasing options to remove carbon from the atmosphere through natural and technological means, the question is how much it would cost to reverse the damage we’ve already done?

Using forests and other natural means to remove and store carbon can cost as little as US$5 per ton, while direct capture using technologies are emerging around US$100 per ton of CO₂.  That means it would cost in the best-case scenario, if the cheapest means possible were able to scale-up, US$3 trillion to remove our excess 600 billion tons.  While a lot of money, it is not beyond human capacity (for context, the US budget deficit in 2020 was approximately this amount).

However, we are a long way from being able to scale carbon removal at US$5 per ton and the current technology would require an even more massive capital injection just to get to US$100 per ton which, in turn, would cost US$60 trillion to do the same job, probably beyond even the combined financial resources of the globe.

While the technology might scale sufficiently to tackle some of the historical emissions, there is an additional problem.  Despite all our efforts, the use of fossil fuels is now contributing more than 30 billion tons of CO₂ each year.  If we don’t transform our economy and lives, we would have to continue to spend between US$150 billion and US$1.5 trillion every year to keep up.  If the initial abatement was already pushing human ingenuity, such an ongoing investment would be well beyond anything we can achieve this century.  Ultimately, our global economy would be doing nothing more than funding more and more carbon removal and we would run out of places to store it all!

These numbers are only rough and don’t even remotely reflect the complexity of the global carbon cycle.  They do, however, confirm for me what I already suspected.  The only path to solving the climate crisis requires a mixture of small changes throughout our global economy combined with investment in some new big-ticket technologies.  To rely on either alone will inevitably condemn us to a dystopian future where we are indeed all issued with ration cards for every gram of greenhouse gas that we each cause to be emitted.