Technology will not solve the problem of climate change

The writer is professor of engineering and the environment at the University of Cambridge

COP26 was a triumph for the high-emitting sectors, but a disastrous failure for the billions of people who will suffer, including from famine and starvation in countries around the equator, as a consequence of global warming.

The climate summit in Glasgow was a failure because it was predicated on the fiction that technology will solve the problem of climate change. Technology will not solve the problem because it cannot be scaled sufficiently in time. But basing the entire meeting on that assumption prevented any discussion of the real solutions which require specific restraints on a number of activities in rich countries and which can scale rapidly.

Every technological solution discussed at COP26 depends on just three resources: nelectricity (non-emitting electricity generated by hydropower, renewables or nuclear fission), carbon capture and storage (CCS) or biomass. The total demand for those resources required by the plans discussed at COP26 cannot be met.

Here are the numbers. Averaged over the world, we currently have 4kWh/day of nelectricity per person, growing at 0.1Wh/day annually. But the COP26 plans require 32 (range 16-48). We currently have 6kg of CCS per person per year, growing at 0.1kg/year annually, but the COP26 plans require 3,600 (range 1,400-5,700). We currently eat 100kg plant-based food per person each year, but producing enough bio-kerosene to fly at today’s levels requires 200kg of additional harvest.

In the 28 years we have left to reach net zero emissions, there is no possibility that our supplies of nelectricity, CCS and biomass will scale to anywhere near the levels required by the plans discussed at COP26. And scale is the only thing that matters when we discuss plans for mitigating climate change.

COP26 was a failure because all the discussion was based on an entirely fictional, unrealisable solution to a real, pressing societal catastrophe. As the climate change campaigner Greta Thunberg put it, accurately, in a speech during the summit: “We don’t have a technology solution that will get anywhere even close.”

She later observed at a rally during the gathering in Glasgow that the goal of COP26 was to “maintain business as usual”. Indeed, this was a great COP for the oil and gas industry, fossil aviation, emitting cement, blast furnace steel, fossil shipping and ruminant farmers. To reach net zero, all of their activities would have to cease completely within 28 years, but no one said so.

Thunberg also noted that “our leaders are not leading, they are actively creating loopholes while we need immediate, drastic annual cuts”. The only agreements at COP26 were on future targets, with no specific commitments to implementation, yet, according to the UN’s report on the “production gap”, we must cut all emissions by 6 per cent year on year, starting now.

The UK government’s leadership, trumpeted in a Net Zero Strategy published before COP26 and based on the loophole word “ambition” rather than “commitment”, is undermined by its continuing support for expanding the fossil sectors, removing air passenger duty, lack of funding and denial about social participation.

No political or business leader at COP26 had climate mitigation as their primary goal. I am sure they and their advisers would respond to my criticisms by saying that they betray a lack of ambition. But it is hardly ambitious if a doctor advises an alcoholic to keep drinking because the government has plans to develop liver-repair technology in future.

One of Thunberg’s claims should be nuanced, however. She said that “we will fundamentally have to change our society”. Certainly we will need specific changes, but we can anticipate about 7kWh-10 kWh per day of nelectricity per person, which is much less than anticipated by the COP plans but still enough to substitute many emitting activities with existing, scalable technologies.

While we must embrace specific restraints on flying, shipping, cement and a few components of our diet, we can continue to enjoy all the things that make life worth living — our families, art, wonder and discovery — on a real and rapid path to net zero emissions.