The long and winding road to net zero

Global environmental change presents us with an unprecedented challenge: preventing the worst outcome will require highly effective, decades-long cooperation of at least 20 of the world’s largest economies. Let’s not forget that, for example, 100 million Vietnamese produce annually less than 0.5 per cent of the world’s and less than 2 per cent of China’s annual greenhouse gas emissions.

Even if the Vietnamese were to switch rapidly and become completely emissions-free, their sacrifice would still be equal to a mere rounding error of the global total. And as the effect of greenhouse gases depends on their absolute atmospheric concentration, and not on any relative measure, all smaller emitters are, as nations and not just as individuals, powerless in the absence of any effective global compact. The likelihood of reaching the latter is best appreciated by imagining China and the US on shared sacrifices sometime soon.

The fundamental error is to see global decarbonisation as just another discrete event that could be solved by targeted technical solutions, like switching from a landline to a mobile phone, or replacing a gas furnace by a heat pump. In reality, global decarbonisation amounts to a fundamental restructuring of the world’s most essential and complex activity − its energy supply and use. It’s therefore a much more complicated and much more expensive proposition that has to tackle everything from fertilisers to jetliners, from steel to plastics, and from grain harvests to intercontinental container shipping. And then there is the sheer scale of it all. Dealing with billions of tons and trillions of cubic metres and kilowatt-hours will need gradual advances extending across decades. The process can be accelerated but it cannot be accomplished using arbitrary scenarios devised by office-bound bureaucrats in Paris or Brussels by years ending in 5 or 0.

Hydrogeneration was the original green solution. The first small hydro plant began working in 1882, the same year Edison built his first coal-fired station, and it remained a great favourite for a century. Then attitudes shifted, hydro became an environmental problem and eventually the World Bank stopped financing any new projects in low-income countries with large remaining hydro capacities. This is most unfortunate because the world – both rich and poor − still abounds in opportunities to build lots of small hydro stations whose combined capacities would be a welcome adjunct to intermittent electricity supplies. China, of course, has kept on building on a gargantuan scale as hydro became a critical part of their generation. Why should Africa, with its large hydro potential, be deprived of the same chance?

Most people don’t seem to realise the extent of the inefficiencies and waste that define their activities, especially as applied to energies embedded in the supply of existential necessities. Here are just three notable examples: We pump, treat (or desalinate) and dis-tribute drinking water, but frequently lose 30–40 per cent of it through leaky pipes and defective plumbing.

We synthesise and distribute nitrogen fertilisers (at very high energy costs) and then often lose 50–70 per cent of the nitrogen after the fertilisers are applied. And we extract, process and distribute natural gas to heat homes and then lose a large part of that heat through single-pane windows and poorly insulated walls. I could go on and on. A rational society would first try to mend its grossly inefficient ways rather than bring in new energy sources to perpetuate the existing inefficiencies.

The most “over-hyped” green inventions we’ve seen in recent years..? That could be a long list. I’ll limit it to just three prominent items. Nuclear fusion: in 2022, after some important experimental progress that still left the technique decades from any profitable commercial deployment, we were once again told (quite mistakenly) how close we are to this ultimate energy solution. Small modular nuclear reactors: I heard Alvin Weinberg, who was involved in the Manhattan Project as a young man and later became director of the Oak Ridge National Laboratory, talk about them for the first time in 1982. If we had a small commercial reactor for every mention of their imminent arrival during the past four decades, the world would not know what to do with all that power.

Carbon sequestration by exposed mantle rocks (in Oman and elsewhere): in theory such rocks could store hundreds of years of anthropogenic carbon emissions; in practice, though, I wouldn’t add this to your pension portfolio. How could it be done on the requisite scale? To sequester just 10 per cent of all CO2 emitted from fossil fuel combustion, we would have to develop a new global industry that could handle the same mass of CO2 annually as the global mass of crude oil production. And the process would have to work in the opposite direction by spending huge amounts of money and energy to force billons of tons of supercritical CO2 fluid underground rather than bringing highly profitable oil above ground.