How to make long-term climate pledges add up

THE CLIMATE law that the German government passed in 2019 required a cut in greenhouse-gas emissions of 55%, from levels in 1990, by 2030. Climate activists saw this as insufficient. They took the government to court on the basis that, by not treating climate action seriously enough, it was denying basic rights to citizens of the future.

The court has now rejected the more ambitious aspects of that complaint. But its ruling at the end of last month did nevertheless find fault with the law. Although the target for 2030 was not in itself deemed to be inadequate, the court decided that it does pose a problem in the context of the law’s longer-term aspiration to “net zero” emissions in 2050. The combination of the two pledges seemed to allow governments to impose a greater share of the total burden of decarbonisation on the future. The burden is all the heavier when you consider that the low-hanging apples are usually the first to be picked.

For justice to be done, the court ruled, there must be intermediate targets. It asked for details of them by the end of 2022. The immediate response, across all parties, was to talk of increasing ambition both in the near term and the longer term: a 65% cut by 2030, net zero by 2045.

To achieve that would presumably require a quick end to the internal-combustion engine, long a wellspring of national engineering pride—and exports. Germany’s coal phase-out would have to accelerate. And massive infrastructure development would be needed to support the Achilles heel of the country’s renewable-energy infrastructure: its vulnerability to kalte Dunkelflaute, the cold, dark doldrums in which sun and wind abandon the land but the hearth must stay warm.

Germans—rich, green and technically adept—may find ways to accomplish all this. Or they may not. Over the past decade they have been quite happy to close down their fleet of emissions-sparing nuclear power plants. It would be odd if a long-standing aversion to nuclear power should prove to be the only political objective the country turns out to put ahead of its commitment to climate action.

However, the court’s reservation also applies well beyond Germany. A near-term goal, expressed as a reduction in emissions with respect to some historical baseline, and a longer-term goal expressed as a date at which they intend to reach net-zero emissions, is increasingly the norm for countries seeking to take the climate seriously. These net-zero goals do not commit a country to a specific level of emissions, but to developing “negative emissions” on a scale that will cover whatever it does end up emitting. This makes what is actually being called for in terms of reduction between 2030 and 2050, or in some cases 2060, impossible to assess. It thus makes the fairness of requiring that effort from future generations impossible to judge.

This is a gateway to endless fudge. Notional negative emissions are based on forestry, new agricultural practices, rewilding and various technologies that suck carbon from the atmosphere and store it underground. Because they can be invoked to make up any shortfall in emission cuts, some activists are sceptical of including them in targets.

Blanket doubt is unreasonable. Net-zero thinking makes geophysical and economic sense. Some emissions will surely prove so hard to abate that it will be cheaper to develop technologies to suck an equivalent amount of warming potential out of the air. And if that balance can be achieved globally, the concentration of greenhouse gases in the atmosphere will stabilise and the warming stop. That is why the Paris agreement of 2015 treats net-zero as a second-half-of-the-century goal.

But net-zero thinking is troublesome, even so. It allows the ultimate scope of emission cuts to remain undefined and sweeps all the uncertainties under a carpet of techno-optimism. To keep governments honest, voters and activists around the world need to echo the German court’s order.

They should insist that governments show how they will create negative emissions in just and robust ways—so, no afforestation on poor people’s land simply because you can and no double counting or leaky carbon reservoirs. And they must insist on good-faith estimates of the negative emissions governments are banking on. That way they can tell if they are feasible and see what cuts will be needed in five, ten or 15 years’ time. ■

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