AT THE UN climate summit in Bonn last November some Americans came up with their own riposte to President Donald Trump’s decision to withdraw from the Paris agreement. Outside the main conference building they put up a tent housing a rowdy coalition of people from 20 states and 110 cities under the banner “We are still in”. Some non-American delegates at the conference found this fringe event more reassuring than the climate talks themselves. It showed that, even without Mr Trump and the federal government, local activists in America are committed to the spirit of the agreement.

The EU and China, each in its own way, are taking up America’s mantle of climate leadership. The task remains daunting (see article). At present the EU has the boldest plans. It wants to lead the clean-energy transition, aiming to reduce its greenhouse-gas emissions in 2050 by 80-95% from 1990 levels, which means almost entirely decarbonising its energy system. Germany reckons that its experience of launching an Energiewende (energy transition) in 2000 qualifies it to help lead the world away from fossil fuels. But not all its neighbours like the model it offers.

Start with gas. For the next few decades Germany is likely to rely on imported natural gas as it phases out its nuclear and coal-fired power plants and brings in more electricity generated by wind and solar. Gas reserves elsewhere in Europe, such as the Netherlands, are declining. So Gazprom, the Russian energy giant, backed by five energy multinationals, has launched a project to lay a new pipeline to Germany, Nord Stream 2, under the Baltic Sea. This would double the capacity for Russian gas piped to Europe by 2019. It would also replace most of the gas flowing to Europe along the Brotherhood pipeline via Ukraine and Slovakia, reducing their transit revenues (see map).

Nord Stream 2 is highly divisive. The European Parliament says it increases Europe’s dependence on a single route for gas imports, which is bad for energy security. American diplomats say it exposes Europe to manipulation of supply by Russia, as happened with Ukraine. (It also undermines America’s export strategy for shipping more LNG to Europe, though they keep quiet about this.) Foreign-policy hawks believe it strengthens Russia’s economic influence over Europe and weakens Ukraine.

Russia and Germany retort that it is purely a commercial venture. Its supporters do not see it as a potential Russian chokehold but as a way to bind Russia more closely to Europe, because trade makes each more dependent on the other. Yet the plan has created a rift between Germany and its eastern neighbours.

That is also true of the Energiewende, underlining how divisive even clean energy can be when its effects spill across borders. Germany initially saw its dash for solar and wind as a purely domestic issue. The decision to phase out nuclear power after Japan’s Fukushima disaster in 2011 was a response to a deep-rooted domestic environmental lobby. Germany did not consult its neighbours on ramping up renewables, even though its grid is linked to many other countries’ energy systems.

The foreign-policy ramifications have become wider since. Notwithstanding Nord Stream 2, renewables are part of a strategy to reduce the country’s dependence on fossil-fuel imports (most of its coal and oil also come from Russia). Moreover, Germany hopes the Energiewende will give it a global edge in clean-energy technology. Siemens, for instance, has become a global leader in wind-turbine manufacturing.

But the rapid spread of wind power in northern Germany, and the lack of transmission lines to the industrial centres farther south, has caused headaches. Thomas Sattich of the University of Stavanger in Norway writes that when the wind blows hard, surplus renewable energy is pushed to neighbours such as Poland, the Czech Republic and the Netherlands, clogging up their electricity systems. Excess renewable energy also brings down wholesale power prices, which is bad for investment. .

On the grid

The best way of dealing with such problems is more cross-border co-ordination, as well as more high-voltage power lines. The European Commission is finalising packages to redesign the block’s electricity markets. In January European lawmakers proposed increasing the EU’s goals for the share of renewables in the energy mix to 35% by 2030.

Norway, with its abundance of round-the-clock hydroelectricity, wants to play a role as Europe’s “green battery”. It is also among ten countries by the North Sea that subscribe to the North Sea Countries’ Offshore Grid Initiative, which aims to create a regional supergrid. Miguel Arias Cañete of the European Commission says that such interconnections are essential if the goal of 35% renewables is to be achieved. But he also notes resistance from local communities to large, unsightly power lines, and from national-grid operators to surrendering autonomy. Sometimes the commission must wish for the sort of control over energy policy that China’s mandarins enjoy.