The daughter of an East German pastor, the German chancellor Angela Merkel owes her political career to the peaceful revolution of autumn 1989 — die Wende (the turnaround) — that led to Germany’s reunification. And she may well be remembered for another turning point in the nation’s post-war history — die Energiewende.

Merkel has long been a driving force behind efforts to tackle global warming. The Energiewende, Germany’s solo effort to radically shift its economy to one dominated by renewable sources of energy, is a pragmatic alternative to the largely fruitless efforts of international climate-change diplomacy. If the country’s do-it-yourself tactics bear fruit, it would be cause for renewed optimism in the fight against anthropogenic climate change.

As we report on page 156, Germany aims by mid-century to produce at least 80% of its electricity, and more than half of the energy it needs for heating, from renewable energy sources such as sunlight and wind. Thousands of scientists and engineers are developing the power-storage and transmission technologies required to accommodate tomorrow’s fluctuating energy sources. The task is enormous. Nevertheless, given the growth rate of renewable energies in recent years — and the high level of public acceptance of the policy — the goals could be achieved even earlier than planned.

In the public’s perception, the Energiewende has less to do with global warming than it has with the nuclear disaster at Fukushima in Japan two years ago, which accelerated the proposed phase-out of nuclear power in Germany. In fact, the closure of eight nuclear power plants has made Germany — at least temporarily — more dependent on coal, which will make near-term reduction targets for greenhouse-gas emissions harder to achieve.

The German effort is no less impressive for all that. Merkel and the German public are displaying admirable courage in turning the country into a laboratory for energy policies (and technologies) which could become models for many industrialized countries. That the nation is running this costly and risky self-experiment against the background of a European arch financial crisis should stand as an enduring testament to Merkel’s leadership.

Germany, with its population of some 80 million, is an ideal test ground. The country can afford the Energiewende — which some commentators estimate will cost more than €1 trillion (US$1.3 trillion) — because its economy is doing well. And the country is large and diverse enough — economically, geographically and socially — to make the outcome of the great experiment relevant to the rest of the world.

Merkel and the German public are displaying admirable courage in turning the country into a laboratory for energy policies.

If German’s transition to cleaner energy succeeds, then the country will have learned scientific, technical and economic lessons that it will take to the market place and that will solidify its leadership in green technologies. Countries that might eye the German plans with some scepticism now could eventually build on these technologies when they start to reshape their own energy systems.

If the Energiewendefounders, however, it will send out a very negative message. Sceptics worldwide will argue that if Germany can’t make it work, then nobody can. It is crucial, therefore, that Germany maintains its chosen path through whatever storms may come and even if moans about high electricity prices become more audible.

Ultimately, any truly green economy must include all economic sectors. The Energiewende will not be complete without a new approach to transport. It took generous incentives to convince millions of German homeowners to invest in expensive (and aesthetically debatable) rooftop solar panels. Convincing Germans — or any other nation — to switch to battery-driven or electric cars will be even harder. Without incentives for car makers to produce those cars, and for motorists to buy them, it will not happen. But as seen in the rush for the ‘cash for clunkers’ bonus (as part of the economic stimulus of 2009 the German government paid car owners a €2,500 premium to exchange a car more than nine years old for a new one), such incentives can mobilize massive behavioural change. An effective green-car programme, backed by investment in the necessary infrastructure, would be an unmistakable signpost on the road to the post-fossil-fuel age — and not only in Germany.