After three straight years of crop losses due to soaring temperatures and crippling droughts, Heiner Luetke Schwienhorst has had enough and is taking Europe’s most powerful government to court.

The dairy farmer from the edge of the Spreewald forest, just south of Berlin, blames German chancellor Angela Merkel’s government for stoking climate change and wants to know why efforts to rein in greenhouse gas emissions have fallen short and put his livelihood at risk.

“We’ve lost over a third of our millet crop, half our hay crop,” Mr Schwienhorst said. “It’s a catastrophe.”

At the end of October, judges in the German capital will hear his case, which is backed by environmental group Greenpeace and two other farmers.

The hearing underscores Ms Merkel’s climate failings as she tries to get Germany back on track with a much-criticised €​50bn (£43bn) environment package.

For Mr Schwienhorst and other farmers near Berlin, this has come too late.

The final grain haul for 2019 was just as grim as the previous year, according to the region’s agricultural association. Their plight shows how farmers in Europe, one of the world’s leading producers and exporters, are on the front line of global warming.

Rising temperatures in Italy have created a plague of crop-eating bugs, causing hundreds of millions of euros in losses.

The Swiss government has recently said that last year’s record temperatures, followed up by more heat waves this year, bring “grave consequences” for agriculture.

And in Finland, a major producer of spring barley and oats, soil fertility is declining as more frequent wet and dry spells strip the earth of nutrients, according to a recent European Environment Agency report.

“New records are being set around the world due to climate change, and the adverse effects are already affecting agricultural production in Europe, especially in the south,” said Hans Bruyninckx, the agency’s executive director.

Asked about Mr Schwienhorst’s lawsuit, a spokesman for Germany’s environment ministry said the government would not comment on ongoing legal cases.

He acknowledged Germany will miss its 2020 climate goals and said it will instead focus on recent plans to hit more stringent 2030 targets.

Turning to the courts has become an increasingly common weapon in the battle to curb environmental pollution.

Exxon Mobil is on trial in the US for allegedly hiding its early knowledge of climate change, while the US Supreme Court this week let government officials press ahead with three lawsuits that accuse more than a dozen oil and gas companies of contributing to climate change.

Meanwhile, politicians are keen to show they are helping farmers, a key constituency. Ms Merkel’s administration has set aside more than €500m (£443m) in aid, while in France, agriculture minister Didier Guillaume presented a package for farmers worth €1bn (£860m) in July.

The European Union does have plentiful grain supplies – at least for the time being. This season’s soft-wheat harvest in France, the bloc’s top producer, was among the largest on record, alongside bumper barley supplies. That is helping to boost global wheat reserves to an all-time high this season, the USDA forecasts.

Warmer temperatures have aided crops in some regions, with the winter-wheat area in Russia - the top shipper - expanding due to improved seed quality and mild weather. Climate change may benefit wheat and corn yields in eastern Europe, according to a European Commission paper.

Rising temperatures are impacting agriculture around the world, not just in Europe. The best growing conditions for many crops are shifting away from the tropics, and from lower lying land, to cooler climes. Fish and other underwater catches, too, are migrating to colder seas as their habitats warm.

Europe is particularly exposed because its weather is dominated by the jet stream. Disturbances to the narrow bands of air that blow west to east across the Atlantic have allowed hot blasts to drift in from the Sahara desert, further damaging crops that evolved to cope with milder conditions.

In Italy, the rising temperatures have unleashed a swarm of Brown marmorated stink bugs, a pest that feeds on grain crops and orchard fruits.

“It’s an emergency,” said Nicola Dalmonte, owner of a 50-hectare fruit farm on the outskirts of Ravenna, who this year lost around 30 per cent of his crops to the bugs. He has covered his peach and apricot plants in nets, but said that has sometimes made things worse when the insects get trapped inside. “They breed explosively.”

Celine Imart, a farmer near Toulouse, France, said in recent years there have been many unusual weather events affecting the land her family has cultivated for six generations, producing crops like sunflowers, peas, sorghum, soybeans and corn.

Hailstorms are becoming more intense and damaged as much as 50 per cent of this season’s crops.

Back in Germany, Mr Schwienhorst hopes his case will help raise awareness of climate change. He wants the court to force the government to come up with a plan to hit its lapsed 2020 climate goals as soon as possible. He argues failure to honour the pledges has infringed property, occupational and health rights.

“It’s not that I blame Ms Merkel,” Mr Schwienhorst said. “This is a problem caused by our whole society.”