One hundred and twenty-six billion euros a year. That is the figure experts estimate the economic damage from droughts and heatwaves in Europe could reach by 2029. This is not a forecast for the end of the century - it is three years from now.

Between April and June much of the continent, from Portugal to southern Finland, recorded below-average rainfall. Combined with heatwaves arriving one after another, that deepened the drought and pushed river levels unusually low. Worst affected are the Danube and the Rhine - the two arteries along which Europe literally moves its industry.

When the river stops, the factory stops

Low water levels have already disrupted freight transport on the Rhine, forcing German factories to cut production. Some economists warn that shipping problems could shave 0.2 percentage points off German economic growth. The Rhine links the industrial centres of Switzerland, Germany and the Netherlands with Rotterdam, Europe's largest port - so a blockage there does not stay local for long.

The list of measures across Europe reads like a wartime chronicle. France fears it could have its weakest maize yield in fifty years. Spain has restricted farmers' access to irrigation water. The Netherlands has introduced special measures over water shortages. A state of emergency has been declared on seven Greek islands.

"We are powerless"

The problem is not confined to the big river courses. Lake Brenets on the Swiss-French border has almost dried up and has not been navigable for over a week. "I am worried, these are disasters we could not even imagine. We expected a lot of things, but not droughts in such rapid succession. It hits us hard because we are simply powerless against climate change like this," said a resident of Les Brenets in Switzerland.

Climatologist Stefan Rahmstorf rejected the favourite phrase of recent years. "I would not call this the new normal, because it is already a trend. Nor will it become the new normal - the situation will keep getting worse." When a scientist tells you "the new normal" is too optimistic a description, it is worth listening.

Biologist Thorsten Rennebarth, from a lake research institute, explained the mechanics of the Rhine: normally water levels are low in winter and high in summer, because the river is fed from the Alps. When the snow melts late in spring, the big inflow arrives. Last winter there was almost no snow - and now there is no water.

The cause that is not hiding

The World Weather Attribution scientific network states that climate change did not itself cause the shortfall of rainfall in Europe between April and June. But rising temperatures increase the atmosphere's capacity to draw moisture out of soil, rivers, lakes and reservoirs. In other words: even when rainfall does not fail dramatically, the heat dries out whatever is left.

The Danube is no European abstraction to us. It is the river half of Central Europe and a large part of the Balkans lives beside, the river our whole neighbourhood depends on for power, irrigation and transport. When Germany calculates how much economic growth it will lose, it is worth asking - is anyone here running that same sum at all?