The Hague - Dutch authorities will have to boost their already significant flood protection measures to cope with increasingly warmer, wetter winters and summer droughts, according to forecasts released Tuesday.

Four possible future climate scenarios for 2050 presented by the official Dutch Meteorological Institute (KNMI) show global warming continuing apace and sea levels rising.

For the Netherlands, the next four and a half decades will bring milder but wetter winters and drier summers interspersed with sudden extreme rainfall.

Already the Netherlands has one of the world's highest standards of flood protection, enough to withstand a storm of a magnitude that statisticians say occurs only once every 10,000 years.

Around 60 percent of the Netherlands is below sea level, protected by an intricate system of dams and dykes. The Dutch also invented the polder, land reclaimed from the water.

"The effects of a future rise in sea level will be felt very strongly here," Deputy Transport Minister Melanie Schultz van Haegen said.

A devastating flood in 1953 that killed more than 2,000 people prompted the authorities to launch an unprecedented plan for coastal protection.

But with the KNMI predicting a rise in sea level of up to 35 centimeters (13.5 inches) by 2050, protection would have to be stepped up.

"We must be prepared for climate change," Schultz van Haegen said.

She said drier summers were also a cause for concern because dykes could dry out and burst.

The KNMI stressed they had left out the worst-case scenarios with the most extreme results.

"With these four scenarios you have a good chance that what happens in the next 50 years will be within these expectations," KNMI director Frits Brouwer said.

The predictions were released to enable the government to anticipate the pace of climate change and adapt policies accordingly, the KNMI said.

There will be changes in energy demand if winters warm up, while a warmer climate can influence agriculture because more can be grown but summer droughts could have adverse effects, and yields from wind energy parks can drop if wind speeds drop, as some scenarios predict, Schultz predicted.

The Netherlands is also working with other European countries on water management.

The country is the end point for several big rivers coming from Germany and Belgium, such as The Rhine and the Meuse that can be affected by either sudden droughts or rising water levels as the earth's temperature rises.

"Hopefully in June the European Union will present a new 'high water' plan based on a joint French-Dutch initiative to make sure the low lying countries are not stuck with the problems," Schultz said.

"We cannot stop glaciers melting but if we work together we can prevent that the Netherlands becomes Europe's drain," she added.

But the hardest blow the KNMI delivered to the Dutch Tuesday was that, according to the latest scenarios, the legendary Elfstedentocht ice skating marathon, held on over 200 kilometers of natural ice in the Friesland province, is less likely to occur in future.

Although the last marathon, named Elfstedentocht because it goes past 11 (elf) towns (steden), was held in 1997, each winter when the temperature drops below zero Celsius the Dutch get so-called Elfsteden fever.

The national primetime news shows report daily on the marathon's "ice masters" who check the state of the ice and have to give the all clear before the marathon can start.

In 1997 over 16,000 people participated in the Elfstedentocht.