By Alister Doyle
OSLO (Reuters) - The Baltic Sea region is likely to warm faster than the world average this century because of climate change, disrupting fisheries and extending crop growing seasons, a report said on Wednesday.
The study, by 80 scientists from Baltic nations including Russia and Germany, said temperatures were already rising more quickly than the global average, cutting the number of days when parts of the sea are clogged by winter ice.
"A warming of the mean annual temperature in the order of 3 to 5 Celsius (5.4 to 9.0 Fahrenheit) is projected for the total basin during this century," according to the report adopted by governments around the sea in the Helsinki Commission.
A U.N. climate panel projected last month a "best estimate" that world temperatures will rise by a lower 1.8 to 4.0 Celsius (3.2 to 7.8 F) this century because of a global warming widely blamed on human activities led by burning fossil fuels.
Wednesday's report said that warming might disrupt life in the almost land-locked Baltic Sea, where species such as herring and sprat are already struggling from pollution, a legacy of the former Soviet Union to the east.
Warmer temperatures might also bring more rains that could decrease the average saltiness of the sea, upsetting marine life adapted to brackish conditions.
Scientists say that northern areas may be warming faster than the world average because darker ground and water, once exposed, soak up more heat than reflective ice and snow.
The Helsinki Commission, representing nine Baltic Sea states and the European Union, seeks to work out ways to fight pollution in the region.
But warming could also extend growing seasons in the Baltic region, where 85 million people live in an area from St. Petersburg in Russia to Copenhagen in Denmark.
A warming of 3 to 5 Celsius "would lead to a lengthening of the growing season by as much as 20 days to 50 days for northern areas and 30 days to 90 days for southern areas by the late 21st century," it said. That could help crops and forest growth.
And the period during which parts if the sea are clogged by ice would be cut. "The length of the ice season would decrease by 1 to 2 months in the northern parts of the Baltic Sea and by 2 to 3 months in the central parts," it said.
The Baltic Sea is open to the North Sea only by straits between Denmark and Sweden. Other Baltic Sea states are Germany, Poland, Russia, Lithuania, Latvia, Estonia and Finland.