Sweden's tree line moving at fastest rate for 7,000 years: study
Pastor Dale Morgan
Sweden's tree line moving at fastest rate for 7,000 years: study*
STOCKHOLM, Jan 16 (AFP) Jan 16, 2007
Climate change over the past two decades has caused Sweden's tree line
to move north at a faster rate than at any time in the past 7,000 years,
Swedish researchers said on Tuesday.
"The tree line has moved by up to 200 metres (656 feet) in some places.
Trees have not grown at such high levels for around 7,000 years," Leif
Kullman, a professor at Umeaa University's department of ecology and
environmental science, told AFP.
The tree line represents a limit in mountainous, northern and southern
latitudes beyond which trees do not grow.
"Recordings began in 1915 but the trend has intensified in the past 15
to 20 years," Kullman said.
Sweden's climate in the past 20 years was as mild as it had been some
7,000 years ago, he added.
While some of the change could be explained by natural phenomena such as
the reduction in global volcanic activity -- allowing more sunlight to
warm the Earth -- the trend was clearly provoked for the most part by
man-made factors.
"We can say that 75 percent of the change is due to the emergence of
greenhouse gases," Kullman said.
As the climate has become milder other plants and animals have ventured
further north from their traditional habitat.
"The number of plants and animals in Swedish forests has grown 100
percent in the last 50 years," Kullman said.