Tuesday, 27 September 2011

Climate change blamed as stronger winds breeze in

22 Sep 2011, Page: 8

WIND speeds in Australia have increased by about 14% over the past two decades, but you may not have noticed because the speed of the air just above the ground has actually slowed down. CSIRO scientists analysing data collected since 1975 at numerous wind stations around the country found the average speed measured 10m above the ground had increased by about 0.7% per year, whereas that measured 2m above the ground had slowed by about 0.4% per year over the same period.

Moreover, they found that the weakest winds had increased in speed but the fastest and strongest winds increased more slowly by comparison good news for wind farm developers but potentially bad news for farmers. Alberto Troccoli, head of the CSIRO's Weather and Energy Research Unit, said the difference between the measure at 2m and 10m was due to the lower stations being shielded by obstacles such as trees and buildings, and that the higher station provided the more accurate measure.

"We think the overall increase is caused by the widening of the tropical belt, due to climate change", he said. He said the findings were important because international studies had found wind speeds generally decreasing overall in other parts of the world. "The way in which the largescale patterns change in the atmosphere is such that we have losers and winners", he said. The findings were significant for wind farm developers as they meant increased productivity, but there were implications for agriculture and building.

Russell Marsh, the policy director at the Clean Energy Council, said the findings would affect investment decisions, but government policy changes were also required. "The bankability of wind power projects is dependent on accurate wind data, and the CSIRO's work will be important for many wind companies in making decisions about investment in Australia", he said. "Although the CSIRO's research on wind speeds is good news for wind-power development, supportive government policies will continue to provide the strongest incentive for the industry". Dick Whitaker, the chief meteorologist with the Weather Channel, said winds were caused by contrasts in atmospheric temperature, and he was not surprised by the finding they had increased due to climate change.