Climate change is real
There is now scientific consensus that the earth’s climate is changing as a result of greenhouse gas emissions of human activity. According to the CSIRO, in its recent publication Climate Change: Science and Solutions for Australia (2011):
“Historical records of temperature show that although temperatures vary naturally between ice ages and warm periods there is no record of temperatures within human history ever having increased as rapidly as they have over the past 100 years.”
CSIRO goes on to note some of the observed climate change which has already occurred, including some regions of the world becoming wetter; others have suffered increased periods of drought; frosts have decreased; heatwaves have increased; mountain glaciers have shrunk; and the sea level has risen.
This climate change is caused by human activity
CSIRO also reports that “there is evidence that the observed changes to the climate system are consistent with changes expected due to increasing greenhouse gases. It is very likely that most of the warming over the last 60 years is due to increases in greenhouse gas emissions due to human activity.”
In Australia, this change in the climate is anticipated to have an impact on water supply and quality, ecosystems and conservation, agriculture and forestry, fisheries, settlements and industry and human health.
The Federal Department of Climate Change and Water (DCCW) reports that greenhouse gas emissions from the stationary energy sector (i.e. energy excluding transport) is the largest and fastest growing area in Australia. According to the DCCW, in its recent National Greenhouse Gas Inventory (Dec 2010).greenhouse gas emissions from power generation in Australia have grown 59% from 1990 to 2009.
Reducing greenhouse gas emissions
Each Megawatt-hour of electricity generated by a wind farm reduces the amount of electricity from fossil fuel sources by an equivalent Megawatt-hour (assuming no additional reduction from reduced transmission losses). In effect, somewhere in Australia, a power station operator reduces the output of the fossil fuel power station, thereby reducing the fuel being burned by that power station. Less fossil fuel being used means less fossil fuel being burned, and results in less carbon dioxide being released to the atmosphere. This is the direct link to a reduction in greenhouse gas emissions.
A typical small wind farm of 15 turbines, with an average annual output of 35% of maximum output, will save around 90,000 tonnes of carbon dioxide emissions per annum.