CLIMATE CHANGE
The Greenhouse Effect is the natural warming of the earth's atmosphere, with the upper atmosphere retaining some of the heat provided from the sun over the last century increases in the concentrations of greenhouse gases have increased the atmosphere's capacity to retain heat, resulting in global warming. the Intergovernmental Panel on Climate Change (IPCC) estimates that world temperatures will rise by 1.4 to 5.8 degrees Celsius between 1990 and 2100 in the 20th century the average world temperature increased by 0.6 degrees Celsius the IPCC attributes temperature increases to the increase in greenhouse gases, in particular carbon dioxide in the atmosphere these gases are largely a result of the combustion of fossil fuels, such as coal, petrol and gas, to provide energy
fossil fuels contain carbon and hydrogen; some fossil fuels are also known as hydro-carbons fossil fuels contain carbon and hydrogen; some fossil fuels are also known as hydro-carbons when they burn, one molecule of carbon combines with two molecules of oxygen from the air to form carbon dioxide, the main "greenhouse gas“ when they burn, one molecule of carbon combines with two molecules of oxygen from the air to form carbon dioxide, the main "greenhouse gas“ fossil fuels are formed from plant and animal fossils fossil fuels are formed from plant and animal fossils carbon absorbed from the atmosphere by millions to hundreds of millions of years of photosynthesis is released back into the atmosphere when we burn fossil fuels. carbon absorbed from the atmosphere by millions to hundreds of millions of years of photosynthesis is released back into the atmosphere when we burn fossil fuels.
the current concentration of carbon dioxide in the atmosphere is around 375 parts per million (ppm) and is now increasing at over 2 ppm per year prior to the industrial revolution the atmospheric concentration was around 270 ppm CO2 levels have increased by nearly 40% - a massive increase imagine a gymnasium measuring 20 metres long by 20 metres wide by 10 meters high - the gymnasium now has four hundred litres more carbon dioxide in it than it would have 200 years ago - or two 44 gallon drums full it’s difficult to imagine this kind of proportional increase throughout the whole atmosphere around the world, and the enormous amounts of fossil fuel burnt to cause this increase.
one of the impacts of global warming is the warming of oceans and rising of sea levels as a graphic example the Larsen-B iceshelf in Antartica, which broke up in March 2002, lost 5,700 square kms in the five years from 1997 to 2002, an area about 10% the size of Tasmania
wwwweather changes are also a result of global warming tttthe apparent increase in the frequency of severe droughts and floods is evidence of this iiiin 2003 there was ample evidence of this: a record heat wave in Europe that killed over 14,000 people in France, a 1 in 100 year storm in Melbourne, and extreme bushfires in Victoria and the ACT at the start of the year ssssimilarly in 2004 the unprecedented series of cyclones in North and Central America are further evidence of climate change.
in Victoria the expected effects of climate change include (from the CSIRO): in Victoria the expected effects of climate change include (from the CSIRO): a reduction in natural winter snow cover of up to 39% by a reduction in natural winter snow cover of up to 39% by an increase in average temperatures of up to 5OC by an increase in average temperatures of up to 5OC by still some uncertainty about impact on rainfall, but up to a 25% decrease in rainfall by still some uncertainty about impact on rainfall, but up to a 25% decrease in rainfall by higher temperatures leading to increased evaporation, coupled with decreased rainfall a much greater chance of drought and bushfire. higher temperatures leading to increased evaporation, coupled with decreased rainfall a much greater chance of drought and bushfire. an increase in sea level rise of up to 55cm by an increase in sea level rise of up to 55cm by 2070.
Australia has the highest greenhouse gas emissions per capita of OECD countries at 27.6 tonnes of CO2-e per capita, which is twice the OECD average this unfortunately makes us the world's worst greenhouse gas polluter
Global greenhouse gas emissions would be 7.4 times higher than they are at present if every country had the same greenhouse gas emissions per capita as Australia. The effects on our weather if global greenhouse gas emissions were 7.4 times higher than present are difficult to model or imagine. Similarly the world's known oil reserves would run out in 10 years if every person used as much oil as the average Australian. Given that climate change is a global problem, our high per-capita emission in Australia means that we in particular have an obligation to reduce our high levels of greenhouse pollution. There is no one easy solution to climate change. Basically there are only 3 ways of slowing climate change: –reducing the amount of fossil fuel combusted through energy conservation and energy efficiency –substituting the combustion of fossil fuels with other energy sources –removing or "sequestering" greenhouse gases from the atmosphere.
► Climate change is a global problem, but it is caused by local emissions ► 23% of the world's fossil fuel caused greenhouse pollution comes from just 5% of the world's population, around 70% comes from 20% of the world's population ► The chances are that if you have internet access and are reading this you are in either that 5% (which includes Australia) or 20%. ► Fossil fuels are a great energy source, and sustain high energy use lifestyles ► As countries such as China and India seek to attain for their populations the lifestyles used by high energy use countries, global greenhouse gas emissions show no sign of abating. ► All three of the solutions outlined above are necessary to deal with the problem of climate change ► Almost all individuals and organisations in high energy use countries can significantly reduce their energy use and wastage through energy conservation and energy efficiency ► Renewable energy technologies can provide clean energy sources ► Sequestration through the planting of trees can take carbon out of the atmosphere.