Are the bushfires a result of climate warming?

A second reason is embers from an existing fire, A strong wind can carry embers perhaps ten kilometres

This writer lives in the Blue Mountains, west of Sydney, in a bushfire prone region. On the edge of the bush, our family is acutely aware of the danger of bush fires. We are also aware of the precautions a house owner must take to reduce the chance of his house going up in flames. These are:

• Lowering woodland density and burnable material around the house, by reducing shrubs and any loose leaves.
• Ensuring trees do not overhang roofs to avoid build-up of leaf litter in gutters. They will go up if burning embers land on them.

Embers are the big problem. Whether to stay and extinguish the embers as they land on your house, or to evacuate when the fire service says leave is a difficult choice. This family has decided to leave, when the firies say "leave ", fully aware that they increase the chances of coming back to a burnt-out house.

There are also steps that the Volunteer Rural Fire Service takes, including:

• "Prescribed burning","controlled" or "planned" burning . Burnoffs around communities designed to increase the distance that embers have to jump.
• "Backburns", which are lit during an emergency with the aim of creating a scorched buffer to inhibit the advancement of an active bushfire.

Neither is a perfect solution, due to the ability of embers from an existing fire to jump large distances.

Climate control, not climate denial, is another, but also imperfect answer. Australia had its hottest and driest year on record this past year. One cause is human activity, a scientifically proven fact, despite the conservative sceptics. In 2008, the Climate Change Review by Ross Garnaut said Australia would face a more dangerous fire season by 2020. His recently stated that his big regret was that he was unable to convince the Australian public, and its politicians of this danger. He added: "although things are bad, they will keep on getting worse if the concentrations of greenhouse gas emissions in the atmosphere keep increasing".

The report said there could be a 300 per cent increase in the number of days with extreme fire weather by 2067.

The main causes of human induced climate change are:

1. Increase in carbon dioxide (CO2) concentration in the atmosphere, caused by increases in fossil fuel combustion for electricity generation, transportation, and heating. CO2 stops the earth's heat escaping to the atmosphere.
2. Increase in ozone levels in the stratosphere over Antarctica. The return of the Sun at the end of winter triggers photochemical reactions that lead to the destruction of ozone in the stratosphere. The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation, a cause of many skin cancers. Elimination of certain CFCs is designed to protect the ozone layer.
3. Deforestation is another cause. Forests are very human friendly, cleaning the air and acting as natural filters to remove and store carbon dioxide from the atmosphere.
4. Methane and Nitrous oxide emissions from agriculture, arctic sea beds and factories.
5. Aerosols present in the atmosphere.

Each time a fossil fuel burns, carbon dioxide levels in the atmosphere increase. As we know, carbon dioxide absorbs infra-red energy emitted from the earth's surface, preventing it from returning to space. NASA describes it as 'the principal control knob that governs the temperature of Earth.' Electricity generation requires coal and is the largest producer of carbon dioxide emissions.