Climate Change

What is climate change?

Climate change or ‘global warming’ is the most serious environmental problem facing the world this century. It has wide reaching implications, posing a threat to biodiversity, water supply, human health and the global economy.

There is now broad scientific consensus that the planet is warming and that this is due to an unprecedented increase in the concentrations of greenhouse gases in the atmosphere, primarily from human activities such as the burning of fossil fuels.

The average global temperature increased by 0.74 degrees C in the 100 years to 2005. This small temperature increase has already changed the global climate with effects including the melting of sea ice, permafrost and glaciers; rising sea levels; reduced rainfall; bleaching of coral reefs; and more frequent extreme weather events, such as drought, cyclones, heatwaves and bushfires.

Global greenhouse gas emissions increased by more than 70% over the last 40 years. Current projections are that, if we continue down our high emission path, the global temperature could rise by as much as 6.4 degrees C by the end of this century.

A temperature increase even a third of this would have considerable impacts on weather patterns and eco-systems. There is also the serious risk of reaching a ‘tipping point’ for catastrophic and irreversible events.

Immediate and concerted action on the part of governments, businesses and communities to stabilise atmospheric greenhouse gas concentrations is needed to avoid further climate change.

What is causing climate change?

The greenhouse effect is a natural phenomenon that keeps the surface temperature of the Earth at a liveable temperature. The Sun’s radiation passes through the atmosphere as light waves and warms the earth’s surface. This energy is then re-radiated in the form of infrared waves. Most of this infrared radiation continues to outer space but some is absorbed by greenhouse gases, such as carbon dioxide, water vapour and methane, in the atmosphere. This absorption of energy allows the average temperature on earth to be maintained at a comfortable 15 degrees celcius, rather than minus 18 degrees celcius which would occur without natural concentrations of greenhouse gases.

The problem is that the human activities since the industrial revolution have dramatically increased the concentrations of greenhouse gases in the atmosphere. These activities include the burning of fossil fuels for electricity production and transport, as well as large-scale land clearing.

The increased concentrations have raised the level of absorption of the infrared radiation and thus increased the temperature on earth, with a significant rise in temperature in the second half of the 20th century.

The testing of air trapped in ice cores has enabled scientists to determine the changes in temperature and carbon dioxide concentrations in the atmosphere over the last 650,000 years. The concentration of carbon dioxide has fluctuated between 180 and 300 parts per million (ppm) for hundreds of thousands of years but in the last one hundred years has increased well beyond this natural range, reaching 379 ppm in 2005.

Scientific consensus, using sophisticated climate modelling, is that the recent increase in the earth’s temperature is primarily due to human activities or ‘anthropogenic forcing’ rather than natural forcing effects.

The key anthropogenic greenhouse gases and their Global Warming Potentials (GWPs) relative to carbon dioxide are shown in the table below:

Source: UNFCCC *Share of global emissions is weighted by GWP

How will climate change affect WA?

Temperatures in inland areas of the South West are projected to increase by 0.5 to 2.1 degrees celcius by 2030.

Water supply is a critical issue for WA. And water resources – so crucial to our lives - are extremely vulnerable to variations in climate. Reduced rainfall in the South West has already contributed to a reduction in streamflows into Perth’s main dams of over 50% since the mid-1970s.

A recent report by the CSIRO states that further reductions in runoff could be around 45% in the next 20 years.

For more detail, go to

http://conservationwa.asn.au/content/view/178/206/

CSIRO Report a wakeup call for State Government on water efficiency and forest management

Final Warning: Climate Science Update

Latest reports predict that Arctic summer ice will disappear entirely within the next 5 years.

Science shows that climate change is accelerating, with devastating impacts if we pass the critical 'tipping point'.

http://www.greenpeace.org/australia/resources/reports/climate-change/finalwarning240309

Sydney Morning Herald item - Climate change is happening here, now: US report
ABC News Online item - Climate change is fact, not opinion
SBS Online item - Climate change 'here now', US report says

To see a 10 minute video on tipping points, go to our Video Gallery and watch 'Wake Up, Freak Out - Then get a Grip'.

To control climate change, we must change.

Get involved in our campaign

See what steps you can take to be part of the change

Climate Change Denial

The evidence regarding Climate Change being caused by human beings has become so overwhelming, that people who still won't accept that we're causing it are now called Climate Deniers. These are people who refuse to accept the science and that 97% of climate scientists agree that the current round of Climate Change - also known as Anthropogenic Global Warming (AGW) - is caused by human activity. They are not merely sceptical but in denial.

Deniosaurs are people who can't be reasoned with regarding Climate Change and won't accept facts. They are blinded by false belief and their thinking is often twisted by political beliefs and motives and particular world views.

To read more about Climate Denial, go to our links page and the section Climate Change Denial

To see some entertaining videos that refute Climate Deniers claims go to our Video Gallery and the Channel Climate Deniers Corner

Download a document here - Climate Skeptics Top 10.pdf - that explains the 10 most common claims by Climate Deniers and also explains the error of the claims.