Climate change slides

1. Climate change slides

2. Major greenhouse gases Greenhouse gas is typically measured in tonnes of carbon dioxide equivalent gases emitted (tCO2-e). There are four major types of greenhouse gas emitted in Australia: • Carbon dioxide (CO2), which represents 74.3% of Australia’s emissions and comes primarily from the combustion of fossil fuels • Methane (CH4), which represents 20.2% of Australia’s emissions and comes primarily from cattle and other livestock (enteric fermentation), and is also emitted from major waste disposal sites • Nitrous oxide (N2O), which represents 4.3% of Australia’s emissions and comes from the production and use of nitrogen fertilizer • Chlorofluorocarbons (CFCs), halocarbons and other manufactured gases, which represent 1.1% of Australia’s emissions and areused in refrigeration systems and other manufactured equipment

3. CO2 concentrations and temperature change Antarctic temperature is measured as the change from average conditions for the period 1850 CE to 2000 CE

4. IPCC Fourth Assessment Report 2007

5. Tasmania’s greenhouse gas emissions

6. What the 2007 IPCC Report says • There is now no doubt that the climate system is warming. • It is more than 90 per cent certain that humans are the main cause of current global warming. • The human-produced greenhouse gases that have already accumulated in our atmosphere will affect our climate for many centuries. • If we continue to produce greenhouse gases at or above current rates, it is more than 90 percent certain that climate change will accelerate in the 21st century. • It is more than 90 percent certain that extreme events including heat waves and heavy rainfall events will continue to become more frequent.

7. The 2009 climate science summary • IPCC worst case predictions are now being realised • Concentrations of greenhouse gases are higher than predicted – especially methane • Significant climate change is happening now, and happening faster expected • Sea level rise predictions have been significantly revised • Climate change will continue for centuries, even if we stop emitting carbon today CO2e emissions (Gt/y) Mapping the current greenhouse gas emissions against the IPCC2000 SRES scenarios (Raupach et al., 2007 and Canadell et al., 2007) CDIAC = Carbon Dioxide Information Analysis Center; EIA = Energy Information Administration, both US Department of Energy

8. Climate change science –take home messages Our current knowledge is not perfect, but we do know: Emissions are growing faster Climate is changing faster Climate will continue to change for decades Risks increase the longer we delay Climate change provides both risks and opportunities for Tasmania.

9. What's been happening to Tasmania’s climate? Over the past 50 years... • Average temperatures have increased by 0.8 to 1.0 degrees, in line with Australian average • Minimum temperatures increasing more than maximum • Rainfall has declined in most settled areas • declines of up to 20mm per decade in the north-west and south-east • increases of 5 to15 mm per decade in the south-west. Source: Bureau of Meteorology

10. What’s likely to happen in the future? • Annual maximum temperatures increasing across the state, highest in the north-east • Annual potential evaporation increasing in all areas except west coast and highlands where small decreases are predicted • Substantial regional variations in rainfall in both quantity and distribution. Currently being modelled by Climate Futures for Tasmania. Source: CSIRO/Hydro Tasmania/Tasmanian Partnership for Advanced Computing