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Climate change slides
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 are used in refrigeration
systems and other manufactured equipment
CO2 concentrations and
temperature change
Antarctic temperature is measured as the change from average conditions for the period 1850 CE to 2000 CE
IPCC Fourth Assessment Report 2007
Tasmania’s greenhouse gas emissions
CO2-e emissions (Mt)
20
18
Tasmania’s
emissions without
renewable energy
(19 Mt CO2-e)
16
14
12
10
8
1990
11.5 Mt CO2-e
2006
8.4 Mt CO2-e
6
4
2
0
Tasmania’s Target
– 60% below 1990
by 2050 (to 4.6 Mt
CO2-e)
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
What the 2007 IPCC Report says
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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.
The 2009 climate science summary
CO2e emissions (Gt/y)
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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
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
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.
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 southeast
• increases of 5 to15 mm per decade in the south-west.
Source: Bureau of Meteorology
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