New projections which are regionally specific about potential climate changes for the Mackay Whitsunday Isaac NRM region, have been released by the CSIRO and the Bureau of Meteorology as part of the national NRM Planning for Climate Change program funded by the Australian Government.
Changes to the ‘average climate’ occur every 10-12,000 years, with cycles between warm periods and Ice Ages.
We have been in a warm period for over 11,000 years, in the geological epoch called the ‘Holocene’. The global climate change issue is a result of the planet ‘warming’ rather than cooling which may have been expected from historical climate change patterns.
Levels of certainty varies dependent on the climate variability being examined. The certainty around future projections include:
- Substantial increases in average, maximum and minimum temperatures
Very high confidence
- Substantial increases in the temperature of hot days, as well as in the
frequency and duration of extreme temperatures
Very high confidence
- Average sea level and height of extreme sea level events will continue to
- Increases in evapotranspiration in all seasons
- Increased intensity of extreme rainfall events High confidence
- Less frequent but more intense tropical cyclones Medium confidence
- Changes to rainfall are possible but unclear due to disagreement between model simulations Low Confidence
Future projections about the climate are dependent on greenhouse gas emissions into the future with the IPCC and international research community establishing Representative Concentration Pathways (RCP’s).
These RCP’s focus on concentrations of greenhouse gases, emissions trajectories and radiative forcing (energy absorbed and retained in the lower atmosphere). The current trajectory for greenhouse emissions is RCP8.5, which is the worst case or Business as usual scenario.
The latest report indicates that Australia could have an average temperature increase of up to 5.1°C by 2090, as the worst case scenario. Implications for the local region are discussed in the ‘Wet Tropics Cluster report’ that can be found on the Climate Change in Australia website.
Temperature increases by the end of the century may be of little consequence to some people, however the implications of other changes within the climate system are having, and will continue to have, effects on the natural environment and society into the future.