Impacts of climate change
The climate is changing!
New climate projections for Australia were released in 2007 by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Bureau of Meteorology.
The report Climate Change in Australia, provides the latest information on observed climate change in Australia and its likely causes. It also updates projections of changes in temperature, rainfall and other aspects of climate which can be expected over coming decades as a result of continued global emissions of greenhouse gases. The new projections are based on 23 climate models and are the most detailed and comprehensive produced in Australia to date.
For the NT, the report shows that average annual temperature increases of up to 1.2ºC have occurred in the Territory since 1910. Projections show that by 2030, annual average temperatures over the NT are projected to increase by a further 1.0ºC - 1.2ºC relative to recent decades.
Small increases in average temperature can lead to very significant increases in the frequency of extreme events such as flooding rainfalls, fires and heatwaves. For example, the number of very hot days per year over 35ºC in Darwin (currently 11) is projected to rise to 44 days by 2030, and up to 227 days by 2070. Changes to rainfall remain ambiguous for the Top End, while decreases in rainfall are generally projected for Central Australia. Increased intensity of tropical cyclones is likely, inundation from storm surge is projected to increase, and global sea level rise is projected to continue.
Impacts of climate change
There are a number of potential impacts resulting from climate change for the NT which need to be considered in developing adaptation strategies. These impacts are likely to affect natural and agricultural ecosystems as well as human health.
The Department of Climate Change has prepared a summary of the projected Australian impacts of climate change by region, that includes projected impacts for the Top End, Mid Northern Territory, and Central Australia. A factsheet that summarises the projected impacts of climate change for the NT has also been developed.
The effects of climate changes on natural and agricultural ecosystems are complex. Climate change will place more stress on natural systems as species seek to move or change their survival strategies in response to changing climatic conditions. Increases in atmospheric carbon dioxide levels can increase plant growth provided water is in adequate supply. However, this effect decreases with increasing temperature and produces leaves, and other plant parts, with different chemical and nutritional qualities. Similarly, potential benefits of increased rainfall may be offset by increased evaporation rates.
The ability of pests and weeds to survive winters is expected to increase and the development of summer pest species is expected to accelerate with increased temperatures. Warmer temperatures would allow tropical diseases to spread southwards. It is possible that some sub-tropical weeds would benefit directly from climate change and, indirectly, from reduced competition from native species.
Global warming is likely to have both direct and indirect impacts on human health. Direct effects include heat stress and potential injury from cyclones and floods. Indirect effects include increases in mosquito-borne diseases such as dengue fever, and water-borne diseases, such as giardia. Mosquito-borne disease infection is likely to increase as warmer conditions would extend the range and breeding season of mosquitoes.
Human adaptation to climate change and increasing temperatures in the NT is likely to include increased usage of air conditioning with associated increased electricity use and greenhouse gas emissions. Adapting to increased temperatures by improving building design and increasing air conditioning appliance efficiency, will assist in abating greenhouse gas emissions.
Although climate change presents many negative impacts, limiting greenhouse gas emissions and adapting to climate change also presents unique opportunities for the NT. Some benefits of preparing for future climate change include:
- Cost savings for government, industry and the community as a result of greenhouse driven improvements in areas such as energy efficiency and cleaner energy production.
- Economic opportunities in new areas including renewable energy products (such as geothermal) and service delivery, energy efficiency and projects to sequester carbon (i.e. capture and store carbon emissions).
- Improvements in public health through indirect improvements in air quality related to bushfires.
The NT may be relatively well-placed to deal with climate change due to the existing natural climate extremes. For example, natural and managed ecosystems are tolerant of extended wet and dry conditions and existing infrastructure has been designed to minimise the impact of storms, cyclones and associated storm surge.