Climate Change and Ecosystems

Australia, and the rest of the world generally, are experiencing rapid climate change. Since the middle of the 20th century, Australian temperatures have, on average, risen by about 1C with an increase in the frequency of heatwaves and a decrease in the numbers of frosts and cold days. Rainfall patterns have also changed - the northwest has seen an increase in rainfall over the last 50 years while much of eastern Australia and the far southwest have experienced a decline.

Many natural systems have been shown to be very sensitive to changes in climate, with evidence mounting that the anomalously high temperatures seen during the 20th century have already been associated with changes in many biological and physical systems around the world. Such changes include: tree line movements, glacial retreat, lengthening of growing seasons, and alterations in the timing (phenology) of breeding, migration and flowering in many species.

So far, most studies associating changes in natural systems with changes in climate come from the Northern Hemisphere. However, we need to exercise some care when using Northern Hemisphere climate impact results and projecting them onto Australian species, due to the high proportion of endemic Australian species, which have already adapted to a highly variable climate system.

In recent years, information on how changes in climate may be affecting our natural systems has begun to emerge. For example, reductions in snow cover, changes in the timing of breeding and migration in birds, genetic changes in fruit fly and range changes in birds and mammals. However, for many natural systems, particularly invertebrates, reptiles and amphibians, we still have little idea how changes in the climate systems will affect these species. There are also regions of Australia where very few studies have been conducted, such as western and central Australia or the northern tropical rainforests.

NEMD will help to address these gaps in our knowledge by encouraging the sharing of information and providing easier access to natural systems data.

Those interested in obtaining more information are invited to read the following articles:

    http://www.greenhouse.gov.au/impacts/overview.html

    Chambers, L.E. 2006. Associations between climate change and natural systems in Australia. Bulletin of the American Meteorological Society 87(2): 201-206.

    Chambers, L.E., Hughes, L., and M.A. Weston. 2005. Climate change and its impact on Australia's avifauna. Emu 105: 1-20.

    Hughes, L. 2000. Biological consequences of global warming: is the signal already apparent? Trends Ecol. Evol. 15(2): 56-61.

    Hughes, L. 2003. Climate change and Australia: Trends, projections and impacts. Austral Ecol. 28: 423-443.

    Menzel, A. 2002. Phenology: Its importance to the global change community. Climatic Change 54: 379-385.

    Pittock, B. 2003. Climate change: An Australian Guide to the Science and Potential Impacts. Australian Greenhouse Office, Canberra.
    (Also available on-line at http://www.greenhouse.gov.au/science/guide/index.html).

    Root, T.L., Price, J.T., Hall, K.R., Schneider, S.H., Rosenzweig, C., and J.A. Pounds. 2003. Fingerprints of global warming on wild animals and plants. Nature 421: 57-60.