Australia's Biodiversity - Impacts of Climate Change

Climate change impacts
Research activities & reports

Biodiversity underpins the ecological processes which make life on Earth possible, such as provision of fresh air, clean water, nutrients and pollination of plants.

Australia is one of the most biologically diverse countries, and is home to more than one million species, many of them endemic. Species found only in Australia include 85% of our flowering plants, 84% of our mammals, 89% of our temperate in-zone fish and 45% of our birds.

The mountain pygmy possum - already vulnerable - is an example
of a species at risk of extinction from climate change
(Picture: Linda Broom)

Australia's biodiversity is already under stress from human impacts such as land use change, regulation of streams, soil salinisation, invasive species, over-harvesting of commercially valuable species and changes to fire regimes. Climate change is an additional stress.

While Australian plants and animals have evolved to cope with large year-to-year climate variability, many terrestrial species have narrow long-term average climate ranges (Pittock, 2003¹).

Many species and ecosystems could be highly vulnerable to the rapid and sustained increase in long-term average temperatures of 1 or 2 °C, projected under climate change scenarios. For, example, climate change modelling indicates that the extent of highland rainforest ecosystems of tropical North Queensland may decrease by up to 50% with a 1 °C increase in temperatures (Pittock, 2003¹; Hilbert et al. 2001²)

Adapting to climate change

The Council of Australian Governments (COAG) and the Natural Resource Management Ministerial Council (NRMMC) have both identified biodiversity as a priority for climate change adaptation. In 2004 the NRMMC released the National Biodiversity and Climate Change Action Plan, which sets out a series of adaptation strategies and actions to minimise the impacts of climate change on biodiversity by maximising the capacity of species and ecosystems to adapt to future climates.

Adaptation options for biodiversity include:

reducing existing threats to biodiversity to build resilience into natural systems and species,
incorporation of climate change information into management tools for biodiversity managers,
assisting the natural adaptation of species and ecosystems through improved on-reserve and off-reserve management of areas of high conservation value,
continual development of a comprehensive, adequate and representative National Reserve System which incorporates adaptation to the impacts of climate change
increased monitoring and research into the impacts of climate change and adaptation options for species and ecosystems threatened by climate change.

Climate change impacts

There is growing evidence that increases in temperatures have caused measurable changes in biodiversity including the distribution, abundance, life cycles and physiology of a number of plants and animals. Observed changes to Australian biodiversity consistent with climate change include: more frequent and intense coral bleaching as a result of high water temperatures, increased numbers of snow gums growing in sub-alpine meadows in the Australian Alps, and intrusion of freshwater swamps by mangroves, particularly in the Northern Territory.

The Australian ecosystems that are most vulnerable to climate change impacts include coral reefs, highland rainforests, alpine regions, coastal wetlands, and the heathlands of southwest Western Australia.

Potential direct physical and ecosystem effects	Potential secondary and indirect impacts
Increases in temperature
Southward species migration Changes in range of weeds, other invasive species and pests and diseases Species migration to higher altitudes Changes in phenology (life-cycle events - flowering, egg-laying, migration) Changes in distribution and abundance of species Changes in metabolism (photosynthesis, respiration, growth and tissue composition) in plants Species loss Increased frequency and intensity of wild fires Genetic changes in species to new climatic conditions	Mismatching of life-cycle interactions between species (predator-prey; plant-herbivore; pathogen-host; pollinators-flowering plants) leading to species declines and extinctions Changes in competitive interactions among species, and the structure and composition of communities and ecosystems Increased occurrence of eutrophication of streams, lakes, wetlands and estuaries Reduced capacity for recovery of natural areas following wild fire and other disturbance regimes.
Sea level rise
Changes in structure of coral reefs and shallow water marine communities Increased inundation of coastal wetlands and lowlands Loss of estuarine, coastal species and communities Increased intrusion of salt water vegetation into freshwater ecosystems in coastal areas
Increases in sea surface temperature
Increased coral bleaching Pole ward species migration Increased algal blooms Decrease in coastal montane cloud forests Changes in species distribution and ecosystem composition
Altered rainfall and runoff patterns (local increases/decreases)
Altered river flow and changes to sediment and nutrient dynamics Altered lowland flood risk Loss of wetlands and associated biodiversity Loss of migratory birds dependent on wetlands and streams Disruption to stream, estuarine, wetland food webs due to reduced supply of nutrients Drying of ecosystems leading to loss of species and changes in community composition Invasion of woody shrubs into drying landscapes	Increased incidence of eutrophication of streams, lakes and estuaries Changes in species distribution and ecosystem composition
Altered frequency of extreme weather events
Increased destruction of coral reefs, other coastal ecosystems and terrestrial ecosystems Mass mortality when climate thresholds are exceeded during extreme events Loss of species due to reduced snowfall and reduced occurrences of frosts	Changes in species competitive interactions and species and community composition Changes in range of invasive species
Elevated CO₂ in the atmosphere and ocean
Increased ocean acidification Increased erosion of coral reefs due to ocean acidification and decreased rates of calcification Increased disruption to food chains (e.g. Southern Ocean) Changes in photosynthesis, respiration, growth and tissue composition in plants Decreased nitrogen content in vegetation Increased invasion of woody shrubs into arid and semi-arid rangelands	Impaired movement and function of high oxygen demand fauna (e.g. squid, fish) Changes to plant-insect prey relations due to decreased nitrogen content in vegetation Changes in species distribution and ecosystem composition (ie changes in C₃ and C₄ plans)

Synthesised from: Intergovernmental Panel on Climate Change (IPCC), Pittock (2003)¹, Howden et al (2003)³

Research activities

A number of significant projects are underway assessing the vulnerability of Australia's biodiversity to climate change and facilitating the sharing of research and information about climate change impacts on biodiversity. The results of this work will inform government policy and management of Australia's biodiversity under a changing climate.

Climate change impacts on the National Reserve System

The National Reserve System represents the collective efforts of the Australian Government, State and Territory Governments, non-government organisations and Indigenous landholders to achieve a nation-wide system of terrestrial protected areas as a major contribution to the conservation of our biodiversity. There are currently more than 7,720 terrestrial protected areas in the National Reserve System covering 80.9 million hectares in all the bioregions of Australia. A study into the vulnerability of the National Reserve System to climate change has commenced.
Project description:

The study will assess the implications of climate change for management of the National Reserve System, using the Interim Biogeographic Regionalisation of Australia framework.
The results will be critical to the management of the National Reserve System, including its future development at a national and regional scale.

Project management: Department of the Environment and Water Resources

Project partners: Department of the Environment and Water Resources, CSIRO

National Ecological Meta Database

Understanding how Australia's biodiversity is being affected by climate change requires detailed comparisons of current and historic records of observations of plant and animal phenology (the branch of science dealing with the relations between climate and periodic biological phenomena such as bird migration or plant flowering).
Project description:

The National Ecological Meta Database is an online database of datasets that have the potential to be used for research and analysis on climate change impacts on species and ecosystems.
Information for the database is being sourced from State agencies, CSIRO, farmers, ecological and field naturalists groups, botanic gardens and the ARC Earth System Science Network.
Web: www.bom.gov.au/nemd

Project partners: Department of the Environment and Water Resources, Bureau of Meteorology, Macquarie University, University of Melbourne

Reports

Biodiversity conservation research in a changing climate - Workshop Report, 2007
National Biodiversity and Climate Change Action Plan 2004-2007
Climate Change Impacts on Biodiversity in Australia - Outcomes of a workshop sponsored by the Biological Diversity Advisory Committee, 1-2 October 2002

¹ Pittock, B. (ed.) 2003
Climate change: An Australian Guide to the Science and Potential Impacts, Australian Greenhouse Office, 2003

² Hilbert, D.W., Ostendorf, B. and Hopkins, M., (2001)
Sensitivity of tropical forests to climate change in the humid tropics of North Queensland. Austral Ecology, 26 590–603.

³ Howden, M et al (2001)
Climate Change Impacts on Biodiversity in Australia, Outcomes of a workshop sponsored by the Biological Diversity Advisory Committee, 1-2 October 2002 Department of the Environment and Heritage, August 2003