What Australia stands to lose
Wet Tropics & Tropical Rainforests
The Wet Tropics in Far North Queensland is the most biologically diverse region in Australia. The rainforests in this region are the oldest remnants surviving on the planet. The Wet Tropics World Heritage area, declared in 1988, is home to 30% of Australia’s marsupials, 60% of its bats, 18% of its birds and 60% of its butterflies. Many species exist in small pockets of limited refugia and are susceptible to small changes in climate. Modelling by rainforest ecologists from James Cook University suggests that a 2-degree temperature rise will condemn many such species to extinction.
The effects of climate change in tropical rainforests are being measured already, the most well-known case being the extinction of the Golden Toads of the cloud forests of Costa Rica, where decreased rainfall has caused the species to perish. Predicted temperature rises will be too rapid for the adaptive capacities of many species and could lead to a catastrophic wave of extinctions in the wet tropic regions of Australia and elsewhere.
Published by The Age, “Ecosystems Under Threat” explores the effects of global warming on tropical rainforests.
Great Barrier Reef
Coral reefs include a collection of biological communities representing one of the most diverse ecosystems in the world. For this reason, coral reefs often are referred to as the ‘rainforests of the oceans.’ No one ecosystem is more endangered by climate change than the reef ecosystem.
Raised water temperatures disrupt a unique symbiotic relationship between plant and animal–algal zooanthellae and coral polyps. Unable to photosynthesise properly, the algae are ejected and polyps then starve, bleaching the coral which eventually breaks down to rubble. Australia’s Great Barrier Reef is undisputedly one of the world’s most important natural assets. It is the largest natural feature on earth, stretching more than 2,300km along the north-east coast of Australia and is one of the most complex ecosystems on the planet.
During 2002, the international coral reef information network ReefBase reported 430 global cases of coral bleaching, most of them on the Great Barrier Reef. With rising temperatures bleaching events could become an annual occurrence from 2030 onwards, which has some scientists predicting the end of reefs across much of the ocean. The economic implications for tourism, fishing and coastal communities are immense.
Published by The Age, “Ecosystems Under Threat” explores the effects of global warming on the Great Barrier Reef.
For further information on the effects of global warming on Coral Reefs visit http://www.coralreefresearch.org/
Australian Alps
Australian alpine ecosystems are at low altitude relative to the mountains over much of the rest of world and have a very restricted distribution. However, despite covering a small area, they are important for many plant and animal species, many of which are listed as threatened. Alpine ecosystems are highly vulnerable to climate change, as small increases in temperature can dramatically reduce snow cover.
Scientists predict that by 2030 a warming of 1.8 degrees Celsius accompanied by 8% less precipitation would reduce the area covered by snow by up to 66%. By 2070 this could result in a 96% reduction in snow cover. Studies suggest a warmer climate would cause lower-elevation habitats to expand into the higher-alpine zone. Such a shift would encroach on rare alpine meadows and other high-altitude habitats. High-elevation plants and animals have limited space available for new habitat as they move higher on mountains in response to long-term changes in temperature.
This scenario would mean a large reduction in many alpine habitats, threatening species such as the mountain pygmy possum. In addition, such change will threaten the viability of the Australian ski industry, a major contributor to the economy.
Published by The Age, “Ecosystems Under Threat” explores the effects of global warming on Alpine environments.
Scientists predict that by 2030 a warming of 1.8 degrees Celsius accompanied by 8% less precipitation would reduce the area covered by snow by up to 66%
Murray Darling Basin
Located in the south-east of Australia, the Murray Darling Basin covers over 1 million square kilometres, encompassing Australia’s three longest rivers: the Murray, Murrumbidgee and Darling. The basin is abundant with biological diversity, containing at least 35 endangered birds, 16 endangered mammal species and over 30,000 wetlands. For fish and other riverine life forms, the Murray Darling Basin is a vast interconnected network, stretching from the saline lakes of the Coorong estuary, east to the alpine streams of the Snowy Mountains and north to the inland semi-arid and tableland streams of southern Queensland. Around 70% of Australia’s irrigated crops and pastures occur in the Basin.
Under expected climate change, the southern parts of the Murray-Darling Basin are likely to experience significantly reduced water availability due to reductions in winter and spring rainfall as well as increased temperatures and evaporation.
In a system already experiencing water scarcity, climate change further threatens the ecological and agricultural integrity of one of Australia’s great natural icons.
Published by The Age, “Ecosystems Under Threat” explores the effects of global warming on the Murray Darling Basin.
Kakadu
Kakadu National Park is one of Australia’s most iconic cultural and environmental regions. It’s renowned for its vast wetlands and cultural heritage, including Aboriginal rock art and archeological sites dating back thousands of years.Located in the wet-dry tropics of the Northern Territory, Kakadu stretches almost 20,000 square kilometers between the Alligator Rivers. The region is a rich tapestry of billabongs, rivers, floodplains, mudflats, mangroves, open woodlands and a sandstone escarpment and plateau.
Kakadu’s low-lying freshwater wetlands make up 90% the park’s coastal zones, and these are under direct threat from climate change.
The wetlands provide important habitat for birds, amphibians and reptiles. In the dry season, an estimated 3 million waterbirds of more than 60 species congregate in the park. And it’s not only birds which flock to the area; the park hosts also 165,000 human visitors a year.
Kakadu’s wetlands are vulnerable to even small variations in sea level rise. Already salt-water intrusion is a problem, but this situation is about to get much worse. The Intergovernmental Panel on Climate Change predicts a sea level rise of between 9 and 88cm by 2100. If the sea level rise is 50cm, these wetlands will become incredibly salty; a rise of more than 88cm will see the wetlands become a mangrove forest.
Scientists believe these predicted impacts of climate change will not only destroy habitat and devastate the tourism industry, but will make the region unpleasant for habitation. Sadly, climate change could become a serious problem for the indigenous people who have lived continuously in the region for 50,000 years.
Published by The Age, “Ecosystems Under Threat” explores the effects of global warming on Kakadu.