Feral animals pose risk to Australia’s ability to offset carbon to combat climate change

Australia has a number of feral animals that degrade its natural environment. With the push to become a more carbon-conscious society and increase our efforts to offset carbon dioxide emissions, are there any obstacles that may prevent us from offsetting our emissions? Will our feral animals undermine our efforts against climate change?

Many Australians have started to become ‘carbon neutral’ by offsetting the carbon dioxide emissions they generate in everyday life. One popular way to achieve carbon neutral status is to plant trees. This has seen the development and growth of a carbon offset industry. This industry includes companies that plant trees on behalf of customers wanting to offset their carbon emissions. As Australia pushes closer to the introduction of an Emissions Trading Scheme (ETS), the size of this industry will continue to grow, leading to the planting of many potential ‘carbon forests’. The early stages of such forests will involve the planting of small seedlings that are sure to catch the eye of our grazing feral animals. These plantations will provide a new and easy source of food for grazing feral animals, which will provide them the additional resources required for population growth.

The prospect of increasing feral animal populations around the country poses a real risk to the functional capacity of our existing natural carbon sinks in the form of remnant native vegetation and the growing carbon offset industry. As a result, the Sporting Shooters’ Association of Australia (SSAA) is asking its members to help.

In late 2007, the Invasive Animals Cooperative Research Centre indicated that rabbit numbers were on the increase since populations crashed following the release of the rabbit haemorrhagic disease (RHD) or rabbit calicivirus in 1996-981.

Many of the new tree seedlings that were able to germinate and grow, while rabbit numbers were at their lowest point, are now being wiped out as rabbit populations increase again. Research has found that just two rabbits per hectare can reduce plant regeneration by three-quarters. Five rabbits per hectare will almost totally prevent plant regeneration1.

If rabbit populations continue to increase, this could paint a bleak picture for the future of our emerging carbon offset Industry. There is a high risk that the rising rabbit population will eat the seedlings that have been planted for carbon offset benefit. This would not only curtail people’s efforts to prevent climate change, but also result in the extra expense of replanting lost seedlings. The Invasive Animals Cooperative Research Centre seems to think that this could be the case. It has said that to ensure that carbon gains are not lost, Australia needs to act now before the rabbit scourge of the past returns with vengeance1. A higher rabbit population has the potential to kill vast numbers of tree seedlings, which could make the carbon offset industry ineffective.

Other grazing feral animal such as goats are also known to kill established plants by defoliation, debarking and by breaking down branches. They also negatively impact native regeneration by reducing the plants ability to produce seed and by eating young plants2. Feral pigs destroy vegetation and increasing the risk of erosion3, which reduces the chances of regeneration. All of these feral grazing animals have an impact on the level of carbon sequestration by existing vegetation and the survival of seedlings planted by carbon offset schemes.

In response to this emerging issue, the SSAA is appealing to all its members and the community, to regularly participate in conservation hunting to help reduce the rabbit and other grazing feral animal populations in Australia. This will not only increase the potential of our natural carbon sinks, but also reduce the potential damage to our future carbon offset plantings and our carbon-conscious future. It’s time to act today for the future.

1 Molly K 2007, Carbon offset industry set to be undermined by rabbit attack, media release, Invasive Animals Cooperative Research Centre.
2 Animal and Plant Control Board SA 2006, The impact of grazing by feral goats in the arid zone, Animal and Plant Board SA, Department of Water, Land and Biodiversity Conservation.
3 Department of the Environment and Heritage 2008, The feral pig, The Australian Government, Department of the Environment and Heritage, www.environment.gov.au/biodiversity/invasive/publications/pig/pubs/pig.pdf

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