In the current panic over the economic crisis, people are still demanding we take action on climate change now. Forty scientists have warned we face a choice between inaction and continuing climatic disasters or directing resources to stabilise the world’s climate. Nicholas Stern, one of the world’s leading economists, warned that the global economy will face much more severe downturns than the current crisis if we fail to halt climate change. Polling this week revealed that two in five Australians believe climate change is the most serious threat facing the planet.
Emissions targets are a crucial first step. Australia’s total energy needs can be supplied sustainably through current technologies using solar, wind, water and “hot rocks”. However, we also need to protect our natural assets against the climate change that will come regardless of emission reductions. All levels of government must provide a strategic plan for protecting Australia’s environment under climate change.
Environmental effects of climate change are there for all to see — rivers are running dry, forests are dying, and bird populations are crashing. The hotter and drier climate predicted for southern Australia will only exacerbate these problems. While the global economic crisis will be temporary, the effects of the climate crisis will be irreversible (e.g. mass extinctions).
We outlined in the Garnaut Review how climate change is and will adversely affect all aspects of biodiversity. Numerous species will go extinct because they are unable to adapt to climate change. Many current invasive species will expand under climate change and new invasives will occur. Human-induced environmental change has already disrupted ecosystem services, such as fresh water and productive soils, and these will be further degraded by climate change. The combination of extinctions, invasion and loss of ecosystem services, will lead to significant ecological surprises that will be detrimental to our environment, economic productivity and human health. These dire ecological problems relate to just a 0.7°C temperature increase — our projections for what is very likely to emerge from a further 4 °C change are catastrophic.
We are sure you are tired of experts spouting that the end is nigh, so we also offer positive actions that can be taken now. There are three key steps that will help protect our environment against climate change.
First, broad-scale restoration and retention of native vegetation (e.g. “Biolinks”) is needed. This will maintain populations of plants and animals, and provide them with the opportunity to migrate as climate changes. It will also have the effect of taking carbon dioxide out of the atmosphere.
Second, substantial amounts of water must be returned to aquatic and terrestrial systems. While achievable, this will require much more dramatic (and immediate) reallocation of resources than current initiatives propose. Crops that are appropriate for our new climate and water-efficient farming practices need to be encouraged to reduce agricultural water demands. Urban water supplies can be supplemented with recycled water and not by draining water from distant, water-stressed catchments.
Third, over-management of ecosystems must be avoided. This includes the practices of frequent fuel-reduction burning and over-regulation of river flows. These practices produce impoverished landscapes composed of the few remaining tolerant species. Instead we must restore natural variability and disturbance regimes — this is how natural ecosystems have worked for millennia.
Biodiversity is not expendable. Services we rely on — productive soils, clean water and pollination of crops — will collapse when the diversity of plants, animals and micro-organisms is lost. Therefore, biodiversity must be considered in the debate about climate change strategies.
Relative ratings of impacts on four biodiversity currencies in relation to six climate-change scenarios. The six climate scenarios are: R1 +4.5 °C mean temperature, -25% water availability; R2 +4.5 °C, +15%; A +1 °C, -25%; B +1 °C, +15%; C +0.55 °C, -7%; and “+3” +3 °C, -7%. Anticipated effects of these scenarios on biodiversity currencies are shown, where ratings to the ‘VERY EXTREME’ ends of the dials are most adverse.
Extract from “Garnaut Climate Change Review — Biodiversity and Climate Change” prepared by R. Mac Nally, S. Cunningham, K. Shelley, C. Sgrò, R. Thompson, S. Lake, P. Sunnucks, T. Cavagnaro, D. O’Dowd, P. Baker & J. Beardall (Australian Centre for Biodiversity, Monash University).