We used to believe that the world’s resources were almost limitless. But as we expand on the planet, we consume more and more of these resources. For decades, scientists have warned that we are approaching the limits of what the environment can tolerate.
In 2009, the influential Stockholm Resilience Center first published its Planetary Boundaries Framework. The idea is simple: to outline the global environmental limits within which humanity could develop and prosper. This concept has become popular as a means of capturing our impact on nature.
For the first time, we’ve taken these boundaries – which can be difficult to visualize on a global scale – and applied them to Australia. We found that Australia had already surpassed three: biodiversity, earth system change, and nitrogen and phosphorus fluxes. We are also approaching the limits of freshwater use and climate change.
The country’s land use is a key driver of these trends, with natural systems coming under increasing pressure from many land management practices. Fortunately, we already know many solutions for living within our limits, such as waste management, conservation and restoration of natural lands in conjunction with agriculture, and changes in food production.
What are the planetary boundaries?
In 2015, scientists took stock of how humanity was tracking, warning that four out of nine frontiers had already been crossed.
While such warnings make global headlines, they can also make people wonder, “What does this really mean to me? »
Read more: Can your actions really save the planet? “Planetary accounting” has the answer
This is the question we sought to answer for Australia and its land use sector. We’ve taken five of these global borders and calculated what Australia’s ‘share’ of those would be in our new technical report.
We then went further, breaking down what these borders mean for Australia’s land use industries, such as agriculture and forestry.
These limits are not abstractions – they are real
These are real world limits. Exceeding them has consequences in the real world.
Take nitrogen and phosphorus fluxes, which refer to the levels of these chemicals in the nation’s waterways.
In about 50% of our watersheds, we already have nitrogen and phosphorus levels above safe levels for environmental health. These chemicals are applied as fertilizer to croplands and pastures. If there is too much, it can flow into waterways. Once in our rivers, these chemicals can fuel dangerous algal blooms that can force the closure of popular recreation areas, fill lakes with weeds, and harm fish and other wildlife.
Tackling one environmental problem often has benefits for others. Improved water quality has benefits for biodiversity, as the plants and animals supported by these rivers have better water to live and live in.
Why is biodiversity important? The diversity of life on our continent plays a vital role in keeping ecosystems stable and maintaining the vital services – such as fresh air and water – they provide to wildlife and to ourselves.
It is well known that areas with lower species numbers and genetic diversity tend to be less resilient to shocks. This means that these environments are more at risk of tipping into a state where they can no longer provide life-saving services.
Different species occupy different niches within ecosystems, which means the loss of one or two can erode the functioning of the system as a whole.
Protecting and restoring biodiversity is therefore essential to achieving planetary health. Unfortunately, biodiversity is one of the limits that Australia has already exceeded. The number of species threatened by our activities continues to increase and many of our endangered animals are threatened with extinction.
We know what we must do
With this report, we contribute to the national conversation about how Australia can stay within its fair share of planetary boundaries and contribute to the global effort for sustainable development.
Read more: Biodiversity loss has finally become political – and that means new thinking left and right
Agriculture, forestry and other land use industries also have a vital role to play in reducing emissions and sequestering carbon. But the land use sector is under increasing pressure due to population growth, the impacts of climate change and extreme weather events.
Understanding what sustainability means in practical and measurable terms for Australia’s land use sector is key to enabling humanity to continue to thrive.