Smoke lingers over suburban Sydney, while bushfires continue to burn. It’s tragic. It’s predictable. And it’s preventable.
Australia has always been dry. But for millions of years, natural processes managed the landscape. Water was plentiful, and temperatures were stable. This made devastating fires rare.
How did nature do it? And can we fireproof the continent again?
To answer the first question, we need to look at the relationship between plants, water, soil and heat.
Anyone knows from personal experience that sweating cools you down. The reason for this is that when liquid sweat evaporates from your skin, some energy – in the form of heat – is needed to transform the liquid to gas. This heat, known as latent heat, is taken away from your body and absorbed by the water vapour. The heat is then released again when that vapour turns back into liquid.
This same process is going on all the time in plants. But when plants “sweat”, we call it transpiration. And when you have vast forests and grasslands transpiring, large amounts of water vapour travels into the sky. This has two effects. First, the evaporated water draws a massive amount of heat up into the atmosphere. This cools the environment on the ground. And second, the evaporated water turns into clouds and eventually rain.
This natural process of water movement and heat transfer leads to cooler temperatures and more rain. Two factors sure to reduce bushfire severity.
The next element to discuss is the soil. Healthy soils capture rain. This reduces erosion and keeps huge amounts of water in the landscape. This water is then available for plants to keep growing, long after the rains have stopped. Soil moisture also has a direct impact on how the landscape deals with fire. Dry, degraded soil allows fire to fly straight over it. Whereas, when there is more water in the soil, the heat is sucked from a fire, stopping it in its path.
It’s foolish to look at any one of the above processes in isolation. Nature is complex. But if we want to fix the mistakes of two centuries of mismanagement, we must comprehend this complexity.
And indeed, innovative researchers and land managers have been building a knowledge base under the umbrella term of regenerative agriculture. This is a toolkit of solutions that show the way to build soil, increase plant growth and hold water in the landscape. Regenerative farmers around the country are working with natural water and ecosystem processes, rather than against them. But we need more people to become informed and join in.
This land has been fireproof before, and it can be fireproof again. We need to let natural water processes work, so plants grow and soils improve. We don’t have to wait for governments to tax carbon or close coal plants. These grassroots solutions will allow us to quickly rehydrate the landscape. And they’re solutions that everyone can work on now.
Peter Andrews OAM, Australian landscape repair specialist, grazier and race horse breeder