22 Oct 2018
RAIN FARMING, DROUGHT ASSISTANCE FOR TOMORROW
By Dr Stuart Blanch and Glenn Morris
Dr Stuart Blanch is a forest conservation policy manager with WWF-Australia. Glenn Morris produces organic beef on holistic farms near Inverell and Grafton.
Trees make rain. They pump water from deep in the ground through the roots and trunk and out through leaves. Water vapour released from leaves lifts biological particles from leaves high into the air. Raindrops form around these, making clouds. Trees are rainmakers.
Like air conditioners, trees cool and humidify air. They slow drying winds, make oxygen, bind soil, purify air, cycle nutrients, build soil carbon and buffer weather extremes.
Trees do it all for free. What’s not to love?
A healthy landscape is a very valuable asset. Healthy land is an absorbent sponge, super-storing water and carbon, balancing Earth’s climate and water cycles.
When trees are bulldozed, we lose these services which protect and nurture us with a safe climate, clean air and water, and healthy soil and food.
Protecting and growing trees in over-cleared landscapes can enable regional communities to farm rain, helping to buffer long dry periods.
University of Queensland scientist Clive McAlpine and colleagues modelled reduced rainfall and higher temperatures from over-clearing of forests and woodlands. Professor McAlpine’s team found a strong correlation between clearing of southeast Australia’s forests and woodlands, and rainfall over the past two centuries. Average air temperatures increased 0.4°C to 2.0°C, and summer rainfall fell between 4 and 12 percent. Modelling showed large scale tree clearing caused this, not global warming. It also revealed large-scale reforestation increased rainfall, with more trees making more rain which grew more trees, and so on.
A 2015 review by Deborah Lawrence and Karen Vandecar in Nature Climate Change found evidence from global climate computer models that critical thresholds exist for the Amazon rainforests where deforestation of more than 30-50% caused rainfall and ecosystems to significantly decline.
Unconvinced? Look at weather maps to see how clouds form more often above vast woodlands east of the rabbit-proof fence in Western Australia, but fewer clouds form to the west where woodlands were bulldozed for cropping. Clouds don’t lie.
From the Amazon to the Congo, West Africa to India, major deforestation has been observed or modelled to make the local weather hotter, drier and windier.
This agrees with what wise people in rural and regional Australia will tell you. Forests make rain, and clearing trees reduces rainfall and heats air temperatures.
So by allowing even more tree clearing, State governments and lobbyists harm rural and regional communities’ climate and economic future.
It ignores meteorological and ecological research that deforestation lowers rainfall, raises temperatures and increases drought risk, and ultimately causes desertification.
A recent report by the NSW Nature Conservation Council and WWF-Australia identified a near tripling in tree clearing in northwestern NSW around Moree and Collarenebri in the 12 months since August 2017, when the NSW Government gutted tree protection laws. Approved clearing leapt 800% after the Government weakened vegetation laws previously.
Yet only 9% of native vegetation in NSW is in good condition. When will the bulldozers stop?
Our proposal does not ignore the terrible dry conditions faced now, but rather faces it head on with a practical cost-effective rain farming solution to naturally reduce the need for expensive support.
Growing trees is drought assistance for the decades ahead. We need more rain farming, as the weather is not going back to ‘normal’. It’s more extreme and less reliable, and getting worse as the climate warms.
Last century, governments invested billions to build dams to water the inland. They demanded farmers bulldoze forests to retain farm leases. It was a taxpayer-funded war on trees.
This century, governments must legislate to protect mature trees, subsidise conservation of regrowing trees, and fund mass reforestation with indigenous seedlings.
For our weather’s sake, it’s time to legally ban clearing of mature trees and high conservation value regrowing trees. More clearing risks making future droughts far worse.
Australia needs to bring back the forests and woodlands, with hundreds of millions of trees, by regenerating and revegetating over-cleared and increasingly marginal country.
Governments should invest billions of taxpayer dollars in this natural infrastructure, with rigorous auditing and satellite monitoring to ensure compliance. We need partnerships between landholders and taxpayers to water the inland again, this time with trees, not dams.
Revenue streams need to sufficiently offset income foregone by landholders who choose rain farming – by protecting regrowing trees and mass plantings – instead of bulldozing these trees to expand grain farming or beef farming.
Decisions made in decades past to over-clear country should not unfairly punish current landholders wanting to farm for rain.
Many landholders in the drying inland are facing grim choices. Those with increasingly marginal country should be offered options to voluntarily reforest over-cleared land. As part of a long-term drought assistance agenda, governments could contract some of their lands for farming rain while continuing to crop or graze the rest, or contract all of the property for farming for more rain.
Payments would be for environmental stewardship payments to plant trees on country cleared decades ago, or to voluntarily not clear land with naturally regrowing trees and seedbanks that had previously been cleared and which are not legally protected. The NSW Biodiversity Conservation Trust provides a ready mechanism. Either way, landholders should be financially supported for the service they provide to rural areas by farming for rain, carbon and wildlife.