Queensland’s new land clearing bill will help turn the tide, despite its flaws


Anita J Cosgrove, The University of Queensland; April Reside, The University of Queensland; James Watson, The University of Queensland, and Martine Maron, The University of Queensland

Queensland’s Labor government this month tabled a bill to tighten the regulation of land clearing. Queensland is by far the worst offender in this area, following a litany of reversals of vegetation protection.

After a period of tightened laws between 2004 and 2013, the Newman government set about unwinding key reforms during its 2012-15 term.

Following these changes, land-clearing rates quadrupled to almost 400,000 hectares per year, to the dismay of conservationists, with rising concern about the impacts on wild animal welfare and wider ecological impacts.




Read more:
Why aren’t Australia’s environment laws preventing widespread land clearing?


The state’s Labor government, which retained power at the November 2017 election, made an election promise to tighten vegetation management laws. However, the bill is likely to be fiercely debated after the parliamentary committee tables its report next month.

Although the bill promises a steep reduction in land clearing, albeit without any firm target, there is likely to be a significant gap between what the government has promised and what its legislation may deliver in reality.

To explain why, let’s look in more detail at what the proposed legislation does, as well as what it doesn’t do.

High-value agriculture

The 2013 amendments legalised the clearing of mature forest for large-scale crop-growing developments. The bill will once again ban it, fulfilling Labor’s election promise, but it remains a major point of friction with agriculturalists.

This will not stop the roughly 114,000 hectares that have already been approved from being cleared. It would, however, stop any more approvals.

About 10% of clearing of mature forest is due to high value agriculture approvals.

Self-assessed clearing

Up to 67% of clearing of regulated vegetation is occurring under self-assessment provisions. No permit is required for this, provided that landowners follow the code and give notice of their plans.

Of this self-assessed clearing, about 60% is for “thinning”. The government has now recognised that “thinning is not a low-risk activity” and is removing the main provision that allows it, but is keeping some self-assessed thinning provisions, such as for advanced regrowth.

Other types of self-assessed clearing would continue, particularly the clearing of mulga forests for livestock fodder, albeit under a tighter code. This was a major concession to agricultural interests.

As the bill has not banned self-assessment outright, future land-clearing rates will ultimately depend on how stringent the new codes turn out to be in practice.

“Area Management Plans” are an older, parallel mechanism for allowing self-assessed clearing. Clearing under these plans accounts for up to 38% of clearing of regulated vegetation. The new legislation would phase out existing plans, but would retain a provision to make new area plans, including for thinning.

Google satellite image of remnant forest that was legally thinned under a self-assessable code in 2015. The top half shows intact forest, and the lower half thinned forest.
WWF-Australia

Regrowth

The government promised to protect “high conservation value regrowth”. This includes threatened ecosystems and species habitats that are needed for recovery. The new law would expand these definitions to regulate clearing of regrowing forests older than 15 years, and of regrowth alongside streams in all Great Barrier Reef catchments, not just the northern ones as at present.

This will bring more than a million hectares that are currently exempt under regulatory control, a major step forward. However, the bill excludes regrowth that has been “locked in” as exempt on property maps. Clearing of regulated regrowth may also still proceed under a new self-assessable code, which apparently lacks protections for endangered species habitats or ecosystems.

Exemptions

Exemptions pose a major stumbling block to the government’s promise to “protect remnant and high conservation value regrowth”. An area currently exempt on a regulatory map can be reclassified, and the government plans to do this for more than 1 million hectares of high conservation value regrowth. However, areas that have been “certified exempt” on a property map cannot be reversed – this represents 23 million hectares (13% of the state’s area). The government has reaffirmed its commitment not to reverse these exempt areas.

What’s more, the bill allows ongoing locking in of exemptions. This is a significant issue because more than 60% of all tree clearing is exempt. Most of this is in already locked-in areas, and a large fraction includes advanced regrowth of high conservation importance.

It remains to be seen how much the A$500 million Land Restoration Fund will protect these locked-in areas.




Read more:
Land clearing isn’t just about trees – it’s an animal welfare issue too


In light of these loopholes and exemptions, the new law looks set to fall short of what the Queensland government has promised. This is primarily due to ongoing reliance on self-assessed clearing and exempt areas. However, the proposed legislation and funding together should go some way towards turning around Queensland’s soaring land-clearing rates.

Tree clearing will continue to be a hotly contested policy space, and not just in Queensland. New South Wales recently trod the same path, placing a heavily reliance on self-assessed codes. These were recently challenged successfully in court. A similar challenge is under way in the Northern Territory, citing the greenhouse emissions caused by a large-scale clearing approval.

The federal opposition has also pledged to tighten land-clearing controls in national legislation. The tide may well be turning, albeit only slowly so far.


The ConversationThe authors acknowledge the contribution of Dr Martin Taylor, Protected Areas and Conservation Science Manager at WWF-Australia and Adjunct Senior Lecturer at The University of Queensland.

Anita J Cosgrove, Senior Research Assistant in the Centre for Biodiversity and Conservation Science, The University of Queensland; April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; James Watson, Professor, The University of Queensland, and Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Advertisements

Why aren’t Australia’s environment laws preventing widespread land clearing?


Samantha Hepburn, Deakin University

Australia has national environment laws – the Environment Protection Biodiversity Conservation Act (EPBC Act). Yet given the staggering rates of land clearing taking place, resulting in the extinction and endangerment of plants and animals in Australia, these laws are clearly not working.

About 395,000 hectares of regrowth and old growth vegetation were cleared during 2015-16 in Queensland. Australia is set to clear up to 3 million hectares of native forest by 2030, and more than 1,800 plant and animal species are currently listed as threatened nationally.




Read more:
Turnbull wants to change Australia’s environment act – here’s what we stand to lose


When the EPBC Act was first implemented in 1999, the idea was for it to provide reinforced federal environmental protection to areas of national environmental significance. But in reality, many projects that come within the ambit of the Act are not rigorously evaluated for their environmental impact.

Why isn’t the EPBC Act working?

Land clearing was listed in the 2001 and 2006 State of the Environment Reports as one of the greatest threats to biodiversity.

Deforestation and excessive land clearing fundamentally impacts existing biodiversity, damages fragile ecosystems, destroys wildlife habitat, and increases greenhouse gas emissions. In Queensland, where much of the land clearing is taking place, the state law (Vegetation Management Act) is not strong enough to diminish incentives for land clearing. Yet the national environmental laws have not provided greater protection.

There are several reasons for this. While land clearing is indirectly regulated by the EPBC Act due to the significant impact it can have on the environment, land clearing is not directly addressed by the EPBC Act.

As it stands, land clearing will only attract EPBC Act application where it can be established that it impacts a directly protected entity such as a World Heritage area, Ramsar wetland, threatened species, ecological community, or migratory species. If this connection cannot be established, no environmental assessment under the EPBC Act will occur.

Even where projects do attract the application of the EPBC Act, its capacity to advance best practice environmental impact assessment is highly questionable. One of the biggest problems is that the process of assessment is insufficiently robust.




Read more:
Commonwealth should keep final say on environment protection


This problem is evident in other environmental issues too. Where a bilateral state and federal assessment is approved, as was the case with the Adani coalmine, the federal department often relies on state counterparts to undertake a thorough environmental assessment. Many of the proposals evaluated by state departments are assessed with reference to the least onerous environmental impact assessment available.

This documentation is generally prepared by the project proponent. Unsurprisingly, as a consequence, many of the projects that are evaluated under the EPBC Act are approved, subject to the imposition of environmental conditions. This means the environmental conditions need to be carefully monitored if environmental protection is to be optimised.

This creates a new set of problems. Where a breach is alleged, it must be proved and appropriate sanctions enforced. In reality, this rarely happens, and the sanctions that are imposed can be woefully inadequate. For example, Adani was fined A$12,000 for breaching an environmental condition relating to the release of coalwater in Abbott Point coal terminal, which flowed into the fragile Caley Valley Wetlands.

The substantive problem with the EPBC Act is that its implementation is subject to departmental discretion and therefore the vagaries of government administration. This is particularly problematic given the political nature of many of these decision-making processes.

Lack of rigorous scrutiny

In circumstances where, for example, there is a need to challenge the approval of a resource title in light of its environmental consequences, the EPBC Act relies heavily on environmental groups or other third parties to scrutinise the federal decision-making process.

For example, the Australian Conservation Foundation took strong action in challenging the issuance of the mining licence for Adani’s proposed Carmichael coal mine. It argued the endangered species and climate change impacts were insufficiently taken into account by the then Environment Minister Greg Hunt in exercising discretion under the EPBC Act.




Read more:
Latest twist in the Adani saga reveals shortcomings in environmental approvals


The case was dismissed because the Federal Court found that this decision was authorised by the discretions included within the EPBC Act. The minister was therefore within his power to decide not to take account of the climate change impacts of such a vast new coalmine. This is concerning given the profound impact that climate change can have upon fragile ecologies in areas of national environmental significance.

These findings indicate a lack of preparedness by the federal minister to accept a causal connection between climate change and domestic coal production, and to focus on narrow jurisdictional boundaries and strict domestic obligations. It also strongly highlights the deficiencies of our national environment act because the existing triggers do not address some of the most important environmental concerns of the modern world.

New environment laws urgently needed

Climate change is almost universally accepted as one the most serious environmental threats. Yet the EPBC Act does not include a climate change trigger (or a land clearing trigger, as discussed above).

This means these key threats to Australia’s environment will not be protected by EPBC Act. They may attract the EPBC Act indirectly, but only if it can be established that they raise a different trigger that is listed under the Act. This calls into question the capacity of our national environment laws to truly protect areas of national environmental significance.

The ConversationIn order to reverse unacceptable rates of land clearing, preserve ecosystems and habitats and diminish greenhouse gas emissions, a new framework for our national environment act is urgently needed.

Samantha Hepburn, Director of the Centre for Energy and Natural Resources Law, Deakin Law School, Deakin University

This article was originally published on The Conversation. Read the original article.

Australia is a global top-ten deforester – and Queensland is leading the way


Noel D Preece, James Cook University and Penny van Oosterzee, James Cook University

When you think of devastating deforestation and extinction you usually think of the Amazon, Borneo and the Congo. But eastern Australia ranks alongside these in the top 10 of the world’s major deforestation fronts – the only one in a developed nation. Most of the clearing is happening in Queensland, and it is accelerating.

Only last year a group of leading ecologists voiced their alarm at new data which showed the clearing of 296,000 hectares of forest in 2013-14. This was three times higher than in 2008-09, kicking Australia up the list as one of the world’s forest-clearing pariahs. At the 2016 Society for Conservation Biology Conference, a Scientists’ Declaration was signed by hundreds of scientists, expressing concern at these clearing rates.


Read more: Queensland land clearing is undermining Australia’s environmental progress


But the latest snapshot, Queensland’s Department of Science report on land cover change published last month, showed a staggering 395,000ha of clearing for 2015-16: an increase of one third on 2014-15. As far as we can tell this rate of increased clearing is unmatched anywhere else on the globe.

showed a staggering 395,000 of clearing for 2015-16: which is an increase of one third on 2014-15, or 133% over the period

Strong vegetation management laws enacted in Queensland – the Vegetation Management Act 1999 – achieved dramatic reductions in forest and woodland loss. But the subsequent Liberal National state government, elected in 2012, overturned these protections.

The current government, elected in 2015, has tried and failed to reinstate the protections. In response, “panic clearing” caused clearing rates to shoot up, in anticipation that the state election will deliver a government that will reintroduce the much-needed protection of forests.

The Queensland Parliament is now in caretaker mode ahead of the November 25 election. The Queensland Labor Party has pledged to reinstate laws to prevent wholesale clearing, while the LNP opposition has vowed to retain current clearing rates.

Forest cleared by bulldozers towing massive chains.
Noel Preece

Australian community and wildlife lose

Whichever way you look at it, there is not a lot of sense in continued clearing. Australia already has some of the highest extinction rates on the planet for plants and animals. With 80% of Queensland’s threatened species living in forest and woodland, more clearing will certainly increase that rate.

Clearing also kills tens of millions of animals across Australia each year, a major animal welfare concern that rarely receives attention. This jeopardises both wildlife and the A$140 million invested in threatened species recovery.


Read more: Land clearing isn’t just about trees – it’s an animal welfare issue too


This rate of clearing neutralises our major environment programs. Just one year of clearing has removed more trees than the bulk of 20 million trees painstakingly planted, at a cost of A$50 million. Australia’s major environment programs simply can’t keep up, and since 2013 are restoring only one-tenth of the extent of land bulldozed just last year.

Restoration costs to improve the quality of waters running onto the Great Barrier Reef are estimated at around A$5 billion to A$10 billion over 10 years. Nearly 40% of the land cleared in Queensland is in reef catchments, which will reverse any water quality gains as sediment pours onto the reef.

Climate efforts nullified

Since 2014, the federal government has invested A$2.55 billion on reducing emissions in the Carbon Farming Initiative through the Emissions Reduction Fund. Currently 189 million tonnes of abatement has been delivered by the Emissions Reduction Fund. This – the central plank of the Australian government’s climate response – will be all but nullified by the end of 2018 with the current clearing rates, and will certainly be wiped out by 2020, when Australia is expected to meet its climate target of 5% below 2000 emissions.

Ironically, this target will be achieved with the help of carried-over results from the first commitment period of the Kyoto Protocol, which Australia was only able to meet because land clearing had decreased between 1990 and 1997.

Why is this happening?

Most of the clearing in Queensland since 1999 has been for pasture. Most good cropping land was cleared decades ago. Removing trees in more marginal lands can increase the carrying capacity for a short time with an immediate, and usually short-lived, financial reward. These rewards come at the expense of long-term sustainability, which future landholders and government will bear.

Large areas of the cleared lands have been subject to substantial erosion and nutrient loss from the newly cleared lands, and land degradation over time, and some areas have suffered massive woody weed incursions.

This is playing out today across the north where pastoralism is a marginal activity at best, with declining terms of trade of about 2% per year, with no net productivity growth, high average debts and low returns, and many enterprises facing insolvency. Clearing vegetation won’t change that.

A recent preliminary valuation of ecosystem services, on the other hand, estimated that uncleared lands are worth A$3,300-$6,100 per hectare per year to the Australian community, compared with productivity of grazing lands of A$18 per hectare.

With a clear divide between the policies Labor and the LNP are taking to the election, now is a good time to give land clearing’s social, economic and environmental impact the scrutiny it deserves.


The ConversationThis article was updated on November 21 to reflect that land clearing increased in by a third in 2015-16 over 2014-15 levels. Previously the article stated an increase of 133%.

Noel D Preece, Adjunct Principal Research Fellow at Charles Darwin and, James Cook University and Penny van Oosterzee, Principal Research Adjunct James Cook University and University Fellow Charles Darwin University, James Cook University

This article was originally published on The Conversation. Read the original article.

Land clearing isn’t just about trees – it’s an animal welfare issue too



File 20170704 10704 10o5p14
This quenda seems to have been a victim of land clearing.
Colin Leonhardt/Birdseyeviewphotography.com.au, Author provided

Hugh Finn, Curtin University

Tens of millions of wild animals are killed each year by land clearing across Australia, according to our research on the harm done to animals when native vegetation is removed for agricultural, urban and industrial development.

As my colleague Nahiid Stephens and I point out in our study, this harm to animals is largely invisible, unlike the obvious effects of clearing on trees and other plants. But just because something is invisible, that does not mean it should be ignored.

We argue that reforms are necessary to ensure that decision-makers take wild animals’ welfare into account when assessing development proposals and land clearing applications.

How does land clearing harm animals?

Land clearing harms animals in two basic ways. First, they may be killed or injured when native vegetation is removed, typically through the use of earth-moving machinery. For example, animals may suffer traumatic injuries or be smothered when vegetation is cut or soil and debris are shifted.

Second, the removal of native vegetation puts animals in harm’s way. Those that survive the clearing process will be left in an environment that is typically hostile, unfamiliar or unsuitable. Animals are likely to find themselves in landscapes that are devoid of food and shelter but filled with predators, disease, and increased aggression from members of their own species as they struggle to make a living.

Land clearing causes animals to die in ways that are physically painful and psychologically distressing. Animals will also suffer physical injuries and other pathological conditions that may persist for days or months as they try to survive in cleared areas or other environments to which they are displaced.

Many reptiles and mammals are territorial or have small home ranges, and thus have strong associations with small areas of habitat. Koalas in urban areas, for example, tend to rely on particular food trees. Likewise, lizards and snakes often rely on particular microhabitat features such as logs, rocks, and leaf litter to provide the combination of temperature and humidity that they need to survive.

Laws are not protecting animals

Land clearing remains a fundamental pressure on the Australian environment. While the regulatory frameworks for land clearing vary greatly across the Australian states and territories, the principal statutes that govern native vegetation clearance in most jurisdictions typically contain some sort of express recognition of the harm that land clearing causes, such as the loss or fragmentation of habitat, land degradation, and salinity.

Habitat lost: land cleared for the now-discontinued Perth Freight Link road project.
Colin Leonhardt/Birdseyeviewphotography.com.au, Author provided

Yet these regulations are uniformly silent on the issue of how land clearing harms animals. No state or territory has developed a clear framework to evaluate this harm, let alone minimise it in future development proposals.

This failure to recognise animal welfare as a significant issue for decision-making about land clearing is troubling, especially given the scale of current land clearing. In Queensland, for example, an estimated 296,000 hectares of woody vegetation was cleared in 2014-15, nearly all of which was for the purpose of converting native vegetation to pasture. In our study we estimate that, on the basis of previous studies and current estimates of clearing rates, land clearing in Queensland and New South Wales combined kills more than 50 million birds, mammals and reptiles each year.

What reforms are necessary?

We suggest that two basic reforms are required. First, state and territory parliaments should amend the laws that govern environmental impact assessments and native vegetation clearance, to require decision-makers to take animal welfare into account when assessing land clearing applications.

Second, we urgently need accurate ways to evaluate the harm that proposed clearing actions may cause to individual animals. Animal welfare is broadly recognised as an important social concern, so it makes sense that in a situation where we know animals are being harmed, we should take steps to measure and prevent that harm.

The basic aim of any reform should be to ensure that the harm that land clearing causes to individual wild animals is appropriately considered in all forms of environmental decision-making and that such evaluations are based on clear and objective criteria for animal welfare.

At a minimum, those who apply to clear native vegetation should be required to provide an estimate of the number and type of native animals that will be killed by the proposed land clearing. This would ensure that all parties – applicants, decision-makers, and the community – understand the harm that the clearing would cause. These estimates could be made by using population density information for species that are likely to be affected – an approach that has been already been used.

We also need to revise our perceptions about the usefulness and necessity of land clearing in Australia. A better idea of what is “acceptable” would include not only the environmental costs of clearing an area of native vegetation, but also the individual suffering that animals will experience.

Issues of causation and responsibility are critical here. While it’s unlikely that someone who wants to clear land actually wants native animals to suffer, such suffering will nevertheless be an inevitable consequence. The relevant question is not whether animals will be killed and harmed when land is cleared, but how much of that harm will occur, how severe it will be, and whether it ought to be avoided.

The ConversationIf such harm is deemed necessary – based on an accepted system for weighing the potential benefits and harms – the next question is how the harm to animals can be minimised by, for example, keeping the amount of vegetation to be cleared to a minimum.

Hugh Finn, Lecturer, Curtin University

This article was originally published on The Conversation. Read the original article.

Land clearing on the rise as legal ‘thinning’ proves far from clear-cut


File 20170619 770 h5c4tb
A ‘thinned’ landscape, which provides far from ideal habitat for many species.
Author provided

April Reside, The University of Queensland; Anita J Cosgrove, The University of Queensland; Jennifer Silcock, The University of Queensland; Leonie Seabrook, The University of Queensland, and Megan C Evans, The University of Queensland

Land clearing is accelerating across eastern Australia, despite our new research providing a clear warning of its impacts on the Great Barrier Reef, regional and global climate, and threatened native wildlife.

Policies in place to control land clearing have been wound back across all Australian states, with major consequences for our natural environment.

One of the recent policy changes made in Queensland and New South Wales has been the introduction of self-assessable codes that allow landholders to clear native vegetation without a permit. These codes are meant to allow small amounts of “low-risk” clearing, so that landholders save time and money and government can focus on regulating activities that have bigger potential impacts on the environment.

However, substantial areas of native forest are set to be cleared in Queensland under the guise of vegetation “thinning”, which is allowed by these self-assessable codes. How did this happen?

Thin on the ground

Thinning involves the selective removal of native trees and shrubs, and is widely used in the grazing industry to improve pasture quality. It has been argued that thinning returns the environment back to its “natural state” and provides better habitat for native wildlife. However, the science supporting this practice is not as clear-cut as it seems.

Vegetation “thickening” is part of a natural, dynamic ecological cycle. Australia’s climate is highly variable, so vegetation tends to grow more in wetter years and then dies off during drought years. These natural cycles of thickening and thinning can span 50 years or more. In most areas of inland eastern Australia, there is little evidence for ongoing vegetation thickening since pastoral settlement.

Thinning of vegetation using tractors, blades and other machinery interrupts this natural cycle, which can make post-drought recovery of native vegetation more difficult. Loss of tree and shrub cover puts native wildlife at much greater risk from introduced predators like cats, and aggressive, “despotic” native birds. Thinning reduces the diversity of wildlife by favouring a few highly dominant species that prefer open vegetation, and reduces the availability of old trees with hollows.

Many native birds and animals can only survive in vegetation that hasn’t been cleared for at least 30 years. So although vegetation of course grows back after clearing, for native wildlife it’s a matter of quality, not just quantity.

Land clearing by stealth?

Thinning codes in Queensland and New South Wales allow landholders to clear vegetation that has thickened beyond its “natural state”. Yet there is little agreement on what the “natural state” is for many native vegetation communities.

Under the Queensland codes, up to 75% of vegetation in an area can be removed without a permit, and in New South Wales thinning can reduce tree density to a level that is too low to support natural ecosystems.

All of this thinning adds up. Since August 2016, the Queensland government has received self-assessable vegetation clearing code notifications totalling more than 260,000 hectares. These areas include habitat for threatened species, and ecosystems that have already been extensively cleared.

It may be that the actual amount of vegetation cleared under thinning codes is less than the notifications suggest. But we will only know for sure when the next report on land clearing is released, and by then it will be too late.

Getting the balance right

Vegetation policy needs to strike a balance between protecting the environment and enabling landholders to manage their businesses efficiently and sustainably. While self-regulation makes sense for some small-scale activities, the current thinning codes allow large areas of vegetation to be removed from high-risk areas without government oversight.

Thinning codes should only allow vegetation to be cleared in areas that are not mapped as habitat for threatened species or ecosystems, and not to an extent where only scattered trees are left standing in a landscape. Stronger regulation is still needed to reduce the rate of land clearing, which in Queensland is now the highest in a decade.

Protecting native vegetation on private land reduces soil erosion and soil salinity, improves water quality, regulates climate, and allows Australia’s unique plants and animals to survive. Landholders who preserve native vegetation alongside farming provide essential services to the Australian community, and should be rewarded. We need long-term incentives to allow landholders to profit from protecting vegetation instead of clearing it.

Our research has shown that Australian governments spend billions of dollars trying to achieve the benefits already provided by native vegetation, through programs such as the Emissions Reduction Fund, the 20 Million Trees program and Reef Rescue. Yet far more damage is inflicted by under-regulated clearing than is “fixed” by these programs.

The ConversationImagine what could be achieved if we spent that money more effectively.

April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Anita J Cosgrove, Research Assistant in the Centre for Biodiversity and Conservation Science, The University of Queensland; Jennifer Silcock, Post-doctoral research fellow, The University of Queensland; Leonie Seabrook, Landscape Ecologist, The University of Queensland, and Megan C Evans, Postdoctoral Research Fellow, Environmental Policy, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Stopping land clearing and replanting trees could help keep Australia cool in a warmer future


Clive McAlpine, The University of Queensland; Jozef Syktus, The University of Queensland, and Leonie Seabrook, The University of Queensland

Land clearing is on the rise in Queensland and New South Wales, with land clearing laws being fiercely debated.

In Queensland in 2013–14, 278,000 hectares of native vegetation were cleared (1.2 times the size of the Australian Capital Territory). A further 296,000ha were cleared in 2014–15. These are the highest rates of deforestation in the developed world.

Land clearing on this scale is bad for a whole host of reasons. But our research shows that it is also likely to make parts of Australia warmer and drier, adding to the effects of climate change.

How do trees change the climate?

Land clearing releases greenhouse gases into the atmosphere, but the effect of land clearing on climate goes well beyond carbon emissions. It causes warming locally, regionally and even globally, and it changes rainfall by altering the circulation of heat and moisture.

Trees evaporate more water than any other vegetation type – up to 10 times more than crops and pastures. This is because trees have root systems that can access moisture deep within the soil. Crops and pastures have 70% of their roots in the top 30cm of the soil, while trees and other woody plants have 43% of their roots in the deeper part of the soil.

The increased evaporation and rough surface of trees creates moist, turbulent layers in the lower atmosphere. This reduces temperatures and contributes to cloud formation and increased rainfall. The increased rainfall then provides more moisture to soils and vegetation.

The clearing of deep-rooted native vegetation for shallow-rooted crops and pastures diminishes this process, resulting in a warmer and drier climate.

We can see this process at work along the “bunny fence” in southwest Western Australia, where there is a moister atmosphere and more clouds over native vegetation compared with nearby farming areas during summer.

Studies in Amazonia also indicate that as deforestation expands rainfall declines. A tipping point may be reached when deforestation reaches 30-50%, after which rainfall is substantially reduced. Complete deforestation results in the greatest decline in rainfall.

More trees, cooler moister climate

We wanted to know how land clearing could affect Australia’s climate in the future. We did this by modelling two scenarios for different amounts of land clearing, using models developed by CSIRO.

In the first scenario, crops and pasture expand in the semi-arid regions of eastern and southwest Australia. The second scenario limits crops and pastures to highly productive lands, and partially restores less productive lands to savanna woodlands.

We found that restoring trees to parts of Australia would reduce surface temperatures by up to 1.6℃, especially in western Queensland and NSW.

We also found that more trees reduced the overall climate-induced warming from 4.1℃ to 3.2℃ between 2050 and 2100.

Replanting trees could increase summer rainfall by 10% overall and by up to 15.2% in the southwest. We found soil moisture would increase by around 20% in replanted regions.

Our study doesn’t mean replanting all farmed land with trees, just areas that are less productive and less cost-effective to farm intensively. In our scenario, the areas that are restored in western Queensland and NSW would need a tree density of around 40%, which would allow a grassy understorey to be maintained. This would allow some production to continue such as cattle grazing at lower numbers or carbon farming.

Political and social challenges

Limiting land clearing represents a major challenge for Australia’s policymakers and farming communities.

The growing pressure to clear reflects a narrow economic focus on achieving short- to medium-term returns by expanding agriculture to meet the growing global demand for food and fibre.

However, temperatures are already increasing and rainfall is decreasing over large areas of eastern and southwest Australia. Tree clearing coupled with climate change will make growing crops and raising livestock even harder.

Balancing farming with managing climate change would give land owners on marginal land new options for income generation, while the most efficient agricultural land would remain in production. This would need a combination of regulation and long-term financial incentives.

The climate benefits of limiting land clearing must play a bigger part in land management as Australia’s climate becomes hotter and drier. Remnant vegetation needs to be conserved and extensive areas of regrowth must be allowed to regenerate. And where regeneration is not possible, we’ll have to plant large numbers of trees.

The Conversation

Clive McAlpine, Professor, The University of Queensland; Jozef Syktus, Principal Research Fellow, Global Change Institute, The University of Queensland, and Leonie Seabrook, Landscape Ecologist, The University of Queensland

This article was originally published on The Conversation. Read the original article.