A leading climate change researcher says industry must not be given a "free ride" when it comes to carbon credits, and companies shouldn't be allowed to offset without first reducing their emissions.
Addressing the Landcare conference in Sydney, Professor Mark Howden from the Australian National University criticised the way companies can continue to pollute by buying offsets.
"Our first priority in terms of emission reductions should be stopping the fossil fuel combustion burning," he said on Wednesday.
Australia's carbon offset scheme allows companies to continue burning fossil fuels by buying offsets, without reducing the amount of their greenhouse gas emissions.
"We should not be using, at this stage of climate change, once off or potentially once off carbon sequestration on our landscapes to give a free ride to other industries," Professor Howden said.
He said big emitters should not be able to just trade their way out of trouble.
"There is a case for using carbon offsets in terms of hard-to-abate sectors," he said on Wednesday.
"We can't use that ... which allows them to continue doing what they're doing, not investing in alternatives, simply because they can get cheap carbon credits, some of which might be dodgy."
Prof Howden - who is director of the ANU's Institute for Climate, Energy and Disaster Solutions - told the conference agricultural productivity has already been "hit big time" by climate change.
He said recent studies showed on average climate change had driven agricultural productivity down about 20 per cent globally.
"The challenges of feeding the world but looking after our land resources will just increase over time if climate change is let rip," he said on Wednesday.
Increasing global temperatures were already having an impact on food supply, he said, with the battle for water destined to get worse as climate change intensifies.
"If we think we've got challenges in terms of competition for water between agriculture, environment, urban and industrial uses (now), this is just going to get far, far more intense."
A spokesperson for the federal Climate Change Minister Chris Bowen said a review of the carbon credit framework is underway and is expected to be finished by the end of the year.
"Carbon credits will have a role in the transition towards net zero, but only where they are legitimate and have integrity," the spokesperson told AAP.
"Even more important though, is actual emissions reductions."
The spokesperson said Labor's Powering Australia plan will help the biggest 215 emitters reduce emissions in line with the target to reach net zero by 2050.
The conference also heard from Australia's national soils advocate Penny Wensley.
She told the audience "inappropriate land clearing" and long-term intensive agricultural practices have left Australian soil "among the most nutrient poor in the world".
Australia's soils "are in trouble", she said.
Ms Wensley said Australia can expect more dust storms, more desertification and more soil contamination as a result of climate change.
"It's a troubling picture," she told the conference.
"Soil organic carbon is declining almost universally. Without remediation this decline will continue."
The chair of Landcare Australia Doug Humann said the recent state of the environment report has left many reeling, and highlights the need for greater investment in the conservation sector.
He told AAP the program "has been starved of funds in recent years", and said the charity needed more money and an injection of young volunteers.
"The twin crises facing land and water management in Australia are climate change and biodiversity loss."
Conservationists, farmers and climate experts are meeting face to face for the first time in four years for the Landcare conference in Sydney.
Australian Associated Press
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