This week saw the Investor Group on Climate and offset industry lobby group the Carbon Market Institute urge the Greens to pass the Safeguard Mechanism even if it allows new fossil fuel projects, while billionaire Andrew Twiggy Forrest reiterated his call to rule them out.

At the last election, the Australian people voted and delivered a climate supermajority into Parliament. It is clear the public want serious and credible action to reduce emissions. With the Coalition rejecting its own climate policy, Labor will need the Greens and two crossbenchers in the Senate to pass the Safeguard Mechanism. Without the Greens, it will not pass.

The Safeguard Mechanism is supposed to reduce emissions from Australia's biggest industrial polluters. It's a pretty straightforward aim. The proposed legislation, on the other hand, is overly complex with enough loopholes for polluters to drive a coal train through. The Greens and other crossbenchers would be on solid ground scientifically and politically to reject it without some serious improvements.

The Greens have offered to pass the legislation if Labor bans new coal and gas projects, with Greens Leader Adam Bandt stressing that it was 'an offer, not an ultimatum'. This is the platform the Greens were elected on and their position is backed by the UN and the International Energy Agency, as well as the climate science. As Twiggy Forrest so colourfully put it: "[I want] Every legislator in the world to bring themselves up to speed with the science. If they don't believe the science then they can just f**k off."

On the face of it, the Greens offer should be a simple one for Labor to agree to - any climate policy put forward by the government should reduce emissions. Of course, opening new methane gas basins and coal mines will increase emissions. And there aren't many coal or gas jobs in the capital city seats Labor must hold. It should be a no brainer.

However, not only does the Safeguard Mechanism do nothing to stop new fossil fuel projects from going ahead, it will actually allow existing projects to increase their emissions, as long as they buy offsets. This is problematic because of the extensive integrity concerns that have been raised about Australia's carbon offsets. Also problematic is the fact that the government has left the door open for the use of international offsets by Australia's big polluters under the safeguard.

This week's Four Corners exposed serious issues with carbon offset projects in Papua New Guinea - one of the countries that Australia has an official carbon trading deal with. The episode follows numerous other independent investigations into community violations and environmental fraud.

At the 2023 Climate Integrity Summit in Parliament House this week, Professor Andrew Macintosh demonstrated how carbon credits are being issued for growing trees that were already there. That's not just a waste of money, it's actually making climate change worse. Once junk carbon credits are used to 'offset' new pollution from new coal mines the result is actually an increase in emissions - the total opposite of what we're trying to achieve. The fact that companies are spending millions of dollars on low integrity carbon offsets in a complex but inefficient market system, rather than investing in genuine decarbonisation is as economically inefficient as it is environmentally damaging.

Another speaker, Karrina Nolan, the CEO of Original Power, showed how remote First Nations communities are leading decarbonisation projects that replace polluting and expensive diesel generators with community-owned and maintained solar projects. The tragedy is every dollar spent on offsets is money that can't be spent on genuine decarbonisation projects like Original Power is trying to roll out. Offsets are no more than an investment in the status quo.

Senator Sarah Hanson-Young used a carbon-neutral certified water bottle to demonstrate how pervasive government-sanctioned greenwashing had become, before making the same point to the ACCC in Senate estimates.

While ACT Senator David Pocock reassured the audience that if they didn't understand the complexities of the Safeguard Mechanism they were in good company - he said that it was easier to understand a briefing on quantum computing than the proposed Safeguard legislation. There's no doubt complexity hides a multitude of sins.

The Australia Institute's climate and energy director Polly Hemming proposed six principles for climate integrity at the Summit.

Climate policy should be: simple, science-based, transparent, independent, government-driven and conservative. Of these principles, I think simplicity is almost the most important.

MORE OPINION:

Effective climate policy is often the simplest-ending fossil fuel subsidies, a renewable energy target, a tax on pollution, an end to native forest logging, or a ban on new gas and coal projects.

Each of these climate policies is simple to understand, hard to wiggle out of and effective at reducing emissions. That's why polluters hate them and why none of those policies are currently being debated by the Parliament.

Australia is the third-largest exporter of fossil fuels in the world behind Russia and Saudi Arabia. Our fossil fuel industry is hugely powerful, unthinkably wealthy and they want to increase pollution with 117 new gas and coal projects. The fossil fuel industry is banking on a lax Safeguard Mechanism and it's so politically effective it has climate investor groups lobbying the Greens on its behalf.

No matter how complex the debate may seem, in the end it is pretty simple. Australia needs to genuinely decarbonise its economy and the Safeguard Mechanism is supposed to reduce emissions. If the legislation allows new gas and coal projects and unlimited offsets, it will be about as effective as a flyscreen door on a nuclear submarine.

That's something we can all understand.