This is great news and long overdue, but just like the Coalition's nuclear fantasy is a distraction, we shouldn't allow big clean tech announcements to distract from the glaring problems with the federal government's climate policies, especially its reliance on carbon offsets.

The idea of carbon offsetting is that someone carries out an activity to help the climate so that someone else can keep harming it. For example, because some farmers in NSW stop clearing their land, Santos and Woodside can keep building new gas fields.

We all instinctively know this sounds a bit dodgy, because it is. It's the same magic pudding promise the fossil fuel industry has always sold us so they can keep polluting, like 'clean coal' and carbon capture and storage.

Likening carbon offsets to the Catholic church's sale of 'indulgences' to sinners wanting to buy their way into heaven, Polly Hemming says carbon offsets are a false economy, telling the Australia Institute's Climate Integrity Summit: "It's not okay to do things that we know are bad, because we do some things that are good."

Yes, we should end native forest logging and land clearing. Yes, we need to invest in clean tech manufacturing, building new solar and wind farms and big batteries.

But Polly Hemming sees the government's climate policy being defined by an offset mentality, where the government is using small, necessary 'good' policy changes to distract from the fact it's still doing all the big bad stuff, like approving new fossil fuel projects and giving out $11 billion in public subsidies to the fossil fuel sector every year.

Modelling suggests by 2033 Australia will be the world's largest carbon offset developer. These are the same offsets that will be used to say the 100 new gas and coal projects recognised as 'under development' by the Australian government are 'net zero'.

But carbon offsets are rigorously monitored and regulated right? Not really. The Australia Institute has previously published research showing that those farmers in NSW I mentioned earlier were never going to clear their land.

Over and over, research and investigations into carbon offset schemes - in Australia and around the world - have found these projects to represent little or no reduction in atmospheric carbon. The Australia Institute has compiled 23 of those studies and reports.

Fundamentally, we can debate the merits of individual offset methods until we're blue in the face, but all carbon offsets - no matter how robust they are - are facilitating real emissions elsewhere in the economy. Usually to prolong or expand a fossil fuel project.

It gets worse. Carbon offsets are resulting in increased emissions. This is because if an offset is used by a fossil fuel producer to justify their extractive activities, it's only being applied to their domestic emissions - not the emissions that come from burning that fuel overseas (the "scope 3" emissions).

As a result, Climate Analytics found that every tonne of "offset" carbon put against gas exports results in 8.4 tonnes of real, lasting emissions. When used to offset coal exports, it could result in up to 67 tonnes. Physics doesn't care whether a tonne of coal mined in Queensland is burned in Brisbane or Beijing - that tonne of coal still pollutes and it still causes global warming.

So, this is not just a story of "good" offsets versus "bad" ones. There's not just a need for better market design and stronger governance as is often claimed. Carbon markets have been around for decades and have not only failed to live up to their promise, they have resulted in a number of perverse outcomes.

While many carbon offset developers and carbon market proponents are acting in good faith, the reality is that carbon offsets are a climate disaster. We undoubtedly need to protect our natural carbon sinks such as our trees, soils and mangroves.

But a majority of offset projects are in the land sector. Which means the land sector is under pressure to 'offset' the rest of the economy and decarbonisation in the sectors where we really need to see it is being delayed.

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Don't just take it from me though - take it from a farmer. As Mark Wootton, who also spoke at the Climate Integrity Summit said: "from a pure carbon point of view, we're going to hit the wall".

This is because even the best managed projects can only absorb carbon up to a certain saturation point. And even that carbon storage (in trees and soil) isn't permanent - all it takes is a drought or a bushfire, and all of that carbon gets released.

Who carries the risk, then? If a fire burns down the tree cover on a farmer's land, do they need to pay back the value of their carbon credits? One thing is certain - the emissions that those burned-up carbon credits facilitated, they're staying up in the air.

Huge swathes of ACCUs are being created by middlemen, sometimes called "aggregators" - or "sharks" as Mark Wootton calls them. They rock up to a farm, offer to do all the legal work to set up credits on your land, and take their cut of the proceeds. It's hard to say no to cash in the hand, but it's a risky proposition because responsibility rests with the landholder.

Droughts and fires aside, farmers "might be in the perverse situation that they're entering into a market 25 years where that carbon credit, which they've sold for 30 or 40 bucks now is going to be three or four hundred dollars".

One thing is certain: the integrity of the government's climate policy still hangs on carbon offsets.

And if Australia continues to facilitate the expansion of gas and coal projects off the back of carbon offsets, then all our investments in renewables and green manufacturing are basically just greenwash to distract from Australia's massive fossil fuel exports.