For more than a decade this country has been paralysed by inaction on climate change. The net zero emissions agreement with the Nationals is a breakthrough for Australia – every major Australian political party is now aimed at net zero emissions by 2050.

But the job isn’t done. There are many unanswered questions: How will net zero be achieved? What is the goal for 2030? The changes in climate we anticipate will create winners and losers right across the nation. The deeper the cuts now the better off we will be.

What we do between now and 2030 matters. This comes down to two factors. First, we are relying on our natural systems to remove CO2 from the atmosphere (with knock-on effects such as ocean acidification). But the capacity for these natural systems to capture CO2 is slower than the rate that we can release emissions from burning fossil fuels. This means that the effects of what we do today, one way or the other, will not be realised for a couple of decades.

The second factor is that as CO2 in the atmosphere increases the natural systems are less efficient at drawing down CO2, which means we end up locking in more warming. It becomes a vicious cycle.

The difference between reducing emissions between now and 2030 and carrying on as we are, is 1.5 degrees warming or 2 degrees warming out to 2050. Two degrees warming doesn’t sound that bad, right? Wrong. With 2 degrees warming we are facing increases in the intensity, frequency and duration of fire weather events, to name just one impact. And if we don’t hit net zero emissions by 2050, we commit our young to face even warmer global temperatures beyond that.

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At present, discussions are focused on meeting our Paris Agreement target of 26-28 per cent emissions reduction by 2030. And politicians are arguing about how that is measured, what baseline is used and whether this or that is included.

Those discussions miss the point. What matters to the climate system are the molecules of greenhouse gases released into the atmosphere, trapping heat, irrespective of the politics of the day.

If we meet our 26-28 per cent emissions reduction target by 2030 (using whatever metric one chooses), then this means we must achieve a net 72 per cent emissions reduction from 2030 to 2050. The task post-2030 is enormous. Doing more now will benefit the climate system and even out the challenge beyond 2030. From here on in every one of our politicians must focus on achieving net zero emissions as quickly as possible. We have already locked in over one degree of warming, let’s not lock in more.

Helen McGregor is an associate professor in the School of Earth, Atmospheric & Life Sciences at the University of Wollongong.

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