Some news you may not have clocked last week while the focus was on important things like a royal tour: 44 of the world’s top climate scientists, including four decorated Australian professors, released an open letter warning that ocean circulation in the Atlantic is at serious risk of collapse sooner than was previously understood.
They said a string of studies suggested the Intergovernmental Panel on Climate Change, a body backed by nearly 200 countries, had greatly underestimated the possibility that the Atlantic meridional overturning circulation – or Amoc, a system of ocean currents that brings heat into the northern Atlantic west of Britain and Ireland – could in the next few decades reach a point at which its breakdown was inevitable. The cause? Rising greenhouse gas emissions.
This is consistent with what climate computer models have forecast but there are signs the circulation is weakening more rapidly than expected. Stefan Rahmstorf, from Germany’s Potsdam Institute, told my colleague Jonathan Watts that by his estimation the risk of crossing a tipping point this century so that collapse was unavoidable had increased from less than 10% to about a 50-50 chance.
If it happens, it will reshape the global climate, including cooling parts of north-western Europe so much that places such as Norway and Scotland could become unliveable while most of the planet gets hotter.
It is estimated that the northern Atlantic could rise an extra half a metre in addition to sea rise caused by global heating. Tropical rainfall would shift south, likely leading to rainforests suffering destructive droughts and regions that are now relatively dry being hit with flooding rains. Humanity would survive but the impact on ecosystems, lives and livelihoods would be, in the words of the 44 scientists, “devastating and irreversible”.
The trajectory of the Amoc echoes a similar story off Antarctica, where scientists have estimated the Southern Ocean overturning circulation, which also affects global weather patterns and ocean temperatures, has slowed by about 30% since the 1990s due to the melting of Antarctic glacial ice. This is also caused by – you guessed it – increasing temperatures linked to CO2 emissions.
I don’t raise this to suggest addressing the climate crisis is hopeless, though climate grief is real and understandable. The global effort to limit the climate emergency is not going well but amid the gloom there are some positive trends. And there is plenty of evidence that much more can be done quickly. As the mantra goes, every action – every fraction of a degree of heating avoided – counts.
I raise the warnings about the Amoc because the reality of what climate scientists are telling us is worth holding up against the energy debate in Australia, and particularly the Coalition’s nuclear power push. Too often it is completely missing from the discussion.
The central point is a familiar one: there are reams of evidence that emissions need to be cut as much and as rapidly as possible. There are other considerations that need to be met – primarily, making the project politically sustainable by ensuring energy reliability, affordability and dealing with social licence concerns. But, at the risk of stating the obvious, the overriding goal, the reason for doing any of this, is to cut pollution.
On this, the Coalition’s position fails spectacularly.
Despite all the oxygen dedicated to talking about it, the nuclear element of the opposition’s plan won’t – can’t – be more than a speculative side issue to the main game of how the country will get electricity over the next couple of decades.
The chair of the Australian Energy Regulator, Clare Savage, said in a parliamentary hearing last week it would take up to a decade to just get a nuclear regulatory framework in place. That takes us to 2035 before building even begins. The evidence from overseas is that construction of a large generator could then take twice as long again (the four nuclear plants completed in western Europe or north America this century took a minimum 18 years from announcement).
Small modular reactors? They still don’t exist, commercially.
But there are parts of the Coalition’s plan where Dutton and his climate change and energy shadow, Ted O’Brien, could move quickly – namely, limiting construction of large-scale renewable energy and instead burning more coal and gas.
Given that this is likely to be the early focus on the ground it seems reasonable to call the Coalition’s plan what it primarily is: a proposal to expand fossil fuels.
It is, of course, not the only pro-fossil fuel plan going around. The Albanese government has approved large expansions of export-focused thermal coal mines. Western Australia’s Labor government is taking the remarkable step of helping out the gas industry by no longer allowing its state Environment Protection Authority to consider climate pollution when it assesses fossil fuel developments.
But federal Labor and the Coalition are not the same on these issues. Labor has introduced some domestic climate policies, most significantly to push the country towards 82% renewable energy by 2030. In nearly every case, the Coalition supports Labor’s pro-fossil fuel plans but opposes its efforts to curtail emissions.
On coal, O’Brien accuses Labor of planning to force plants to shut early. As evidence, he points to an Australian Energy Market Operator “step change” scenario under which about 90% of coal plants will close by 2035. O’Brien says this differs markedly from the closure dates previously announced by coal plant owners.
In reality, the coal closure dates announced by companies generally don’t mean a great deal. Australia’s coal generators are becoming less reliable as they age – 26% of capacity was offline late last week – and experts including Savage have made clear their view is that the coal fleet just cannot last until a nuclear industry would be possible.
On the other, if it is possible to shut 90% of the coal fleet in a decade by accelerating renewable energy and firming support technology – as Aemo and others have suggested it is – then this is clearly good news. And a strange thing to oppose.
And, for all their rhetoric, the Coalition and its backers are yet to produce compelling evidence that explains why they think Aemo is wrong.
Adam Morton is Guardian Australia’s climate and environment editor
