The planet has changed. This is Iceland’s Skaftafellsjokull glacier in 1989 and 2020:
As reported in Al Jazeera, Christiana Figueres, one of the architects of the Paris Agreement, was stunned speechless when:
- She was told by leading climate scientist Johan Rockström, the director of the Potsdam Institute for Climate Impact Research, that we have already gone beyond some key tipping points. Losing the resilience of the planet was the nightmare that is keeping scientists awake at night, Rockström said.
He was referring to (1) the Arctic summer sea ice (2) West Antarctic glaciers, and (3) tropical coral reef systems.
Back in 2009 when Rockström worked at the Stockholm Resilience Centre he developed with Will Steffen and others the Planetary Boundaries concept, (see also my Climate emergency – ecological sustainability within planetary boundaries, and a safe climate).
When researchers did a systematic review in 2019, Rockström said he was personally shocked by how much the planet had deteriorated in 10 years.
David Spratt summed up the state of play in a talk RESET.21 | MATTERS OF FACTS: THE SCIENCE OF GETTING IT RIGHT ON CLIMATE with this slide:
The slides from Spratt’s talk which contain a mass of information are posted at Climate Code Red as Matters of fact that we ignore at our peril.
Spratt points out that reducing emissions by 5% annually would have no statistical effect on warming for more than two decades. Aerosols from burning fossil fuels, which provide around 0.5°C cooling, would only last 10 to 15 years in the atmosphere if we stopped emitting.
He points out that our current greenhouse gas levels imply a Pliocene climate of 3-5 million years ago, when we had temperatures of 2-4°C higher than pre-industrial and sea levels of 20 to 25 metres higher. Equilibrium would be achieved over centuries to millennia, but our current commitment could give us 2°C or more by the end on the century together with multi-metre sea level rise.
I was surprised to read that the US government already uses 2.5 metres as the upper bound of sea level rise this century, and the Pentagon uses 2 metres. Karl Braganza from the BOM says business as usual could see a tidal surge of 3.08 metres in Cairns this century.
James Hansen estimates that if we want to restore Arctic ice, then we should aim for 300 t0 320 ppm.
On fairness, Spratt does the sums going by the IPCC playbook for 2°C to find that because of our high per capita emissions we would use up our carbon budget by July 2025.
So the situation is dire, requiring maximum effort. Spratt thinks we should aim for zero emissions by 2030. Here are two slides from the end of his talk:
Rockström’s talk was part of a podcast series Outrage + Optimism hosted by Christiana Figueres, Tom Rivett-Carnac and Paul Dickinson. It’s not search-friendly, but it may be possible to find 86. The Scientific Case for The Race to Zero with Johan Rockström. In it he says that scientists should not spare people’s feeling, or worry about frightening them into inaction. People have the right to know the truth.
He says rapid climate action will certainly help. Effectively we should halve emissions every decade and hope it works.
Last November in Our beds are burning I went into tipping points in more detail, including an important article by Timothy Lenton, Johan Rockström, Owen Gaffney, Stefan Rahmstorf, Katherine Richardson, Will Steffen & Hans Joachim Schellnhuber Climate tipping points too risky to bet against.
That article was published in December 2019. If Figueres had seen it, Rockström’s news should have been no surprise.
The Lenton paper emphasises the interactive nature of the various tipping points, and a cascading process leading to a point where humans lose control. This cascading process may have already begun. However, this does not mean that humans lose all agency and should just prepare for the worst. There is hope.
Lenton et al think that three decades to reach zero emissions is about the quickest that can be achieved.
They also indicate that whatever we do matters. For example, current levels of GHG may give us 10 metres or more in sea level rise. If we stabilise at 1.5°C that may take 10,000 years, but if we allow the temperature to reach 2°C that time-frame may be shortened to 1,000 years. Moreover, the higher warming goes above 1°C the more likely we will get existentially threatening runaway heating beyond our control.
So we have reached the ‘age of consequences’. We already have dangerous climate change which is impinging on lived experience. Leaving aside bad weather (droughts, floods and storms, heat waves etc), chronic wildfires, and bleaching events on Great Barrier Reef, alarming news about the die-off and extinction of plants and animals and sea life, we are getting daily stories about the impact of sea level rise.
In Vietnam Ho Chi Min City, with a population of around 9 million, sits in a flat delta region where 40 to 45 per cent of the city is less than one metre above sea level. So we have Under siege by climate, man-made problems, a sinking Ho Chi Minh City fights to survive.
Sea levels are rising at 45mm per annum, about 50% above the global average. Furthermore, the city is sinking, in large part but not totally through groundwater extraction.
There is a proposal to build a 33 km sea wall, but apart from the cost:
In South Korea, the 33-km Saemangeum sea dyke and land reclamation project has taken 30 years since construction began, cites Ky. The sea wall itself needed almost 20 years to construct.
Meanwhile there is an active business in raising buildings. Construction engineer Nguyen Van Cu whose specialty is raising homes raised a 6,000-tonne church a few years ago.
In Florida some homes could lose 15% in value this decade, a report finds 35% by mid-century. For further reading see McKinsey Global Institute Will mortgages and markets stay afloat in Florida? That report is part of McKinsey’s broader series Climate risk and response: Physical hazards and socioeconomic impacts.
Melting sea ice in the Arctic may seem far away, but Rockström says:
- We’ve passed the point of no return there, which is, as you know, affecting weather systems in the northern hemisphere with heat waves and droughts and forest fires. It is impacting the entire Gulf Stream, is even impacting the monsoon system that provides the rainfall for the Amazon rainforest. And it’s even causing warmer surface temperatures that accelerate the melting of the West Antarctic ice shelf.
If it’s affecting the monsoon, it is affecting us directly.
While the area of Arctic sea ice is in trend decline, the volume is collapsing rapidly:
- Since 1979, the ice volume has shrunk by 80% and in just the past decade the volume declined by 36% in the autumn and 9% in the winter.
It is time for our politicians to seriously engage with the science and decide what they must do.
Clearly, though, 1.5°C is neither safe nor stable. As such it is not a longer term resting point. Our only path to a sustainable and safe future lies in no more than 1°C, of warming. Spratt and Ian Dunlop say make that 0.5°C. Either way we need to think seriously about emissions drawdown, where there are debates to be had.
Is any politician talking about it?