100s of climate scientists expect 2.5 degrees

 From The Guardian

Hundreds of the world’s leading climate scientists expect global temperatures to rise to at least 2.5C (4.5F) above preindustrial levels this century, blasting past internationally agreed targets and causing catastrophic consequences for humanity and the planet, an exclusive Guardian survey has revealed.

Almost 80% of the respondents, all from the authoritative Intergovernmental Panel on Climate Change (IPCC), foresee at least 2.5C of global heating, while almost half anticipate at least 3C (5.4F). Only 6% thought the internationally agreed 1.5C (2.7F) limit would be met.

Many of the scientists envisage a “semi-dystopian” future, with famines, conflicts and mass migration, driven by heatwaves, wildfires, floods and storms of an intensity and frequency far beyond those that have already struck.

Numerous experts said they had been left feeling hopeless, infuriated and scared by the failure of governments to act despite the clear scientific evidence provided.

“I think we are headed for major societal disruption within the next five years,” said Gretta Pecl, at the University of Tasmania. “[Authorities] will be overwhelmed by extreme event after extreme event, food production will be disrupted. I could not feel greater despair over the future.”

But many said the climate fight must continue, however high global temperature rose, because every fraction of a degree avoided would reduce human suffering.

Peter Cox, at the University of Exeter, UK, said: “Climate change will not suddenly become dangerous at 1.5C – it already is. And it will not be ‘game over’ if we pass 2C, which we might well do.”

The Guardian approached every contactable lead author or review editor of IPCC reports since 2018. Almost half replied, 380 of 843. The IPCC’s reports are the gold standard assessments of climate change, approved by all governments and produced by experts in physical and social sciences. The results show that many of the most knowledgeable people on the planet expect climate havoc to unfold in the coming decades.

Younger scientists were more pessimistic, with 52% of respondents under 50 expecting a rise of at least 3C, compared with 38% of those over 50. Female scientists were also more downbeat than male scientists, with 49% thinking global temperature would rise at least 3C, compared with 38%. There was little difference between scientists from different continents.

Dipak Dasgupta, at the Energy and Resources Institute in New Delhi, said: “If the world, unbelievably wealthy as it is, stands by and does little to address the plight of the poor, we will all lose eventually.”

The experts were clear on why the world is failing to tackle the climate crisis. A lack of political will was cited by almost three-quarters of the respondents, while 60% also blamed vested corporate interests, such as the fossil fuel industry.

Many also mentioned inequality and a failure of the rich world to help the poor, who suffer most from climate impacts. “I expect a semi-dystopian future with substantial pain and suffering for the people of the global south,” said a South African scientist, who chose not to be named. “The world’s response to date is reprehensible – we live in an age of fools.”

About a quarter of the IPCC experts who responded thought global temperature rise would be kept to 2C or below but even they tempered their hopes.

“I am convinced that we have all the solutions needed for a 1.5C path and that we will implement them in the coming 20 years,” said Henry Neufeldt, at the UN’s Copenhagen Climate Centre. “But I fear that our actions might come too late and we cross one or several tipping points.”

 Are they right?  

Temperatures are rising by 0.2 degrees C per decade, or possibly more.  If we halved emissions, that increase would fall to 0.1 degree per decade.   (Assuming the rate of increase per decade hasn't accelerated to 0.3 degrees) If we halved them again, the decadal increase would decline to 0.05 degrees.  However, even as (if) we cut emissions, temperatures will go on rising, only stabilising when emissions approach zero.   So the longer we take, the longer and higher temperatures will rise.

To halve emissions over 10 years would require emissions to fall by 6.7% per annum compound.   To halve them over 20 years would require emissions to fall by 3.4% per annum. 

The introduction of CATL's super cheap batteries, at US$56/kWh, and their sodium-ion batteries at around $40/kWh will do two things.  First of all, it will make the EV revolution inevitable.  The standard (60 kWh) EV battery pack cost ~US$10,000 in 2020 and will cost ~$2,500 by the end of this year.  Even with swingeing taxes in the US and Europe, EVs will head inexorably towards 100% of sales, globally.  

The second result will be to make grid storage dirt cheap.  Lazard's latest estimate of the cost of 4 hours of storage for a solar farm is $14/MWh of production.  The halving in battery costs will allow 8 hours of storage, and of course, neither solar panels nor batteries have stopped falling in price.  This will mean that grid operators and utilities will choose batteries plus storage in preference to all other sources of electricity generation, but also to replace gas peaking with batteries.  

Electricity generation contributes ~30% of emissions, and road transport ~15%. Even after EVs reach 100% of car and truck sales, it will take 10-15 years for the whole vehicle fleet to become electric.  What about the additional electric demand from EVs?, I hear you cry.  With solar+8 hours of storage becoming so cheap, no new fossil fuel power stations will be built.  As electricity demand rises, it will be met by solar plus storage.  Though switching electricity generation to solar will also take time because of sunk costs, lethargy, vested interests, etc.  

So, let's assume it will take 20 years for emissions in electricity generation and land transport to halve.  (Governments could make that happen much faster if they chose, and as temperatures rise, I have no doubt they will so choose.)    

Three-quarters of all emissions come from energy.  With the new low battery costs, all of that can potentially be stopped, as fossil fuels are replaced by solar plus storage.   I say potentially, because vested interests.  However, replacing fossil fuels no longer requires altruism.  You no longer have to care about the climate.   You just have to want to save money.  But, if you care about the climate too, you will want a faster shift.  And as temperatures rise, the political push to do something, instead of just pretending and greenwashing, will be unstoppable.  So, there is a chance that we could cut emissions by 75% over the next 20 years, reducing the decade by decade rise in temperatures to 0.05 degrees.  That would still leave hard sectors like agriculture, waste and cement, but it would give us 20 years to find solutions for them.

If all this optimistic stuff happens, temperatures will rise by another 0.8 degrees by 2100.  Assuming 1.5 degrees already since 1850-1900, that means global temperatures will rise by 2.3 degrees.

So, yes, they're prolly right.