The world must stick to its most rigorous target for limiting climate warming to 1.5°C if it is to avoid the catastrophic thawing of ice sheets and glaciers, according to a report by the International Cryosphere Climate Initiative (ICCI).
ICCI, a group of scientists who study ice-covered parts of the world, says a rise as high as 2°C would melt most tropical and mid-latitude glaciers and set off long-term melting of the Greenland and Antarctic ice sheets, leading to 12 to 20 metres of sea level rise.
Quite how long this could take to happen is unclear. ICCI acknowledges that the worst effects might not be seen for centuries or even millennia. But, sooner or later, catastrophe would be inevitable, it insists.
All the countries which signed the 2015 Paris climate agreement undertook to hold global average temperature rises to “well below 2°C” over pre-industrial levels and to try to limit them to 1.5°C. But humanity’s still-rising greenhouse gas emissions have already caused almost 1.2°C of that warming and have put the world on course to exceed 3°C.
Now, more than 350 cryosphere scientists have signed an open letter calling on countries to commit to the 1.5°C limit at the COP28 climate summit, which opens November 30 in Dubai.
“From the cryosphere point of view, 1.5°C is not simply preferable to 2°C or higher. It is the only option,” Iceland’s Prime Minister Katrín Jakobsdóttir said in a statement.
“Earth’s regions of snow and ice are melting faster than we expected and already approaching tipping points,” added Prof. Jonathan Bamber of the University of Bristol, UK, who reviewed the ICCI report. “We need to put the brakes on, big time. Otherwise, we’re going to see irreversible changes in the polar regions that are going to have global consequences.”
In the past two years, the sea ice around Antarctica shrank to the smallest area ever recorded and there were exceptionally high temperatures at both poles. Swiss glaciers have lost 10% of their volume and a winter heatwave melted snow as high as 3,000 metres up in the Andes.
But 2°C of warming would be much worse, the report warns. The Arctic Ocean would be ice-free almost every summer. Annual carbon emissions from thawing permafrost would equal those of the European Union today. And absorption of atmospheric CO2 would permanently acidify polar seas and threaten key species including krill, salmon, and king crab.
The Himalayas would lose half of their ice, disrupting water supplies for agriculture and hydropower and raising the threat of floods caused by glacial meltwater breaking through a barrier of ice or rock. A study this year found that 15 million people are at risk from these glacial lake outburst floods, or GLOFs, mostly in India, Pakistan, Peru, and China.
Himalayan glacier
“The lakes will start to get larger and larger,” says Tenzing Chogyal Sherpa at Nepal’s International Centre for Integrated Mountain Development (ICIMOD), whose home town of Namche Bazaar was damaged by an outburst flood in 1985. “They’ll be more and more hazardous, and once they get to a point, something can just trigger them, like a landslide.”
Far to the north, comparisons with aerial photographs dating back to the Second World War have shown that glaciers in Greenland are retreating twice as fast this century as they were in the 20th.
Keeping to 1.5°C now needs the world to reach net-zero emissions by 2034. Some scientists have argued 1.5°C is dead, although others point to the rapid uptake of solar and wind energy as reasons for continued hope.
“It could be that [above 1.5°C] is where we end up,” said Twila Moon of the University of Colorado Boulder, who helped to organize the scientists’ letter. “But I think talking ourselves out of rapid change now is selling ourselves short on what is possible because [of] cultural tipping points, social tipping points.”
From Prof. Bamber comes a sobering word of caution, however: even above 1.5°C, “every tenth of one degree counts.”
Chris Packham has filed a High Court legal challenge to the UK Government for a decision to weaken key climate policies.
The broadcaster and environmental campaigner has applied for a judicial review of the Government’s decision to ditch the timetable for phasing out petrol and diesel powered cars and vans, gas boilers, off-grid fossil fuel domestic heating and minimum energy ratings for homes.
Chris Packham
A Department for Energy Security and Net Zero spokesperson said it rejects Mr Packham’s claims and will “robustly” defend the challenge.
The measures and their schedule had been set out in the Government’s Carbon Budget Delivery Plan, which was put before Parliament in March this year.
In September, Rishi Sunak announced he would delay the ban on selling new diesel and petrol cars from 2030 to 2035 and that 20% of households will be exempt from a new gas boiler ban among other changes, arguing that he does not want to burden ordinary people with the costs.
Following the announcement, Mr Packham wrote to Mr Sunak, the Energy Secretary and the Transport Secretary to challenge the decision, arguing that Mr Sunak does not have the legal right to change the timeline of carbon budget pledges at will, since the actioning of the Carbon Budget Delivery Plan is governed by statute.
Mr Packham said he did not receive a satisfactory response to his letter and, therefore, filed the judicial review application at the High Court.
He added that the Government’s response to his letter made clear that the decision was made without any public consultation, without informing the Climate Change Committee, without informing Parliament and without providing any reasons for the delays to the policies.
The grounds for his judicial review include obligations under various sections of the Climate Change Act, he said.
The legal challenge cites the requirement to have plans in place to meet the budgets if the proposals and policies within them are altered.
Mr Packham argues that the secretaries of state have breached this obligation by not confirming or outlining how they still intend to meet the latest budget.
The legal challenge also alleges that there was a failure to consult on the changes, particularly a failure to take into account ongoing consultations about off-grid heating and minimum energy efficiency in rental properties.
It also claims that the decisions were based on misinformation, such as the Government’s argument that the UK’s “over delivery” on previous greenhouse gas reduction targets meant that some measures were no longer needed, that carbon budgets “impose unacceptable costs on hard-pressed British families … that no-one was ever told about” and that the latest budget was “voted through with barely any consideration given the hard choices needed to fulfil it”.
Mr Packham argues that this messaging is wrong, because under section 10 of the Climate Change Act, the financing and social impact of the policies were taken into account when setting the sixth carbon budget
The legal challenge also alleges that there was a breach of the duty to inform the public of the reasons for the decisions to change the policies.
Mr Packham said: “We are in a crisis which threatens the whole world, everything living is in danger, including all of us.
“We have the potential to reduce that threat, we have the solutions and we have plans and targets. We must not divert from these.
“To do so on a whim for short term political gain is reckless and betrays a disregard for the future security of the planet.”
Mr Packham argued that the emissions reductions from the vehicle and gas boiler policies were “intrinsically important to the UK’s ability to reach somewhere near its net zero commitments”.
He said: “They should not have been changed without proper process and consultation. I believe that action was unlawful.”
Rowan Smith, a solicitor at Leigh Day, said: “If the Government’s lawyers are correct, then the Secretary of State would have carte blanche to rip up climate change policy at the drop of the hat, without any repercussions whatsoever.
“Chris and his supporters believe that would be an acute abuse of process, made even worse at the time of climate and ecological breakdown.
“That’s why this legal challenge is so important: if successful, it will mean that the Secretary of State has to keep to their promises to have in place policies that will enable carbon budgets to be met.”
Leigh Day said it has instructed barristers David Wolfe KC, Catherine Dobson and Toby Fisher for the legal challenge.
It comes after a successful legal challenge by Friends of the Earth that the 2021 sixth carbon budget did not include sufficient detail in order to demonstrate how the UK would reach net zero by 2050 as the Climate Change Act 2008 says it must.
A spokesperson for the Department for Energy Security and Net Zero said: “We strongly reject these claims and will be robustly defending this challenge.
“We have overdelivered on every carbon budget to date and these changes keep us on track to meet our legal net zero commitments. We routinely publish future emissions projections across all sectors and will continue to do so.
“Recent independent Climate Change Committee analysis shows our more pragmatic approach has no material difference on our progress to cut emissions.
“Households will now have more time to make the transition saving some families thousands of pounds at a time when cost of living is high.”
Much criticism has been directed at the UK government for its decision to delay the phasing out of petrol- and diesel-powered cars and van in favour of their electric (or possibly hydrogen) equivalents, but rather less has been said about the need for a wider range of transport options to reduce emissions of carbon dioxide (CO2), nitrogen oxides (NOx) and particulates in order to help tackle climate change and air pollution.
Forgotten emissions
In recent years, filters and catalysts have cleaned up petrol and diesel car exhausts considerably, but they still emit some particulates and large amounts of CO2 and NOx – and particulates are also emitted from brake and tyre wear. Electric cars are often described as ‘zero emissions’ but in reality allowance should be made for emissions from the power stations which generate the electricity and also the particulates they emit from brake and tyre wear. Therefore, although electric power is cleaner, the benefits are not as large as they first appear.
The thermal efficiency of a typical car engine is 20-30% (petrol) or 30-40% (diesel), depending on driving conditions. Even the latest Toyota Prius hybrid is still only 41% efficient. Thus, most of the energy in the burnt fuel is wasted.
On the other hand, generating electricity from wind, solar panels or hydro power stations produces no direct emissions, although there are emissions from construction and maintenance. However, a substantial amount of UK electricity also comes from gas, nuclear, coal, bioenergy (wood pellets and anaerobic digestion), oil and other sources. Gas-fired power stations have a typical efficiency of about 50%; coal-fired power stations in the past were typically 30-35% efficient but current designs can achieve 40-45%.
Increased combustion of biomass – most commonly in the form of wood fuels – has contributed to an increase in particulate emissions, worsening air quality. In addition, net CO2 emissions – the emissions once forest regrowth is appropriately accounted for – have generally being underestimated, as a recent paper in Nature showed. In short, burning wood is also a lot worse for the climate than many had thought.
Nuclear power is also often claimed to be zero-carbon but this omits emissions from mining and processing fuel, power station construction, maintenance, and waste disposal. We should also not forget the problem of nuclear waste management and the connection with nuclear weapons production.
Table 1 shows the breakdown of UK electricity generation in 2021 and 2022 according to the government publication, UK energy in brief.
Table 1 – Percentage of UK electricity generation from main sources
2021
2022
Onshore wind
9.5%
10.8%
Offshore wind
11.5%
13.8%
Solar
3.9%
4.1%
Hydro
1.8%
1.7%
Fossil (‘natural’) gas
39.8%
38.4%
Bioenergy
11.9%
10.1%
Landfill gas
1.0%
1.0%
Coal
2.1%
1.7%
Oil & other
3.5%
3.7%
Nuclear
14.9%
14.7%
Thus in 2022, 30.5% of UK electricity was generated from the ‘cleanest’ sources: wind, solar and hydro power; 54.9% was generated by burning fossil gas, biomass, coal, oil, and landfill gas; and 14.7% was generated from nuclear power. Thus, the cleanest renewable sources are now producing over 30% of total electricity generated. It could be argued that the picture is rather better than this, as a gas-fired or nuclear power station creates rather less CO2 per kilowatt-hour (kWh) than a car engine. However, although emissions from electricity generation are lower than petrol or diesel engines, electric power is ‘reduced emissions’, not ‘zero emissions’.
In order to achieve the government’s timetable for changing to battery-powered cars, a massive number of new charging stations will need to be constructed in the next few years, including arrangements for charging cars parked on the street. Policies recommendations by the Climate Change Committee would have seen the proportion of all-electric cars on the roads reach 55% by 2032, with all diesel and petrol cars being replaced by 2050. In practice, reaching a level of 50% for all-electric cars may not now be achieved until some time after 2035 and it may be significantly later than 2050 before petrol and diesel cars are completely eliminated.
Another issue to consider is the weight of electric cars: plug-in hybrids are typically 20-25% heavier than similar petrol or diesel cars and all-electric cars with a reasonable range are typically 40-50% heavier. Added to this, consumers have been buying the heavier ‘sports utility vehicles’ (SUVs) in much greater numbers – 44% of new electric vehicles are now SUVs, a proportion even higher than among fossil-fuelled vehicles. Therefore, if all else is equal, all-electric cars will consume more energy and emit more particulates from tyre wear.
So changing to electric cars is not a panacea: the resulting reduction in CO2 emissions is likely to be more limited and take rather longer than many hope. However, given what climate scientists are saying about the action necessary to hit the targets in the Paris Agreement, a narrow focus will not be nearly enough. The idea that the problem can be solved by changing over to electric cars while we continue with ‘business as usual’ in the meantime is a fantasy.
Pursuing a wider range of options
The only way to achieve major CO2 reductions in the transport sector in the timescale that is required will be to focus initially on measures which can be implemented and produce results quickly without waiting for new technical developments. Other developments can then be planned to complement these, so that their effects combine for maximum benefit.
Measures which would significantly reduce transport CO2 emissions and could be introduced almost immediately at little cost are:
(i) reduce maximum speed limits for cars and coaches to 60mph (100km/h) on motorways and dual carriageways, and 50mph (80km/h) on other roads;
(ii) reduce maximum speed limits for lorries to 50mph (80km/h) on motorways and dual carriageways, and 40mph (65km/h) on other roads;
(iii) increase fuel duty and the number of toll roads;
(iv) expanding the use of car clubs;
(v) increase the cost of flying, e.g. by taxing aviation fuel and increasing airport landing charges;
(vi) improve surface public transport by taking buses, trams, and trains back under public control, and reduce fares and improve services;
(vii) construct more and better cycle lanes.
Measures which could reduce transport emissions further in subsequent years include:
(viii) introduce more electric trams and trolley buses in towns and cities to replace conventional buses;
(ix) a rolling programme of railway electrification and line improvements, including more high-speed services to link with mainland Europe, and replace short-haul air transport;
(x) construct a comprehensive, effective, and robust nationwide network of charging points to encourage use of electric cars and vans;
(xi) further expansion of wind, solar and tidal electricity generation and storage.
These proposals are generally obvious, well known, would be practical to implement and would substantially reduce transport CO2 emissions. Items (i) and (ii) could reduce transport CO2 emissions almost immediately by at about 15%, with further reductions following as measures (iii)-(vii) start to affect behaviour and reduce the amount of travel by car or aeroplane. Substantial further reductions in emissions could then be expected over time as progress is made on items (viii)-(xi).
Listing these measures illustrates what could and should be done to reduce emissions but it also raises a question: if this is what needs to be done, why are government plans for items (viii)-(xi) so sketchy and undeveloped – and why are there so few plans for items (i)-(vii), which should be happening now if they are serious about tackling climate change?
I think the answer is that making vague promises about possible future technological improvements in cars, trains and buses is easy. However, although introducing measures which would make people drive more slowly, make fewer road journeys, and stop flying abroad for cheap holidays would make perfect sense in climate terms, from a political point of view these would all be regarded as ‘difficult’ or ‘courageous’. Politicians fear that people would simply not accept them and a government which tried to implement them might find itself voted out of office at the next election. However, these changes are technically the easiest and cheapest to implement and the only way to achieve sizeable reductions in emissions within the next few years. Furthermore, they will also be an unavoidable part of any plan to achieve more ambitious emission reductions in future.
The purpose of this article is not to argue against electric cars, or other action to tackle climate change. It is to draw attention to the scale of the challenge we now face: it is easy for politicians (and scientists and pressure groups) to make speeches about the dangers of climate change and announce grand plans and ambitious targets for reductions in CO2 by 2030, 2040 or 2050. The hard part is making the necessary changes actually happen in practice.
Alasdair Beal CEng FICE FIStructE is a chartered civil engineer, based in Leeds, and a former member of SGR’s National Co-ordinating Committee.
The UK is responsible for nearly twice as much global warming as previously thought, due to its colonial history, Carbon Brief analysis shows.
History matters because the cumulative amount of carbon dioxide (CO2) emitted since the start of the industrial revolution is closely tied to the record temperatures expected in 2023.
Previous analysis had put the UK’s share of cumulative historical emissions at 3.0% of the global total, including CO2 from fossil fuels, cement, land use, land use change and forestry (LULUCF).
This made the UK the eighth largest contributor to current warming, behind the US (1), China (2), Russia (3), Brazil (4), Germany (5), Indonesia (6) and its former colony India (7).
According to Carbon Brief’s new analysis, however, the UK is responsible for nearly twice as much warming as previously thought – some 5.1% of the global total – due to its colonial history.
This bumps the UK up to fourth place in terms of its historical responsibility for climate change, still behind the US, China and Russia – but now ahead of India, Brazil and Germany.
Moreover, the UK’s population are the second-highest emitters on a per-capita basis, when accounting for emissions under colonial rule.
For full details on the methods and data used in the analysis for this piece, as well as information on other countries, see the detailed companion article.
Historical emissions
Looking at emissions taking place within the borders of the UK alone, the country released some 76.4bn tonnes of CO2 (GtCO2) between 1850-2023.
This amounts to some 3.0% of global cumulative emissions over the same period, including CO2 from fossil fuel use, cement production and LULUCF, the world’s eighth highest share.
After adding emissions outside the UK, but under its colonial rule, its emissions rise to 130.2GtCO2, the fourth highest contribution and accounting for 5.1% of the global total.
The top 20 countries for cumulative CO2 emissions from fossil fuels, cement, land use, land use change and forestry, 1850-2023, billion tonnes. CO2 emissions that occurred within each country’s national borders are shown in dark blue, while those that took place overseas during periods of imperial rule are coloured red. Emissions reallocated to former imperial powers are shaded light blue. EU+UK is shown in addition to the relevant individual countries. Source: Carbon Brief analysis of figures from Jones et al (2023), Lamboll et al (2023), the Global Carbon Project, CDIAC, Our World in Data, the InternationalEnergy Agency and Carbon Monitor. Chart by Carbon Brief.
Other former imperial powers, such as the Netherlands and France, see similarly dramatic jumps in their historical responsibility for warming. The Netherlands rises from 35th to 12th in the rankings, with its cumulative emissions nearly tripling, while the French total rises by 50%.
Editor: To see the graphic representation of these figures, go to the original article, link above.
In today’s blog we’re celebrating the three-year anniversary of the Tristan da Cunha Marine Protection Zone, the largest no-take zone in the Atlantic Ocean. In this blog Janine Lavarello, Marine Protection Zone Officer, Tristan da Cunha Government reports on what the world’s most remote island community have been doing over those three years to safeguard their marine environment.
In 2020, the community of Tristan da Cunha, a UK Overseas Territory in the South Atlantic, made the bold decision to protect 91% of their waters as a no-take Marine Protection Zone, protecting millions of seabirds including albatross and penguins and a wealth of marine life that use their waters.
Later that year, the Tristan community with support from the RSPB, Blue Nature Alliance and the Tristan da Cunha Government established the Atlantic Guardians project to build a strong and sustainable future for the Marine Protection Zone through community engagement, knowledge exchange, science, and global outreach.
Appointing a marine team
The first job was the recruitment of a Tristan da Cunha Government, Marine Protection Zone Officer. I felt very lucky to be appointed and I have been learning the ropes from a Marine Management Support Officer. I visited the UK to shadow other ocean professionals and I have gained a qualification in marine biology as well as many other skills including learning to sail.
Community involvement
My community of 250 residents have taken on roles as ‘guardians’ of the Atlantic Ocean and have been connecting with their marine environment by attending marine-themed public presentations, beach cleans and marine heritage projects including getting involved in the construction of a traditional dinghy longboat once used to sail to the neighbouring islands.
Inspiring the next generation
Inspiring the younger members of our community is an important way for us to build custodians for the future. Our school children have been enjoying marine school sessions, field trips and even snorkelling in the pool. Some school leavers with a keen interest in their marine environments have been appointed as Young Ocean Champions and will be visiting the UK to learn from other ocean professionals and share their stories.
Sharing stories with the rest of the world
One of the things my community wanted was to challenge the rest of the world to take steps to protect their oceans. If my small community of only 250 residents could make such a huge impact, then others should follow in their footsteps. To share our story we have been blogging and presenting at conferences and events all over the globe including Canada, Tasmania and a six month trip to the UK where I met with many different organisations to learn more about marine conservation and presented on a panel at a UK Overseas Territories event in Westminster.
New science discoveries
There is still so much to learn about the marine life in Tristan’s waters. Some of Tristan’s seamounts and deep-sea marine environments are still yet to be explored! The community have been monitoring seabirds, trialling underwater cameras and sound recorders, and recording marine mammal sightings. Only last month we saw a pod of 60 Pilot Whales by the harbour!
Sustainable fishing
The Marine Protection Zone consists of three zones, a Marine Protection Zone which is fully protected and where no extractive activities are permitted, this covers a huge 687,000 km². Sustainable lobster fishing and fishing by the local community is permitted in the Inshore Fishing Zones around the islands of Tristan da Cunha and sustainable longline demersal fishing is permitted in the Seamount Fishing Zones. Our map below outlines these different zones.
As a community, we manage our on-island, Marine Stewardship Council certified sustainable lobster fishery. Our fishery makes up over half the island’s economy and employs most members of the community in various roles.
To keep the lobster population healthy, we only take what we need. For example, we fish to a strict quota, return females with eggs to the sea, and only fish in the Inshore Fishing Zones using traditional, low impact methods.
The lobster is processed in our on-island factory for export to South Africa.
Location of Tristan da Cunha
Preventing illegal fishing – monitoring, surveillance, and enforcement
Although Tristan’s waters are protected as a no-take zone they are still vulnerable to illegal fishing. Being the largest Marine Protected Area in the Atlantic Ocean, at 690,000km² (that’s almost three times the size of the UK), and without a patrol boat it makes it difficult for the community to check for illegal fishing.
As Tristan da Cunha is a UK Overseas Territory, the UK Government Marine Management Organisation support the island with monitoring. They use satellite technology to provide 24/7 coverage of Tristan’s waters, reporting and taking necessary steps to prevent illegal fishing.
What’s next for Tristan’s Marine Protection Zone
The community will continue our journey to protect Tristan da Cunha’s marine environment for future generations and for wildlife.
Some of the things we hope to achieve over the next year include a dive school teaching islanders to scuba dive so they can explore their marine environments, deploying underwater acoustic recorders and cameras to record marine life and attending global conferences including the Albatross and Petrel conference in Mexico to further raise the profile of our Marine Protection Zone.
Protecting existing forests so they grow to maturity could theoretically remove as much as 228 billion tonnes of carbon from the air, according to a team made up of hundreds of researchers. This is equivalent to removing around a third of the carbon humans have added to the atmosphere to date, but critics say it is unlikely we could actually achieve this level of carbon absorption.
The finding will fuel a heated debate over the role of trees in mitigating climate change, which was ignited by a 2019 paper by Thomas Crowther at ETH Zürich in Switzerland and his colleagues. That team estimated that restoring forests outside existing forested areascould store more than 200 billion tonnes of carbon. Other researchers argued the study overstated this potential by as much as five times by counting areas like deserts where growing trees would be impractical or by failing to account for other factors, such as fire.
“Prediction is very difficult, especially about the future.” This quote is particularly pertinent to the future of our planet’s climate, which anthropogenic global heating is transforming possibly more rapidly – notwithstanding transient cataclysms like asteroid impacts – than at any time in our world’s 4.6-billion-year history. What the end game will be is still anyone’s guess, and despite the best efforts of climate scientists, there are so many imponderables that we really have no idea where our world will end up.
Projections of what our thermally-challenged world will be like in the decades and centuries ahead are based largely upon computer modelling. Climate scientists are always very careful about what they put into a model, so that the output is as reliable and as accurate as it can be. Even with the best will in the world, however, the climate system – and the manifold responses of society and the economy to global heating – are so complex and interwoven, that getting the model input right is far from straightforward. The real flies in the ointment, however, are so-called ‘tipping points’, which can see dangerous elements of our changing climate locked onto courses that are impossible to turn around, at least on a scale of the human life-span, and which are notoriously difficult to model.
Defining climate tipping points
There are plenty of definitions for ‘tipping point’ out there, but the most apposite – in the context of climate breakdown – is that provided by the American Heritage Dictionary of the English Language, which describes it as “the point at which a slow, reversible change becomes irreversible, often with dramatic consequences”. This really does hit the nail on the head, and describes exactly what will happen if we don’t rein in greenhouse gas emissions immediately – although even this may no longer be enough. In broad terms, ‘climate tipping points’ (CTPs) mark thresholds beyond which negative feedback effects, which act to maintain stability, are overwhelmed by positive feedbacks, which drive and reinforce self-perpetuating change. The consequences of crossing a tipping point may be obvious within decades or even years, or it may take centuries for the full ramifications to become apparent.
Our understanding of CTPs has changed significantly over the last couple of decades. Twenty years ago, they were recognised as serious threats only if and when unmitigated global heating raised the average temperature of the planet (compared to pre-industrial times) by 4°C or more. Now, however, we know that critical components of the climate system could tip following a hike in global temperature of little more than 1°C [1]. Given that this year is (as of November) 1.43°C hotter than the 1850-1900 average [2], with the temperature rise even breaching the 2°C mark for a few days in November [3], this is a huge cause for concern.
As the global average temperature rise closes in on the permanent breaching of the 1.5°C mark – widely trailed as the ‘dangerous climate change guardrail’ – so the risk of crossing a number of tipping points, which will have dire consequences for our world and our civilisation, becomes more serious by the year [4].
Those parts of the overall climate system that are capable of tipping have been identified through the analysis of past episodes of climate change, and they are known as ‘climate tipping elements’ (CTEs) [1]. There are plenty to choose from, with nine global and seven regional CTEs having been identified as being critical to how our world will look in the future [4].
CTEs can be grouped together according to those parts of the climate system they relate to. ‘Cryosphere tipping elements’, for example, involve large-scale changes to the cryosphere, which is the catch-all term for all the planet’s frozen water, including ice sheets, ice caps and glaciers. The two attracting most concern involve the collapse of the Greenland and West Antarctic ice sheets which, together, would raise global sea-level by 10 m-12 m. A third involves the wholesale, abrupt thawing of permafrost across Alaska, northern Canada and Siberia. If this happens, colossal quantities of methane – a greenhouse gas far more potent, at shorter times-scales, than carbon dioxide – would be released into the atmosphere, accelerating the rate of global heating.
Tipping points that affect the biosphere include the loss of the Amazon Rainforest and the high-latitude boreal (coniferous) forests. Ocean currents can have tipping points too, and particular attention is focused on the Gulf Stream and associated North Atlantic currents that make up what is known as the Atlantic Meridional Overturning Circulation (AMOC), and its potential future shutdown.
How soon will we reach them?
Many countries are coalescing around the goal of achieving net zero emissions by 2050 [5], not for any solid scientific reason, but because it is a nice round number and far enough away to justify inaction in the near term. The global average temperature rise is predicted to climb permanently above 1.5°C by between 2026 and 2042, with a central estimate of 2032, while business as usual will see the 2°C breached by 2050 or very soon after [6]. This means that by mid-century a number of tipping points may already have tipped [4], ensuring a major transformation of our world from which there is no return. Neither rapid cuts in emissions nor the direct removal of carbon from the atmosphere will turn back the clock.
Tipping points that may have been crossed by mid-century include collapse of the system of rotating currents that make up the so-called Sub-polar Gyre in the northernmost Atlantic. This could be instigated as a consequence of a global average temperature rise of as little as 1.1°C and, once begun, collapse could happen in as short a time-frame as five years. The consequences of this would be severe, including a fall of as much as 3°C in temperatures across the North Atlantic region, elevated levels of extreme weather in Europe and serious knock-on effects across the world [6]. There is also the possibility that the AMOC itself could shut down at any point upwards of a global average temperature rise of 1.4°C. Indeed, a recent study [7] proposes that AMOC collapse could happen at any time from 2025 to 2090, with a central estimate of 2050. This is projected to result in regional cooling of anything from 4°C to 10°C.
The fates of both the Greenland and West Antarctic ice sheets could also be sealed long before 2050. The estimated threshold temperature for the unstoppable collapse of these great ice masses is 1.5°C, but could be 1°C or even less, suggesting that it could already be too late to prevent wholesale melting and – as mentioned earlier – an ultimate sea-level rise of 10m-12m.
Greenland
Climate elements having regional rather than global consequences, which could tip at 1.5°C or less, include the abrupt thaw of high-latitude Northern Hemisphere permafrost, the decay of mountain glaciers, and the sudden loss of Barents Sea winter ice.
A 2°C global average temperature hike, easily possible by 2050, could see the irreversible dieback of the Amazon Rainforest, resulting in the addition of colossal amounts of carbon dioxide to the atmosphere. Unstoppable melting of parts of the prodigious East Antarctic Ice Sheet could also be initiated at a threshold as low as 2°C, augmenting sea-level rise due to collapse of the Greenland and West Antarctic ice sheets.
As if all this wasn’t bad enough, an additional major concern is that climate elements might well tip in clusters rather than in isolation. This is because the knock-on effects of one tipped element may lead to conditions that bring forward the timing of another – and so on – resulting in a cascade or domino effect that could have devastating consequences for society and the economy [8, 9]. For example, tipping of the Greenland Ice Sheet significantly increases the likelihood of AMOC shutdown, which would have global ramifications for weather and climate. This, in turn, could lead to an intensification of the Pacific El Niño – Southern Oscillation (ENSO), bringing further unwelcome changes to the world’s weather [8, 9]. Detailed discussion of the impacts of cascading tipping elements, including how these differ according to the order with which elements tip, is beyond the scope of this article, and readers who wish to know more are referred to the 2016 Nature paper by Cai et al. [8], and the comprehensive 2023 Global Tipping Points report by Lenton et al. [9].
The fact that there is no linear relationship between the level of global heating and geophysical responses such as ice sheet melting, permafrost thaw, and ocean current shutdown, means that the time-frame of climate breakdown is hard to pin down, which in turn makes it more perilous. Consequently, any overshoot of the 1.5°C ‘dangerous climate change guardrail’ is extremely risky. Bringing temperatures down to below this mark, at a later stage, by sucking carbon out of the air will do nothing to reverse tipping elements that have already tipped. The corollary of this is that a net zero target of 2050 is far too late. The longer we delay action to slash emissions as the science demands, the more likely it becomes that we will push one or more climate tipping elements beyond the point of no return, locking in changes to our world with the potential to threaten the very existence of our civilisation.
Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL, and a Patron of Scientists for Global Responsibility. His latest book is Hothouse Earth: an Inhabitant’s Guide.
The Conflict and Environment Observatory reports as follows:
Amendments to the European Parliament’s annual COP resolution would position bloc as military decarbonisation leader if implemented.
The European Parliament has called for the closure of the military emissions gap ahead of COP28. Each year, parliamentarians vote on a COP resolution outlining the European Union’s calls for action ahead of the annual climate conference. This year, parliamentarians have voted to act on military emissions – action that can’t come soon enough.
Shining a spotlight on defence
The European Parliament prepares an annual resolution ahead of each UN climate conference, with new amendments proposed and debated, and which build on the text of previous years. This year’s text P9_TA(2023)0407 UN Climate Change Conference 2023 in Dubai, United Arab Emirates (COP28), was adopted by the plenary on 21st November, and marks the end of several months’ work by MEPs on new amendments in the parliament’s environment subcommittee.
The first amendment passed at plenary was proposed by MEPs from the Left in the European Parliament and highlights the role that the defence sector has to play in reducing global emissions:
‘Stresses that all sectors must contribute to the reduction of emissions, including the defence sector, while maintaining operational effectiveness, and that the development of decarbonisation technologies and strategies in the defence sector should be accelerated;’
The second half of this amendment, proposed by Greens-European Free Alliance MEP Pär Holmgren, addresses the fact that military emissions reporting to the UNFCCC is voluntary, and calls on the EU to be active in changing this:
‘…notes that the inclusion of disaggregated military emissions in UNFCCC submissions is voluntary and it is not currently possible to identify reported military GHG emissions from the submitted UNFCCC data; calls on the High Representative of the Union for Foreign Affairs and Security Policy, the Commission and the Council to formulate a proposal for the transparent accounting of military emissions to the UNFCCC which acknowledges the adoption of the Strategic Compass for Security and Defence, and in order to fully implement the Climate Change and Defence Roadmap;’
The European Parliament’s acknowledgement of the Military Emissions Gap is long-overdue, and we hope that this important commitment to transparent accounting will move beyond words and into action.
The Guardian report from Dhana Noor (2.12.23) states:
Divert military spending to fund climate aid, activists urge Cop28
World’s militaries produce at least 5.5% of emissions, as evidence mounts that climate crisis puts regions at greater risk of war.
Wealthy nations should divert 5% of their military budgets to climate finance, advocates argue.
The call comes as global leaders at Cop28 in Dubai gather for a special-themed day on “relief, recovery, and peace” on Sunday, marking the first time climate-fueled conflict has ever been on an international climate conference agenda.
Participants will discuss the need to direct aid to “highly vulnerable, fragile, and conflict-affected communities” as evidence mounts that climate disasters put regions at greater risk of war, and amid ongoing conflict in Palestine as well as Ukraine, Sudan, and other areas.
But truly protecting communities from climate and conflict will require a shift in priorities, says the Transnational Institute, an international research and advocacy group.
“Money is being spent on militarization rather than on climate action,” said Nick Buxton, a researcher with the Transnational Institute, “though the climate crisis is the biggest [common] security threat that we face today.”
By diverting just 5% of global military budgets, the world could raise $110.4bn for climate finance – more than enough to meet a repeatedly broken annual climate finance target of $100bn, the organization has found.
“National – and global – security in the 21st century will depend on limiting the rise in temperature and resulting havoc more than on any other thing,” said the environmental activist and author Bill McKibben.
The world’s militaries produce at least 5.5% of greenhouse gas emissions – more than the total footprint of Japan – according to one 2022 estimate. But no country is required to provide data on military emissions thanks to successful lobbying by the US at the Kyoto conference in 1997. Leaders removed the exemption in 2015 but made reporting military emissions optional.
Military spending has grown by more than a quarter in the past decade, exceeding $2.2tn in 2022. During the same time period, attempts to mobilize funds for climate finance have faltered.
In 2009, for instance, rich countries agreed to spend $100bn on climate finance for developing world annually by 2020, but they broke that promise, providing only $90bn for climate finance in 2021.
Preliminary data from the Organization for Economic Cooperation and Development released this month indicates that the $100bn goal may have finally been met in 2022, but some experts say that assessment is based on inflated numbers. A 2022 investigation from Oxfam concluded that due to wealthy nations’ “dishonest and misleading” accounting, climate finance estimates in 2020 were as much as 225% too high.
Even if it turns out wealthy nations genuinely met the commitment, said Buxton, countries should still reallocate 5% of their military budgets. The $100bn number is widely understood to be far below the true need in poor countries; one 2022 report found that developing nations need $1tn per year to cope with the climate crisis.
Highly polluting nations will also need to come up with funding for loss and damage in poor countries. The need is already greater than $400bn annually and rising, by one estimate.
Countries with the largest militaries – largely the richest, most polluting nations – should bear the most responsibility for cutting global defense spending, the researchers say. They place particular focus on Nato, whose 31 members include the UK, Canada and the US, whose military, which is the world’s top-funded, is also the world’s largest institutional emitter.
Nato members accounted for more than half of all global military spending last year, and budgets are expected to rise. This year, members made “an enduring commitment to invest at least 2%” of their national budgets to their militaries. If that promise is fulfilled, by 2028, the additional funding would be enough to pay for all needed climate adaptation in hard-hit countries for seven years, the researchers calculated based on United Nations data.
Increased militarization harms climate-affected countries in other ways, too, the researchers say. For instance, they found that Nato members are currently selling arms to 39 of the 40 most climate-vulnerable countries; 17 of which are already in armed conflict.
“It’s a real perversion: rather than providing support for communities we are actually making the situation more dangerous and more unstable,” said Buxton.
Diverting some military spending to climate finance would make the world safer, said Perry O’Brien, climate justice organizer at US veteran-led advocacy group Common Defense.
“We know true national security means protecting people and communities from harm,” he said.
Leading science and health groups recommend that the UK prepare better for rising temperatures, in a report to the Physiological Society, November 20th 2023
The UK is unprepared for rising temperatures due to climate change and must act now to develop a joined-up approach to protect the most vulnerable, says a new report by leading science and health organisations released today.
The Physiological Society and Faculty of Public Health are calling for the formation of a Heat Resilience Strategy that is focused on improving the understanding of how heat impacts vulnerable groups and improving the preparedness of the nation to deal with extreme temperatures.
Their latest report, ‘Red Alert: Developing a human-centred national Heat Resilience Strategy’ is being launched in the Houses of Parliament on Monday 20 November.
The length and frequency of extreme heat episodes in the UK are expected to intensify in the years ahead, as are the number of preventable heat-related deaths. In 2022, the UK experienced record-breaking temperatures of over 40°C, resulting in the Met Office issuing its first ‘red warning’ for extreme heat and the Government declaring a national emergency. During that summer alone, there were an estimated 2,985 excess deaths associated with five heat episodes in England, the highest number in any given year.
The UK Government needs to respond quickly to our changing climate and develop a human-centred heat response plan through a coordinated effort from national, devolved and local authorities, the NHS, research funders, businesses and individuals.
Heat related impacts occur mostly among vulnerable groups either due to reduced physiological capacity to cope with extreme temperatures or living and working in environments that are inappropriate for the rising temperatures. These vulnerable groups include older people, people who are pregnant, people with pre-existing health conditions or people who take certain medications, as well as those exposed to higher temperatures at work, or due to lack of shelter (such as people who experience homelessness). The report demonstrates the crucial need for this national strategy to be rooted in an understanding of how heat impacts the physiology of individuals, particularly these vulnerable groups.
To support and protect individuals and communities across the country, the new report makes four recommendations for the UK Government and devolved administrations to develop such a Heat Resilience Strategy:
RESEARCH: Establish a Heat Adaptation Research Exchange Taskforce to tackle research gaps related to vulnerable groups and increase the speed of research translation into policy and action.
BUILT ENVIRONMENT: Form a Human Centred Climate Adaption Design and Planning Institute to ensure the built environment uses thermally efficient design principles.
BUSINESSES: Employers must develop a physiologically-informed plan for workers during extreme heat events to protect health and safety, and Government should introduce statutory guidance on maximum temperatures for different levels of activity and types of Personal Protective Equipment worn.
PUBLIC HEALTH: Expand early warning systems and coordinate a public health campaign to improve long term resilience and preparedness to extreme heat.
Writing in the foreword of the report, Julia King, Baroness Brown of Cambridge, Chair of Climate Change Committee’s Adaptation Committee and the Lords Science and Technology Committee, said:
“This report from The Physiological Society and the Faculty of Public Health is timely. It recognises that while progress has been made in some areas in response to extreme heat, we must go further to ensure that there is an integrated response across government and other responsible organisations that is grounded in an understanding of the human capacity to respond to extreme heat.
“Just as we need rapid, collective action to limit carbon emissions to meet the Paris Agreement target of limiting warming to 1.5°C, we must also work together to adapt, to ensure that our response to more frequent and intense extreme weather events provides protection to those most vulnerable and most exposed to them. Putting physiology and human health at the heart of our response will be critical.”
Professor Mike Tipton, Professor of Human and Applied Physiology, University of Portsmouth, said:
“Climate change is here, and the UK is unprepared for the increased heat we are going to experience.
“As a nation we need to improve the resilience of our infrastructure and communities, as well as supporting individuals to prepare. That requires a comprehensive long-term solution that is rooted in an understanding of how increased heat impacts all aspects of a person’s physiology. This is particularly important for vulnerable groups such as pregnant and older people, who we know are at increased risk from rising temperatures.
“The four recommendations in this report for a National Heat Resilience Strategy coordinates activity across research, the built environment, business and public health.”
Dr Ana-Catarina Pinho-Gomes, NIHR Clinical Lecturer in Public Health Medicine, UCL and Public Health Registrar said:
“Our ability to adapt to extreme heat is limited and the health impacts of rising temperatures are increasingly felt in the UK and across the globe, particularly amongst vulnerable populations.
“Public health complements physiology by understanding how heat vulnerability depends on complex interactions between individual and environmental factors. Our response to extreme heat needs to be multi-disciplinary and targeted to avoid exacerbating existing health inequalities. Working together we can mitigate the impacts of extreme heat and achieve the health co-benefits of climate action, for instance by promoting active travel and sustainable diets.
“A society in which everyone lives healthy, sustainable, and happy lives is possible – we just need the will to do so.”
The report will be launched in the Houses of Parliament on Monday 20 November as part of the Parliamentary and Scientific Committee meeting taking place from 17:15 to 18:45 GMT
Interviews/comments
Interviews can be arranged through The Physiological Society:
The Physiological Society has been at the forefront of science for 150 years and is Europe’s largest network of physiologists. It supports physiologists by organising world-class conferences and offering grants for research and also publishes the latest developments in the field in its three leading scientific journals, The Journal of Physiology, Experimental Physiology and Physiological Reports. physoc.org
The Faculty of Public Health
The Faculty of Public Health is a membership organisation for over 5,000 public health professionals across the UK and around the world. They are a registered charity with the mission to improve health and wellbeing of local communities and national populations.
As greenhouse gas emissions hit new highs, temperature records tumble and climate impacts intensify, the Emissions Gap Report 2023: Broken Record – Temperatures hit new highs, yet world fails to cut emissions (again) finds that the world is heading for a temperature rise far above the Paris Agreement goals unless countries deliver more than they have promised. The report is the 14th edition in a series that brings together many of the world’s top climate scientists to look at future trends in greenhouse gas emissions and provide potential solutions to the challenge of global warming.
The report finds that there has been progress since the Paris Agreement was signed in 2015. Greenhouse gas emissions in 2030, based on policies in place, were projected to increase by 16 per cent at the time of the agreement’s adoption. Today, the projected increase is 3 per cent. However, predicted 2030 greenhouse gas emissions still must fall by 28 per cent for the Paris Agreement 2°C pathway and 42 per cent for the 1.5°C pathway.
As things stand, fully implementing unconditional Nationally Determined Contributions (NDCs) made under the Paris Agreement would put the world on track for limiting temperature rise to 2.9°C above pre-industrial levels this century. Fully implementing conditional NDCs would lower this to 2.5°C.
The report calls for all nations to accelerate economy-wide, low-carbon development transformations. Countries with greater capacity and responsibility for emissions will need to take more ambitious action and support developing nations as they pursue low-emissions development growth.
The report looks at how stronger implementation can increase the chances of the next round of NDCs, due in 2025, bringing down greenhouse gas emissions in 2035 to levels consistent with 2°C and 1.5°C pathways. It also looks at the potential and risks of Carbon Dioxide Removal methods – such as nature-based solutions and direct air carbon capture and storage.
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