I wrote an article for the UK National Preparedness Commission about the blind spots in security assessment and management, with a particular focus on the potential collapse of Atlantic Ocean circulations. You can read the original article here.
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Recently, something extraordinary happened in the House of Lords. In September, Baroness Jenny Jones, a Green Party peer, submitted a written question to the government. She asked whether it had assessed ‘the effect of any slowing or collapse of the Atlantic Meridional Overturning Circulation (AMOC) on their economic planning’.[1] Jones is only the second person in history to ask the government about the AMOC.
The AMOC is a vast system of Atlantic-spanning currents that acts like a conveyor belt, drawing heat from the tropics and releasing it in the North Atlantic. It mediates the climate in the UK, Europe, and the wider world. It is one of the reasons England has vineyards at roughly the latitude that Canada has polar bears.
The effects of climate change are disrupting the AMOC, weakening the conveyor mechanism. This disruption could become so acute that the AMOC collapses, shutting down the conveyor.[2] This has been known about for many years. It is one of the many ‘climate tipping points’ that could be triggered as climate change escalates.[3]
In the first instance, collapse would stop the transfer of heat northwards. Over the following decades, temperatures would drop across the Atlantic region, including by over 5oC in Britain.[4] Colder, drier conditions would largely wipe out crop growing in the British Isles.[5] All tropical monsoons would be dangerously disrupted, affecting billions of people.[6]Combined with the other effects of climate change, the growing area for wheat and maize – two crops underpinning the global food system – would be reduced by well over a half.[7]
The knock-on effects would be profound, impacting everything, from economic stability and trade, through social cohesion and geopolitics, to human health and the integrity of nature. It would be a planetary-scale cataclysm – and an existential threat to Britain. Hence Jenny Jones’s question.
In response, a minister said that the government has ‘not assessed the effect of any slowing or collapse of [the AMOC] on economic planning’, that ‘an abrupt collapse is unlikely’ to occur this century, and that the government was ‘monitoring ongoing research’.[8]
What is going on? AMOC collapse is clearly a major threat to national and international security. Indeed, while Jones was questioning the government, the Nordic Council of Ministers was being warned that ‘adaptation to such a severe climate catastrophe is not a viable option’.[9] Yet the UK government is not assessing the impact on economic planning and in response to Jones, it chose to emphasise that a collapse this century is ‘unlikely’.
In a recent report, we have identified several ‘blind spots’ in how the major security threats from climate change – like AMOC collapse – are assessed and managed.[10] They were on show in the exchange between Jenny Jones and the government.
Likelihood
That AMOC collapse might be ‘unlikely’ – as the government says – may seem reassuring; a tiny chance, nothing to worry about. But this word has a technical definition, one that differs from the lay perception, and that difference can mean the risk is misunderstood.[11]
The government quoted the Intergovernmental Panel on Climate Change (IPCC), the UN body that synthesises climate science. When the IPCC says something is ‘unlikely’, it means that there is between a 0% and 33% chance it could occur.[12] So, the government could have said that there is up to a third chance that a catastrophic shock to the global food system could occur this century.[13]
In comparison, the UK Covid-19 Inquiry found that between 2005 and 2020, the government had considered an influenza pandemic as the most significant civil emergency risk facing the UK, judging the likelihood to be 3% in any given year.[14]This was enough to warrant ongoing assessments, early warning systems, strategies, governance arrangements, a cross-government exercise, and so on.
The evidence suggests that this threshold has been met for AMOC collapse. Yet there is no early warning system for a collapse, no explicit strategy to manage the threat. It is unclear who ‘owns’ the threat in government, and there have been no cross-government exercises. Too often, low- or uncertain-likelihood threats are effectively treated as no-likelihood. The pandemic is a cautionary tale. We cannot afford for AMOC collapse to be the next.
Uncertainty
The IPCC has also said that it has ‘medium confidence’ in its conclusion about the likelihood of AMOC collapse.[15] We could translate this as: ‘not really sure’. This should raise more alarm bells: we’re not sure whether a global-scale catastrophe could soon be triggered.
Climate change is very complex and therefore predictions of what it could do are uncertain. This uncertainty is highly concerning. It means that we cannot rule out catastrophic events like AMOC collapse. Indeed, so far, the impacts of climate change are hitting on the hardest and soonest end of what was anticipated.[16] As climate change plays out and the fog of uncertainty is lifted, the reality is proving worse than expected.
Indeed, as analysis has improved, scientists have only ever moved the threat level upwards. For example, it is now clear that the possibility of ‘multiple breadbasket failure’ – major food growing regions being damaged by simultaneous climate shocks – has been significantly underestimated.[17] In the case of AMOC collapse, the letter to the Nordic Council concluded that this risk has ‘been greatly underestimated’ and that ‘passing of this tipping point is a serious possibility already in the next few decades’.[18]
Even with this evidence, a fixation on likelihoods for uncertain and high impact events might be a distraction. Both the Royal Academy of Engineers and the UK Covid-19 Inquiry have analysed the government’s risk assessment and management procedures and concluded that a fixation on likelihood is inappropriate for such threats as it ‘can be difficult to assess with a high degree of confidence across all risks’.[19] Uncertainty and the inability to accurately judge likelihood can breed a dangerous complacency.
Instead, decision-making should be guided by impact and preparedness across a wide range of scenarios. Even a negligible chance of a catastrophic impact warrants the full force of attention.
Cascading risks
The previous parliamentary question about the effects of AMOC collapse was back in 2020.[20] The government responded by saying there would be ‘more winter storms over northern Europe, a decrease in marine biological productivity in the North Atlantic and changes in sea level’. This reply highlights two common problems in methods used to assess climate threats.
Firstly, they often focus on changes in weather and the immediate impacts for things like marine biological productivity. These are important. But they are not useful nor intuitive enough for senior decision-makers, particularly those who need information on the security threats now posed by climate change. Instead, it is the impact on food production, the integrity of infrastructure, public health, and so on that are important. There is underinvestment in assessing the most ‘decision-useful’ impacts when it comes to tipping points like AMOC collapse.
Secondly, first-order climate impacts have cascading consequences. This is already playing out. For example, it is estimated that as much as one third of UK food price inflation in recent years has been caused by the cascading consequences of extreme climate events ricocheting globally, interacting with and exacerbating other inflationary problems.[21]
Yet media stories and decision-makers often perceive the climate threat as relating to first order impacts; the hurricanes and heatwaves on the news. As the Covid-19 pandemic taught us, the immediate health impacts were only the start. It was the cascading consequences that made the pandemic an epochal crisis. The lockdowns to protect NHS integrity, the furlough scheme, the effect on the public finances, the challenges for economic stability and trade and geopolitics, the consequences for political trust, misinformation: the list of cascading consequences goes on.
These interconnected risks and domino effects are often missed from government risk assessments, both in general and in relation to climate change. This means that threats are routinely underassessed.
It also means that even if AMOC collapse or other global-scale climate disasters do not transpire, the UK is facing far more danger – and is far more vulnerable – than is generally accepted. This was certainly the case with Covid-19. For climate change, we are lucky that a multiple breadbasket failure has not already happened, triggering an unprecedented food crisis, which would compound the other economic, geopolitical, and humanitarian crises currently afflicting the world.
Unfortunately, these scenarios are now eminently possible, and the UK is exposed and vulnerable to the cascading risks. Climate change is not just creating a series of worsening events; it is creating a new era of complex and evolving challenges for all areas of national and international security.
Security priorities
If we limit our assessment of the climate threat to first order impacts and misinterpret uncertainty and information on likelihood, then climate change might not appear a pressing security threat. This is a mistake that has been made by previous governments. AMOC collapse is just one of many profound threats to security now made possible by escalating climate change. The new government needs to catch up.
There are positive signs. In response to the UK Covid-19 Inquiry’s report on national preparedness, the Cabinet Office is initiating a review of national resilience policy.[22] In his first major speech, the Foreign Secretary recognised that action on climate change is critical to national and international security.[23] To support these efforts, our report recommends several ‘quick wins’ for closing the blind spots.
The government should undertake a rapid risk assessment of the national security consequences of climate change and related threats, like nature loss. The government’s existing climate change risk assessment is not primarily intended for the top table of security decision-making and therefore some pressing security questions are not in scope. Other countries are undertaking security-specific assessments, like Australia, where the Labor Party undertook a rapid analysis on entering government in 2022.[24]
Ongoing capabilities are needed to deepen understanding and guide decision-making. These threats will only escalate, particularly as the world is set to breach the 1.5oC target for limiting warming. The UK needs more than just static risk assessments; a dynamic capacity to help forecast, pre-empt, and prepare to handle this new era is needed.
We recommend the creation of an independent Centre for Climate and Nature Security, a centre of excellence with the purpose of improving the ability of the UK’s security community to integrate an understanding of climate and nature threats into routine assessments and decision-making. Priorities should include providing routine usable climate information for security assessment and planning, closing major knowledge gaps, and developing early-warning systems.
All this should inform government strategies for tackling climate change and adapting to its unavoidable impacts. AMOC collapse is clearly unmanageable and must therefore be avoided. Yet the approach to climate change from governments around the world does not seem to consider this, otherwise decarbonisation efforts might be far more forceful. This must change.
As the UK government re-establishes its climate leadership on the global stage it has an opportunity to carry this message. The non-zero chance of AMOC collapse further validates the claim, long made by scientists and others, that this is a crisis and requires an emergency response.
Meanwhile, the UK is not adapted even to current levels of climate change. The unavoidable will have to be managed. Worse impacts are guaranteed and as with the pandemic, will destabilise entire systems. So the government will have to quickly make the investments needed to improve UK resilience. Indeed, it is called upon to do that for other threats, like pandemics.
Thankfully, the investments needed to ensure greater resilience across society can be common. More sustainable farm systems and diets can reduce zoonotic diseases, lower carbon emissions, and ensure greater resilience to climate shocks. Local renewable energy production reduces exposure to volatile fossil fuel prices while lowering emissions.
The list goes on, which points to a deeper truth: the clustering of bewildering risks we now face can be responded to by making society more generally resilient and sustainable. This is important not just to reduce the costs and harm of living in the gathering storm of the climate crisis. It could also help us stay focused – no matter what climate change throws at us – on decarbonising and navigating out of this storm. For there are limits to adaptation. The threat posed by AMOC collapse shows this.
Laurie Laybourn 