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Introduction

David Kilcullen’s appearance on CHACR, RMAS and Staff College reading lists means that almost every British military officer is (or should be) aware of the growing likelihood of increasingly complex urban operations in any future conflict. Recent examples in Ukraine of Ilovaisk in 2014 and Donetsk in 2015, or Mosul in Iraq from October 2016 to July 2017 have demonstrated Kilcullen’s predictions of the enormous costs and increasing complexity of urban operations (Fox, 2021, pg.21-24). However, there may be even greater challenges for the armed forces of the future. In addition to emerging technologies, new methods of competition, and new competitors, the urban operating environment will also face mounting environmental threats.

The increasing urbanisation of coastal areas will lead to future operations occurring more frequently in the coastal urban environment, especially in the global South (NATO, 2017). These locations are significantly more at risk from emerging environmental threats, and this article will illustrate how these will significantly affect future urban operations. The UK government has stated that environmental threats are a priority for future military spending and development (HM Government, 2021, pg.4-7). However, there have been only vague articulations of what effects these threats will actually impose on military operations. This essay accepts David Kilcullen and other academics’ arguments that populations will increasingly concentrate in coastal cities and argue that this transformation will make environmental threats a far greater cause for concern in future operating environments (Kilcullen, 2013 pg.4-8). Environmental threats will only increase the complexity of this environment by causing damage and disruption, limiting manoeuvrability, constraining logistics, and drawing greater scrutiny over the actions of British forces to prevent further damage and support the local population.

The purpose of this article is to sensitise the audience to these growing threats and begin to question how environmental threats as both short-term events and long-term trends will affect how we sustain, operate, fight, and win in a complex and uncertain future. This article will first assess how populations in urban coastal environments will likely respond to short-term environmental disasters, before assessing how long-term environmental trends will affect the future operating environment more generally. This article has limited its scope to the effects of climate change causing human and environmental threats on British forces conducting coastalised urban operations. It will not cover conflicts, such as water wars, caused by climate change.

The rise of environmental threats in the 21^st Century 

The consequences of climate change are characterised by an overall increase in global temperatures by up to 3.4C by 2100, alongside more unpredictable weather (IPCC, 2015, pg.12). On the local scale, changes to atmospheric conditions have been linked to an increase in extreme weather events, such as flooding or drought (Mann et al., 2017, pg.1-3). Not only is this changing the environments in which the UK operates, but the unpredictability of a changing environment also increases the risk to those operating within it. Environmental threats increase the complexity of the operating environment and are composed of both short-term threats and long-term trends. Therefore, it is crucial that environmental change and damage is understood so British forces can be better prepared to operate in more dynamic and potentially dangerous environments.

How will increasingly urbanised and coastalised operating environments be affected by short-term environmental events?

Urbanisation is the process by which areas become more built-up, and the population density increases. This occurs as a result of human populations moving from rural to more urban areas. The availability of modern services is a great driver behind people’s movement, particularly in poorer countries where rural services are often limited by the availability of funding and infrastructure (McGranahan and Satterthwaite, 2014, pg.4-8). The consequences of continued urbanisation for military operations are significant. Firstly, and most obviously, the trend means that higher proportions of populations will reside in urban areas, which increase the demands for and of infrastructure and sustainment systems. For example, in the UK the urban population is more than five times greater than the rural population (Statista, 2019). This results in sparser rural areas along with more extensive and increasingly complicated urban centres. Second, as more people look to live in towns and cities, these areas struggle to grow at the required rate. As such, average population density is increasing exponentially, creating more confined, more dynamic, and potentially more risky operations within the urban environment. Many cities also face significant risk as they have traditionally been built on coasts or rivers, which are more at risk of environmental threats. This means that as urban populations increase, this disproportionately increases the populations in coastal areas, which are at an increased risk of climate threats (Kilcullen, 2013, pg.14-23). 

In 2013, David Kilcullen’s book Out of the Mountains raised the profile of increasing coastal settlements as a key terrain of future conflicts. While he makes several important arguments, he only briefly addresses the effects of climate change on operating in coastal, urban environments, most likely due to developments in conceptions of the climate threat since the book was published. Kilcullen identified trends that have only increased in recent years, with both developed and developing states experiencing increasing migration to coastal settlements. An important trend is that while most coastal migration is towards growing coastal cities, a substantial proportion of the transient population also moves to non-metropolitan coastal areas (Blakely and Gurran, 2008, pg.115). These population changes can lead to the growth of new coastal urban areas and cities, creating a global trend of more inhabited coastal areas. This can impede amphibious and infiltration operations and cause further second-order consequences for operations in larger coastal cities. 

Increasing coastal settlements expose a greater proportion of the population to environmental threats, ranging from rising sea levels in the long-term to tsunamis as damaging short-term events. Kilcullen has examined in depth the consequences of operating in coastal, urban environments, yet the increasing risk of environmental threats adds new complexity to operating in these environments. A critical impact that must be considered is how these coastal populations will react to an environmental disaster as a short-term event, as this will likely affect military forces operating in these areas. Climate hazard-related migration has been studied in Bangladesh, and populations have been documented as acting in very similar ways to each of these crises. The ‘push’ factors identified were prioritised, with populations migrating firstly for safety and secondly for income recovery after a crisis (Penning-Rowsell, Sultana, and Thompson, 2012, pg.44-48). However, there was also a notable trend for some parts of the population to refuse to migrate in the face of disasters. This was due to either concern over transitioning from a known rural to an uncertain urban setting and fears over land displacement, which mean that migration is often temporary until a crisis has passed when populations may return to their previous locations (Penning-Rowsell, Sultana, and Thompson, 2012, pg.44-48).

Additionally, environmental disasters such as droughts may lead to migration from internal areas of a country to coastal areas in search of relief. These displaced populations create logistical and public-order concerns, and substantially compound the risk of urban public violence. There are numerous examples of law and order collapsing in the wake of environmental disasters, which add further risk, complexity, and resource constraints (Nel and Righarts, 2008, pg.159-162). The collapse of public order occurs both in low-income countries such as Myanmar in 2008 and high-income countries like the US in 2005 (Hendrix, 2013). Therefore, British forces must be prepared to support the host nation government during these crises. Crucially, coastal populations present several considerations for operating in the coastal, urban environment when a short-term environmental disaster event occurs:

• Coastal cities are unlikely to be capable of self-sustainment for more than a short period if an environmental threat occurs due to limited infrastructure and distribution networks, as well as limited stockpiles. This may lead to forces operating in this environment conducting peacekeeping, stabilisation and humanitarian aid operations if a disaster strikes.
• Troops may be required to support the maintenance of law and order during a disaster to prevent the collapse of the local government and the undoing of previous stabilisation operations.
• Access may be constrained, through damaged harbours and airports, so troops may be required to repair these and other vital infrastructure – potentially while under threat of conventional or unconventional attacks or public disorder.
• Non-metropolitan coastal populations may move to coastal cities in search of aid, blocking transport routes and increasing the population in coastal cities. This may cause an increase in crime, disruption, and resource consumption.
• Non-metropolitan coastal populations may refuse to evacuate voluntarily, and this may lead to evacuations being required as potential taskings, such as in Haiti in 2011 where hundreds of disparate villagers were evacuated inland (United Nations, 2011).
• There may be a further influx of people from inland areas searching for aid in coastal cities, creating further disruption and population growth.
• If the disaster was caused by a non-state actor, for example, an oil spill killing the local marine life and causing food shortages, British forces may have to act as an intermediary between a multi-national corporation and a developing state’s government to prevent escalation and public disorder.
• Uncertainty and disorder post-disaster will be exploited by our adversaries and offer them the opportunity for significant tactical advantages and strategic reputational damage. As such, British forces must train and understand how to cope with these situations to reduce this opportunity.

Any action British forces take in these situations will affect the population and their responses. By providing aid and security, we may attract a growing population that we may lack the resources to sustain. Meanwhile, opponents will exploit the chaos from an environmental disaster, and commanders will need to continue warfighting or stabilisation operations while supporting the local government, providing aid, repairing vital infrastructure, and upholding public order. Future headquarters must be exercised and trained to respond to these diverse challenges, as our enemies will not hesitate to exploit these events for a tactical advantage. Therefore, we must prepare for uncertainty and make our forces increasingly agile and flexible to conduct multiple operations simultaneously across contested domains, while also fighting the environmental challenges that will hamper logistics, mobility, and public perceptions. For example, deploying battlegroups should have access to specialists in relevant fields such as harbour infrastructure, water, and utility supply, and particularly, disaster management. These are only some examples of factors to consider in a short-term environmental crisis, and many more outcomes are possible that we cannot conceptualise yet. Thus, British forces must be flexible in our thinking and approach towards these upcoming threats.

How will long-term environmental trends and threats affect the operational environment?

Environmental threats also consist of long-term trends, many of which we may be unaware of yet or unable to conceptualise. For example, rising sea levels could lead to new migration to floating structures or inland migration with rivers or UAVs allowing trade to continue unhindered with vessels by the coast. These environmental trends occur in a world with an increasing scope and frequency of subthreshold competition, which will affect all future operations. The long-term trends from climate change could fill several essays alone, so instead, here is a condensed list of what some of the most significant effects upon the operational environment as a result of long-term trends:

1.    Increasing Complexity

Environmental threats will only increase the already substantial complexity of the future operating environment, caused by increasing access and advancement of technology, growing interconnectedness, the increasing contestation of all domains, and many other factors. This complexity, often summarised as the ‘5 C’s’ of the future character of conflict, stretches from the tactical urban operating environment to the broader strategic context of constant subthreshold competition (MoD, 2015, pg.44). This growing interconnectedness is due to globalisation caused by improving technology, communications and inter-state interactions and dependencies. This has led to the development of complexity theory, by which the world is treated as a system of interconnected systems (Urry, 2006, pg.115). With this lens, actions that damage a single actor or piece of infrastructure could have far-reaching and potentially unforeseen knock-on consequences.

This is particularly challenging for states as more technologies are being utilised and developed before their potential weaknesses have been identified. Therefore, it is imperative that we assess how our systems and actions will interact with coalition members, enemy actors, non-state actors, non-governmental organisations, and any other actors. We must also consider the second and third-order effects of these interactions and how they will be perceived as they may signal cascading changes throughout the system from other actors. The effect of unstable weather patterns, rising sea levels, more frequent droughts and famines and other climate trends will only create greater instability in these complex relationships that we must identify, understand, and mitigate to prevent adversaries undermining us.

2.    The need for greater flexibility

This refers to the agility, responsiveness, and adaptability of all elements of a UK force from all three services and our coalition allies. As environmental threats continue to create new and unforeseen secondary impacts, it is imperative that British forces improve their ability to understand and adapt to changing operating environments. For example, the sustainment of our forces and host-nation allies will be increasingly challenged in an urban, coastal environment. Technological proliferation will prevent arms embargoes (through advancements in 3D printing and other expansions of specialist manufacturing), with anti-ship or anti-aircraft missiles becoming more available and concealable in the increasingly inhabited areas of coastline (which we may be unable to strike), which will make Anti-Access/Area Denial operations more prevalent (Singer, 2019). This will deny, constrain, or increase the risk of amphibious and infiltration operations while preventing replenishment by ships in temporary harbours. Solutions such as mass swarms of UAVs for replenishment to increase the likelihood of success may be costly and still be threatened by enemy counter-UAS systems. However, these solutions must be conceptualised now to allow for development, industry design, trials and procurement before the next conflict as even non-state actors are developing these capabilities. This is only one example, but the overarching requirement is that we should expect to have our current methods of operation challenged by both our enemies, and increasingly, by the environment. The opponents we face are intelligent, insightful, and adaptable and will understand the limitations that environmental factors will impose on us. The increasing use of coastal areas for habitation and the rise in technological proliferation and access will mean that power projection from maritime task forces will have to be conducted further from the shore. This will increase the physical distance and isolation of a shore-based expeditionary force from its supporting elements – especially in a highly-populated, constrained and potentially disorderly urban environment where ammunition and other consumables will be expended more rapidly than in other environments and resupply may be limited.

Alongside this, how we physically and conceptually operate will also be challenged. The compression of the operating environment in time and space has already been modelled extensively. From General Krulak’s conception of the three-block war, where high-intensity warfighting, peacekeeping operations, and humanitarian aid are all conducted concurrently in the same city by military forces (Annis, 2020). General Mattis expanded this metaphor to the four-block war to include information operations (although critics argue this is less of a block and more of an overarching strategic requirement). While the more recent four-floor war conceptualises how the battlespace may be further compressed, with civilians being evacuated on the ground floor, while prisoners are detained in the basement, and warfighting is conducted on the second floor (Manaugh, 2015). The message that future urban warfare will be incredibly complex is clear, while there will be growing temporal and physical compression of the battlespace. However, environmental trends, such as more frequent droughts, famines, or floods, will constantly reshape the human and physical operating environment. If a slum floods, British forces may not be prepared to conduct warfighting as the situation changes rapidly, and must find new insertion, isolation, entry, and extraction methods.

Similarly, a drought and desperate population may be an eventuality we are not prepared to face when conducting warfighting operations. For example, all cordon troops potentially require non-lethal weapon systems to mitigate the risk from public violence, but this is not something we are routinely scaled for when conducting conventional warfighting or counterinsurgency. As we can see, the growing environmental threats will create more complex situations, where both commanders and their forces must be increasingly flexible. These are problems we must be imaginative and adaptable in thinking about and be willing to try and fail in training to solve. 

3.    New military challenges

The broader scope for change in the operating environment is enormous, from UAVs small enough to search buildings internally, to real-time ISTAR access for commanders, and new weapon systems. As has been well documented and discussed, the next major conflicts of the 21st Century will, more than likely, be dominated by cities and urban sprawl. Over half the world’s population already live in urban areas, and this number is expected to climb to two thirds by 2050 (United Nations, 2018). Being the centres of government, industry, wealth, and population, it is clear that any future conflict will be highly likely to revolve around these centres of gravity.

What is less discussed is the impact of climate change on these urban landscapes, with most of the focus only considering the first-order effects, such as rising sea levels, extreme weather events, temperature retention in urban areas. Of equally significant importance is the second-order effects which will include our attempts to mitigate the impact of climate change. How the urban environment is set to change in the near future will have far-reaching implications on the future of warfare as an already complex environment becomes even more cluttered. Some significant considerations about how our attempts to mitigate environmental threats will challenge coastal urban operations include:

• The move towards renewable energy has inadvertently created networks of tall structures on the outskirts of many major towns and cities, significantly reducing the approaches available to aircraft and significantly reducing the number of potential landing zones (NATO, 2017).
• The addition of offshore windfarms, hydro and tidal plants has similarly created another ring of obstacles that will surround most coastal cities. These will significantly affect these waters' navigability and reduce the number of potential approaches for amphibious operations.
• The addition of solar panels and small turbines on the rooftops of buildings will have significant implications, reducing the number of workable rooftop entry points, suitable locations for urban observation points and snipers (NATO, 2017).
• As sprawling urban areas with high population density grow and merge into megacities there may become no clear ‘break-in’ point to a city. Transport, energy, and utilities infrastructure networks will also grow in complexity and scope, further complicating operations. This makes the possibility for urban ‘sieges’ to be far more protracted and exhausting, with isolation and clearance being made more challenging (Fox, 2021, pg.23-26).
• Infrastructure will increase in scale and complexity, with old and new systems interfacing and expanding. These networks will be both increasingly vulnerable dependencies and exploitable opportunities for all actors. The resilience of these systems to environmental disasters, changing climatic conditions and increasing user demands will shape the operating environment.

As climate change becomes an ever more prevalent issue, both in the developed and developing world, it is clear that any future conflict that takes place in these urban centres will be chaotic and cluttered. This is because the number of actors and obstacles in this environment will only increase as methods of mitigating the impacts of climate change become more widespread. British forces must consider how they will mitigate new challenges as these obstacles and developments become more prevalent around the world.

The “Climate and Geographical Implications for Future Urban Operations” NATO paper available online is one of several excellent resources available on this subject, going into far greater depth than this essay can on specific predicted implications.

4.    Commanders and Headquarters must be prepared for the uncertain and changeable operating environment.

Increasing subthreshold threats and the changing character of conflict will only be made more volatile and changeable by climate change. We must do more to prepare commanders to operate in chaotic and uncertain environments intended to overwhelm us. To prevent commanders from being overloaded by complexity and new threats, we must begin to incorporate them into training and planning now, ready for the future. At the tactical level, British forces have little tangible understanding of how environmental threats will amplify existing challenges – this is compounded by a poor understanding of how increasing subthreshold competition will affect us operationally. Therefore, we must conceptualise these challenges in an accessible format that can be understood by all ranks while beginning to incorporate environmental shocks and trends into training and exercises. While conventional warfighting should absolutely be our priority (with a renewed focus on Continental Europe), we must prepare to fight future wars where environmental factors will play a key role. If the UK wishes to maintain our competitive advantages in our staff and planning processes, then they must expose them to expected future challenges to prevent tactical, operational or even strategic surprise.

Both the regular and reserve army should understand and train for these threats. With the IR21's “tilt” to South East Asia, one of the most natural disaster-prone and coastalised regions of the world, means we must consider how British forces will respond to a short-term shock during warfighting operations or long-term trends that may challenge our planned methods of operation (MoD, 2021, pg.60). Meanwhile, the Army Reserve has been nominated as the lead for UK resilience, therefore, we must plan for how we will react to floods, fires, and other natural disasters (eventualities that reservists can provide troops for, yet commanders do not even receive training for) (MoD, 2021, pg.7). Expectations that we can be flexible need to be proven in the new operational environment, and so we must be trained and tested to failure. Crucially, operating in coastal, urban environments will require us to move beyond jointness and achieve greater integration, as stressed in the Integrated Operating Concept - especially when faced with dynamic environmental and emerging threats (MoD, 2021, pg.5-11). We must become familiar with working with other services at all levels and face chaotic scenarios that incorporate ‘black swan’ events. New and interconnected technologies increase the potential for ‘black swan’ events, where an unpredicted event occurs with significant impact and achieves strategic surprise (Poonawala, 2016, pg.1). These can range from epidemics like the COVID-19 exacerbated by increased interconnectedness, or the 2008 financial crisis.

Future exercises should begin to incorporate these new challenges as part of the wider situation as a factor to consider, or even as a core part of the construct. Exercises with Joint HQs and allied participation could develop to the point where a conventional warfighting operation unexpectedly faces a small earthquake, drought, or other short-term environmental disaster during the exercise. British forces would face chaos which the enemy would exploit, and this learning experience would be invaluable. The Chinese ‘unrestricted warfare’ or the Russian Primakov doctrine would encourage them or their proxies to exploit environmental disasters to overwhelm these forces when they are isolated, blind, and emaciated. Therefore, we must plan, prepare, and conceptualise now to develop our force and procure equipment ready for the future. Once this has been achieved, the UK can adapt its force structure, doctrine, and training to meet these challenges.

Conclusion

Ultimately, environmental threats as events or trends will contribute to an increasingly complex future operating environment. Our increasing reliance on technology, data, ISTAR and air superiority will only amplify our Command and Control, logistics and intelligence challenges. We must understand and expect adversaries to exploit these changes in conjunction with constant new challenges across other domains. New environmental changes can lead to an expansion of subthreshold actions and to new types of competition, which will further challenge our conceptions of conflict. More broadly, the UK’s civil resilience and crisis response will also be impacted. Therefore, we must begin conceptualising these challenges now, in order to allow time for trials, procurement, training and development before these crises occur. While damaging in isolation, environmental threats will also be another exploitable opportunity for adversaries to achieve strategic surprise and overwhelm us with complexity in the future if we are not adequately prepared.

Bibliography

Annis, F., 2020. Krulak Revisited: The Three-Block War, Strategic Corporals, and the Future Battlefield - Modern War Institute. [online] Modern War Institute. Available at: https://mwi.usma.edu/krulak-revisited-three-block-war-strategic-corporals-future-battlefield/ [Accessed 6 August 2021].

Betz, D. and Stanford-Tuck, H., 2019. The City Is Neutral: On Urban Warfare in the 21st Century - Texas National Security Review. [online] Texas National Security Review. Available at: https://tnsr.org/2019/10/the-city-is-neutral-on-urban-warfare-in-the-21st-century/ [Accessed 6 August 2021].

Blakely, E. and Gurran, N., 2008. Suffer a Sea Change? Contrasting perspectives towards urban policy and migration in coastal Australia. Australian Geographer, [online] 38(1), pp.113-131. Available at: https://www.tandfonline.com/doi/pdf/10.1080/00049180601175899?needAccess=true  [Accessed 6 August 2021].

Fox, A., 2021. On Sieges. The RUSI Journal, [online] 166(2), pp.18-28. Available at:

https://doi.org/10.1080/03071847.2021.1924077 [Accessed 22 November 2021].

Hendrix, C., 2013. Do Natural Disasters Fuel Unrest? - Political Violence at a Glance. [online] Political Violence at a Glance. Available at: https://politicalviolenceataglance.org/2013/11/19/do-natural-disasters-fuel-unrest/ [Accessed 26 August 2021].

HM Government, 2015. National Security Strategy And Strategic Defence And Security Review 2015. [online] London: HM Government, pp.29-31. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/555607/2015_Strategic_Defence_and_Security_Review.pdf [Accessed on 22 May 2020].

HM Government, 2021. Defence in a Competitive Age. Defence Command Paper. [online] London: HM Government, pp.4-7. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/974661/CP411_-Defence_Command_Plan.pdf [Accessed 6 August 2021].

IPCC, 2015. Climate Change 2014 Synthesis Report. [online] Geneva: The Intergovernmental Panel on Climate Change, pp.12-27. Available at: https://www.ipcc.ch/site/assets/uploads/2018/02/SYR_AR5_FINAL_full.pdf [Accessed 6 August 2021].

Kilcullen, D., 2013. Out of the Mountains: The Coming Age of the Urban Gorilla. 1st ed. Oxford University Press, pp.4-12, 14-28.

Manaugh, G., 2015. The Four-Floor War. [online] BLDGBLOG. Available at: https://www.bldgblog.com/2015/12/four-floor-war/ [Accessed 6 August 2021].

Mann, M., Rahmstorf, S., Kornhuber, K., Steinmann, B., Miller, S. and Coumou, D., 2017. Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events. Scientific Reports, [online] 7, pp.1-10. Available at: https://www.nature.com/articles/srep45242?iu=&iap=false&exception=true&cust_params [Accessed 6 August 2021].

McGranahan, G. and Satterthwaite, D., 2014. Urbanisation concepts and trends. IIED, [online] Working paper 2014, pp.4-8. Available at: https://www.jstor.org/stable/pdf/resrep01297.pdf?acceptTC=true&coverpage=false&addFooter=false [Accessed 6 August 2021].

MoD, 2015. Future Operating Environment 2035. Strategic Trends Program. [online] London: MoD, pp.40-44. Available at: https://www.gov.uk/government/publications/future-operating-environment-2035 [Accessed 6 August 2021].

MoD, 2021. Global Britain in a Competitive Age: the Integrated Review of Security, Defence, Development and Foreign Policy [online] London: HM Government, pp.60, 85, 92. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/969402/The_Integrated_Review_of_Security__Defence__Development_and_Foreign_Policy.pdf [Accessed 29 March 2021].

MoD, 2021. Integrated Operating Concept. London: HM Government, pp.5-11. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1014659/Integrated_Operating_Concept_2025.pdf [Accessed 24 August 2021].

MoD, 2021. Reserve Forces Review 2030. [online] London: MoD, pp.7-9. Available at: https://www.gov.uk/government/publications/reserve-forces-review-2030 [Accessed 6 August 2021].

NATO, 2017. Climate and Geographical Implications for Future Urban Operations. Allied Command Transformation Urbanization Project. [online] Brussels: NATO, pp.2-8. Available at: https://akxonline.defencegateway.mod.uk/sites/vault/_layouts/15/WopiFrame2.aspx?sourcedoc=%7b1EE8E2C4-A072-4150-8A62-50DF448177DC%7d&file=Final--Climate%20Change%20and%20Geographical%20Implications%20on%20a%20Future%20Urban%20Environment.docx&action=default&DefaultItemOpen=1 [Accessed 6 August 2021].

Nel, P. and Righarts, M., 2008. Natural Disasters and the Risk of Violent Civil Conflict. International Studies Quarterly, [online] 52(1), pp.159-185. Available at: https://www.jstor.org/stable/29734228 [Accessed 6 August 2021].

Penning-Rowsell, E., Sultana, P. and Thompson, P., 2012. The ‘last resort’? Population movement in response to climate-related hazards in Bangladesh. Environmental Science & Policy, [online] 27(1), pp.44-59. Available at: https://www.sciencedirect.com/science/article/pii/S1462901112000470?via%3Dihub [Accessed 6 August 2021].

Poonawala, M., 2016. Black Swans—From Expecting Risk to Expanding Technology. ISACA Journal, [online] 3, pp.1-4. Available at: https://www.isaca.org/resources/isaca-journal/issues/2016/volume-3/black-swansfrom-expecting-risk-to-expanding-technology [Accessed 11 March 2021].

Singer, P., 2019. What Insurgency Will Look Like in 2030. [online] Defense One. Available at: https://www.defenseone.com/ideas/2019/04/what-insurgency-will-look-2030/156594/ [Accessed 6 August 2021].

Statista, 2019. Urban and rural population of the UK 2019. [online] Statista. Available at: https://www.statista.com/statistics/984702/urban-and-rural-population-of-the-uk/ [Accessed 6 August 2021].

Urry, J. ,2006. Complexity, Theory, Culture & Society [online], 23(2–3), pp. 111–115. doi: 10.1177/0263276406062818. Available at: https://journals-sagepub-com.ezproxy.lancs.ac.uk/doi/pdf/10.1177/0263276406062818 [Accessed 27 July 2021].

United Nations, 2011. 2011 Haiti Evacuations. [online] United Nations UN Audiovisual Library. Available at: https://www.unmultimedia.org/tv/unifeed/asset/U110/U110606f/ [Accessed 2 September 2021].

United Nations (2018). 68% of the World Population Projected to Live in Urban Areas by 2050, Says UN [online], United Nations Department of Economic and Social Affairs. Available at: https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html [Accessed 28 July 2021].