Category: Natural Hazards and Disaster Risk

IPCC blog series: Working Group 1 – The Physical Science Basis

Posted on by janet.crompton

This blog is part of a series from the Cabot Institute for the Environment on the Intergovernmental Panel on Climate Change’s recent AR6 report (IPCC, AR6), with this post covering the output of Working Group 1 and the physical scientific basis of climate change. This article also features a chat with Professor Dan Lunt, a Climate Scientist at the University of Bristol who focusses on paleoclimates and climate modelling, and a Lead Author on the IPCC’s AR6 report. For links to the rest of the series, see the bottom of the post.

The IPCC begins their 6th Assessment Report by explaining the physical science basis and publishing the finding of Working Group 1 (WG1) in August 2021. This means that, rather than considering the impact on humans, ecosystems and societies covered by later working groups, this report only looks at the effects on the planet from a physical standpoint. Consider this part of the report to be describing the problem, where later reports describe the impacts and then the possible solutions.

Here are the key points from WG1, detailing the physical science basis:

Human activity has unequivocally caused a change in the global climate.

If you were in any doubt before, let this be the sole key message you take away from this report.

Human activity has caused widespread warming of the land, ocean an atmosphere, affecting weather systems, ecosystems, and the cryosphere (areas covered by ice such as mountain glaciers and the polar regions).

One of the main drivers of this change has been Greenhouse Gases (GHGs), which have been observed to be increasing in atmospheric concentration since as far back as 1750 and the beginning. These gases, such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), come from human processes that burn fossil fuels – transport, energy production, intense cattle farming for example.

Greenhouse gases in the atmosphere act like blanket, trapping rather than heart from the sun, warming the Earth. We also know from studying past climates that the Earth will get warmer with greater atmospheric CO2 levels.

Changes to the climate are happening at an unprecedented rate.

Figure 1: Graph from AR6-WG1 showing the unprecedented levels of warming seen in the last 2000 years.

You may have heard that the Earth’s climate has naturally ebbed between periods of hot and cold. This is completely true, however it can be a misleading statement that completely undersells the issue. Human activity has caused the planet to warm at an unprecedented rate. We are currently undergoing thousands of years of warming in just a few decades (fig.1) – much to fast for adaptation from the world’s ecosystems.

As such, the Earth will take millions of years to recover and reach an equilibrium. I highly encourage you to check out climatearchive.org’s simulations of the next million years using cutting edge modelling data – created by the Cabot Institute for the Environment’s Sebastian Steinig.

Climate change is ALREADY affecting every inhabited region on Earth, with observed increases in extreme weather and climate extremes.

Many people believe that the climate crisis is far off in the future, a problem to prevent before it arrives. However, this is not the case. It’s already happening under our noses. And everywhere. Every inhabited region in the world currently experiences an increased likelihood of an extreme weather event, extreme heat drought, or extreme precipitation. This summer for example, temperatures in the UK have been modelled and subsequently measured to creep above 40°C, unprecedented for a region with a usually temperate climate and setting national records.

Increased warming leads to an increase in effect and creeps towards a tipping point from which recovery is impossible.

You might have heard phrases like “2 degree C future” or “1.5 degree C rise” in the news, but what do these really mean? These numbers refer to the global mean temperature rise using a rolling average of the previous 20 years, relative to the temperature measured between 1850-1900 when climate change started to begin. Currently, the average global temperature anomaly sits above 1 degree C of warming (fig.1).

The Earth system is remarkably robust, but not quite robust enough to maintain an equilibrium with such rapid warming in a short space of time. One place where this is most stark is the cryosphere – parts of the Earth usually covered by ice all year round (glaciers, polar regions for example).

Melting has already begun and will continue to happen for decades even if emissions magically ended tomorrow. This is incredibly troubling, since the cryosphere also happens to be huge carbon store in the form of methane trapped in the ice. This creates what’s known as a feedback loop, where the effects of warming lead to greater warming in themselves.

Through studying paleoclimates, the IPCC reports that climate sensitivity and therefore “tipping point” sits at around 3 degree C, resulting in total climate breakdown.

Significant and immediate action limiting Greenhouse Gas emissions will be a major key in fighting climate change.

The one silver lining the report alludes to is that IPCC scientists are confident that the climate crisis is caused primarily by greenhouse gas concentrations, therefore we know the solution – reducing emissions quickly and effectively will mitigate against the worst warming in a big way. Pursuing a net-zero CO2 strategy and limiting other GHG emissions will be absolutely necessary. Working Group 3’s report on the Mitigation of Climate Change goes into greater detail on how governments can work together to go about this. This will be published on 29 August 2022.

Insight from IPCC WG1 author Professor Dan Lunt

Professor Dan Lunt is a Professor of Climate Science, Cabot Institute member and a key author on the IPCC’s WGI report.

How did you get involved with IPCC AR6?

Dan Lunt

“I was involved with the previous IPCC report, AR5, providing some data and graphs for a section on polar amplification in past and future climates (the disproportionate warming of the polar regions relative to the rest of the Earth system). This time round, a call went out around four or five years ago for authors to work on the upcoming Sixth Assessment Report. I applied for and was chosen to be a Lead Author on Chapter 7 of the AR6 report – a section focussed the Earth’s radiation budget and Climate Sensitivity, as well as on paleoclimates as evidence for the patterns of global warming, such as polar amplification.”

What’s one key point you’d like to get across from the work of Working Group 1?

“For me, what I would interpret as the key message would be climate change is already happening, and it’s happening all over the globe. It’s unprecedented in terms of its magnitude and its speed of change, relative to the past tens of thousands of years. It’s unequivocally caused by human activity.”

“One of the new key points in this assessment report is that there’s a lot more evidence now that there are changes in the frequency of extreme events. We now have enough data to say that this increased frequency is human induced. So that’s more droughts, floods, extreme heat events etc.”

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We recommend taking a look at the IPCC’s full reports and report summaries for yourself if you seek to further understand the evidence and reasoning behind their headline statements.

As we’ve discussed the scientific basis for climate change, you may be wondering what the real-world impacts. The specific impacts on ecosystems, global health and on human society will be covered in greater detail in our summary of WG2’s report titled “Impacts, Adaption and Vulnerability”, publishing tomorrow (Thursday, 28th of August).

 

This blog was written by Cabot Communications Assistant Andy Lyford, an MScR Student studying Paleoclimates and Climate modelling on the Cabot Institute Master’s by Research in Global Environmental Challenges at the University of Bristol.

Andy Lyford

 

 

What protections are available to people displaced by climate change?

Posted on by janet.crompton

Climate change will impact all our lives in the coming years and many people will experience extreme events due to climate  change resulting in displacement, both internally and across international borders. This has become the reality for some already within low-lying archipelago islands within the South Pacific, such as Tuvalu and Kiribati. Despite the certainty of increased climate change-related displacement, there is still no specific frameworks which protect those moving for climate related reasons (see a detailed discussion here). 

The site of the village of Tebunginako, Kiribati – relocated due to severe coastal erosion and saltwater intrusion (image: Department of Foreign Affairs and Trade, Australia)

Are people displaced by climate change refugees? 

Under Article 1(A) of the 1951 Refugee Convention, climate-related displacement does not constitute grounds for international protection. I will take the essential elements of Article 1(A) in turn. First, a refugee must have crossed an international border, whereas climate-related displacement is expected to be predominantly internal. 

 

Second, a refugee must have a well-founded fear of persecution. Persecution requires an egregious violation of human rights, which is assessed in light of the nature of the right and the severity of the violation (see here for further discussion). It also requires that the fear of persecution must be well-founded – this does not require certainty – but it must not be far-fetched and should be based upon both an objective assessment of the likelihood of persecution and the subjective nature of the individual’s fear (see Chan v Minister for Immigration and Ethnic Affairs, 1989). Climate change is unlikely to fulfil this requirement despite the detriment it can have on an individual’s access to human rights. It is unlikely to meet the severity threshold even in relation to socio-economic rights and, as McAdam (2016) highlights, it is difficult to identify a ‘persecutor’ that the refugee fears; instead, many refugees are likely to be moving to states that are major greenhouse gas contributors. 

 

Third, persecution must be related to a reason given by the Convention of ‘race, religion, nationality, membership of a particular social group or political opinion…’ The impacts of climate change do not discriminate. Even if an individual did establish persecution based upon an egregious socio-economic rights violation caused by climate change, they would need to argue that this affected them because of their membership of one of these groups. At best, an individual could argue that a government had consciously withheld assistance to address the impacts of climate change to a specific group, amounting to persecution (see here) but the group must be connected by an immutable characteristic (Applicant A v Minister for Immigration and Ethnic Affairs, 1997), not just the impact of the climate change. 

 

Courts have firmly established that the Refugee Convention does not protect victims of natural disasters, slow-onset degradation, poor economic conditions or famine – even when the country of origin is unable or unwilling to provide protection (Canada (Attorney General) v Ward, 1993; Horvath v Secretary of State for the Home Department, 2001). UNHCR has echoed this in its own discussions of how to respond to climate-related displacement (see here and here).  

 

What protections are available to people displaced by climate change?

A response to climate-change related displacement must therefore be sought through other international legal mechanisms. In 2009, the UN Human Rights Council recognised under resolution 10/4 that there is a ‘core inter-linkage between human rights and climate change’ such that those displaced by climate change would be able to rely on the obligations outlined in the ICCPR and the ICESCR. In particular, this would include state’s non-refoulment obligations as the cumulative effect of socio-economic harms can amount to inhumane and degrading treatment such that an individual cannot be returned to such conditions (see Sufi v Elmi, 2011). However, courts may require an immediacy to the rights violation such that future fear of climate-related impacts is insufficient grounds to provide protection from return (see AF(Kiribati), 2013).  

 

In the specific situation of small island states whose territory is threatened by climate change, the law relating to statelessness may also be able to provide some protection and a remedy (see the 1954 Statelessness Convention; Rayfuse 2009). UNHCR has a mandate to prevent and reduce statelessness enabling them to work with states to respond, including coordinating international cooperation, providing protection and resettlement. However, issues concerning when a state will have ceased to exist under international law remains unsettled. For example, for a state to be recognised by international law, Article 1 of the Montevideo Convention requires a permanent population, territory, government and capacity to enter international relations (see Lauterpacht, 1944, and Crawford, 2007, for further discussion). However, there is a lack of clarity on when these criteria will cease to be fulfilled. The problem that international law has grappled with until now has been when new states are formed, not when existing ones have disappeared. As a result, it is unclear when protection for stateless persons of ‘disappeared’ states will be triggered. 

 

There are also regional frameworks that provide broader protections to displaced people, beyond the narrow 1951 definition. In particular, the 1969 OAU Convention Governing the Specific Aspects of Refugee Problems and the 1984 Cartagena Declaration both contain provisions relating to ‘events seriously disturbing public order’, which could be taken to include the events resulting from the effects of climate change. These are both non-binding instruments, whereas Article 5(4) of the Kampala Convention is within a binding instrument and explicitly includes protection for those affected by climate change: 

States parties shall take measures to protect and assist persons who have been internally displaced due to natural or human made disasters, including climate change. 

This focusses protection on internally displaced individuals and ensures that signatory states are required to provides protection and assist those displaced by climate change.  

 

The Kampala Convention is largely based upon the UN Guiding Principles on internal displacement which, under Principle 6(d), outlines that internal displacement is prohibited including in the context of disasters. The principles then provide a framework for states to respond to internal displacement, including that resulting from disasters. The extension of human rights protections to those fleeing climate change is echoed in the Global Compact on Migration, which calls for humanitarian visas for people migrating due to natural disasters and climate change (see objective 2 and 5), as well as similar commitments in the Sustainable Development Goals. Such a response to climate-change related displacement is required under the commitments of Article 14(f) of the Cancun Adaptation of the United Nations Framework Convention on Climate Change (UNFCCC). This aims to enhance understanding, coordination and cooperation with regard to climate change induced displacement…’ These instruments represent moves by the international community to consolidate existing legal frameworks to respond to climate-change related displacement. However, they are not binding treaty law. They demonstrate political commitments not legal obligations. It is evident that, outside the Africa region, mechanisms for protecting individuals from climate-change related displacement are often non-binding and ad-hoc.  

 

The future of climate-related displacement

The term ‘climate refugee’ is conceptually flawed. Such individuals will not constitute refugees for the term ignores the complex causation involved in any displacement, let alone that related to climate change, which in itself is a multi-causal phenomenon. Whilst human rights law, the law relating to statelessness and regional arrangements do provide for some protections to individuals displaced by climate change, these approaches remain disparate and uncoordinated. A lack of clarity can lead to legal loopholes that are abused by states to limit protections.  

 

To respond to this complexity, there are calls for a separate framework for cross-border climate migrants. Commitments within the Global Compact on Migration and the Sustainable Development Goals, as well as the Cancun Agreement, represent attempts by the international community to start to coordinate and elucidate protection for climate-related displacement. However, much more must be done to ensure clarity on the personal, material and temporal scope of protections and obligations for climate change-related displacement. 

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This blog is written by Dr Kathryn Allinson, a Lecturer in Law, University of Bristol Law School. Her research concerns the establishment of state responsibility for breaches of international law focussing on the interaction of human rights and humanitarian law in relation to displacement, and the protection of socio-economic human rights during conflict.  

Kathryn Allinson

 

 

A previous MMB blog by Ignacio Odriozola looked at a landmark decision by the United Nations Human Rights Committee on people seeking international protection due to the effects of climate change: Climate-change displacement: a step closer to human rights protection.  

Hydrological hazards across timescales

Posted on by janet.crompton

University of Bristol – Met Office Academic Partnership Meeting 

From droughts and floods to water quality and water resource management, researchers at the University of Bristol and the Met Office are world-leaders in climate and hydrological research. Building on the new academic partnership between Bristol and the Met Office, the goal of this meeting was to foster new collaborations and strengthen existing partnerships between Bristol and the Met Office on the topic of weather, climate and hydrology. 

In total, we had 29 attendees attend the workshop, with 10 from the Met Office, 17 from the University of Bristol and 2 from Fathom including weather and climate scientists, catchment hydrologists and flood modellers at a wide range of career stages. 

 

The meeting explored two key themes, the first half of the meeting focused on ‘Exploiting convection permitting weather and climate models for flood and drought prediction’, while the second half focused on ‘Quantifying uncertainty in hydrological projections’. For each theme, there were two short plenary talks that highlighted existing research across the Met Office and University of Bristol and then a presentation focused on an exciting piece of research covering topics on exploiting convection permitting models for flood and drought prediction (Lizzie Kendon) and towards large ensembles of km-scale precipitation simulations using AI (Peter Watson and Henry Addison).  We also had eight lighting talks on topics ranging from tropical cyclones to pan-tropics convection-permitting climate simulations to compound wind and flood risk.  

 

Alongside the talks, there was time for attendees to discuss ideas and opportunities focused around five key discussion topics; uncertainty estimation, compound events and multi-hazard coupling, evaluation of weather and climate driving information for hydrology, exploiting higher resolution capabilities for hydrology and from hydrological predictions to ‘services’. 

 

Overall, the meeting was a success and we appreciated an in person meeting fuelled by coffee, cake and cheese! Tangible outputs from the day included contributions on a NERC proposal, making new connections, ideas for future collaborations, sharing of data and methodologies and the foundations for a collaborative climate and hydrology community.  

 

Further details from the meeting can be requested from Gemma Coxon (gemma.coxon@bristol.ac.uk). 

India heatwave: why the region should prepare for even more extreme heat in the near future

Posted on by janet.crompton

An extreme heatwave in India and Pakistan has left more than a billion people in one of the most densely populated parts of the world facing temperatures well above 40℃. Although this has not broken all-time records for the regions, the hottest part of the year is yet to come.

Though the heatwave is already testing people’s ability to survive, and has led to crop failures and power blackouts, the really scary thing is that it could be worse: based on what has happened elsewhere at some point India is “due” an even more intense heatwave.

Together with a few other climate scientists, we recently looked for the most extreme heatwaves globally over the past 60 years – based on the greatest difference from expected temperature variability in that area, rather than by maximum heat alone. India and Pakistan do not feature in our results, now published in the journal Science Advances. Despite regularly having extremely high temperatures and levels of heat stress in absolute terms, when defined in terms of deviation from the local normal, heatwaves in India and Pakistan to date have not been all that extreme.

In fact, we highlighted India as a region with a particularly low greatest historical extreme. In the data we assessed, we didn’t find any heatwaves in India or Pakistan outside three standard deviations from the mean, when statistically such an event would be expected once every 30 or so years. The most severe heatwave we identified, in southeast Asia in 1998, was five standard deviations from the mean. An equivalent outlier heatwave in India today would mean temperatures of over 50℃ across large swaths of the country – such temperatures have only been seen at localised points so far.

Our work therefore suggests India may experience even more extreme heat. Assuming the statistical distribution of daily maximum temperatures is broadly the same across the world, statistically a record-breaking heatwave is likely to occur in India at some point. The region has not yet had reason to adapt to such temperatures, so may be particularly vulnerable.

Harvests and health

Although the current heatwave has not broken any all-time records, it is still exceptional. Many parts of India have experienced their hottest April on record. Such heat this early in the year will have devastating impacts on crops in a region where many rely on the wheat harvest both to eat and to earn a living. Usually, extreme heat in this area is closely followed by cooling monsoons – but these are still months away.

It is not just crop harvests that will bear the brunt, as heatwaves affect infrastructure, ecosystems and human health. The impacts on human health are complex as both meteorological factors (how hot and humid it is) and socioeconomic factors (how people live and how they are able to adapt) come into play. We do know that heat stress can lead to long-term health issues such as cardiovascular diseases, kidney failure, respiratory distress and liver failure, though we will be unable to know exactly how many people will die in this heatwave due to the lack of necessary health data from India and Pakistan.

What the future holds

To consider the impact of extreme heat over the next few decades, we have to look at both climate change and population growth, since it is a combination of the two that will amplify the human-health impacts of heat extremes in the Indian subcontinent.

world map with some countries shaded yellow
Hotspots of population increases over the next 50 years (red circles), all coincide with locations where no daily mortality data exists (yellow).
Mitchell, Nature Climate Change (2021), CC BY-SA

In our new study, we investigated how extremes are projected to increase in the future. We used a large ensemble of climate model simulations, which gave us many times more data than is available for the real world. We found that the statistical distribution of extremes, relative to a shift in the underlying climate as it generally gets warmer, does not change. In the climate models the daily temperature extremes increase at the same rate as the shift in the mean climate. The IPCC’s latest report stated that heat waves will become more intense and more frequent in south Asia this century. Our results support this.

The current heatwave is affecting over 1.5 billion people and over the next 50 years the population of the Indian subcontinent is projected to increase by a further 30%. That means hundreds of millions more people will be born into a region that is likely to experience more frequent and more severe heatwaves. With even larger numbers of people being affected by even greater heat extremes in the future, measures to adapt to climate change must be accelerated – urgently.The Conversation

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This blog is written by Cabot Institute for the Environment members Dr Vikki Thompson, Senior Research Associate in Geographical Sciences, University of Bristol and Dr Alan Thomas Kennedy-Asser, Research Associate in Climate Science, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate change isn’t just making cyclones worse, it’s making the floods they cause worse too – new research

Posted on by janet.crompton
People take refuge on a sports ground following flooding caused by Cyclone Idai in Mozambique.
DFID/Flickr, CC BY-SA

Laurence Hawker, University of Bristol; Dann Mitchell, University of Bristol, and Natalie Lord, University of Bristol

Super cyclones, known as hurricanes or typhoons in different parts of the world, are among the most destructive weather events on our planet.

Although wind speeds within these storms can reach 270 km/h, the largest loss of life comes from the flooding they cause – known as a “storm surge” – when sea water is pushed onto the coast. Climate change is predicted to worsen these floods, swelling cyclone clouds with more water and driving rising sea levels that allow storm surges to be blown further inland.

In May 2020, Super Cyclone Amphan hit the India-Bangladesh border, bringing heavy rainfall and strong winds and affecting more than 13 million citizens. The cyclone also caused storm surges of 2-4 metres, flooding coastal regions in the Bay of Bengal.

While over the ocean, this category five storm – that’s a storm’s highest possible rating – became the strongest cyclone to have formed in the Bay of Bengal since 1999, reaching wind speeds of up to 260 km/h. Although it weakened to a category two storm following landfall, it remained the strongest cyclone to hit the Ganges Delta since 2007.

Amphan had severe consequences for people, agriculture, the local economy and the environment. It tragically resulted in more than 120 deaths, as well as damaging or destroying homes and power grids: leaving millions without electricity or communication in the midst of an ongoing pandemic.

Relief and aid efforts were hampered by flood damage to roads and bridges, as well as by coronavirus restrictions. Large areas of crops including rice, sesame and mangos were damaged, and fertile soils were either washed away or contaminated by saline sea water. Overall, Super Cyclone Amphan was the costliest event ever recorded in the North Indian Ocean, resulting in over $13 billion (£10 billion) of damage.

Two people assess a tree that has fallen across a road
In Kolkata, India, Super Cyclone Amphan caused widespread damage.
Indrajit Das/Wikimedia

In a recent study led by the University of Bristol and drawing on research from Bangladesh and France, we’ve investigated how the effects of storm surges like that caused by Amphan on the populations of India and Bangladesh might change under different future climate and population scenarios.

Amphan: Mark II

Rising sea levels – thanks largely to melting glaciers and ice sheets – appear to be behind the greatest uptick in future risk from cyclone flooding, since they allow storm surges to reach further inland. It’s therefore key to understand and predict how higher sea levels might exacerbate storm-driven flooding, in order to minimise loss and damage in coastal regions.

Our research used climate models from CMIP6, the latest in a series of projects aiming to improve our understanding of climate by comparing simulations produced by different modelling groups around the world. First we modelled future sea-level rise according to different future emissions scenarios, then we added that data to storm surge estimates taken from a model of Super Cyclone Amphan.

We ran three scenarios: a low emission scenario, a business-as-usual scenario and a high emission scenario. And in addition to modelling sea-level rise, we also estimated future populations across India and Bangladesh to assess how many more people storm surges could affect. In most cases, we found that populations are likely to rise: especially in urban areas.

Our findings were clear: exposure to flooding from cyclone storm surges is extremely likely to increase. In India, exposure increase ranged from 50-90% for the lowest emission scenario, to a 250% increase for the highest emission scenario. In Bangladesh, we found a 0-20% exposure increase for the lowest emission scenario and a 60-70% increase for the highest emission scenario. The difference in exposure between the two countries is mostly due to declining coastal populations as a result of urban migration inland.

Imagine we’re now in 2100. Even in a scenario where we’ve managed to keep global emissions relatively low, the local population exposed to storm surge flooding from an event like Amphan will have jumped by ~350,000. Compare this to a high emission scenario, where an extra 1.35 million people will now be exposed to flooding. And for flood depths of over one metre – a depth that poses immediate danger to life – almost half a million more people will be exposed to storm surge flooding in a high emission scenario, compared to a low emission scenario.

A composite satellite image of a large white cyclone
A satellite image shows Amphan approaching the coasts of India and Bangladesh.
Pierre Markuse/Wikimedia

This research provides yet more support for rapidly and permanently reducing our greenhouse gas emissions to keep global warming at 1.5°C above pre-industrial levels.

Although we’ve focused on storm surge flooding, other cyclone-related hazards are also projected to worsen, including deadly heatwaves following cyclones hitting land. And in the case of Amphan, interplay between climate change and coronavirus likely made the situation for people on the ground far worse. As the world warms, we mustn’t avoid the reality that pandemics and other climate-related crises are only forecast to increase.

Urgent action on emissions is vital to protect highly climate-vulnerable countries from the fatal effects of extreme weather. Amphan Mark II need not be as destructive as we’ve projected if the world’s governments act now to meet Paris agreement climate goals.The Conversation

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This blog is written by Cabot Institute for the Environment members Dr Laurence Hawker, Senior Research Associate in Geography, University of Bristol; Professor Dann Mitchell, Professor of Climate Science, University of Bristol, and Dr Natalie Lord, Honorary Research Associate in Climate Science, University of Bristol

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The politics of climate justice, migration and mobility

Posted on by janet.crompton

Migration Mobilities Bristol (MMB) and the Cabot Institute for the Environment bring together researchers from across the University of Bristol to explore connections between movement and the environment from a multi-disciplinary perspective. Their diverse approaches highlight the importance of developing frames that incorporate both migration and environment, and in so doing benefit our understandings of both. Here, the directors of MMB and the Cabot Institute for the Environment introduce the blog series through the lens of the politics of climate justice, migration and mobility.

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Migration is often mobilised to illustrate the enormity of the challenge of climate change. Some Small Island States in the Pacific, for instance, may become uninhabitable with sea-level rise. Highly vulnerable countries in South Asia, including Bangladesh and the Maldives, may see large proportions of their populations forced to move because of sea-level rise, floods and salinisation of water. US climate envoy John Kerry recently fuelled fears of a future where food production collapse would force a ‘hundred million people’ to move. His comments strongly implied that even those of us who imagine we are protected from the frontline of climate change will be faced with the challenges of ‘climate refugees’ in their millions.

Moniruzzaman Sazal / Climate Visuals Countdown

Kerry’s remarks were heavily criticised, but this is not to deny that there is a connection between the world’s ecosystems and environment and human movement. It is easiest to causally relate environmental factors to migration in situations of ‘rapid onset disasters’ – destructive events that occur suddenly, such as typhoons or floods. In these situations, people move to survive, but often to a place of safety a short distance away, and they return to rebuild homes and lives once the emergency has abated. But many environmental changes are taking place over periods spanning two or three generations. ‘Slow onset’ environmental change can be a primary or contributing factor to deteriorating socio-economic conditions – increasing periods of drought, or crop yields declining rather than collapsing, for instance. In these circumstances, migration can be an important way to diversify income streams. Environmental change may also contribute to shifts in land usage and land ownership, which again may result in migration.

Declining resources can also prevent people from moving, especially when resources are slowly depleted over a generation or more. Limited access to capital can force people into illegal or exploitative migration or lead them to delay moving until forced to do so in an unplanned way – perhaps because of a rapid onset disaster that they no longer have the resilience to cope with.

The challenges faced by people who don’t move may become more severe when combined with conflict. For example, in Somalia, armed conflict has hindered the movement of pastoralists, who would otherwise relocate as a response to drought. It has also limited the possibilities of humanitarian organisations to assist them. Human mobility and environmental change are deeply interconnected but need to be understood systemically not simplistically if we are work towards climate justice.

Understanding the relationship between migration and environmental change in a more holistic and integrated way has important policy implications. For example, economic factors can mean that people migrate to places of environmental instability as well as migrating from places of environmental instability. Currently 55% of the world’s population lives in cities, and it is forecast that by 2050 this will increase to nearly 70%; nearly 60% of forcibly displaced people move to urban areas (World Bank, 2020). Many cities are extremely vulnerable to future environmental change, and already experience high temperatures, sea level rise, water stress and threats to health. Rural to urban migrants are often especially vulnerable, as they tend to move to neighbourhoods with high population density that are prone to environmental risks – think of the favelas in Rio de Janeiro and São Paulo, or the slums of Dhaka, Nairobi and Mumbai.

Peter Castleton (CC BY 2.0)

In these contexts, migrants, whether rural-urban or international, can be represented as an environmental problem in themselves. The movements of the poor are also represented as a root cause of problems: migration destroys carbon sinks, ‘environmental refugees’ put pressure on already scarce resources and services and so on. Rather than seeing the interconnections of human movement and climate change, the risk is that the politics of climate and the mobility of the poor – that is, ‘migration’ – are framed as oppositional. As a result, in wealthy countries we are seeing increasing tensions between politics of the environment and politics of migration, as illustrated by John Kerry’s remarks.

It is critical, then, to recognise the complexity of the connections between (human) movement and ecosystems. This new blog series, co-published by MMB and the Cabot Institute for the Environment, draws attention to some of these connections and raises questions for further research to help us understand in more depth the relationship between movement and the environment, and its political significance. The contributions in the series approach this relationship from many angles, ranging from the role of water access in shaping migration to debates around the status of the ‘environmental refugee’. One analyses the environmental footprint of home working versus office working to explore the sustainability potential of our increasing immobility. Others focus on animals and plants on the move: we have writing on the ecological context of bird migrations and on the hyper-mobility of the European eel. Meanwhile, other posts look at the movement of goods and how humans locate themselves in, and move through, landscapes of extraction and risk. In bringing together such diverse topics we hope this series will encourage new conversations about the connections between migrations, mobilities and environments.

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This blog is written by Bridget Anderson, Professor of Migration, Mobilities and Citizenship at the University of Bristol, and Director of Migration Mobilities Bristol; and Professor Guy Howard, Global Research Chair Environmental and Infrastructure Resilience at the University of Bristol, and Director of the Cabot Institute for the Environment.

Bridget Anderson
Guy Howard

 

Climate Change 2022: Impacts, Adaptations and Vulnerability – an IPCC lead author report summary

Posted on by janet.crompton

Professor Daniela Schmidt, a lead author of the recently published IPCC (Intergovernmental Panel on Climate Change)  report, Working Group II: Impacts, Adaptations and Vulnerability, recently gave an internal presentation to University of Bristol staff to summarise the report’s findings.

Recent geo-political events have meant that this report has understandably been overlooked in comparison to its predecessor, however, at 3500 pages and being the product of analysis of 34,000 papers since 2014, it is certainly not light reading. This writing aims to pinpoint and amplify the key messages from Daniela’s summary of Working Group II: Impacts, Adaptations and Vulnerability, as the Working Group III: Mitigation of Climate Change report has been released this week.

Solutions

The key take home message, was that the report offers solutions, but they are needed now. Daniela explained that it is not all doom and gloom, and it is important for our survival not to take it that way. From the report itself, the key quote, which you have perhaps seen shared elsewhere, is

The science is clear. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a livable future. This report offers solutions to the world.

Nature

One of the key solutions proposed in the report is nature, both in terms of its conservation and restoration and that it offers promising solutions to many of the threats we face. For example, the potential of natural carbon sinks, coastal protection, water management and urban cooling systems has been repeatedly evidenced, as well as the importance of integrating nature and natural solutions into urban spaces.

The report stresses that humans are part of ecosystems, not separate from them, and nature is crucial to our survival because of the essential and irreplaceable ecosystem services it provides. Fragmented, polluted and overexploited ecosystems are much more vulnerable to climate change, therefore, the report stresses it is therefore important to take a coordinated approach, with their protection and restoration in mind.

Interconnection

As well as the interconnectedness of humans and nature, the report evidences previously unrealised interconnections of climate risks. Risks are becoming more complex and there are compound and cascading risks through systems. For example, in terms of food scarcity, we need to consider that heat stress will not only reduce crop yields, but also the well-being and productivity of farm workers, further exacerbating the situation. There is an increased recognition of the interconnections between people, regions, society, ecosystems, biodiversity. This means that climate change cannot be seen as an individual problem, but as one intrinsically linked with natural resource depletion, ecosystem destruction, and growing urbanisation and inequity across the world.

Equality

Another key focus of the report was the importance of but lack of global equality, which will continue to be exacerbated in the face of climate change. 3.3  – 3.6 billion live in hotspots of high vulnerability to climate change, due to high levels of poverty, limited access to water, sanitation and health services, climate sensitive livelihoods and lack of funding and accountability in government. I would like to point out, that in the vast majority of cases, it is these communities whose carbon contributions are the least, which in my opinion strongly evidences to the fact that climate change is a political problem as well as a scientific one.

Due to inequality being a big problem, the report places an emphasis on the importance of promoting equality in the solutions and with this the need to listen to marginalised voices. Daniela explained that of global climate funding, 80% goes to mitigation, or reduction of emissions, while only 20% goes to adaptation, which is likely to be what is most consequential to more vulnerable communities.

After lack of action on deals made at COP26, which scientists have already argued at best would not be sufficient to solve the problem, a continued lack of action following these urgent messages will be deeply concerning for the fate of the planet, and especially for its most vulnerable communities.

Watch Daniela’s presentation to University of Bristol staff.

 

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This blog is written by Cabot Institute for the Environment member Hilary McCarthy, University of Bristol.
Hilary McCarthy

 

New flood maps show US damage rising 26% in next 30 years due to climate change alone, and the inequity is stark

Posted on by janet.crompton

 

Coastal cities like Port Arthur, Texas, are at increasing risk from flooding during storms.
Joe Raedle/Getty Images

Climate change is raising flood risks in neighborhoods across the U.S. much faster than many people realize. Over the next three decades, the cost of flood damage is on pace to rise 26% due to climate change alone, an analysis of our new flood risk maps shows.

That’s only part of the risk. Despite recent devastating floods, people are still building in high-risk areas. With population growth factored in, we found the increase in U.S. flood losses will be four times higher than the climate-only effect.

Our team develops cutting-edge flood risk maps that incorporate climate change. It’s the data that drives local risk estimates you’re likely to see on real estate websites.

In the new analysis, published Jan. 31, 2022, we estimated where flood risk is rising fastest and who is in harm’s way. The results show the high costs of flooding and lay bare the inequities of who has to endure America’s crippling flood problem. They also show the importance of altering development patterns now.

The role of climate change

Flooding is the most frequent and costliest natural disaster in the United States, and its costs are projected to rise as the climate warms. Decades of measurements, computer models and basic physics all point to increasing precipitation and sea level rise.

As the atmosphere warms, it holds about 7% more moisture for every degree Celsius that the temperature rises, meaning more moisture is available to fall as rain, potentially raising the risk of inland flooding. A warmer climate also leads to rising sea levels and higher storm surges as land ice melts and warming ocean water expands.

Yet, translating that understanding into the detailed impact of future flooding has been beyond the grasp of existing flood mapping approaches.

A map of Houston showing flooding extending much farther inland.
A map of Houston shows flood risk changing over the next 30 years. Blue areas are today’s 100-year flood-risk zones. The red areas reflect the same zones in 2050.
Wing et al., 2022

Previous efforts to link climate change to flood models offered only a broad view of the threat and didn’t zoom in close enough to provide reliable measures of local risk, although they could illustrate the general direction of change. Most local flood maps, such as those produced by the Federal Emergency Management Agency, have a different problem: They’re based on historical changes rather than incorporating the risks ahead, and the government is slow to update them.

Our maps account for flooding from rivers, rainfall and the oceans – both now and into the future – across the entire contiguous United States. They are produced at scales that show street-by-street impacts, and unlike FEMA maps, they cover floods of many different sizes, from nuisance flooding that may occur every few years to once-in-a-millennium disasters.

While hazard maps only show where floods might occur, our new risk analysis combines that with data on the U.S. building stock to understand the damage that occurs when floodwaters collide with homes and businesses. It’s the first validated analysis of climate-driven flood risk for the U.S.

The inequity of America’s flood problem

We estimated that the annual cost of flooding today is over US$32 billion nationwide, with an outsized burden on communities in Appalachia, the Gulf Coast and the Northwest.

When we looked at demographics, we found that today’s flood risk is predominantly concentrated in white, impoverished communities. Many of these are in low-lying areas directly on the coasts or Appalachian valleys at risk from heavy rainfall.

But the increase in risk as rising oceans reach farther inland during storms and high tides over the next 30 years falls disproportionately on communities with large African American populations on the Atlantic and Gulf coasts. Urban and rural areas from Texas to Florida to Virginia contain predominantly Black communities projected to see at least a 20% increase in flood risk over the next 30 years.

Historically, poorer communities haven’t seen as much investment in flood adaptation or infrastructure, leaving them more exposed. The new data, reflecting the cost of damage, contradicts a common misconception that flood risk exacerbated by sea level rise is concentrated in whiter, wealthier areas.

A woman carries a child past an area where flood water surrounds low-rise apartment buildings.
Hurricane Florence’s storm surge and extreme rainfall flooded towns on North Carolina’s Neuse River many miles inland from the ocean in 2018.
Chip Somodevilla/Getty Images

Our findings raise policy questions about disaster recovery. Prior research has found that these groups recover less quickly than more privileged residents and that disasters can further exacerbate existing inequities. Current federal disaster aid disproportionately helps wealthier residents. Without financial safety nets, disasters can be tipping points into financial stress or deeper poverty.

Population growth is a major driver of flood risk

Another important contributor to flood risk is the growing population.

As urban areas expand, people are building in riskier locations, including expanding into existing floodplains – areas that were already at risk of flooding, even in a stable climate. That’s making adapting to the rising climate risks even more difficult.

A satellite image of Kansas City showing flood risk overlaid along the rivers.
A Kansas City flood map shows developments in the 100-year flood zone.
Fathom

Hurricane Harvey made that risk painfully clear when its record rainfall sent two reservoirs spilling into neighborhoods, inundating homes that had been built in the reservoirs’ flood zones. That was in 2017, and communities in Houston are rebuilding in risky areas again.

We integrated into our model predictions how and where the increasing numbers of people will live in order to assess their future flood risk. The result: Future development patterns have a four times greater impact on 2050 flood risk than climate change alone.

On borrowed time

If these results seem alarming, consider that these are conservative estimates. We used a middle-of-the-road trajectory for atmospheric greenhouse gas concentrations, one in which global carbon emissions peak in the 2040s and then fall.

Importantly, much of this impact over the next three decades is already locked into the climate system. While cutting emissions now is crucial to slow the rate of sea level rise and reduce future flood risk, adaptation is required to protect against the losses we project to 2050.

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If future development was directed outside of the riskiest areas, and new construction met higher standards for flood mitigation, some of these projected losses could be avoided. In previous research, we found that for a third of currently undeveloped U.S. floodplains it is cheaper to buy the land at today’s prices and preserve it for recreation and wildlife than develop it and pay for the inevitable flood damages later.

The results stress how critical land use and building codes are when it comes to adapting to climate change and managing future losses from increasing climate extremes. Protecting lives and property will mean moving existing populations out of harm’s way and stopping new construction in flood-risk areas.The Conversation

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This blog is written by Cabot Institute for the Environment members Dr Oliver Wing, Research Fellow, and Paul Bates, Professor of Hydrology, School of Geographical Sciences, University of Bristol; and Carolyn Kousky, Executive Director, Wharton Risk Center, University of Pennsylvania and Jeremy Porter, Professor of Quantitative Methods in the Social Sciences, City University of New York.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

#CabotNext10 Spotlight on Natural Hazards & Disaster Risk

Posted on by janet.crompton

 

Dr Ryerson Christie

In conversation with Dr Ryerson Christie, theme lead at the Cabot Institute

Why did you choose to become a theme leader at Cabot Institute?

Obviously with a decision such as this, there are numerous reasons informing our choices. However, there are three specific factors that were central to my agreeing to take this on.  First, and foremost, I am passionate about the theme.  Secondly, I have personally benefited from the work of the Cabot Institute, and as such I feel a responsibility to contribute back to the research institute.  Finally, while I have always seen value in interdisciplinarity, my own research on disasters has convinced me of the fundamental importance in increasing the ties between academic disciplines.  I should add as well that I would not have agreed to take on this role if I didn’t enjoy the people I am able to work with.

In your opinion, what is one of the biggest global challenges associated with your theme?

There are a multitude, and identifying one is difficult.  The nature of our area of focus, on natural hazards and disasters, means that we are dealing with the complex interface between geophysical processes, a changing climate, and societies.  Work across the working group relates to everything from seeking to better understand the science behind natural hazards, to how we can better design and maintain physical infrastructure, to how states and communities can reduce the potential impact of hazards.  However, if I have to pick one specific global challenge, it is how we can ensure that development can take place in a way that reduces vulnerabilities in a way that privileges the local voices in these paramount policy decisions.

As we are looking into the future, what longer term projects are there in your theme?

In a way that longer term projects that we will be undertaking in the years to come are no different from the ones in which we are currently engaged.  However, the impact of climate change is going to make the importance of these issues all the more acute.  So, we will be exploring in greater depth the intersectionality of vulnerabilities to disasters, expanding our geographic focus, and seeking further interdisciplinary approaches to these questions.

We have a number of ongoing research projects across Bristol, and I will note a few here:

Tomorrow’s Cities – The University of Bristol has a central role in this Global Challenges Research Fund (GCRF) Hub project, which is working with partners in Istanbul, Nairobi, Kathmandu, and Quito. The aim is to better understand disaster risk in the rapidly urbanising environment with the aim to ensure that future city development is resilient and addresses underlying drivers of disaster risk.

UK Flood Impacts project – This project is seeking to produce more accurate projections of the nature of UK flood risk which is crucial to ensure that policy decisions on mitigation, adaptation and development are fit for purpose.

Helping East Africa get Earthquake-Ready – focused on the East African Rift, this project is seeking to develop usable risk assessment tools to assist Malawi in disaster preparedness.  The project will also work with local authorities to co-produce planning guidelines to ensure development is resilient. A new statistical tool is being developed to help identify and help the most vulnerable sectors of society within disaster effected states.

Across the portfolio of projects in your theme, what type of institutions are you working with? (For example, governments, NGO’s)

The work that has been taking place within the hub has been extraordinary in the breadth of partners involved in the activities.  Crucially, the work is not only about targeting and helping states and communities, but it is motivated by a drive to empower communities and governments in alleviating disaster risk.  This means that the range of partners are actively involved in the entire life cycle of projects, from the identification of problems, co-designing research projects, the collection, interpretation and writing up of research, and the development and implementation of policy.  We actively work with local communities, social movements, and Non-Governmental Organizations (both local and international), all levels of Government, as well as regional and international organizations.

Please can you give some examples and state the relevant project

Tomorrow’s Cities is an exemplar here, where we are partners include community groups and formal NGOs in Quito, academics at FLACSO, the Instituto Geofisico, local and city level government representatives, and professional bodies representing engineers.  Without bringing all of these actors together we would not be able to fully appreciate the complexity of the problems, let alone develop and implement effective policies to reduce disaster risk.

What disciplines are currently represented within your theme?

We have been drawing on a broad range of disciplines, including Economics, Modern Languages, Sociology, Politics, Law, History, Civil Engineering, Geography, and the Earth Sciences.

In your opinion, why is it important to highlight interdisciplinary research both in general and here at Bristol?

The only way to redress the complex problems posed by natural hazards, is by bringing together the skills and expertise across the breadth of academia.  We can not bring about positive change by working in silos, and interdisciplinarity, while sometimes difficult, is fundamental.  We all come at the problems with different perspectives, tools and indeed language.  But we are all working for the same common ideal, of improving the lives of people, of reducing disaster risk, and doing so in a way that is empowering and sustainable.

Are there any projects which are currently underway in your theme which are interdisciplinary that you believe should be highlighted in this campaign?

All of our projects are interdisciplinary to one degree or another.  To highlight one in this respect is very difficult.  I suppose, if pushed, I would point to the work of the Tomorrow’s Cities team.  I would also like to highlight a previous project, BRACE, which was innovative in its integration of history, seismology, education, and engineering in a focused project seeking to increase resilience to Earthquakes in Bhutan.

Is there anything else you would like to mention about your theme, interdisciplinary research and working as part of Cabot Institute?

As with other working groups, our activities crosscut the breadth of Cabot and drawing lines between this working group and others is exceptionally difficult.  Cabot has been a fantastic catalyst to our work, and it is likely that little of these endeavours would have been possible without the support of the research institute.

For more information, visit Natural Hazards and Disaster Risk.

Canada’s flood havoc after summer heatwave shows how climate disasters combine to do extra damage

Posted on by janet.crompton

People living in British Columbia will feel like they have had more than their fair share of climate disasters in 2021. After a record-breaking heatwave in June, the state in western Canada has been inundated by intense rain storms in November. It’s also likely the long-lasting effects of the heatwave made the results of the recent rainfall worse, causing more landslides – which have destroyed highways and railroads – than would otherwise have happened.

In June 2021, temperature records across western North America were shattered. The town of Lytton in British Columbia registered 49.6°C, breaking the previous Canadian national record by 5°C. The unprecedented weather was caused by a high pressure system, a so-called “heat dome”, which sat over the region for several days.

Heat intensified within the dome as the high pressure compressed the air. Dry ground conditions forced temperatures even higher, as there was less water evaporating to cool things down. Although unconfirmed, it’s estimated that the heatwave caused over 400 deaths in British Columbia alone.

A helicopter flies over a burning pine forest beneath a blue sky.
Wildfires ravaged British Columbia during the hot and dry summer of 2021.
EB Adventure Photography/Shutterstock

The hot and dry weather also sparked wildfires. Just days after recording the hottest national temperature ever, the town of Lytton burned to the ground. The summer’s fires and drought left the ground charred and barren, incapable of absorbing water. These conditions make landslides more likely, as damaged tree roots can no longer hold soil in place. It also ensures water flows over the soil quicker, as it cannot soak into the baked ground.

The huge rain storm which lasted from Saturday November 13 to Monday 15 was caused by an atmospheric river – a long, narrow, band of moisture in the atmosphere stretching hundreds of miles. When this band travels over land it can generate extreme rainfall, and it did: in 48 hours, over 250mm of rain fell in the town of Hope, 100km east of Vancouver.

This much rainfall on its own would probably cause extensive flooding. But combined with the parched soil, the results have been catastrophic. Landslides have destroyed many of the region’s transport links, leaving Vancouver cut off by rail and road. But the bad news doesn’t end there; sediment washed away by these floods could make future floods this winter even worse.

British Columbia is in the grip of what scientists call a compound climate disaster. The effects of one extreme weather event, like a heatwave, amplify the effects of the next one, like a rain storm. Instead of seeing floods and wildfires as discrete events, compound disasters force us to comprehend the cascading crises which are likely to multiply as the planet warms.

How to understand compound climate disasters

The port of Vancouver is the busiest in Canada, moving US$550 million worth of cargo every day. Because rail links are damaged, ships laden with commodities sit offshore. Canada’s mining and farming industries are having to divert exports through the US. Depending on how quickly the rail links recover, significant economic impacts are possible.

Both the June heatwave and the November rainstorm are unprecedented, record-breaking events, but is their occurrence in the same year just bad luck? A rapid attribution study found that the heatwave was virtually impossible without climate change. The atmospheric river which brought the deluge is also likely to become more common and intense in a warming climate.

In British Columbia, future flooding is almost guaranteed to be more frequent and severe. This is life at 1.2°C above the pre-industrial temperature average, yet most politicians don’t seem too worried about taking the necessary action to prevent warming beyond 1.5°C – the limit which countries agreed in 2015 is a threshold beyond which catastrophic climate change becomes more likely.

Western Canada’s year of weather extremes did not come from nowhere. Past trends and future projections tell us to expect hotter summers and wetter winters in this part of the world, and record-shattering climate extremes are on the rise.

Worldwide, compound climate disasters are becoming more common as climate change accelerates. Risk assessments typically measure the impacts of one event at a time, like the damage caused by intense rain storms, without considering how the earlier drought influenced it. This leads to scientists and insurers underestimating the overall damage. With so many combinations of climate extremes – flooding following wildfires, hurricanes passing as cold spells arrive – we must prepare for every possibility.The Conversation

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This blog is written by Cabot Institute for the Environment member Dr Vikki Thompson, Senior Research Associate in Geographical Sciences, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Vikki Thompson
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