climate crisis – Page 2 – Cabot Institute for the Environment blog

Life in the deep freeze – the revolution that changed our view of glaciers forever

Posted on May 18, 2021March 30, 2023 by janet.crompton

I’ve been fascinated by glaciers since I was 14, when geography textbooks taught me about strange rivers of ice that crept down yawning valleys like giant serpents stalking their next meal. That kernel of wonder has carried me through a career of more than 25 years. I’ve travelled to the world’s peaks and its poles to see over 20 glaciers. Yet, when I first started out as a researcher in the early 1990s, we were convinced glaciers were lifeless deserts.

Then in 1999, Professor Martin Sharp and colleagues discovered bacteria living beneath the Haut Glacier d’Arolla in Switzerland. It seemed that glaciers, like the soil or our stomachs, had their own community of microbes, their own microbiome. Since then, we’ve found microorganisms just about everywhere within glaciers, transforming what we thought were sterile wastelands into vibrant ecosystems.

So what’s all that glacier life doing? These life forms may be invisible to the naked eye, but they can control how fast glaciers melt – and may even influence the global climate.

The glacier microbiome

Just like people, glacier microbes modify their homes. When I first saw the melting fringes of Greenland’s vast ice sheet, it looked as if a dust storm had scattered a vast blanket of dirt on the ice. Our team later discovered the dirt included extensive mats of glacier algae. These microscopic plant-like organisms contain pigments to help them harvest the Sun’s rays and protect them from harsh UV radiation. By coating the melting ice surface, they darken it, ensuring the ice absorbs more sunlight which causes more of it to melt. In western Greenland, more than 10% of the summer ice melt is caused by algae.

Bright blue glacier ice on rocky terrain. — The margin of Engabreen glacier, Norway.
Grzegorz Lis, Author provided

Again, just like us, microbes extract things from their environment to survive. The murky depths of glaciers are among the most challenging habitats for life on Earth. Microbes called chemolithotrophs – from the Greek meaning “eaters of rock” – survive here without light and get their energy from breaking down rock, releasing vital nutrients like iron, phosphorous and silicon to the meltwater.

Rivers and icebergs carry these nutrients to the ocean where they sustain the plant-like phytoplankton – the base of marine food webs which ultimately feed entire ecosystems, from microscopic animals, to fish and even whales. Models and satellite observations show a lot of the photosynthesis in the iron-starved Southern Ocean could be sustained by rusty icebergs and meltwaters, which contain iron unlocked by glacier microbes. Recent evidence suggests something similar occurs off west and east Greenland too.

A microscope image depicting chains of brown rectangular cells. — Glacier algae from the Greenland ice sheet.
Chris Williamson, Author provided

But glacier bugs also produce waste, the most worrying of which is the greenhouse gas methane. When ice sheets grow, they bury old soils and sediments, all sources of carbon and the building blocks for earthly life. We think there could be thousands of billions of tonnes of carbon buried beneath ice sheets – potentially more than Arctic permafrost. But who can use it in the oxygen-starved belly of an ice sheet? One type of microbe that flourishes here is the methanogen (meaning “methane maker”), which also thrives in landfill sites and rice paddies.

A waterfall at the edge of a glacier. — Leverett Glacier’s wild river, Greenland.
Jemma Wadham, Author provided

Some methane produced by methanogens escapes in meltwaters flowing from the ice sheet edges. The clever thing about microbial communities, though, is that one microbe’s waste is another’s food. We humans could learn a lot from them about recycling. Some methane beneath glaciers is consumed by bacteria called methanotrophs (methane eaters) which generate energy by converting it to carbon dioxide. They have been detected in Greenlandic glaciers, but most notably in Lake Whillans beneath the West Antarctic Ice Sheet. Here, bacteria have years to chomp on the gas, and almost all of the methane produced in the lake is eaten – a good thing for the climate, since carbon dioxide is 80 times less potent as a greenhouse gas when measured over two decades.

We’re not sure this happens everywhere though. Fast-flowing rivers emerging from the Greenland Ice Sheet are super-saturated with microbial methane because there just isn’t enough time for the methanotrophs to get to work. Will melting glaciers release stored methane faster than these bacteria can convert it?

Within the thick interior of ice sheets, scientists worry that there may be vast reserves of methane. The cold and high pressure here mean that it may be trapped in its solid form, methane hydrate (or clathrate), which is stable unless the ice retreats and thins. It happened before and it could happen again.

Waking the sleeping giant

Despite the climate crisis, when I spend time around glaciers I’m not surprised by their continuing vitality. As I amble up to the gently sloping snout of a glacier – traversing its rubbly lunar-like fore-fields – I often feel like I’m approaching the hulk of an enormous creature. Sleeping or seemingly dormant, the evidence of its last meal is clear from the mass of tawny-coloured rocks, pebbles and boulders strewn around its edges – a tantalising record of where it once rested when the climate was cooler.

As I get closer, I catch the sound of the glacier’s roaring chocolate meltwaters as they explode through an ice cave, punctuated by a cascade of bangs and booms as moving ice collapses into hollow melt channels below. The winds off the ice play ominously in my ears, like the whisper of the beast, a warning: “You’re on my land now.”

The author inside a giant icy chasm within a glacier. — Exploring a frozen melt channel of the Finsterwalderbeeen glacier in Svalbard.
Jon Ove Hagen, Author provided

This sense of aliveness with glaciers changes everything. Resident microbes connect these hulking frozen masses with the Earth’s carbon cycle, ecosystems and climate. How will these connections change if we take away the frigid homes of our tiny glacier dwellers? These creatures may be microscopic, but the effects of their industry span entire continents and oceans.

After a period of uncertainty in my own life, which involved the removal of a satsuma-sized growth in my brain, I felt compelled to tell the story of glaciers to a wider audience. My book, Ice Rivers, is the result. I hope the memoir raises awareness of the dramatic changes that threaten glaciers – unless we act now.

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This blog is written by Cabot Institute for the Environment Director Jemma Wadham, Professor of Glaciology, University of Bristol.

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

Professor Jemma Wadham

Learning lessons from the past to inform the future

Posted on August 24, 2020April 4, 2023 by janet.crompton

A fairly recent blog post on the EGU blog site reiterated the compelling comparison between the current COVID-19 crisis and the ongoing climate emergency, focusing on extreme events such as hurricanes, heatwaves and severe rainfall-related flooding, all of which are likely to get worse as the climate warms (Langendijk & Osman 2020). This comparison has been made by us Climate Scientists since the COVID-19 crisis began; both the virus and the disastrous impacts of anthropogenic climate change were (and indeed are) predictable but little was done in the ways of preparedness, both were (and are still being) underestimated by those in power despite warnings from science, and both are global in extent and therefore require united action. Another comparison is that both are being intensively, and urgently, researched across the world by many centres of excellence. We don’t have all the answers yet for either, but progress is being made on both.

When it comes to understanding our climate, there are several approaches; these are, of course, not mutually exclusive. We can focus on present-day climate variability, to understand the physical mechanisms behind our current climate; examples include, but are not limited to, ocean-atmosphere interactions, land-atmosphere feedbacks, or extreme events (see Williams et al. 2008, Williams & Kniveton 2012 or Williams et al. 2012, as well as work from many others).

Alternatively, we can use our current understanding of the physical mechanisms driving current climate to make projections of the future, either globally or regionally. State-of-the-art General Circulation Models (GCMs) can provide projections of future climate under various scenarios of socio-economic development, including but not limited to greenhouse gas (GHG) emissions (Williams 2017).

A third approach is to focus on climates during the deep (i.e. geological) past, using tools to determine past climate such as ice cores, tree rings and carbon dating. Unlike the historical period, which usually includes the past in which there are human observations or documents, the deep past usually refers to the prehistoric era and includes timescales ranging from thousands of years ago (ka) to millions of years ago (Ma). Understanding past climate changes and mechanisms is highly important in improving our projections of possible future climate change (e.g. Haywood et al. 2016, Otto-Bliesner et al. 2017, Kageyama et al. 2018, and many others).

One reason for looking at the deep past is that it provides an opportunity to use our GCMs to simulate climate scenarios very different to today, and compare these to scenarios based on past.

These days I am primarily focusing on the latter approach, and am involved in almost all of the palaeoclimate scenarios coming out of UK’s physical climate model, called HadGEM3-GC3.1. These focus on different times in the past, such as the mid-Holocene (MH, ~6 ka), the Last Glacial Maximum (LGM, ~26.5 ka), the Last Interglacial (LIG, ~127 ka), the mid-Pliocene Warm Period (Pliocene, ~3.3 Ma) and the Early Eocene Climate Optimum / Paleocene-Eocene Thermal Maximum (EECO / PETM, collectively referred to here as the Eocene, ~50-55 Ma). All of these have been (or are being) conducted under the auspices of the 6th phase of the Coupled Modelling Intercomparison Project (CMIP6) and 4th phase of the Palaeoclimate Modelling Intercomparison Project (PMIP4).

Figure 1: Calendar adjusted 1.5 m air temperature climatology differences, mid-Holocene and last interglacial simulations from the UK’s physical climate model, relative to the preindustrial era: a-c) mid Holocene – preindustrial; d-f) last interglacial – preindustrial. Top row: Annual; Middle row: Northern Hemisphere summer (June-August); Bottom row: Northern Hemisphere winter (December-February). Stippling shows statistical significance (as calculated by a Student’s T-test) at the 99% level. Taken from Williams et al. (2020).

These five periods are of particular interest to the above projects for a number of different reasons. Before these are discussed, however, the fundamentals of deep past climate change need to be briefly introduced. In short, climate changes in the geological past (i.e. without human influence) can either be internal to the planet (e.g. volcanic eruptions, oceanic CO2 release) or external to the planet (e.g. changes in the Earth’s orbit around the Sun). Arguably, it is changes to the amount of incoming solar radiation (known as insolation) that is the primary driver behind all long-term climate change. Theories for long-term climate change, such as the beginning and ending of ice ages, began to be proposed during the 1800s. However, it wasn’t until 1913 that the Serbian mathematician, Milutin Milankovitch, developed our modern day understanding of glacial cycles. In short, Milankovitch identified three interacting cycles concerning the Earth’s position relative to the Sun: a) Eccentricity, in which the Earth’s orbit around the Sun changes from being more or less circular on a period of 100-400 ka; b) Obliquity, in which the Earth’s axis changes from being more or less tilted towards the Sun on a period of ~41 ka; and c) Precession, in which the Earth’s polar regions appear to ‘wobble’ around the axis (like a spinning top coming to its end) on a period of ~19-24 ka. All of these three cycles not only change the overall amount of insolation received by the planet, and therefore its average temperature, but also where the most energy is received; this ultimately determines the strength and timing of our seasons.

With this background in mind, and returning to the paleoclimate scenarios mentioned above, the MH and the LIG collectively represent a ‘warm climate’ state. During these periods the Earth’s axis was tilted slightly more towards the Sun, resulting in an increase in Northern Hemisphere insolation (because of the larger landmasses here relative to the Southern Hemisphere). This caused much warmer Northern Hemisphere summers and enhanced African, Asian and South American monsoons (Kageyama et al. 2018). The increase in temperatures can be seen in Figure 1, where clearly the largest increases relative to the preindustrial era (PI) are in the Northern Hemisphere during June-August (Williams et al. 2020). By comparing model simulations to palaeoclimate reconstructions during these periods, the models’ ability to simulate these climates can be tested and this therefore assesses our confidence in future projections of climate change; which, as mentioned above, may result in more rainfall extremes and enhanced monsoons.

In contrast, the LGM represents a ‘cold climate’ state which, although unlikely to return as a result of increasing anthropogenic GHG emissions, nevertheless provides a well-documented climatic period during which to test the models. Going back further in time, the Pliocene is the most recent time in the geological past when CO2 levels were roughly equivalent to today, and was a time when global annual mean temperatures were 1.8-3.6°C higher than today (Haywood et al. 2016). See Figure 2 for the increases in sea surface temperature (SST) during the Pliocene, relative to today. This annual mean temperature increase is clearly much higher than the current target, as specified by the Paris Agreement, of keeping warming below 1.5°C (at most 2°C) by the end of 2100. Importantly, the CO2 increases and subsequent warming during the Pliocene occurred over timescales of thousands to millions of years, whereas anthropogenic GHG emissions have caused a similar increase in CO2 (from ~280 parts per million (ppmv) during the PI to just over 400 ppmv today) in under 300 years. The Pliocene, therefore, provides an excellent analogy for what our climate might be like in the (possibly near) future.

Finally, going back even further, the Eocene is the most recent time in the past that was characterised by very high CO2 concentrations, twice or more than that of today at >800-1000 ppmv; this resulted in temperatures ~5°C higher than today in the tropics and ~20°C higher than today at high latitudes (Lunt et al. 2012, Lunt et al. 2017). The reason the Eocene is highly relevant, and of concern, is that these CO2 concentrations are roughly equivalent to those projected to occur by the end of 2100, if the Representative Concentration Pathway (RCP) 8.5 scenario, also known as the ‘Business-as-usual’ scenario, which was used in the most recent IPCC report (IPCC 2014), becomes reality. The Eocene, therefore, provides an excellent albeit concerning analogy for what the worse-case scenario could be like in the future, if action is not taken.

Figure 2: 1.5 m air temperature climatology differences, Pliocene simulation from the UK’s physical climate model, relative to the preindustrial era.

Understanding the climate, how it has changed in the past and how it might change in the future is a complex task and subject to various interrelated approaches. One of these approaches, the concept of using the past to inform the future (e.g. Braconnot et al. 2011), has been described here. Just like in the case of COVID-19, it is our responsibility as Climate Scientists to work together across approaches and disciplines, as well as reliably communicating the science to governments, policymakers and the general public, in order to mitigate the crisis as much as possible.

References

Braconnot, P., Harrison, S. P., Otto-Bliesner, B, et al. (2011). ‘The palaeoclimate modelling intercomparison project contribution to CMIP5’. CLIVAR Exchanges Newsletter. 56: 15-19

Haywood, A. M., Dowsett, H. J., Dolan, A. M. et al. (2016). ‘The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: scientific objectives and experimental design’. Climate of the Past. 12: 663-675

IPCC (2014). ‘Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change’ [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC. Geneva, Switzerland, 151 pp

Kageyama, M., Braconnot, P., Harrison, S. P. et al. (2018). ‘The PMIP4 contribution to CMIP6 – Part 1: Overview and over-arching analysis plan’. Geoscientific Model Development. 11: 1033-1057

Langendijk, G. S. & Osman, M. (2020). ‘Hurricane COVID-19: What can COVID-19 tell us about tackling climate change?’. EGU Blogs: Climate. https://blogs.egu.eu/divisions/cl/2020/04/16/corona-2/. Accessed 24/7/20

Lunt, D. J., Dunkley-Jones, T., Heinemann, M. et al. (2012). ‘A model–data comparison for a multi-model ensemble of early Eocene atmosphere–ocean simulations: EoMIP’. Climate of the Past. 8: 1717-1736

Lunt, D. J., Huber, M., Anagnostou, E. et al. (2017). ‘The DeepMIP contribution to PMIP4: experimental design for model simulations of the EECO, PETM, and pre-PETM (version 1.0)’. Geoscientific Model Development. 10: 889-901

Otto-Bliesner, B. L., Braconnot, P., Harrison, S. P. et al. (2017). ‘The PMIP4 contribution to CMIP6 – Part 2: Two interglacials, scientific objective and experimental design for Holocene and Last Interglacial simulations’. Geoscientific Model Development. 10: 3979-4003

Williams, C. J. R., Kniveton, D. R. & Layberry, R. (2008). ‘Influence of South Atlantic sea surface temperatures on rainfall variability and extremes over southern Africa’. Journal of Climate. 21: 6498-6520

Williams, C. J. R., Allan, R. P. & Kniveton, D. R. (2012). ‘Diagnosing atmosphere-land feedbacks in CMIP5 climate models’. Environmental Research Letters. 7 (4)

Williams, C. J. R. & Kniveton, D. R. (2012). ‘Atmosphere-land surface interactions and their influence on extreme rainfall and potential abrupt climate change over southern Africa’. Climatic Change. 112 (3-4): 981-996

Williams, C. J. R. (2017). ‘Climate change in Chile: an analysis of state-of-the-art observations, satellite-derived estimates and climate model simulations’. Journal of Earth Science & Climatic Change. 8 (5): 1-11

Williams, C. J. R., Guarino, M-V., Capron, E. (2020). ‘CMIP6/PMIP4 simulations of the mid-Holocene and Last Interglacial using HadGEM3: comparison to the pre-industrial era, previous model versions, and proxy data’. Climate of the Past. Accepted

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This blog was written by Cabot Institute member Dr Charles Williams, a climate scientist within the School of Geographical Sciences, University of Bristol. His research focusses on deep time to understand how climate has behaved in the warmer worlds experienced during the early Eocene and mid-Pliocene (ca. 50 – 3 Mio years ago). This blog was reposted with kind permission from Charles. View the original blog on the EGU blog site.

Dr Charles Williams

Coronavirus: have we already missed the opportunity to build a better world?

Posted on August 17, 2020April 4, 2023 by janet.crompton

Many people like to say that the coronavirus is teaching us a lesson, as if the pandemic were a kind of morality play that should lead to a change in our behaviour. It shows us that we can make big shifts quickly if we want to. That we can build back better. That social inequality is starkly revealed at times of crisis. That there is a “magic money tree”. The idea that crisis leads to change was also common during the financial crunch over a decade ago, but that didn’t produce any lasting transformations. So will post-COVID life be any different?

At the start of lockdown, in the middle of the anxiety and confusion, I started to notice that I was enjoying myself. I was cooking and gardening more; the air was cleaner, my city was quieter and I was spending more time with my partner. Lots of people started to write about the idea that there should be #NoGoingBack. It seemed that we had taken a deep collective breath, and then started to think about coronavirus as a stimulus to encourage us to think how we might address other big issues – climate, inequality, racism and so on.

Being an academic, I decided to put together a quick and dirty book on what life might look like after the crisis. I persuaded various activists and academics to write short pieces on working at home, money, leadership and lots of other topics. The idea was to show that the world could change if we wanted it to. The book is out now, but it already feels, only four months after I imagined it, like the document of a lost time. The city noises are back, and jet trails are beginning to scar the sky. Has the moment been lost?

The second lesson of coronavirus, it seems, is just how stubborn the old structures are. Wanting the world to be different does not translate into making it so. Slogans do not produce change when power, habits and infrastructure remain substantially the same. So what can we learn now about crisis and making enduring change?

Aerial view of beach with sun umbrellas. — Getting back to ‘normal’.
Alex Blăjan/Unsplash, FAL

Think about holidays in Spain and Portugal. Sunny beaches, cold drinks and cheap food. For many people, getting back to normal means going back to what they had before, and they don’t want to hear some killjoy – whether a head of state or spokesperson for Extinction Rebellion, telling them that they can’t have it. To add to the problem, there are thousands of jobs at stake in the various industries that take people on holiday – manufacturing and servicing planes, working in airports and hotels, selling duty free, aviation fuel and tourist special lunches.

The world that we live in now has a kind of stickiness to it, both in terms of the expectations of people and the infrastructure that already exists and that reinforces those expectations. The pre-COVID world was sculpted by flows of money and trade, motorways and shipping containers. As we gradually begin to stir from lockdown, these channels are already waiting, ready to be refilled with people and things.

In the social sciences, people often refer to “path dependency”, the idea that our history constrains our present choices. If we have cities that are organised around large numbers of people commuting into the centre, or houses and flats that don’t have workspaces, then it is going to be difficult for large numbers of people to work at home. If you have to park your car on the street, then charging an electric one means running a cable on the pavement. If our pensions funds rely on oil companies making huge profits, then encouraging investment in green technologies is going to be an uphill struggle.

Wind turbines on a green hillside. — A hill we need to climb.
Appolinary Kalashnikova/Unsplash, FAL

No wonder then that it is easier for most people to assume that the future will be like the past because the shape of the present limits how we can think about things to come. This is what worries me most about my book. I think it might be pushing against a door that is already closing. And the people who are pushing it are not stupid or evil, just politicians, businesses and ordinary people who all want to go back to what they had.

If lesson one of coronavirus is that things can change, and lesson two is that they easily slip back again, then lesson three must be about the importance of presenting images of the future that motivate people to imagine change. It is clear that we can’t carry on as we are and need to stop doing things that we were doing, but just saying that is a really bad way to encourage people to change.

Instead, we need to imagine futures which are just as exciting and fulfilling as the high speed, high consumption, high carbon ones we must leave behind. We need to give people good reasons to jump the tracks because it is much easier just to slide back to what you know. So let’s imagine the city quieter, and the air cleaner, less need to fight with traffic jams and more time to spend with family and friends. That seems like a good start to learning from COVID-19.

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This blog was written by Martin Parker, Professor of Organisation Studies, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Martin Parker

Innovating for sustainable oceans

Posted on June 5, 2020March 31, 2023 by janet.crompton

University of Bristol’s Cabot Institute researchers come together for the oceans’ critical decade

World Oceans Day 2020 – the start of something big

Since 1992, World Oceans Day has been bringing communities and countries together on 8 June to shine a light on the benefits we derive from – and the threats faced by – our oceans. But this year, there’s an even bigger event on the horizon. One that may go a long way to determining our planet’s future, and which researchers at the Cabot Institute for the Environment intend to be an integral part of.

From next year, the United Nations launches its Decade of Ocean Science for Sustainable Development, a major new initiative that aims to “support efforts to reverse the cycle of decline in ocean health”.

Oceans are of enormous importance to humans and all life on our planet – they regulate our climate, provide food, help us breathe and support worldwide economies. They absorb 50 times more carbon dioxide than our atmosphere, and sea-dwelling phytoplankton alone produce at least half the world’s oxygen. The OECD estimates that three billion people, mostly in developing countries, rely on the oceans for their livelihoods and that by the end of the decade, ocean-based industry, including fishing, tourism and offshore wind, may be worth $3 trillion of added economic value.

A decade to decide the future of our oceans

But ocean health is ailing. The first World Ocean Assessment in 2016 underlined the extent of the damaging breakdown of systems vital to life on Earth. As the human population speeds towards nine billion and the effects of our global climate crisis and other environmental stressors take hold, “Adaptation strategies and science-informed policy responses to global [ocean] change are urgently needed,” states the UN.

By announcing a Decade of Ocean Science, the UN recognises the pressing need for researchers everywhere and from all backgrounds to come together and deliver the evidence base and solutions that will tackle these urgent ocean challenges. At the Cabot Institute, we kicked off our support for that vision a year early by holding our first Ocean’s Workshop.

Cabot Institute Ocean’s Workshop – seeing things differently

From our diverse community of hundreds of experts seeking to protect the environment and identify ways of living better with our changing planet, we brought together researchers from a wide range of specialisms to explore how we might confront the challenges of the coming decades. The University of Bristol has recently appointed new experts in geographical, biological and earth sciences, as well as environmental humanities, who are experienced in ocean study, so, excitingly, we had a pool of new, untapped Caboteers to connect with.

During a fast-paced and far-reaching workshop, we shared insights and ideas and initiated some potentially highly valuable journeys together.

Biogeochemists helped us consider the importance of the oceans’ delicately balanced nutrient cycle that influences everything from ecosystems to the atmosphere, biologists shared their work on invertebrate vision and the impact of anthropogenic noise on dolphins and other species, and literature scholars helped us understand how the cultural significance and documentation of the oceans has evolved throughout history, altering our relationship with the seas.

We highlighted how Marine Protected Areas (MPAs) deliver mixed results based on regional differences and outdated assumptions – individual MPAs are siloed, rarely part of a more holistic strategy, and rely on data from the 1980s which fail to account for much faster-than-predicted changes to our oceans since then. Our ocean modellers noted the lack of reliable, consistent and joined-up observational data on which to base their work, as well as the limitations of only being able to model the top layers of the ocean, leaving the vast depths beneath largely unexplored. And the fruitful link between biological and geographical sciences was starkly apparent – scientists measuring the chemical composition of oceans can collaborate with biologists who have specialist knowledge about species tipping points, for example, to mitigate and prioritise society’s responses to a variety of environmental stressors.

Collaboration creates innovation

One overriding message arose again and again though – the power of many, diverse minds coming together in a single mission to engage in pioneering, solutions-focused research for our oceans. Whether it’s the need for ocean scientists to work more closely with the social scientists who co-create with coastal communities or the interdisciplinary thinking that can resolve maritime noise and light pollution, protecting our oceans requires us to operate in more joined-up ways. It is the work we conduct at this intersection that will throw new light on established and emerging problems. We can already see so many opportunities to dive into.

So, as we celebrate World Oceans Day and look ahead to a critical Decade of Ocean Science, it’s our intention to keep connecting inspiring people and innovative ideas from many seemingly disparate disciplines and to keep doing so in a way that delivers the research we need for the oceans we want.

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This blog was written by Chris Parsons on behalf of the Oceans Research Group at the Cabot Institute for the Environment.

Climate change displacement: a step closer to human rights protection

Posted on March 17, 2020April 13, 2023 by janet.crompton

On 20th January this year the United Nations Human Rights Committee released a landmark decision on people seeking international protection due to the effects of climate change. The decision did not include specific guidance as to where the tipping point lies, but it nevertheless remains highly relevant to future similar potential cases around the world.

The case and the plot twist

The case deals with the individual communication made by Ioane Teitiota, a national from the South Pacific country of Kiribati, under the Optional Protocol to the International Covenant on Civil and Political Rights (ICCPR). Based on this Protocol, he claimed that New Zealand had violated his right to life by rejecting his request for refugee status and returning him and his family home in 2015.

Flooded sea wall by a village on Tarawa, Kiribati (UN)

Teitiota argued in his case that the effects of climate change, such as sea-level rise, had forced him to migrate from Tarawa (the principle island in Kiribati) to New Zealand. He claimed that freshwater on Tarawa had become scarce due to salinization and that eroded inhabitable lands had resulted in not only a housing crisis but also land disputes. These, combined with social-political instability, created a dangerous environment for him and his family.

New Zealand’s judicial system did not find evidence that Teitiota had been involved in a land dispute or that he faced a real chance of being harmed in this context – that he was unable to grow food, find accommodation or access to potable water; that he faced life-threatening environmental conditions; and that his situation was materially different from other residents of Kiribati.

The Human Rights Committee supported the decision adopted by New Zealand and rejected almost all arguments brought by Teitiota. However, it specifically acknowledged that “without robust national and international efforts, the effects of climate change in receiving states may expose individuals to a violation of their rights under Article 6 or 7 of the Covenant, thereby triggering the non-refoulement obligations of sending states […] given that the risk of an entire country becoming submerged under the water is such an extreme risk, the conditions of life in such country may become incompatible with the right to life with dignity before the risk is realized.” (Parag. 9.11)

This paragraph has caught international attention. To be clear, the Committee is not expressly banning the return home of someone requesting international protection due to the impacts of climate change. But it indicates that states, individually and/or collectively, could be prohibited from sending people back to life-threatening conditions if they don’t cooperate to tackle the adverse effects of climate change in those countries. If the conditions in those countries are not thoroughly analyzed before discarding risk, they could breach the powerful international obligation of non-refoulement.

Landmark decision or a passing storm?

Despite delivering an important message, the Human Rights Committee ruling does not provide explicit guidance for its implementation. Nevertheless, assumptions can be extracted from the document that shed light on its relevance and growing significance.

To begin with, it is the first-ever ruling adopted by a UN Committee regarding the claim of a person seeking refuge due to climate change. It also reinforces the idea that environmental degradation, climate change and unsustainable development can compromise effective enjoyment of the right to life, as stated previously in the General Comment No. 36 and the case of Portillo Cáceres et al. v. Paraguay.

Furthermore, despite not being legally binding, the decision is based on international legal obligations assumed by the 172 States Parties to the ICCPR, and almost 106 States Parties to the Optional Protocol. The latter allows individual claims against the ICCPR such as Teitiota’s.

Contrary to media reports, such as those by CNN and The Guardian, the Human Rights Committee did not address Teitiota as a climate refugee. Instead it considered him a person under the protection of the ICCPR whose life could be at risk of being exposed to cruel, inhuman or degrading treatment due to the impacts of climate change. This means that the Committee´s examination was based on factors and standards intended to consider if there was a threat to Teitiota’s life in Kiribati from the perspective of International Human Rights Law, which is wider and more inclusive than that of International Refugee Law.

Sandbags attempt to prevent village huts flooding on Tarawa, Kiribati (Brad Hinton)

The Committee established that individuals seeking refugee status are not required to prove that they would face imminent harm if returned to their countries, implicitly relaxing the probatory standard required for pursuing international protection under a human rights scope. It argued that individuals could be pushed to cross borders looking for protection from climate change-related harm, caused not only by sudden-onset events but also slow-onset processes (Parag. 9.11).

The Human Rights Committee has continually raised the standard of states’ analyses of protection requests. In this ruling, it recognised that New Zealand’s courts carried out a careful and in-depth examination of both Kiribati’s and Teitiota’s situations before proceeding to deport him. But alongside this it highlighted factors that must be considered in future similar cases: for example, the prevailing conditions in the person’s country of origin; the foreseeable risks; the time left for authorities and the international community to intervene; and the efforts already underway (Parag. 9.13).

In this way, the Committee’s ruling represents a significant step forward. It has established new standards that may lead to the eventual international protection of people impacted by climate change. From now on, states should examine in detail the climatic and environmental conditions of a migrant’s country of origin under the possibility of breaching the non-refoulement obligation. As the former UN Special Rapporteur on human rights and the environment, John Knox, said: “If the crisis continues to worsen, a similar case in a few years may reach a very different result.”

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This blog is written by Ignacio Odriozola, who is studying the MSc in Migration and Mobility Studies at the University of Bristol. He is a lawyer for the Universidad de Buenos Aires and a researcher for the South American Network for Environmental Migrations (RESAMA). This blog has been republished with kind permission from the Migration Mobilities Bristol. View the original blog.