climate – Cabot Institute for the Environment blog

Fresh reflection on COP 16 of the Convention on Biological Diversity

Posted on November 11, 2024December 9, 2024 by amanda.woodman-hardy

Margherita Pieraccini and Naomi Millner at COP16. Sat down and holding a block representing the SDGs, — Margherita Pieraccini and Naomi Millner at COP16.

As 2024 is drawing to a close, Conferences of the Parties (COPs) of three major Multilateral Environmental Agreements are happening in close succession: COP 16 of the Convention on Biological Diversity (CBD) was held between end of October and the beginning of November, COP 29 of the UN Convention on Climate Change (UNFCCC) is happening in mid-November, and COP 16 of the UN Convention to Combat Desertification will take place in early December.

Although exploring the synergies between these three COPs is of great importance and their close temporal proximity this year facilitates such discussion, I will focus solely on the CBD COP 16 as I had the opportunity to attend it in person as a University of Bristol academic observer.

CBD COP 16, held in Cali, Colombia started on the 21^st of October and was due to end on the 1^st of November. Negotiations overrun until the morning of the 2^nd of November but they were suspended as the quorum was lost, leaving discussions on some key issues such as the strategy for resource mobilization to be resumed at a later date.

As biodiversity COPs are held biannually, COP 16 was the first COP since the adoption of the Kunming-Montreal Global Biodiversity Framework (GBF) at COP 15 in 2022. No one was expecting the negotiation of another major agreement at COP 16, with the key issue being the implementation of the GBF framework.

An introduction to the GBF

Differently from the Paris Agreement under the UNFCCC, the GBF is not legally binding. Nevertheless, given that the boundary between binding and non-binding instruments in international environmental law is not always so clear-cut, the GBF has a central role in directing biodiversity law and policy. The GBF is a largely aspirational goal and target-oriented instrument. It contains four Goals to ‘live in harmony with nature’ by 2050 and 23 global Targets for 2030, split into three categories, namely ‘reducing threats to biodiversity’, ‘meeting people’s needs through sustainable use and benefit-sharing’ and ‘tools and solutions for implementation and mainstreaming’. The Targets have different degrees of ‘quantifiability’, impacting also on Parties’ strategies and methodologies of implementation.

For example, the well- known ‘30 by 30’ target (Target 3) sets the threshold of 30% of the coverage of protected areas and other effective area-based conservation measures (OECMs) in terrestrial and inland water areas as well as marine and coastal areas to be reached by 2030. In contrast, Target 5, which still falls within the first category of ‘reducing threats to biodiversity’, is framed using a more general language: ‘ensure that the use, harvesting and trade of wild species is sustainable, safe and legal, preventing overexploitation, minimizing impacts on non-target species and ecosystems, and reducing the risk of pathogen spillover, applying the ecosystem approach, while respecting and protecting customary sustainable use by indigenous peoples and local communities.’

There are not only differences between Targets but the wordings of individual Targets themselves is sometimes contradictory, making for complex implementation as conflicting directions are suggested. For example, Target 19 pushes for the marketisation of nature, encouraging the private sector to invest in biodiversity and employing uncritically the language of green bonds and payments for ecosystem services, whilst, at the same, promoting the role of ‘Mother Earth centric action and non-market approaches’. Even if not all targets are rife with internal contradictions, other internal differences may exist, with some objectives expressed in a qualitative rather than a quantitative manner or by reference to concepts that lack unified legal definitions. This makes it more difficult to devise specific indicators, with the consequence that Parties will likely concentrate on the objectives requiring easier interpretative skills. For example, going back to the ‘30 by 30’ Target 3, the quantitative component is followed by references to ‘equitably governed systems’, which could mean very different things to different regulatory actors and there is still much work to be done on the identification of OECMs.

It should be recalled that this is not the first time the CBD employs the language of Targets and Goals. Notably, the CBD Strategic Plan for Biodiversity 2011-2020 included the Aichi Biodiversity Targets structured around 5 strategic goals, though most were not achieved and few partially achieved, as reported in the Global Biodiversity Outlook 5. COP 16’s focus on implementation was therefore crucial to avoid historical failures repeating themselves in 2030.

The spaces and voices of COP 16

COPs are notoriously busy and chaotic events. COP 16 of the CBD did indeed feel busy, with many side events happening simultaneously and in parallel to the formal negotiations of the two Working Groups and plenaries, as well as press conferences and Pavilion events. It was also the largest-ever CBD COP with some 23,000 registered delegates. Yet, the Conference Centre that hosted COP 16 in Cali was very capacious and the horizontal disposition of the spaces facilitated inter-ethnic, inter-generational, inter-disciplinary and of course inter-jurisdictional discussions under a Colombian sky often veiled by clouds.

It was a pleasant surprise to witness the high representation of youth, as well as indigenous peoples and local communities advocating for their rights and the rights of nature, though one may wonder if this was primarily due to the fact that COP 16 was organised in South America where the question of who is indigenous and who is not is not as contested as in other continents (such as Africa) and where youth environmental activism is thriving.

Side events also saw the participation of a plurality of voices, hosting delegates from a myriad of Inter-governmental organisations (IGOs) and Non-Governmental Organisations (NGOs), as well as researchers, Secretariat members and sometimes Parties. Thus, cross-fertilisation of ideas dominated the Conference with the hope that points made in side events by activists, academics, and others could filter through Parties to the negotiation tables. Indeed, many times in side events speakers addressed the audience as if it were an audience entirely made up by Parties’ delegates (seldom the case in practice), encouraging it to report back to the contact groups, which are closed working groups attended by Parties discussing draft texts of decisions.

Human rights as a framing device for different world-makings

The language of human rights pervaded the whole COP 16. This is a recent turn for the CBD, considering that the CBD itself and its instruments pre-GBF do not explicitly refer to human rights. In contrast, the GBF lists among the considerations for the implementation of the Framework a ‘human rights-based approach’. Section C 7(g) states in full that ‘the implementation of the Framework should follow a human rights-based approach, respecting, protecting, promoting and fulfilling human rights. The Framework acknowledges the human right to a clean, healthy and sustainable environment’. There are a few other references to human rights language scattered in the text. For example, in Target 22, reference is made to the ‘full protection of environmental human rights defenders’. The GBF’s explicit inclusion of human rights language and also the acknowledgement of a substantive human right to a clean, healthy and sustainable environment—which cross references the UN General Assembly Resolution of 28 July 2022—has solidified the link between human rights and biodiversity protection. Thus, it is not surprising that delegates at COP 16 used human rights language extensively.

In this context, it was interesting to observe that different groups internalised and strategically deployed human rights language to advance different, sometimes, but not always complementary, world-makings. Youth representatives referred to human rights as a tool for achieving inter-generational equity in biodiversity conservation; many indigenous peoples’ representatives employed human rights language to advance substantive claims such as rights to land and resources as well as procedural ones such as participatory rights in conservation decision-making; women representatives employed human rights language to address gender inequalities in conservation; some UN representatives strongly supported a human rights-based approach to area-based conservation as a means to avoid the tragedies brought about by ‘fortress conservation’; others used human rights language to reiterate key objectives of existing international law instruments.

The concept of human rights returned over and over in COP discussions intersecting with other reflections that unwrap the many lines around which biodiversity is framed and practiced by different communities and actors.

Outcomes and beyond

As mentioned above, COP 16 was suspended leaving for a later date, decisions on some critical issues, such as finance mechanisms and monitoring mechanism to measure Parties’ progress in achieving GBF Targets and Goals. Considering the slow implementation of the GBF- only 44 Parties have submitted revised National Biodiversity Strategies and Action Plans (NBSAPs), which are the main national implementation tools under Article 6 of the CBD- it is disappointing that decisions on budget and monitoring mechanisms have been left pending. However, there were also many achievements at COP 16, including:

the launch of the ‘Cali fund’ to operationalise the sharing of benefits from uses of digital sequence information (DSI);
decisions on Article 8(j), focused on traditional knowledge, innovations and practices of indigenous and local communities, including the adoption of a new Programme of Work on Article 8(j) and the establishment of a new permanent subsidiary body on Article 8(j);
a number of sectoral decisions, including one on the mechanism for identifying ecologically or biologically significant marine areas (EBSAs), which had been the subject of legal and political discussion for eight years.

The decisions related to Article 8(j) stand out considering the central role indigenous peoples and local communities play in the protection of biodiversity and the importance of including different epistemologies in biodiversity decision-making. During COP itself, there were arguments in favour and against the creation of such subsidiary body. Concerns revolved around questions such as ‘Why fixating on only one article of the CBD? Why a subsidiary body on this specific article and not others?’, ‘Would the subsidiary body silo indigenous peoples and local communities concerns?’, ‘Should indigenous peoples and local communities still be clustered together?’ Many counter-arguments were raised promoting the establishment of the subsidiary body as a way to legitimise and render more visible indigenous peoples and local communities’ practices turning these actors as policy makers instead of policy takers included in NBSAPs. The new subsidiary body’s modus operandi will be developed over the next two years, and it will be interesting to follow such development.

Outcomes are important, and in a goal and target-oriented environmental law world such as the one the CBD governance infrastructure presents, it is natural and logical to focus on what is achieved and what is not. However, the success of COP 16, like all COPs, should not solely be determined by its outcomes. It is essential to remember the spaces and the conversations that unfolded in between, the sharing of knowledge by a global community coming together for a few days from very different paths of life and with different agendas, a multitude unified by the shared concern of biodiversity loss, which continues at unprecedented rates and deserves everyone attention in COPs and beyond.

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This blog is written by Cabot Institute for the Environment member, Professor Margherita Pieraccini, Professor of Law at the University of Bristol Law School.

Why UN climate summits still matter – and what to expect from Cop29

Posted on November 8, 2024 by amanda.woodman-hardy

Every autumn, the UN holds its international climate summit or “Cop” (Conference of the Parties). Between each Cop, a smaller, lower-profile gathering takes place. Called the SB – short for “subsidary bodies” of the UN’s Framework Convention on Climate Change (UNFCCC) – these smaller meetings matter but don’t draw as much public attention.

The SB meetings are a world apart from Cops. Held in the same small venue in the German city of Bonn every year, the latest, SB60, had 8,606 participants whereas last year’s Cop28 in Dubai had around 100,000. Observers make up about half of the SB participants, and the atmosphere is less about being there to show you care and more focused on the matter at hand – global negotiations.

In contrast to Cops, there are no pavilions and exhibition spaces. The focus is on negotiations and side events. In June 2024, our team of climate law and policy experts from the Cabot Institute at the University of Bristol attended SB60 as observers. We prioritised going to Bonn instead of the upcoming Cop29 in Baku, Azerbaijan, because SBs offer a chance to see negotiations in flux.

In Bonn, there’s more chance to speak directly to negotiators including diplomats, heads of state, and UNFCCC staff (who are less pressed for time) – and to have an influence on policy outcomes (because positions are not yet as cemented as they are at Cops).

SB60 revealed some important sticking points and challenges for delegates going to Cop29 in Baku, which starts on November 11. The negotiations proved to be particularly difficult in three key areas.

1. A stalled transition

The first is “just transition” – the idea of making society fairer for everyone as we respond to climate change. Negotiations collapsed before the end of SB60 due to disagreements on scope, timelines and implementation planning.

The term just transition was only defined and planned for at a global governance level for the first time at last year’s Cop28. There was a real push and pull between developing and developed countries when it came to setting out the aims and scope of this plan.

Developed countries, including Norway, the US and the EU, pushed to focus on jobs and technology. Developing countries, including the UN’s coalition of 77 developing countries known as the G-77, China, small island developing states, and 54 states of the UN’s Africa Group, wanted costs to be shared fairly in a way that recognises existing inequalities between countries, and with compensation for past harms.

There was a sense that developing countries wanted to see broader system changes within the UNFCCC. One of us (Alix Dietzel) noted down how the G-77 plus China stressed that getting just transition right was “key for the future of the Cops and the regime of the UNFCCC”.

Eventually, the developed countries’ version won out at Cop28. But at SB60, it became clear there were still deep disagreements over what a just transition means and how this will play out. Negotiations over how to achieve the targets for a just transition collapsed when states could not agree whether to include wider discussions of systemic inequality and new finance goals, and whether the UNFCCC’s five-yearly global stocktake required a scaling up of ambition.

The outcome document produced on the final day of SB60 stated that parties met and negotiated – but frustratingly, did not capture any views that can be used as a basis for further negotiations.

Co-authors Alice Venn and Alix Dietzel at SB60.
Alix Dietzel, CC BY-NC-ND

2. Responding to climate loss and damage

There is increasing urgency to deliver meaningful support to developing countries experiencing the worst economic and non-economic losses from climate impacts. These range from extreme weather and sea level rise to damage to ecosystems and communities. A key priority is funding to support the recovery and preparedness of the most at-risk countries and communities.

A new loss and damage fund, currently hosted by the World Bank, was established at Cop28. So far, it has received more than US$702 million (£540 million) in pledges. At SB60, the debate focused on how best to urgently scale up this funding and make it more easily available to the communities most in need of it.

Many countries and observers called for a more inclusive approach based on human rights, and stressed the need for technical support in less developed countries.

3. Finance is key

Cop29 is all about money. Billed as “the finance Cop”, leaders in Baku must agree on a new climate finance goal. Known as the “new collective quantified goal” (NCQG), this aims to support developing countries with climate action. Industrialised nations have only met the current annual target of US$100 billion once, in 2022. SB60 was meant to lay the groundwork for a finance deal at Cop29. The outcome in Bonn, however, was disappointing.

We observed that developing countries felt frustrated at the dithering of developed nations over who should pay and how much. The Colombian government, for example, is committed to decarbonisation, but in Bonn expressed dismay at the lack of concessionary climate finance to support this process.

Developing countries seemed angry that finance flows prioritise private infrastructure investment over key sectors that are considered non-profitable, such as education, health, coastal flooding defences or landslide prevention. This makes climate adaptation harder, especially in the context of high debt burdens.

The road to Baku

The intimate setting of the SB negotiation space might look like it could deliver better climate outcomes compared to huge Cops. Negotiators at Cop28 were crowded out by lobbyists and industry representatives. In Bonn this year, smaller numbers meant delegates could more easily meet for informal huddles outside the negotiation rooms.

conference room with chairs, signs for country names and big screen with blue presentation for climate finance discussions — Finance negotiations will be centre stage at Cop29.
Alix Dietzel, CC BY-NC-ND

At the Cop climate summits, observers like us normally don’t have a significant voice. But at SB60, interactive workshops and contact groups gave observers opportunities to speak. We held a side event with the global mayors network, C40 Cities, and Earthshot prize winners, the environmental and youth empowerment group Green Africa Youth Organization. Discussions focused on how to make urban climate policy more inclusive, and we later introduced ourselves to the UK negotiation team.

Contributions from civil society observers were recorded by the UNFCCC and incorporated into official SB reports on finance and loss and damage. Nevertheless, big decisions on just transition, loss and damage, and climate finance are constrained by competing geopolitical and economic interests, regardless of the size of the negotiating space.

SB60 set the scene for two weeks of fractious negotiations in Baku. Climate change-induced extreme weather events and changing weather patterns are accelerating. Key climate tipping points could be breached soon.

Developing countries will require trillions of dollars a year to adapt to and mitigate these extreme scenarios. Based on what we experienced in Bonn, a finance deal at Baku that delivers climate action for developing countries seems a long way off.

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This blog is written by Cabot Institute for the Environment members, Drs Alix Dietzel, Senior Lecturer in Climate Justice, University of Bristol; Alice Venn, Senior Lecturer in Climate Law, University of Bristol, and Katharina Richter, Lecturer in Climate Change, Politics and Society, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Earth’s greatest mass extinction 250 million years ago shows what happens when El Niño gets out of control – new study

Posted on September 20, 2024 by amanda.woodman-hardy

252 million years ago, there was only one supercontinent: Pangaea.
ManuMata / shutterstock

Around 252 million years ago, the world suddenly heated up. Over a geologically brief period of tens of thousands of years, 90% of species were wiped out. Even insects, which are rarely touched by such events, suffered catastrophic losses. The Permian-Triassic mass extinction, as it’s known, was the greatest of the “big five” mass extinctions in Earth’s history.

Scientists have generally blamed the mass extinction on greenhouse gases released from a vast network of volcanoes which covered much of modern day Siberia in lava. But the volcanic explanation was incomplete. In our new study, we show that an enormous El Niño weather pattern in the world’s major ocean added to climate chaos and led to extinctions spreading across the globe.

It’s easy to see why volcanoes were blamed. The onset of extinction coincides almost perfectly with the beginning of the second phase of volcanism in the region known as the Siberian Traps. This led to acid rain, oceans losing their oxygen and, most notably, temperatures beyond the tolerance levels of almost all organisms. It was the greatest episode of global warming in the past 500 million years.

The world 252 million years ago

Map of world with one big supercontinent — Alex Farnsworth

However, there were outstanding questions for proponents of this seemingly simple extinction scenario: when the tropics became too hot, why did species not just migrate to cooler, higher latitudes (as is happening today)? If warming was sudden and rapid, why did species on land die off tens of thousands of years before those in the sea?

There have also been many instances of volcanic eruptions of similar scale, and even other episodes of rapid warming, but why did none of these cause a similarly catastrophic mass extinction?

Our new study reveals that the oceans rapidly heated up all across the world’s low and mid latitudes. Normally, it gets cooler as you move away from the tropics, but not this time. It simply became too hot for life in too many places.

A world prone to extremes

Using a state-of-the-art computer program, we were able to simulate what the weather and climate was like 252 million years ago. We found that, even before the rapid warming, the world would have been prone to extremes of temperature and rainfall.

That’s a consequence of all the land at the time forming into one large supercontinent, Pangaea. This meant that the climates we see today at the centre of continents – dry, with hot summers and freezing winters – were magnified.

Pangaea was surrounded by a vast ocean, Panthalassa, the surface of which would fluctuate between warm and cool periods over the years, much like the El Niño phenomenon in the Pacific today. Yet once the mass Siberian volcanism started and carbon dioxide in the atmosphere increased, those prehistoric El Niños became more intense and lasted longer thanks to the larger Panthalassa ocean being able to store more heat.

An El Niño far stronger than anything today

chart of el nino fluctuations — Change in sea surface temperature (SST) compared to the long-term average. El Niño conditions are red, La Niña (or its prehistoric equivalent) is blue. Left = modern day pre-industrial Pacific Ocean. Centre = 252 million years ago, before the Siberian Traps volcanism. Right = at the peak of the mass extinction.
Alex Farnsworth

These El Niños had a profound impact on life on land, and kicked off a sequence of events that made the climate more and more extreme. Temperatures got hotter, especially in the tropics, and huge droughts and fires caused tropical forests to die off.

This in turn was bad news for the climate, as less carbon was stored by trees, allowing more to linger in the atmosphere, leading to further warming, and even stronger and longer El Niños.

252 million years ago, pre crisis:

Animated map of temperature 252m years ago — Before the Siberian Traps volcanism 252 million years ago, the world was slightly hotter than today. (Animation shows average monthly temperatures according to the authors’ climate model).
Alex Farnsworth

These stronger El Niños caused the extreme temperatures and droughts to push outside of the tropics towards the poles, and more vegetation died off and more carbon was released. Over tens of thousands of years, extreme temperatures spread over much of the world’s surface. Eventually, the warming began to harm life in the oceans, particularly tiny organisms at the bottom of the food chain.

…and at the peak of the extinction:

During the peak of the crisis, in a world that was already warming thanks to volcanic gases, an El Niño would boost average temperatures by a further 4°C. That’s more than three times the total warming we have caused over the past few centuries. Back then, the El Niño-charged climate would have regularly seen peak daytime temperatures on land of 60°C or more.

The future of El Niño

In recent years El Niños have caused major changes to rainfall and temperature patterns, around the Pacific and even further afield. A strong El Niño was a factor in record-breaking temperatures through 2023 and 2024.

Fortunately, such events typically only last a few years. However, on top of human-caused warming, even these smaller scale El Niños of the present day may be enough to push fragile ecosystems beyond their limit.

El Niño is predicted to become more variable as the climate changes, though we should note that the oceans are still yet to fully respond to current warming rates. At present, nobody is forecasting another mass extinction on the scale of the one 252 million years ago, but that event provides a worrying snapshot of what happens when El Niño gets out of control.

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This blog is written by Dr Alex Farnsworth, Senior Research Associate in Meteorology, University of Bristol; David Bond, Palaeoenvironmental Scientist, University of Hull, and Paul Wignall, Professor of Palaeoenvironments, University of Leeds. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Building resilience of the UK food system to weather and climate shocks

Posted on September 11, 2024 by amanda.woodman-hardy

Climate-driven changes in extreme weather events are one of the highest-risk future shocks to the UK food system, underlining the importance of preparedness across the food chain. However, the CCC’s 2023 report on adaptation progress highlighted that current climate adaptation plans and policies, and their delivery and implementation for UK food security are either insufficient or limited. Through an ongoing Met Office cross-academic partnership activity (‘SuperRAP’) working across all eight partner universities (including Bristol), Defra, the Food Standards Agency, UKRI-BBSRC and the Global Food Security Programme, a recent perspective paper, and associated online workshops and surveys in January 2023 have:

Scoped out the direct impacts of weather and climate extremes on the UK food supply chain,
Highlighted areas where weather and climate information could support resilience across time and space scales through decision making and action,
Identified key knowledge gaps,
Made recommendations for future research and funding, and
Scoped out the potential adaptation/policy responses to the direct impacts of weather and climate extremes on the food chain, and the resulting trade-offs and consequences

The potential for weather and climate information to support decision making in agricultural and food system-related activities, and improved resilience to weather and climate shocks across time and space scales. Grey background boxes represent generalised meteorological capabilities; light blue ellipses with white outlines denote potential applications. © Crown Copyright 2021, Met Office. From Falloon et al. 2022.

However, a major gap remains in understanding the changes needed to rapidly increase the delivery and implementation of climate adaptation in support of resilience in the UK food system. A workshop on this topic was held at the University of Reading’s Henley Business School on 13-14 June 2024 bringing together academics across a wide range of disciplines and presented findings back to industry and government stakeholders for their feedback and prioritisation.

The workshop aimed to consider key areas for supporting resilience and adaptation to climate change identified by the January 2023 workshop including innovation and trialling novel management and production approaches, social innovation and enabling behavioural shifts, mutual learning, and underpinning evidence gaps. The workshop was supported by a cross-sector survey on adaptation barriers and priorities.

Overarching themes identified in the workshop included the need for a strategic, system-wide, and long-term approach, underpinned by strong inter- and transdisciplinary collaboration.

Critical evidence gaps include improving understanding of:

Impacts of international dimensions and trade on UK food ingredient and packaging availability, compared to UK-sourced products – and their interactions
Impacts of climate extremes on production and transport and effective adaptation options
Impacts of climate shocks on UK livelihood systems, households and consumers
Broader adaptation and transformation needed to escape existing ‘doom loops’
Application of tech solutions (e.g. GM/gene editing) for climate resilience and adaptation

Other issues raised included thresholds for change, land pressures, substitutability of different foods, impacts of government policy, nutrition, regenerative practices, and interactions with the energy sector.

Recommended ways forward include:

Tools, models, and methods that consider risks across the food chain and system outcomes
A focus on inter- and trans-disciplinary approaches.
Increased international collaboration/cooperation, and stronger government-science interactions
Enhancing food chain data access, use and integration, and a supportive enabling environment
Long-term trials: to provide evidence of impacts of alternative practices
Preparing the transport network for climate extremes.
A refresh of the National Food Strategy, building on latest science
A new funding landscape: long-term, strategic, visionary, systemic, trans- and interdisciplinary, co-designed and coordinated.

Other issues raised included: sharing responsibility and joined-up, transparent approaches across sectors and institutions; risk mitigation tools; use cases and roadmaps; welfare responses; interdisciplinary skills training; and research across a wider range of crops.

We are aiming to produce a peer-reviewed perspective paper on critical research (and practice) gaps, and recommendations for the way forward.

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This blog was written by Professor Pete Falloon from the Cabot Institute for the Environment and Met Office.

A bald headed man smiling with dark rimmed glasses. — Professor Pete Falloon

How glacier algae are challenging the way we think about evolution

Posted on June 19, 2024 by amanda.woodman-hardy

People often underestimate tiny beings. But microscopic algal cells not only evolved to thrive in one of the most extreme habitats on Earth – glaciers – but are also shaping them.

With a team of scientists from the UK and Canada, we traced the evolution of purple algae back hundreds of millions of years and our findings challenge a key idea about how evolution works. Though small, these algae are having a dramatic effect on the glaciers they live on.

Glaciers are among the planet’s fastest changing ecosystems. During the summer melt season as liquid water forms on glaciers, blooms of purple algae darken the surface of the ice, accelerating the rate of melt. This fascinating adaptation to glaciers requires microscopic algae to control their growth and photosynthesis. This must be balanced with tolerance of extreme ice melt, temperature and light exposure.

Our study, published in New Phytologist, reveals how and when their adaptations to live in these extreme environments first evolved. We sequenced and analysed genome data of the glacier algae Ancylonema nordenskiöldii. Our results show that the purple colour of glacier algae, which acts like a sunscreen, was generated by new genes involved in pigment production.

This pigment, purpurogallin, protects algal cells from damage of ultraviolet (UV) and visible light. It is also linked with tolerance of low temperatures and desiccation, characteristic features of glacial environments. Our genetic analysis suggests that the evolution of this purple pigment was probably vital for several adaptations in glacier algae.

We also identified new genes that helped increase the algae’s tolerance to UV and visible light, important adaptations for living in a bright, exposed environment. Interestingly these were linked to increased light perception as well as improved mechanisms of repair to sun damage. This work reveals how algae are adapted to live on glaciers in the present day.

Next, we wanted to understand when this adaptation evolved in Earth’s deep history.

The evolution of glacier algae

Earth has experienced many fluctuations of colder and warmer climates. Across thousands and sometimes millions of years, global climates have changed slowly between glacial (cold) to interglacial (warm) periods.

One of the most dramatic cold periods was the Cryogenian, dating back to 720-635 million years ago, when Earth was almost entirely covered in snow and ice. So widespread were these glaciations, they are sometimes referred to by scientists as “Snowball Earth”.

Scientists think that these conditions would have been similar to the glaciers and ice sheets we see on Earth today. So we wondered could this period be the force driving the evolution of glacier algae?

After analysing genetic data and fossilised algae, we estimated that glacier algae evolved around 520-455 million years ago. This suggests that the evolution of glacier algae was not linked to the Snowball Earth environments of the Cryogenian.

As the origin of glacier algae is later than the Cryogenian, a more recent glacial period must have been the driver of glacial adaptations in algae. Scientists think there has continuously been glacial environments on Earth up to 60 million years ago.

We did, however, identify that the common ancestor of glacier algae and land plants evolved around the Cryogenian.

In February 2024, our previous analysis demonstrated that this ancient algae was multicellular. The group containing glacier algae lost the ability to create complex multicellular forms, possibly in response to the extreme environmental pressures of the Cryogenian.

Rather than becoming more complex, we have demonstrated that these algae became simple and persevered to the present day. This is an example of evolution by reducing complexity. It also contradicts the well-established “march of progress” hypothesis, the idea that organisms evolve into increasingly complex versions of their ancestors.

Our work showed that this loss of multicellularity was accompanied by a huge loss of genetic diversity. These lost genes were mainly linked to multicellular development. This is a signature of the evolution of their simple morphology from a more complex ancestor.

Over the last 700 million years, these algae have survived by being tiny, insulated from cold and protected from the Sun. These adaptations prepared them for life on glaciers in the present day.

So specialised is this adaptation, that only a handful of algae have evolved to live on glaciers. This is in contrast to the hundreds of algal species living on snow. Despite this, glacier algae have dramatic effects across vast ice fields when liquid water forms on glacier surfaces. In 2016, on the Greenland ice sheet, algal growth led to an additional 4,400–6,000 million tonnes of runoff.

Understanding these algae helps us appreciate their role in shaping fragile ecosystems.

Our study gives insight into the evolutionary journey of glacier algae from the deep past to the present. As we face a changing climate, understanding these microscopic organisms is key to predicting the future of Earth’s icy environments.

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This blog is written by Dr Alexander Bowles, Postdoctoral research associate, University of Bristol

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

East Africa must prepare for more extreme rainfall during the short rainy season – new study

Posted on March 11, 2024 by amanda.woodman-hardy

Rainy season in Kenya

East Africa has recently had an unprecedented series of failed rains. But some rainy seasons are bringing the opposite: huge amounts of rainfall.

In the last few months of 2023, the rainy season known as the “short rains” was much wetter than normal. It brought severe flooding to Kenya, Somalia and Tanzania. In Somalia, more than 2 million people were affected, with over 100 killed and 750,000 displaced from their homes. Tens of thousands of people in northern Kenya lost livestock, farmland and homes.

The very wet short rainy seasons are linked to a climate event known as a positive Indian Ocean Dipole (known as the “IOD”). And climate model projections show an increasing trend of extreme Indian Ocean dipoles.

In a new research paper, we set out to investigate what effect more frequent extreme Indian Ocean Dipole events would have on rainfall in east Africa. We did this using a large number of climate simulations and models.

Our results show that they increase the likelihood of very wet days – therefore making very wet seasons.

This could lead to extreme weather events, even more extreme than the floods of 1997, which led to 10 million people requiring emergency assistance, or those of 2019, when hundreds of thousands were displaced.

We recommend that decision-makers plan for this kind of extreme rainfall, and the resulting devastating floods.

How the Indian Ocean Dipole works

Indian Ocean Dipole events tend to occur in the second half of the year, and can last for months. They have two phases: positive and negative.

Positive events occur when the temperature of the sea surface in the western Indian Ocean is warmer than normal and the temperature in the eastern Indian Ocean is cooler than normal. Put simply, this temperature difference happens when winds move warmer water away from the ocean surface in the eastern region, allowing cooler water to rise.

In the warmer western Indian Ocean, more heated air will rise, along with water vapour. This forms clouds, bringing rain. Meanwhile, the eastern part of the Indian Ocean will be cooler and drier. This is why flooding in east Africa can happen at the same time as bushfires in Australia.

The opposite is true for negative dipole events: drier in the western Indian Ocean and wetter in the east.

Under climate change we’re expecting to see more frequent and more extreme positive dipole events – bigger differences between east and west. This is shown by climate model projections. They are believed to be driven by different paces of warming across the tropical Indian Ocean – with western and northern regions projected to warm faster than eastern parts.

Often heavy rain seasons in east Africa are attributed to El Niño, but recent research has shown that the direct impact of El Niño on east African rainfall is actually relatively modest. El Niño’s principal influence lies in its capacity to bring about positive dipole events. This occurs since El Niño events tend to cool the water in the western Pacific Ocean – around Indonesia – which also helps to cool down the water in the eastern Indian Ocean. These cooler temperatures then help kick-start a positive Indian Ocean Dipole.

Examining unprecedented events

Extreme positive Indian Ocean Dipole events are rare in the recent climate record. So to examine their potential impacts on rainfall extremes, we used a large set of climate simulations. The data allowed us to diagnose the sensitivity of rainfall to larger Indian Ocean Dipole events in a statistically robust way.

Our results show that as positive dipole events become more extreme, more wet days during the short rains season can be expected. This effect was found to be largest for the frequency of extremely wet days. Additionally, we found that as the dipole strength increases, the influence on the most extreme days becomes even larger. This means that dipole events which are even slightly “record-breaking” could lead to unprecedented levels of seasonal rainfall.

Ultimately, if positive Indian Ocean Dipole seasons increase in frequency, as predicted, regular seasons of flooding impacts will become a new normal.

One aspect not included in our analysis is the influence of a warmer atmosphere on rainfall extremes. A warmer atmosphere holds more moisture, allowing for the development of more intense rain storms. This effect could combine with the influence of extreme positive dipoles to bring unprecedented levels of rainfall to the Horn of Africa.

2023 was a year of record-breaking temperatures driven both by El Niño and global warming. We might expect that this warmer air could have intensified rain storms during the season. Indeed, evidence from a recent assessment suggests that climate change-driven warming is highly likely responsible for increased rainfall totals.

Responding to an unprecedented future

Policymakers need to plan for this.

In the long term it is crucial to ensure that any new infrastructure is robust to withstand more frequent and heavier rains, and that government, development and humanitarian actors have the capacity to respond to the challenges.

Better use of technology, such as innovations in disseminating satellite rainfall monitoring via mobile phones, can communicate immediate risk. New frontiers in AI-based weather prediction could improve the ability to anticipate localised rain storms, including initiatives focusing on eastern Africa specifically.

Linking rainfall information with hydrological models designed for dryland environments is also essential. These will help to translate weather forecasts into impact forecasts, such as identifying risks of flash flooding down normally dry channels or bank overflow of key rivers in drylands.

These technological improvements are crucial. But better use of the forecast information we already have can also make a big difference. For instance, initiatives like “forecast-based financing”, pioneered by the Red Cross Red Crescent movement, link forecast triggers to pre-approved financing and predefined action plans, helping communities protect themselves before hazards have even started.

For these endeavours to succeed, there must be dialogue between the science and practitioner communities. The scientific community can work with practitioners to integrate key insights into decisions, while practitioners can help to ensure research efforts target critical needs. With this, we can effectively build resilience to natural hazards and resist the increasing risks of our changing climate.

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This blog is written by David MacLeod, Lecturer in Climate Risk, Cardiff University; Erik W. Kolstad, Research professor, Uni Research; Cabot Institute for the Environment member Katerina Michaelides, Professor of Dryland Hydrology, School of Geographical Sciences, University of Bristol, and Michael Singer, Professor of Hydrology and Geomorphology, Cardiff University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dune: what the climate of Arrakis can tell us about the hunt for habitable exoplanets

Posted on March 11, 2024March 11, 2024 by amanda.woodman-hardy

Frank Herbert’s Dune is epic sci-fi storytelling with an environmental message at its heart. The novels and movies are set on the desert planet of Arrakis, which various characters dream of transforming into a greener world – much like some envision for Mars today.

We investigated Arrakis using a climate model, a computer program similar to those used to give weather forecasts. We found the world that Herbert had created, well before climate models even existed, was remarkably accurate – and would be habitable, if not hospitable.

However, Arrakis wasn’t always a desert. In Dune lore, 91% of the planet was once covered by oceans, until some ancient catastrophe led to its desertification. What water remained was further removed by sand trout, an invasive species brought to Arrakis. These proliferated and carried liquid into cavities deep underground, leading to the planet becoming more and more arid.

To see what a large ocean would mean for the planet’s climate and habitability, we have now used the same climate model – putting in an ocean while changing no other factors.

When most of Arrakis is flooded, we calculate that the global average temperature would be reduced by 4°C. This is mostly because oceans add moisture to the atmosphere, which leads to more snow and certain types of cloud, both of which reflect the sun’s energy back into space. But it’s also because oceans on Earth and (we assume) on Arrakis emit “halogens” that cool the planet by depleting ozone, a potent greenhouse gas which Arrakis would have significantly more of than Earth.

Map of Arrakis — The authors gathered information from the books and the Dune Encyclopedia to build their original model. Then they added an ocean with 1,000 metres average depth.
Farnsworth et al, CC BY-SA

Unsurprisingly, the ocean world is a whopping 86 times wetter, as so much water evaporates from the oceans. This means plants can grow as water is no longer a finite resource, as it is on desert Arrakis.

A wetter world would be more stable

Oceans also reduce temperature extremes, as water heats and cools more slowly than land. (This is one reason Britain, surrounded by oceans, has relatively mild winters and summers, while places far inland tend to be hotter in summer and very cold in winter). The climate of an ocean planet is therefore more stable than a desert world.

In desert Arrakis, temperatures would reach 70°C or more, while in its ocean state, we put the highest recorded temperatures at about 45°C. That means the ocean Arrakis would be liveable even in summer. Forests and arable crops could grow outside of the (still cold and snowy) poles.

There is one downside, however. Tropical regions would be buffeted by large cyclones since the huge, warm oceans would contain lots of the energy and moisture required to drive hurricanes.

The search for habitable planets

All this isn’t an entirely abstract exercise, as scientists searching for habitable “exoplanets” in distant galaxies are looking for these sorts of things too. At the moment, we can only detect such planets using huge telescopes in space to search for those that are similar to Earth in size, temperature, available energy, ability to host water, and other factors.

Scatter chart of planets comparing habitability and similarity to Earth. — Both desert and ocean Arrakis are considerably more habitable than any other planet we have discovered.
Farnsworth et al, CC BY-SA

We know that desert worlds are probably more common than Earth-like planets in the universe. Planets with potentially life-sustaining oceans will usually be found in the so-called “Goldilocks zone”: far enough from the Sun to avoid being too hot (so further away than boiling hot Venus), but close enough to avoid everything being frozen (so nearer than Jupiter’s icy moon Ganymede).

Research has found this habitable zone is particularly small for planets with large oceans. Their water is at risk of either completely freezing, therefore making the planet even colder, or of evaporating as part of a runaway greenhouse effect in which a layer of water vapour prevents heat from escaping and the planet gets hotter and hotter.

The habitable zone is therefore much larger for desert planets, since at the outer edge they will have less snow and ice cover and will absorb more of their sun’s heat, while at the inner edge there is less water vapour and so less risk of a runaway greenhouse effect.

It’s also important to note that, though distance from their local star can give a general average temperature for a planet, such an average can be misleading. For instance, both desert and ocean Arrakis have a habitable average temperature, but the day-to-day temperature extremes on the ocean planet are much more hospitable.

Currently, even the most powerful telescopes cannot sense temperatures at this detail. They also cannot see in detail how the continents are arranged on distant planets. This again could mean the averages are misleading. For instance, while the ocean Arrakis we modelled would be very habitable, most of the land is in the polar regions which are under snow year-round – so the actual amount of inhabitable land is much less.

Such considerations could be important in our own far-future, when the Earth is projected to form a supercontinent centred on the equator. That continent would make the planet far too hot for mammals and other life to survive, potentially leading to mass extinction.

If the most likely liveable planets in the universe are deserts, they may well be very extreme environments that require significant technological solutions and resources to enable life – desert worlds will probably not have an oxygen-rich atmosphere, for instance.

But that won’t stop humans from trying. For instance, Elon Musk and SpaceX have grand ambitions to create a colony on our closest desert world, Mars. But the many challenges they will face only emphasises how important our own Earth is as the cradle of civilisation – especially as ocean-rich worlds may not be as plentiful as we’d hope. If humans eventually colonise other worlds, they’re likely to have to deal with many of the same problems as the characters in Dune.

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This blog is written by Cabot Institute for the Environment members Dr Alex Farnsworth, Senior Research Associate in Meteorology, and Sebastian Steinig, Research Associate in Paleoclimate Modelling, University of Bristol; and Michael Farnsworth, Research Lead Future Electrical Machines Manufacturing Hub, University of Sheffield. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate summits are too big and key voices are being crowded out – here’s a better solution

Posted on December 18, 2023December 18, 2023 by amanda.woodman-hardy

Every year, the official UN climate summits are getting bigger. In 2021 at COP26 in Glasgow there were around 40,000 participants, COP27 in 2022 in Sharm el-Sheikh had 50,000.

But this year blew all previous records out of the water. More than 97,000 participants had badges to attend COP28 in Dubai in person. This raises questions about who is attending COPs and what they are doing there, who gets their voices heard and, on a more practical note, how this affects the negotiations.

For those not familiar with the COP setup, there are two “worlds” that exist side by side. One is the negotiations, which are run under the UN’s climate change body the UNFCCC, and the other is a very long list of talks and social events. These take place in pavilion exhibition spaces and are open to anyone attending, in contrast to the negotiations which are often closed to the media and sometimes closed to observers.

There is a stark difference between these worlds, with pavilion spaces featuring elaborate and inviting settings, particularly if they are well funded, while negotiations often happen in windowless rooms.

A growing sense exists among those invested in the “traditional” side of the COPs that many delegates have no intention of observing the climate talks themselves, and instead spend their time networking in the pavilions.

Indigenous people visiting COP28 from Brazilian Amazon.

In terms of who attends, at COP28 there were around 25,000 “party” (country) delegates, 27,000 “party overflow” delegates (usually guests, sponsors, or advisors), 900 UNFCCC secretariat members (who run the COPs), 600 “UN overflow”, and 1,350 from “specialised agencies” such as the World Health Organization or World Bank and their overflows. That makes up just under 55,000 or half of the attendees.

The rest are intergovernmental organisations (2,000), UN Global Climate Action award winners (600), host country guests (5,000), temporary passes (500 – many issued to big private companies), NGOs (14,000 – including one of us, as part of a university delegation), and media (4,000). This is according to the UNFCCC, which places the number of attendees closer to 80,000.

The “party overflow” badges are particularly concerning. The number of delegates connected to the oil and gas industries has quadrupled from last year to around 2,400, many of whom were invited as part of country delegations. As another example, meat industry representatives became part of Brazil’s delegation, while dairy associations organised official COP side events. In the official programme, the Energy and Industry, Just Transition, and Indigenous Peoples Day featured more events by industrial giant Siemens than by indigenous people.

Practically speaking, huge numbers cause problems – this year for example there were delayed meetings, long queues, and several negotiation rooms were beyond capacity with observers and even party delegates asked to limit their numbers and leave.

Even with access to an observer badge, there is little one can contribute to negotiations. The negotiating positions are decided long before the COPs begin, and observers are rarely permitted to speak in negotiations. In addition, a lot of the negotiations are either conducted behind closed doors (called “informal-informals” with no access for the UN or observers) or even in the corridors, where negotiators meet informally to cement positions. The negotiations you can (silently) observe are usually a series of prepared statements, rather than a discussion.

So if COPs are too big and bloated, what is the alternative?

Smaller and more online

One alternative is being a virtual delegate, which one of us tried. This year’s COP trialled live streams and recordings of some of the negotiations, side events and press conferences on an official UNFCCC virtual platform for the first time. The option is a long overdue, but welcome addition. It reduces travel emissions and makes it more accessible, for instance for people with caring responsibilities and others who are unable to travel (or perhaps who refuse to fly).

Some technical teething problems are to be expected. Yet when we queried why the virtual platform didn’t livestream many of the sessions, the COP28 support team pointed us to the official COP28 app. Our employer, the University of Bristol, had advised us not to download the app because of security concerns, which again raises serious issues around transparency and accountability in UNFCCC spaces, as well as freedom of speech and assembly in COP host countries.

Not being there in person also has downsides. As a virtual observer, it’s harder to judge the atmosphere in a negotiation room, to stumble upon and observe spontaneous negotiations happening in corridors, or participate in or observe protests. While indigenous voices were rarely heard in the livestreamed negotiations and events, the Indigenous People’s Pavilion offered a chance to hear them – but only if you were in Dubai. The virtual alternative is a good option to observe negotiations, but it means missing out on some of the civil society lifeblood of COP.

Another option is to limit access to COPs – for example, limiting the in-person negotiations only to the most vital participants. Party tickets could be limited, with lobbyists from fossil fuel industries tightly controlled and priority given to climate victims, indigenous communities and underrepresented countries. Side events and pavilions could take place a few months before the COPs, increasing the chances of influencing negotiations, since positions are cemented early. There is no reason these only need to happen in one place once a year, there could be regional meetups in between, allowing for formal contact more often.

These issues of access, transparency and influence have serious implications on negotiation outcomes and climate action. After undergoing various draft iterations that offered options ranging from “no text” to “phasing out” or “down” fossil fuels, this year’s final agreement does not include a commitment to phasing out. This watered-down agreement reflects the inability of indigenous peoples and the most climate vulnerable countries to meaningfully participate in the negotiations – future COPs must trim down to make their voices heard.

This blog is written by Cabot Institute for the Environment members, Drs Alix Dietzel, Senior Lecturer in Climate Justice, University of Bristol and Katharina Richter, Lecturer in Climate Change, Politics and Society, University of Bristol.

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

Are you a journalist looking for climate experts for COP28? We’ve got you covered

Posted on October 30, 2023November 28, 2023 by amanda.woodman-hardy

We’ve got lots of media trained climate change experts. If you need an expert for an interview, here is a list of our experts you can approach. All media enquiries should be made via Victoria Tagg, our dedicated Media and PR Manager at the University of Bristol.

Email victoria.tagg@bristol.ac.uk or call +44 (0)117 428 2489.

Climate change / climate emergency / climate science / climate-induced disasters

Dr Eunice Lo – expert in changes in extreme weather events such as heatwaves and cold spells, and how these changes translate to negative health outcomes including illnesses and deaths. Follow on Twitter/X @EuniceLoClimate.

Professor Daniela Schmidt – expert in the causes and effects of climate change on marine systems. Dani is also a Lead Author on the IPCC reports.

Dr Katerina Michalides – expert in drylands, drought and desertification and helping East African rural communities to adapt to droughts and future climate change. Follow on Twitter/X @_kmichaelides.

Professor Dann Mitchell – expert in how climate change alters the atmospheric circulation, extreme events, and impacts on human health. Dann is also a Met Office Chair. Follow on Twitter/X @ClimateDann.

Professor Dan Lunt – expert on past climate change, with a focus on understanding how and why climate has changed in the past and what we can learn about the future from the past. Dan is also a Lead Author on IPCC AR6. Follow on Twitter/X @ClimateSamwell.

Professor Jonathan Bamber – expert on the impact of melting land ice on sea level rise (SLR) and the response of the ocean to changes in freshwater forcing. Follow on Twitter/X @jlbamber

Professor Paul Bates CBE – expert in the science of flooding, risk and reducing threats to life and economic losses worldwide. Follow on Twitter/X @paul_d_bates

Dr Matt Palmer – expert in sea level and ocean heat content at the Met Office Hadley Centre and University of Bristol. Follow on Twitter/X @mpclimate.

Professor Guy Howard – expertise in building resilience and supporting adaptation in water systems, sanitation, health care facilities, and housing. Expert in wider infrastructure resilience assessment.

Net Zero / Energy / Renewables

Dr Caitlin Robinson – expert on energy poverty and energy justice and also in mapping ambient vulnerabilities in UK cities. Caitlin will be virtually attending COP28. Follow on Twitter/X @CaitHRobin.

Professor Philip Taylor – Expert in net zero, energy systems, energy storage, utilities, electric power distribution. Also Pro-Vice Chancellor at the University of Bristol. Follow on Twitter/X @rolyatlihp.

Dr Colin Nolden – expert in sustainable energy policy, regulation and business models and interactions with secondary markets such as carbon markets and other sectors such as mobility. Colin will be in attendance in the Blue Zone at COP28 during week 2.

Professor Charl Faul – expert in novel functional materials for sustainable energy applications e.g. in CO2 capture and conversion and energy storage devices. Follow on Twitter/X @Charl_FJ_Faul.

Climate finance / Loss and damage

Dr Rachel James – Expert in climate finance, damage, loss and decision making. Also has expertise in African climate systems and contemporary and future climate change. Follow on Twitter/X @_RachelJames.

Dr Katharina Richter – expert in decolonial environmental politics and equitable development in times of climate crises. Also an expert on degrowth and Buen Vivir, two alternatives to growth-based development from the Global North and South. Katarina will be virtually attending COP28. @DrKatRichter.

Climate justice

Dr Alix Dietzel – climate justice and climate policy expert. Focusing on the global and local scale and interested in how just the response to climate change is and how we can ensure a just transition. Alix will be in attendance in the Blue Zone at COP28 during week 1. Follow on Twitter/X @alixdietzel.

Dr Ed Atkins – expert on environmental and energy policy, politics and governance and how they must be equitable and inclusive. Also interested in local politics of climate change policies and energy generation and consumption. Follow on Twitter/X @edatkins_.

Dr Karen Tucker – expert on colonial politics of knowledge that shape encounters with indigenous knowledges, bodies and natures, and the decolonial practices that can reveal and remake them. Karen will be in attending the Blue Zone of COP28 in week 2.

Climate change and health

Dr Dan O’Hare – expert in climate anxiety and educational psychologist. Follow on Twitter/X @edpsydan.

Professor Guy Howard – expert in influence of climate change on infectious water-related disease, including waterborne disease and vector-borne disease.

Professor Rachael Gooberman-Hill – expert in health research, including long-term health conditions and design of ways to support and improve health. @EBIBristol (this account is only monitored in office hours).

Youth, children, education and skills

Dr Dan O’Hare – expert in climate anxiety in children and educational psychologist. Follow on Twitter/X @edpsydan.

Dr Camilla Morelli – expert in how children and young people imagine the future, asking what are the key challenges they face towards the adulthoods they desire and implementing impact strategies to make these desires attainable. Follow on Twitter/X @DrCamiMorelli.

Dr Helen Thomas-Hughes – expert in engaging, empowering, and inspiring diverse student bodies as collaborative environmental change makers. Also Lead of the Cabot Institute’s MScR in Global Environmental Challenges. Follow on Twitter/X @Researchhelen.

Professor Daniela Schmidt – expert in the causes and effects of climate change on marine systems. Dani is also a Lead Author on the IPCC reports. Also part of the Waves of Change project with Dr Camilla Morelli, looking at the intersection of social, economic and climatic impacts on young people’s lives and futures around the world.

Climate activism / Extinction Rebellion

Dr Oscar Berglund – expert on climate change activism and particularly Extinction Rebellion (XR) and the use of civil disobedience. Follow on Twitter @berglund_oscar.

Land / Nature / Food

Dr Jo House – expert on land and climate interactions, including emissions of carbon dioxide from land use change (e.g. deforestation), climate mitigation potential from the land (e.g. afforestation, bioenergy), and implications of science for policy. Previously Government Office for Science’s Head of Climate Advice. Follow on Twitter @Drjohouse.

Professor Steve Simpson – expert marine biology and fish ecology, with particular interests in the behaviour of coral reef fishes, bioacoustics, effects of climate change on marine ecosystems, conservation and management. Follow on Twitter/X @DrSteveSimpson.

Dr Taro Takahashi – expert on farming, livestock production systems as well as programme evaluation and general equilibrium modelling of pasture and livestock-based economies.

Dr Maria Paula Escobar-Tello – expert on tensions and intersections between livestock farming and the environment.

Air pollution / Greenhouse gases

Dr Aoife Grant – expert in greenhouse gases and methane. Set up a monitoring station at Glasgow for COP26 to record emissions.

Professor Matt Rigby – expert on sources and sinks of greenhouse gases and ozone depleting substances. Follow on Twitter @TheOtherMRigby.

Professor Guy Howard – expert in contribution of waste and wastewater systems to methane emissions in low- and middle-income countries

Plastic and the environment

Dr Charlotte Lloyd – expert on the fate of chemicals in the terrestrial environment, including plastics, bioplastics and agricultural wastes. Follow on Twitter @DrCharlLloyd.

Cabot Institute for the Environment at COP28

We will have three media trained academics in attendance at the Blue Zone at COP28. These are: Dr Alix Dietzel (week 1), Dr Colin Nolden (week 2) and Dr Karen Tucker (week 2). We will also have two academics attending virtually: Dr Caitlin Robinson and Dr Katharina Richter.

Read more about COP on our website at https://bristol.ac.uk/cabot/what-we-do/projects/cop/
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This blog was written by Amanda Woodman-Hardy, Communications and Engagement Officer at the Cabot Institute for the Environment. Follow on Twitter @Enviro_Mand and @cabotinstitute.

Watch our Cabot Conversations – 10 conversations between 2 experts on a climate change issue, all whilst an artist listens in the background and interprets the conversation into a beautiful piece of art in real time. Find out more at bristol.ac.uk/cabot/conversations.

Arctic Ocean could be ice-free in summer by 2030s, say scientists – this would have global, damaging and dangerous consequences

Posted on June 8, 2023 by amanda.woodman-hardy

Ice in the Chukchi Sea, north of Alaska and Siberia.
NASA Goddard Space Flight Center

The Arctic Ocean could be ice-free in summer by the 2030s, even if we do a good job of reducing emissions between now and then. That’s the worrying conclusion of a new study in Nature Communications.

Predictions of an ice-free Arctic Ocean have a long and complicated history, and the 2030s is sooner than most scientists had thought possible (though it is later than some had wrongly forecast). What we know for sure is the disappearance of sea ice at the top of the world would not only be an emblematic sign of climate breakdown, but it would have global, damaging and dangerous consequences.

The Arctic has been experiencing climate heating faster than any other part of the planet. As it is at the frontline of climate change, the eyes of many scientists and local indigenous people have been on the sea ice that covers much of the Arctic Ocean in winter. This thin film of frozen seawater expands and contracts with the seasons, reaching a minimum area in September each year.

Animation of Arctic sea ice from space — Arctic sea ice grows until March and then shrinks until September.
NASA

The ice which remains at the end of summer is called multiyear sea ice and is considerably thicker than its seasonal counterpart. It acts as barrier to the transfer of both moisture and heat between the ocean and atmosphere. Over the past 40 years this multiyear sea ice has shrunk from around 7 million sq km to 4 million. That is a loss equivalent to roughly the size of India or 12 UKs. In other words, it’s a big signal, one of the most stark and dramatic signs of fundamental change to the climate system anywhere in the world.

As a consequence, there has been considerable effort invested in determining when the Arctic Ocean might first become ice-free in summer, sometimes called a “blue ocean event” and defined as when the sea ice area drops below 1 million sq kms. This threshold is used mainly because older, thicker ice along parts of Canada and northern Greenland is expected to remain long after the rest of the Arctic Ocean is ice-free. We can’t put an exact date on the last blue ocean event, but one in the near future would likely mean open water at the North Pole for the first time in thousands of years.

Annotated map of Arctic — The thickest ice (highlighted in pink) is likely to remain even if the North Pole is ice-free.
NERC Center for Polar Observation and Modelling, CC BY-SA

One problem with predicting when this might occur is that sea ice is notoriously difficult to model because it is influenced by both atmospheric and oceanic circulation as well as the flow of heat between these two parts of the climate system. That means that the climate models – powerful computer programs used to simulate the environment – need to get all of these components right to be able to accurately predict changes in sea ice extent.

Melting faster than models predicted

Back in the 2000s, an assessment of early generations of climate models found they generally underpredicted the loss of sea ice when compared to satellite data showing what actually happened. The models predicted a loss of about 2.5% per decade, while the observations were closer to 8%.

The next generation of models did better but were still not matching observations which, at that time were suggesting a blue ocean event would happen by mid-century. Indeed, the latest IPCC climate science report, published in 2021, reaches a similar conclusion about the timing of an ice-free Arctic Ocean.

As a consequence of the problems with the climate models, some scientists have attempted to extrapolate the observational record resulting in the controversial and, ultimately, incorrect assertion that this would happen during the mid 2010s. This did not help the credibility of the scientific community and its ability to make reliable projections.

Ice-free by 2030?

The scientists behind the latest study have taken a different approach by, in effect, calibrating the models with the observations and then using this calibrated solution to project sea ice decline. This makes a lot of sense, because it reduces the effect of small biases in the climate models that can in turn bias the sea ice projections. They call these “observationally constrained” projections and find that the Arctic could become ice-free in summer as early as 2030, even if we do a good job of reducing emissions between now and then.

Walruses on ice floe — Walruses depend on sea ice. As it melts, they’re being forced onto land.
outdoorsman / shutterstock

There is still plenty of uncertainty around the exact date – about 20 years or so – because of natural chaotic fluctuations in the climate system. But compared to previous research, the new study still brings forward the most likely timing of a blue ocean event by about a decade.

Why this matters

You might be asking the question: so what? Other than some polar bears not being able to hunt in the same way, why does it matter? Perhaps there are even benefits as the previous US secretary of state, Mike Pompeo, once declared – it means ships from Asia can potentially save around 3,000 miles of journey to European ports in summer at least.

But Arctic sea ice is an important component of the climate system. As it dramatically reduces the amount of sunlight absorbed by the ocean, removing this ice is predicted to further accelerate warming, through a process known as a positive feedback. This, in turn, will make the Greenland ice sheet melt faster, which is already a major contributor to sea level rise.

The loss of sea ice in summer would also mean changes in atmospheric circulation and storm tracks, and fundamental shifts in ocean biological activity. These are just some of the highly undesirable consequences and it is fair to say that the disadvantages will far outweigh the slender benefits.

This blog is written by Cabot Institute for the Environment member Jonathan Bamber, Professor of Physical Geography, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.