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

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.

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.

Jonathan Bamber
Jonathan Bamber

Arctic is warming nearly four times faster than the rest of the world – new research

New research estimates that the Arctic may be warming four times faster than the rest of the world.
Netta Arobas/Shutterstock

The Earth is approximately 1.1℃ warmer than it was at the start of the industrial revolution. That warming has not been uniform, with some regions warming at a far greater pace. One such region is the Arctic.

A new study shows that the Arctic has warmed nearly four times faster than the rest of the world over the past 43 years. This means the Arctic is on average around 3℃ warmer than it was in 1980.

This is alarming, because the Arctic contains sensitive and delicately balanced climate components that, if pushed too hard, will respond with global consequences.

Why is the Arctic warming so much faster?

A large part of the explanation relates to sea ice. This is a thin layer (typically one metre to five metres thick) of sea water that freezes in winter and partially melts in the summer.

The sea ice is covered in a bright layer of snow which reflects around 85% of incoming solar radiation back out to space. The opposite occurs in the open ocean. As the darkest natural surface on the planet, the ocean absorbs 90% of solar radiation.

When covered with sea ice, the Arctic Ocean acts like a large reflective blanket, reducing the absorption of solar radiation. As the sea ice melts, absorption rates increase, resulting in a positive feedback loop where the rapid pace of ocean warming further amplifies sea ice melt, contributing to even faster ocean warming.

This feedback loop is largely responsible for what is known as Arctic amplification, and is the explanation for why the Arctic is warming so much more than the rest of the planet.

Blocks of melting sea ice revealing a deep blue sea.
Melting sea ice in the Arctic Ocean.

Is Arctic amplification underestimated?

Numerical climate models have been used to quantify the magnitude of Arctic amplification. They typically estimate the amplification ratio to be about 2.5, meaning the Arctic is warming 2.5 times faster than the global average. Based on the observational record of surface temperatures over the last 43 years, the new study estimates the Arctic amplification rate to be about four.

Rarely do the climate models obtain values as high that. This suggests the models may not fully capture the complete feedback loops responsible for Arctic amplification and may, as a consequence, underestimate future Arctic warming and the potential consequences that accompany that.

How concerned should we be?

Besides sea ice, the Arctic contains other climate components that are extremely sensitive to warming. If pushed too hard, they will also have global consequences.

One of those elements is permafrost, a (now not so) permanently frozen layer of the Earth’s surface. As temperatures rise across the Arctic, the active layer, the topmost layer of soil that thaws each summer, deepens. This, in turn, increases biological activity in the active layer resulting in the release of carbon into the atmosphere.

Arctic permafrost contains enough carbon to raise global mean temperatures by more than 3℃. Should permafrost thawing accelerate, there is the potential for a runaway positive feedback process, often referred to as the permafrost carbon time bomb. The release of previously stored carbon dioxide and methane will contribute to further Arctic warming, subsequently accelerating future permafrost thaw.

A second Arctic component vulnerable to temperature rise is the Greenland ice sheet. As the largest ice mass in the northern hemisphere, it contains enough frozen ice to raise global sea levels by 7.4 metres if melted completely.

A man and woman standing on the edge of a flooded coastal road.
The Greenland ice sheet contains enough frozen ice to raise global sea levels by 7.4 metres if completely melted.

When the amount of melting at the surface of an ice cap exceeds the rate of winter snow accumulation, it will lose mass faster than it gains any. When this threshold is exceeded, its surface lowers. This will quicken the pace of melting, because temperatures are higher at lower elevations.

This feedback loop is often called the small ice cap instability. Prior research puts the required temperature rise around Greenland for this threshold to be be passed at around 4.5℃ above pre-industrial levels. Given the exceptional pace of Arctic warming, passing this critical threshold is rapidly becoming likely.

Although there are some regional differences in the magnitude of Arctic amplification, the observed pace of Arctic warming is far higher than the models implied. This brings us perilously close to key climate thresholds that if passed will have global consequences. As anyone who works on these problems knows, what happens in the Arctic doesn’t stay in the Arctic.The Conversation


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.

Introducing our IPCC blog series


This blog is the first part of a series from the Cabot Institute for the Environment on the Intergovernmental Panel on Climate Change’s recent Sixth Assessment Report (IPCC AR6). This post is an introduction to the blog series, explaining what we’re aiming to do here and with a glossary of some climate change terms that come up in the later posts. Look out for links to the rest of the series this week.

What is the IPCC?

The IPCC is the Intergovernmental Panel on Climate Change. Formed in 1988 by scientists concerned about the state of the global climate, they’ve been publishing assessment reports on the climate to advise policymakers and governments to act. This year they published their 6th assessment report (AR6), which has been described as their ‘starkest warning’ about the dangers of climate change. The report was built up of 3 Working Groups and over 2800 experts representing 105 countries covering different aspects, from the base science to the sociological impacts of a climate crisis. Alongside their assessment reports, the IPCC also publish special reports on key issues to explore them in more detail. These topics have included Land Use, Impact on the Ocean and Cryosphere and further clarifications on the goal of mitigating 1.5°C global warming.

The IPCC are the most trusted climate group worldwide, with their work being used in policy decisions all over the world.

What are the three Working Groups?

Each of the working groups focuses on a different part of the climate story, looking at causes, effects, and solutions.

• Working Group 1: The Physical Science Basis (WGI)

• Working Group 2: Impacts, Adaptation and Vulnerability (WGII)

• Working Group 3: Mitigation of Climate Change (WGIII)

What is this blog series covering?

The full reports are well over 1000 pages each, with many chapters, subchapters, and footnotes to wade through. As previously mentioned, the full report is split into the domains of the working groups.

Each report from the Working Groups is then filtered down into its own Summary for Policy Makers, which is still dense and features a lot of explanation of evidence. This is further broken down into the headline statements that get released to the press. Even at this level, it’s hard for ordinary members of the public to take the time to read all the evidence and digest the key points.

The aim of this campaign is to distil the key points in each Working Group report in a short, easily understood, and shareable blog as a tool for public outreach. As well as this, the campaign will feature voices from across the Cabot Institute for the Environment including IPCC authors from each of the working groups.

It’s a nearly impossible job trying to filter down the output of thousands of experts into a digestible snippet, but hopefully readers will come away more informed about the IPCC reports and the climate crisis than before.

This week, we’ll be sharing my report summaries here on the Cabot Institute for the Environment blog as well as on Twitter and LinkedIn, starting this Wednesday [27 July] on the output of Working Group I: The Physical Science basis. Keep an eye out for it!

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

Net Zero Oceanographic Capability: the future of marine research


Image credit: Eleanor Frajka-Williams, NOC.

Our oceans are crucial in regulating global climate and are essential to life on Earth. The marine environment is being impacted severely by multiple and cumulative stressors, including pollution, ocean acidification, resource extraction, and climate change. Scientific understanding of marine systems today and in the future, and their sensitivity to these stressors, is essential if we are to manage our oceans, and achieve the United Nations Sustainable Development Goals (SDGs). However, these systems are complex – with a vast array of interacting physical, chemical, biological and sociological components – and operate on scales of microns to kilometres, and milliseconds to millennia. To address these challenges, modern marine science spans a wide range of multidisciplinary topics, including understanding the fundamental drivers of ocean circulation, ecosystem behaviour and its response to climate change, causes of and consequences of polar ice cap melt, and the impacts of ocean warming on sea level, weather and climate. Marine scientists investigate problems of societal relevance such as food security, hazards relating to sea level rise, storm surges and underwater volcanoes, and understanding the consequences of offshore development on the health of the ocean in the context of building a sustainable blue economy. With the start of the UN Decade of Ocean Science for Sustainable Development in 2021, there is a clear motivation not only for more research, but for sustainable approaches.

However, a key challenge facing all scientists in the near future is the absolute necessity to reduce and mitigate all carbon emissions, achieving ‘Net Zero’. Among many of the high-impact pledges made over recent months, UK Research and Innovation (UKRI) have promised to achieve Net Zero by 2040. UKRI is the umbrella organisation encompassing all of the UK Research Councils including the Natural Environment Research Council, which funds the National Oceanography Centre and British Antarctic Survey to operate the large-scale UK marine research infrastructure.

Whilst marine science is intrinsically linked to Net Zero objectives since the ocean is a major sink of anthropogenic carbon and excess heat, the carrying out marine research itself contributes to the problem in question: ocean-going research vessels use considerable amounts of fossil fuels. Ship-based observations allow scientists to address global challenges, to support ocean observing networks, make measurements not possible via satellite, or in remote and extreme environments. Such observations are essential to establish a thorough picture of how the ocean is changing, and the underlying processes behind the complex interweaving of physics, chemistry, biology and geology within marine systems, but can only continue into the future if the carbon footprint of sea-going research is cut dramatically.

Image credit: Eleanor Frajka-Williams, NOC.


The Net Zero Oceanographic Capability (NZOC) scoping review, led by the National Oceanography Centre but supported by researchers from around the UK, is a groundbreaking project aimed at understanding the drivers and enablers of future oceanographic research in a Net Zero world. New technologies and infrastructure – together with multidisciplinary, international approaches, and collaborations with private and public sector stakeholders – are going to be increasingly important to advance understanding of the oceans and climate, while accomplishing Net Zero. The NZOC team are building a picture of a future research ecosystem that capitalises upon emerging technologies in shipping, marine autonomous systems (MAS) sensor technology and data science.  Ships will still be an essential linchpin of a new marine observing network, to gather critical information that may not be accessible using MAS, and to enable the maximum value to be extracted from datastreams collected during oceanographic expeditions.  The new Net Zero approaches have the potential to not just replace existing marine research capability with one less damaging to the environment, but also to expand and extend it, with new tools available more marine observing, new avenues of research opened up, and wider accessibility.  In order to achieve its potential, the development of new systems, and adaptation and improvement of existing methodologies, must be co-designed between technologists and scientists, including modellers and data scientists, as well as those engaged with sea-going observations.  Investment in an equitable, diverse and inclusive marine workforce must be considered from the beginning, with engagement in skills training for existing and future marine researchers so that scientists are primed to use the new approaches afforded by a Net Zero approach to their full potential.  All of these initiatives have to deliver on their promise in a co-ordinated way and in a short timeframe.  Many of them will rely upon global infrastructures and international systems that must similarly adapt at pace.

Image credit: Eleanor Frajka-Williams, NOC.

Environmental and climate scientists overwhelmingly and urgently support a move towards Net Zero. However, we cannot overstate the importance of getting the transition to Net Zero right. Whilst an ever-growing number of UK marine scientists are using MAS and low carbon options, NZOC also identified a number of case studies where achieving Net Zero will limit marine science – possibly permanently – if not addressed.  These include research areas where scientists need to drill into deep rock, or carry out intricate biological or geochemical experiments and measurements. Any transition to using new methods must be managed flexibly, requiring intersection between old and new technologies, due consideration to accessibility, and verification and validation by the wider scientific community.

Achieving Net Zero is one of the most important societal goals over the next decade. We can not only maintain but also build on marine science capability – essential for meeting Net Zero targets – with equitable and fair strategic planning, co-design of new approaches, and by taking advantage of new opportunities that arise from emerging technologies.

This blog is written by Cabot Institute member Dr Katharine Hendry is an Associate Professor in the School of Earth Sciences at the University of Bristol. With Contributions by Eleanor Frajka-Williams, National Oceanography Centre (NOC).
Dr Katharine Hendry


Equity, diversity and inclusivity at sea

In summer 2017 – for the first time that we know of! – all three of the main UK ships, the RRS Discovery (pictured, with Kate’s ICY-LAB science team!), the RRS James Cook and the RRS James Clark Ross were out at the same time on expeditions, all led by female chief scientists.
Today, we can celebrate a strong representation of women in sea-going science in the United Kingdom, providing positive role models and mentors to encourage and support early career female marine scientists. However, women continue to face challenges to their progression in their careers, especially those who are also members of other underrepresented groups. 

Dr Kate Hendry led a group of women from around the UK from a range of career stages and backgrounds, who are all active or recently active in sea-going research, with the aim of writing a discussion of equity, diversity and inclusivity (EDI) issues in UK marine science. The group has recently published an article in Ocean Challenge with a focus on both successes in gender equality over the last few decades and lessons learned for improving diversity of sea-going science further and more broadly into the future.

Some of the earliest female career marine scientists in the UK started off in fisheries research in the early twentieth century, including Rosa Lee (1884-1976), who was the first woman to graduate in Maths from Bangor University and the first woman to be employed by the Marine Biological Association. She worked at the Lowestoft Laboratory (that later became the Centre for Environment, Fisheries and Aquaculture Science, Cefas), and published highly-renowned articles including in Nature. “All of this, whilst never being allowed to step foot on a research vessel, and having to leave her employment in the civil service when she got married”, commented Dr Hendry.

Rosa Lee, one of the first female UK marine scientists, in a group of staff at the Marine Biological Association’s Lowestoft laboratory in 1907(Photo courtesy of Cefas)

Dr Hendry added: “As a science community, we’ve come a long way in terms of gender balance and representation, not only in the top science jobs but also in other roles at sea including crew and marine technicians. We wanted to document the history of how these changes happened, and whether any of the pathways to gender equity could be transferred to tackling other forms of underrepresentation in UK marine science, at all career levels”.

The article ends with some firm recommendations to the community to improve sea-going EDI into the future, including the formation of a special interest group by the UK marine science organisation, The Challenger Society, and guidance to the Natural Environment Research Council (NERC) for additional training, financial support, and recognition.


Cabot Institute member Dr Kate Hendry is an Associate Professor in the School of Earth Sciences at the University of Bristol.

Dr Kate Hendry



Innovating for sustainable oceans

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.

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

The future of sustainable ocean science

Westminster Central Hall

May 9th ushered in the 9th National Oceanography Centre (NOC) Association meeting, held among the crowds, statues, flags, and banners, at Central Hall in an unseasonably chilly and rainy Westminster. But it was the first such meeting where the University of Bristol was represented, and I was honoured to fly our own flag, for both University of Bristol and the Cabot Institute for the Environment.

NOC is – currently – a part of the Natural Environment Research Council (one of the UK Research Councils, under the umbrella of UKRI), but is undergoing a transformation in the very near future to an independent entity, and a charitable organisation in its own right aimed at the advancement of science. If you’ve heard of NOC, you’re likely aware of the NOC buildings in Southampton (and the sister institute in Liverpool). However, the NOC Association is a wider group of UK universities and research institutes with interests in marine science, and with a wider aim: to promote a two-way conversation between scientists and other stakeholders, from policy makers to the infrastructure organisations that facilitate – and build our national capability in – oceanographic research.

The meeting started with an introduction by the out-going chair of the NOC Association, Professor Peter Liss from the University of East Anglia, who is handing over the reins to Professor Gideon Henderson from Oxford University. The newly independent NOC Board will face the new challenges of changing scientific community, including the challenge of making the Association more visible and more diverse.

Professor Peter Liss, outgoing chair of the NOC Association,
giving the welcome talk

As well as the changes and challenges facing the whole scientific community, there are some exciting developments in the field of UK and international marine science in the next two years, which are likely to push the marine science agenda forward. In the UK, the Foreign Commonwealth Office International Ocean Strategy will be released in the next few months, and there is an imminent announcement of a new tranche of ecologically-linked UK Marine Protected Areas (MPAs) for consultation. On the international stage, a new Intergovernmental Panel on Climate Change special report on the Oceans and Cryosphere is due to be released in September; the Biodiversity Beyond National Jurisdiction (BBNJ) report on deep sea mining will be announced in the next few months; and the next United Nations Framework Convention on Climate Change (UNFCCC ) Conference of Parties (COP) climate change conference, scheduled for the end of this year in Chile, has been branded the “Blue COP”.

The afternoon was dedicated to a discussion of the upcoming UN Decade of Ocean Science for Sustainable Development, starting in 2021. With such a wealth of national and international agreements and announcements in next two years, the UN Decade will help to “galvanise and organise” the novel, scientific advice in the light of ever increasing and cumulative human impacts on the oceans.
Alan Evans, Head of the International and Strategic
Partnerships Office and a Marine Science Policy Adviser, giving a presentation
on the UN Decade of Ocean Science for Sustainable Development
The UN Decade is aligned strongly with the key global goals for sustainable development and has two overarching aims: to generate ocean science, and to generate policy and communication mechanisms and strategies. The emphasis is being placed on “science for solutions”, bringing in social scientists and building societal benefits: making the oceans cleaner, safer, healthier and – of course – all in a sustainable way.

Research and development priorities include mapping the seafloor; developing sustainable and workable ocean observing systems; understanding ecosystems; management and dissemination of open access data; multi-hazard warning systems (from tsunamis to harmful algal blooms); modelling the ocean as a compartment of the Earth system; and pushing for a robust education and policy strategy to improve “ocean literacy”.

Whilst these are exciting areas for development, the scheme is still in its very early stages, and there’s a lot to do in the next two years. As the discussion progressed, it was clear that there is a need for more “joined-up” thinking regarding international collaboration. There are so many international marine science-based organisations such that collaboration can be “messy” and needs to be more constructive: we need to be talking on behalf of each other. On a national level, there is a need to build a clear UK profile, with a clear strategy, that can be projected internationally. The NOC Association is a good place to start, and Bristol and the Cabot Institute for the Environment can play their parts.

Lastly, a decade is a long time. If the efforts are to be sustained throughout, and be sustainable beyond The Decade, we need to make sure that there is engagement with Early Career Researchers (ECRs) and mid-career researchers, as well as robust buy-in from all stakeholders. Whilst there are several national-scale organisations with fantastic programs to promote ECRs, such as the Climate Linked Atlantic Sector Science (CLASS) fellowship scheme and the Marine Alliance for Science and Technology for Scotland (MASTS) doctoral training program, this needs to be extended to ambitious international ECR networking schemes. Together with the future generation of researchers, we can use the momentum of the UN Decade make marine research sustainable, energised and diverse.


This blog is written by Dr Kate Hendry, a reader in Geochemistry in the University of Bristol School of Earth Sciences and a committee member for the Cabot Institute for the Environment Environmental Change Theme. She is the UoB/Cabot representative on the NOC Association, a member of the Marine Facilities Advisory Board (MFAB), and a co-chair of a regional Southern Ocean Observing System (SOOS) working group.

The social animals that are inspiring new behaviours for robot swarms

File 20190326 36252 wdqi1n.jpg?ixlib=rb 1.1
Termite team.
7th Son Studio/Shutterstock

From flocks of birds to fish schools in the sea, or towering termite mounds, many social groups in nature exist together to survive and thrive. This cooperative behaviour can be used by engineers as “bio-inspiration” to solve practical human problems, and by computer scientists studying swarm intelligence.

“Swarm robotics” took off in the early 2000s, an early example being the “s-bot” (short for swarm-bot). This is a fully autonomous robot that can perform basic tasks including navigation and the grasping of objects, and which can self-assemble into chains to cross gaps or pull heavy loads. More recently, “TERMES” robots have been developed as a concept in construction, and the “CoCoRo” project has developed an underwater robot swarm that functions like a school of fish that exchanges information to monitor the environment. So far, we’ve only just begun to explore the vast possibilities that animal collectives and their behaviour can offer as inspiration to robot swarm design.

Swarm behaviour in birds – or robots designed to mimic them?

Robots that can cooperate in large numbers could achieve things that would be difficult or even impossible for a single entity. Following an earthquake, for example, a swarm of search and rescue robots could quickly explore multiple collapsed buildings looking for signs of life. Threatened by a large wildfire, a swarm of drones could help emergency services track and predict the fire’s spread. Or a swarm of floating robots (“Row-bots”) could nibble away at oceanic garbage patches, powered by plastic-eating bacteria.

A future where floating robots powered by plastic-eating bacteria could tackle ocean waste.

Bio-inspiration in swarm robotics usually starts with social insects – ants, bees and termites – because colony members are highly related, which favours impressive cooperation. Three further characteristics appeal to researchers: robustness, because individuals can be lost without affecting performance; flexibility, because social insect workers are able to respond to changing work needs; and scalability, because a colony’s decentralised organisation is sustainable with 100 workers or 100,000. These characteristics could be especially useful for doing jobs such as environmental monitoring, which requires coverage of huge, varied and sometimes hazardous areas.

Social learning

Beyond social insects, other species and behavioural phenomena in the animal kingdom offer inspiration to engineers. A growing area of biological research is in animal cultures, where animals engage in social learning to pick up behaviours that they are unlikely to innovate alone. For example, whales and dolphins can have distinctive foraging methods that are passed down through the generations. This includes forms of tool use – dolphins have been observed breaking off marine sponges to protect their beaks as they go rooting around for fish, like a person might put a glove over a hand.

Bottlenose dolphin playing with a sponge. Some have learned to use them to help them catch fish.
Yann Hubert/Shutterstock

Forms of social learning and artificial robotic cultures, perhaps using forms of artificial intelligence, could be very powerful in adapting robots to their environment over time. For example, assistive robots for home care could adapt to human behavioural differences in different communities and countries over time.

Robot (or animal) cultures, however, depend on learning abilities that are costly to develop, requiring a larger brain – or, in the case of robots, a more advanced computer. But the value of the “swarm” approach is to deploy robots that are simple, cheap and disposable. Swarm robotics exploits the reality of emergence (“more is different”) to create social complexity from individual simplicity. A more fundamental form of “learning” about the environment is seen in nature – in sensitive developmental processes – which do not require a big brain.

‘Phenotypic plasticity’

Some animals can change behavioural type, or even develop different forms, shapes or internal functions, within the same species, despite having the same initial “programming”. This is known as “phenotypic plasticity” – where the genes of an organism produce different observable results depending on environmental conditions. Such flexibility can be seen in the social insects, but sometimes even more dramatically in other animals.
Most spiders are decidedly solitary, but in about 20 of 45,000 spider species, individuals live in a shared nest and capture food on a shared web. These social spiders benefit from having a mixture of “personality” types in their group, for example bold and shy.

Social spider (Stegodyphus) spin collective webs in Addo Elephant Park, South Africa.

My research identified a flexibility in behaviour where shy spiders would step into a role vacated by absent bold nestmates. This is necessary because the spider colony needs a balance of bold individuals to encourage collective predation, and shyer ones to focus on nest maintenance and parental care. Robots could be programmed with adjustable risk-taking behaviour, sensitive to group composition, with bolder robots entering into hazardous environments while shyer ones know to hold back. This could be very helpful in mapping a disaster area such as Fukushima, including its most dangerous parts, while avoiding too many robots in the swarm being damaged at once.

The ability to adapt

Cane toads were introduced in Australia in the 1930s as a pest control, and have since become an invasive species themselves. In new areas cane toads are seen to be somewhat social. One reason for their growth in numbers is that they are able to adapt to a wide temperature range, a form of physiological plasticity. Swarms of robots with the capability to switch power consumption mode, depending on environmental conditions such as ambient temperature, could be considerably more durable if we want them to function autonomously for the long term. For example, if we want to send robots off to map Mars then they will need to cope with temperatures that can swing from -150°C at the poles to 20°C at the equator.

Cane toads can adapt to temperature changes.
Radek Ziemniewicz/Shutterstock

In addition to behavioural and physiological plasticity, some organisms show morphological (shape) plasticity. For example, some bacteria change their shape in response to stress, becoming elongated and so more resilient to being “eaten” by other organisms. If swarms of robots can combine together in a modular fashion and (re)assemble into more suitable structures this could be very helpful in unpredictable environments. For example, groups of robots could aggregate together for safety when the weather takes a challenging turn.

Whether it’s the “cultures” developed by animal groups that are reliant on learning abilities, or the more fundamental ability to change “personality”, internal function or shape, swarm robotics still has plenty of mileage left when it comes to drawing inspiration from nature. We might even wish to mix and match behaviours from different species, to create robot “hybrids” of our own. Humanity faces challenges ranging from climate change affecting ocean currents, to a growing need for food production, to space exploration – and swarm robotics can play a decisive part given the right bio-inspiration.The Conversation

This blog was written by Cabot Institute member Dr Edmund Hunt, EPSRC Doctoral Prize Fellow, University of BristolThis article is republished from The Conversation under a Creative Commons license. Read the original article.

Edmund Hunt

Why we’re looking for chemicals in the seabed to help predict climate change

File 20190128 108370 ansjbe.jpg?ixlib=rb 1.1
Alex Fox, Author provided

Hidden in even the clearest waters of the ocean are clues to what’s happening to the seas and the climate on a global scale. Trace amounts of various chemical elements are found throughout the seas and can reveal what’s going on with the biological reactions and physical processes that take place in them.

Researchers have been working for years to understand exactly what these trace elements can tell us about the ocean. This includes how microscopic algae capture carbon from the atmosphere via photosynthesis in a way that produces food for much marine life, and how this carbon sequestration and biological production are changing in response to climate change.

But now scientists have proposed that they may also be able to learn how these systems were affected by climate change long ago by digging deep into the seabed to find the sedimentary record of past trace elements. And understanding the past could be key to working out what will happen in the future.

Trace elements can teach us an amazing amount about the oceans. For example, ocean zinc concentrations strikingly resemble the physical properties of deep waters that move huge quantities of heat and nutrients around the planet via the “ocean conveyor belt”. This remarkable link between zinc and ocean circulation is only just beginning to be understood through high-resolution observations and modelling studies.

Dissolved zinc concentrations in the oceans.
Reiner Schlitzer, data from eGEOTRACES., Author provided

Some trace elements, such as iron, are essential to life, and others, such as barium and neodymium, reveal important information about the biological productivity of algae. Different isotopes of these elements (variants with different atomic masses) can shed light on the types and rates of chemical and biological reactions going on.

Many of these elements are only found in vanishingly small amounts. But over the last few years, an ambitious international project called GEOTRACES has been using cutting-edge technological and analytical methods to sample and analyse trace elements and understand the chemistry of the modern ocean in unprecedented detail. This is providing us with the most complete picture to date of how nutrients and carbon move around the oceans and how they impact biological production.

Carbon factories

Biological production is a tangled web of different processes and cycles. Primary production is the amount of carbon converted into organic matter by algae. Net export production refers to the small fraction of this carbon bound up in organic matter that doesn’t end up being used by the microbes as food and sinks into the deep. An even smaller portion of this carbon will eventually be stored in sediment on the ocean floor.

As well as carbon, these algae capture and store a variety of trace elements in their organic matter. So by using all the chemical information available to us, we can get a complete view of how the algae grow, sink and become buried within the oceans. And by looking at how different metals and isotopes are integrated into ancient layers of sedimentary rock, we can reconstruct these changes through time.

Sampling the seabed.
Micha Rijkenberg, Author provided

This means we can use these sedimentary archives as proxy records of nutrient use and net primary production, or export production, or sinking rates. This should enable us to start answering some of the mysteries of how oceans are affected by climate change, not only in relatively recent Earth history but also in deep time.

For example, as well as enlightening us on active processes within the modern ocean, scientists have analysed what zinc isotopes are in seabed fossils from tens of thousands of years ago, and even in ancient rocks from over half a billion years ago. The hope is that they can use this information to reconstruct a picture of how marine nutrients have changes throughout geological history.

But this work comes with a note of caution. We need to bring our knowledge about modern biogeochemistry together with our understanding of how rocks form and geochemical signals are preserved. This will enable us to be sure that we can make robust interpretations of the proxy records of the prehistoric seabeds.

Collecting the samples.
Micha Rijkenberg, Author provided

How do we go about doing this? In December 2018, scientists from GEOTRACES met with members of another research project, PAGES, who are experts in reconstructing how the Earth has responded to past climate change. One approach we developed is to essentially work backwards.

First we need to ask: what archives (shells, sediment grains, organic matter) are preserved in marine sediments? Then, which of the useful metal and isotope signatures from seawater get locked up in these archives? Can we check – using material from the surface of deep-sea sediments – whether these archives do provide useful and accurate information about oceanic conditions?

The question can also be turned around, allowing us to ask whether there new isotope systems that have yet to be investigated. We want to know if GEOTRACES uncovered interesting patterns in ocean chemistry that could be the start of new proxies. If so, we might be able to use these ocean archives to shed light on
how the uptake of carbon in marine organic matter responds to, and acts as a feedback on, climate in the future.

For example, will a warmer world with more carbon dioxide enhance the growth of algae, which could then absorb more of this excess CO₂ and help to act as a break on man-made carbon emissions? Or will algae productivity decline, trapping less organic matter and spurring on further atmospheric warming into the future? The secrets could all be in the seabed.

This blog is written by Cabot Institute member Katharine Hendry, Reader in Geochemistry, University of Bristol and Allyson Tessin, Visiting research fellows, University of Leeds.  This article is republished from The Conversation under a Creative Commons license. Read the original article.