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

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

Indigenous strategies for community engagement to combat climate change in the Amazon

Posted on June 27, 2024 by amanda.woodman-hardy

View of the Tapajós River in the City of Santarém. Credit James Moura.

In the heart of the Amazon Rainforest, a group of young indigenous activists gathered to co-produce strategies for fostering community engagement through audiovisual production to combat climate change. Funded by the Cabot Institute for the Environment and the National Institute of Science and Technology for Amazon Biodiversity Synthesis, the voices of various indigenous peoples found collective strength to develop these strategies in the Lower Tapajós region in the city of Santarém at the Federal University of Western Pará.

This activity took place during the National Seminar of the Tapajós National Forest, which is celebrating its 50th anniversary. The organization of this workshop with young indigenous people began with Kumaruara indigenous leaders who participated in the Amazon Policy Synthesis Project (SynPAm) funded by the Cabot Institute and Policy Bristol at the University of Bristol. This project aimed to identify conservation strategies and gaps in knowledge production related to the Amazon region’s biodiversity. The project involved over 100 stakeholders (researchers, representatives of Non-Governmental Organizations, decision-makers, community leaders, indigenous and quilombola leaders) who engaged in interviews, focus groups, and participatory workshops. One of the suggestions from these various stakeholders was to develop activities where indigenous peoples would also facilitate knowledge production and mobilization processes.

Thus, one of the indigenous activists from the Kumaruara people proposed the development of a participatory workshop to create community engagement strategies through audiovisual production to the Kumaruara Territory Indigenous Council (@povokumaruara). The Indigenous Council collectively deliberated that they could co-facilitate the development of the workshop with the presence of some young indigenous leaders from different territories (see photo below).

Indigenous workshop facilitators. Credit: James Moura.

This activity was the only one co-facilitated by indigenous leaders at the National Seminar. The workshop was conducted collaboratively. The indigenous leaders began with a moment of connection and respect for the sacred spirituality present in the Lower Tapajós territory. With the blessings of the sacred beings, we proceeded to discuss how climate change has been affecting the different territories of the participants. Most of the workshop participants were indigenous people from other ethnic groups, with a small number of non-indigenous participants. A consensus among all present was that climate change is affecting different regions of the Amazon. They commented on how the regions are now drier, hotter, and with fewer fish in the rivers. There is also a greater presence of irregular fires in the region. They pointed out that there is a strong presence of agribusiness, mining, and illegal logging. These factors contribute to the worsening scenario related to climate change.

one of the conversation circle moments during the workshop — One of the conversation circle moments during the workshop. Credit: James Moura.

After this collective sharing moment, it was evaluated how we could produce strategies to promote community engagement to combat climate change. The participants identified that the collective production of audiovisual content could be an important strategy for community mobilization, denouncing human degradation actions in the territories, and raising awareness to fight climate change. The indigenous leaders commented that this struggle is collective. It requires the engagement of both indigenous and non-indigenous people to bring about a transformation in the ways of life of our society. Excessive consumption, waste production, and economic development models were identified as factors promoting global warming. The Kumuaruara indigenous people provided examples of some audiovisual productions they have developed in the territory (see more of these productions here: https://youtu.be/c0atRyk640k?si=Ksnwek1TblnMoPRe; https://youtu.be/i29UR49wwdo?si=3PW5JVKjn_mpf6F9).

Participatory activities took place with the organization of two subgroups, including indigenous and non-indigenous people. They reflected on the need to engage people about the impacts of climate change in the territories. A walk was facilitated on the Campus of the Federal University of Western Pará to identify possible causes and impacts of climate change. Participants reflected on the importance of being attentive to small actions that can increase global warming. They also highlighted the need to understand the impacts of large agribusiness, logging, and mining companies operating in the region. They said that the native forest, along with the rivers, has been destroyed by soybean plantations, cattle raising, illegal logging, and mining activities. Thus, the participants created audiovisual productions demonstrating these relationships, from small personal actions to the significant impacts of the logging, mining, and agribusiness sectors in the region. It is necessary to have a critical and attentive view of the entire production chain to identify whether that specific product being sold in the supermarket is not related to environmental degradation and deforestation in different parts of the world.

video production moment on the UFOPA campus — Video production moment on the UFOPA campus. Credit James Moura

The indigenous peoples of the Amazon, represented by young Kumaruara leaders, call on everyone to combat climate change through daily actions. These actions involve raising awareness of the impacts of climate change on our lives. They highlight the need to compare our contexts over the years and evaluate temperature, vegetation, and climatic events. Furthermore, with this more attentive understanding, we must change habits in a more sustainable and supportive way. Thus, we must understand the production chain of manufactured products and identify if a particular company has been associated with environmental degradation actions. Similarly, we should reduce our need to consume these products and try to consume with less excess. Finally, we must support the actions of indigenous communities worldwide and in the Amazon, which have historically worked on environmental conservation and mitigating climate change.

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This blog is written by Cabot Institute for the Environment members Dr James Moura, Community psychologist, Senior Research Associate of the Synthesis for Policy in Amazonia in the School of Biological Sciences; Dr Filipe França, Lecturer in the School of Biological Sciences; and Dr James Palmer, School of Geographical Sciences, University of Bristol.

Left to right: James Moura, Filipe Franca and James Palmer

On track for change: how to travel more sustainably to European conferences

Posted on June 24, 2024 by amanda.woodman-hardy

Train station at Bonn — Train station on the journey to Bonn

A significant part of the University’s carbon footprint comes from business travel and the Sustainability Team has published a Business Travel Toolkit to help staff choose the most appropriate and low carbon option. That’s why we were thrilled to hear about Alix Dietzel’s recent trip to Bonn Climate Conference, where she opted to travel by rail over flying. We caught up with her to find out how it went, and hopefully inspire more of our research community to do the same!

Can you share your reasons for going to the conference?

“I went to Bonn to observe the climate change negotiations ahead of the next Conference of the Parties (COP29) in Azerbaijan. These ‘intersessional’ negotiations mark the halfway point between COPs and it is a good chance to see what is on the table at the next COP, where we are after COP28 and what the major sticking points are. In addition, this year Dr Alice Venn, Dr Katharina Richter and myself, got the chance to present a ‘side-event’, which was selected from over 400 applications by the UNFCCC. We teamed up with C40 cities, Green Africa Youth Organization and the Youth Climate Change Council Alliance to discuss how to pursue inclusive urban climate policies.”

Why did you decide to travel by rail?

“My main consideration was the emissions. Bonn is 8-10 hours away by train – about the same amount of time it took me to get to Dubai by plane for COP28. I avoid flying when I can, but sometimes it is unavoidable due to practicalities. In this case, I was able to add two travel days to my itinerary by only attending the conference for four days. I don’t like to leave my four-year-old daughter for longer than a week – she needs me. I’m privileged to have her in full-time nursery and am married to a very involved father, which made it possible to leave for this long.”

Can you tell us about the journey?

“I did a four-leg journey. Bristol to London (1.5 hours), London to Brussels (2 hours), Brussels to Cologne (2 hours) and finally Cologne to Bonn (half an hour).

In terms of comfort, I preferred the train journey to flying! I’m quite tall and train seats are roomier, especially the Eurostar and ICE trains in Germany. There’s also free Wi-Fi, multiple plugs for charging, plenty of room for a laptop, and it’s easier to get up and buy snacks or stretch your legs on the train than on a plane.

The changes between trains were great for getting fresh air and trying foods from different countries. I haven’t been to three countries in one day before, and that is a perk – having lunch in London, a coffee break in Brussels and then dinner in Germany was a culinary treat!

I missed one connection due to a delayed train from London to Brussels, which meant I queued for 20 minutes to get a special ticket from the Eurostar counter. I was only delayed by an hour and it didn’t cost me any more money.”

Alix Dietzel at the Bonn climate change conference

How was your experience at the conference?

“I really enjoyed watching the intersessional negotiations because they felt more relaxed, honest, and open compared to the COPs where there is a lot of pressure to find agreement. It’s also a space where you can approach negotiators more easily, because things are less hectic. For example, I was able to have a chat with a UK negotiator and share a bit about my research with him between negotiations.

It’s much smaller than a COP. COP28 had 100k people present and sprawled over a huge venue that has not only the negotiations, but ‘exhibition spaces’ which have events, meaning at times there are about 400 talks at once you could attend! SB60 had 8,600 people and was contained in a single building. This makes it much easier to navigate and focus on the negotiations, with only 5-10 events overlapping at any one time.”

What would you say to colleagues considering land-based business travel instead of flying?

“Try it! Speak to the University’s business travel booking team at Clarity and consider your options. Even doing half of the journey by rail would have huge emissions savings and enable them to compare. I am mindful of equality and inclusion issues, such as caring responsibilities, and would reassure them that sometimes, you do have to fly, and that this is understandable.”

We estimate that Alix’s journey by rail saved 159kg of CO2 – the equivalent to heating an average home for nearly two months.

If you’d like to explore routes travelling over land rather than flying visit https://routezero.world/.

If you’re a member of staff considering how to take low impact business travel, visit the Business Travel Toolkit or contact the University of Bristol Business Travel Team.

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This blog has been written by Hannah Morgans, Sustainability Communications Project Officer and Dr Alix Dietzel, Senior Lecturer in Climate Justice in the School of Sociology, Politics and International Studies and Associate Director for Impact and Innovation at the Cabot Institute for the Environment. This blog has been reposted with kind permission from the University of Bristol’s Sustainability Team. View the original blog.

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.

The last ozone-layer damaging chemicals to be phased out are finally falling in the atmosphere

Posted on June 18, 2024 by amanda.woodman-hardy

The high-altitude AGAGE Jungfraujoch station in Switzerland is used to take measurements of Earth’s atmosphere.
Jungfrau.ch

Since the discovery of the ozone layer, countries have agreed and amended treaties to aid its recovery. The most notable of these is the Montreal protocol on substances that deplete the ozone layer, which is widely regarded as the most successful environmental agreement ever devised.

Ratified by every UN member state and first adopted in 1987, the Montreal protocol aimed to reduce the release of ozone-depleting substances into the atmosphere. The most well known of these are chlorofluorocarbons (CFCs).

Starting in 1989, the protocol phased out the global production of CFCs by 2010 and prohibited their use in equipment like refrigerators, air-conditioners and insulating foam. This gradual phase-out allowed countries with less established economies time to transition to alternatives and provided funding to help them comply with the protocol’s regulations.

Today, refrigerators and aerosol cans contain gases like propane which, although flammable, does not deplete ozone in Earth’s upper atmosphere when released. However, ozone-friendly alternatives to CFCs in some products, such as certain foams used to insulate fridges, buildings and air-conditioning units, took longer to find. Another set of gases, hydrochlorofluorocarbons (HCFCs), was used as a temporary replacement.

A collection of used refrigerators. — HCFCs can leak to the atmosphere from discarded fridges.
RichardJohnson/Shutterstock

Unfortunately, HCFCs still destroy ozone. The good news is that levels of HCFCs in the atmosphere are now falling and indeed have been since 2021 according to research I led with colleagues. This marks a major milestone in the recovery of Earth’s ozone layer – and offers a rare success story in humanity’s efforts to tackle climate-warming gases too.

HCFCs v CFCs

HCFCs and CFCs have much in common. These similarities are what made the former suitable alternatives.

HCFCs contain chlorine, the chemical element in CFCs that causes these compounds to destroy the ozone layer. HCFCs deplete ozone to a much smaller extent than the CFCs they have replaced – you would have to release around ten times as much HCFC to have a comparable impact on the ozone layer.

But both CFCs and HCFCs are potent greenhouse gases. The most commonly used HCFC, HCFC-22, has a global warming potential of 1,910 times that of carbon dioxide, but only lasts for around 12 years in the atmosphere compared with several centuries for CO₂.

As non-ozone depleting alternatives to HCFCs became available it was decided that amendments to the Montreal protocol were needed to phase HCFCs out. These were agreed in Copenhagen and Beijing in 1992 and 1999 respectively.

This phase-out is still underway. A global target to end most production of HCFCs is set for 2030, with only very minor amounts allowed until 2040.

Turning the corner on a bumpy road

Our findings show that levels of HCFCs in the atmosphere have been falling since 2021 – the first decline since scientists started taking measurements in the late 1970s. This milestone shows the enormous success of the Montreal protocol in not only tackling the original problem of CFCs but also its lesser known and less destructive successor.

Two graphs side by side showing a the climate warming and ozone-destroying influence of HCFCs declining from 2021. — The influence of HCFCs on the atmosphere is set to fall steadily.
Western et al. (2024)/Nature

This is very good news for the ozone layer’s continuing recovery. The most recent scientific prediction, made in 2022, anticipated that HCFC levels would not start falling until 2026.

Despite HCFC levels in the atmosphere going in the right direction, not everything has been smooth sailing in the phase-out of ozone-depleting substances. In 2019 a team of scientists, including myself, provided evidence that CFC-11, a common constituent of foam insulation, was still being used in parts of China despite the global ban on production.

The United Nations Environment Programme also reported that HCFCs were illegally produced in 2020 contrary to the phase-down schedule.

In 2023, I and others showed that levels of five more CFCs were increasing in the atmosphere. Rather than illegal production, this increase was more likely the result of a different process: a loophole in the Montreal protocol which allowed CFCs to be produced if they are used to make other substances, such as plastics or non-ozone depleting alternatives to CFCs and HCFCs.

Some HCFCs at very low levels in the atmosphere have also been shown to be increasing or not falling fast enough, despite few or no known uses.

Most of the CFCs and HCFCs still increasing in the atmosphere are released in the production of fluoropolymers – perhaps best known for their application in non-stick frying pans – or hydrofluorocarbons (HFCs).

HFCs are the ozone-friendly alternative that was developed and commercialised in the early 1990s to replace HCFCs, but their role as a potent greenhouse gas means that they are subject to international climate emission reduction treaties such as the Paris agreement and the Kigali amendment to the Montreal protocol.

The next best alternative to climate-warming HFCs is a matter of ongoing discussion. In many applications, it was thought that HFCs would be replaced by hydrofluoroolefins (HFOs), but these have created their own environmental problems in the formation of trifluoroacetic acid which does not break down in the environment and, like other poly- and per-fluorinated substances (PFAS), may pose a risk to human health.

A column of air-conditioning units attached to the exterior of a building. — HFOs enable air-conditioners to use less electricity than competing alternatives.
AndriiKoval/Shutterstock

HFOs are at least more energy-efficient refrigerants than older alternatives like propane, however.

Hope for the future

In discovering this fall in atmospheric levels of HCFCs, I feel like we may be turning the final corner in the global effort to repair the ozone layer. There is still a long way to go before it is back to its original state, but there are now good reasons to be optimistic.

Climate and optimism are two words rarely seen together. But we now know that a small group of potent greenhouse gases called HCFCs have been contributing less and less to climate change since 2021 – and look to set to continue this trend for the foreseeable future.

With policies already in place to phase down HFCs, there is hope that environmental agreements and international cooperation can work in combating climate change.

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This blog is written by Cabot Institute for the Environment member Dr Luke Western, Research Associate in Atmospheric Science, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Wisdom of Generations: Learning from the Hills and Valleys of the Northeast India

Posted on June 4, 2024June 4, 2024 by amanda.woodman-hardy

A tea garden in Dibrugarh, Assam. Image credit: Nborkakoty at English Wikipedia.

Northeast (NE) India is more than just a region on the map; it is a treasure trove of beautiful
natural landscapes and ecological wealth that plays an essential role in our planet’s health. As
we celebrate World Environment Day 2024 with the theme of restoration, let us highlight the
ecological richness of Assam and the other Northeastern states of India. From the slopes of
Arunachal Pradesh to the lowlands of Assam, the NE region is a biodiversity hotspot, home to
unique species found nowhere else on Earth. The more we explore this ecological richness,
the more we discover the wonders and mysteries it holds, sparking our curiosity and interest.

The scenic landscapes of the NE region exemplify a dynamic and harmonious relationship
between humans and nature. Indigenous communities here have cultivated a profound
repository of traditional ecological knowledge passed down through generations. The Bodos,
Mishings, Karbis, Nyishis, Angamis, Khasis, and many others have developed a deep-rooted
understanding of their natural surroundings through intimate interactions with forests, rivers,
and mountains.

One of the most remarkable aspects of this traditional wisdom is the extensive knowledge of
local plants and their uses. These communities have identified and utilized numerous plant
species for food, medicine, shelter, and rituals, demonstrating a profound understanding of
the ecological roles of each species. For instance, the Bodos have long made use of medicinal
plants like Bhut Jolokia (ghost chili) for their therapeutic properties, contributing to the
preservation of traditional healing practices. This knowledge not only highlights the ecological
and cultural diversity of the region but also supports sustainable development and
conservation efforts.

Beyond plant knowledge, these communities have developed sophisticated ecosystem
management practices. Indigenous forest management practices in NE India have
significantly contributed to maintaining biodiversity hotspots and preserving wildlife habitats.
Traditional agroforestry systems, such as jhum cultivation practiced by the Karbi and Khasi
tribes, have shown resilience to climate variability while supporting local livelihoods. According
to a recent United Nations report, indigenous peoples’ territories encompass about 80% of the
world’s remaining biodiversity, underscoring the importance of their stewardship in
conservation efforts.

The wisdom of the hills and valleys also embodies resilience—a capacity to adapt and thrive
amidst changing circumstances. Indigenous communities have overcome challenges like
floods, droughts, and shifting climates by drawing on their deep ecological knowledge.

According to the Indian State Forest Report 2021, Assam’s forest cover is around 35% of its
geographical area, highlighting its critical role in biodiversity conservation and carbon
sequestration. However, this forest cover is declining, and the region faces environmental and
climate challenges, including deforestation, riverbank erosion, and climate change impacts.

Preserving and promoting traditional ecological knowledge is crucial in the face of the global
climate crisis. According to UNESCO, indigenous communities’ traditional knowledge
significantly contributes to the sustainable management of natural resources, benefiting both
local communities and global biodiversity. Recognizing, valuing, and supporting these
practices are essential for environmental conservation, cultural identity, and community
resilience.

Celebrating the wisdom of Assam and Northeast India’s hills and valleys on World
Environment Day reminds us of the transformative power of indigenous knowledge.
Integrating their insights into broader restoration efforts can contribute to building a sustainable
future for all. By embracing the wisdom passed down through generations and augmenting it
with contemporary research and statistics, we, the #GenerationRestoration, can pave the way
toward ecological harmony and resilience in the years to come.

Let us change gears to the tea communities of the NE region. Assam also plays a vital role in
India’s tea production, boasting over 312 210 hectares of tea cultivation. These tea plantations
not only fuel the state’s economy but also hold significant cultural and ecological value. Assam
is among the world’s largest tea-producing regions, with an annual production of 500-700
million kilograms (Mkgs) of tea leaves. The tea industry employs a vast workforce and
supports livelihoods throughout the region, contributing significantly to India’s overall tea
production. The tea plantations in Assam are not only unique but also serve as a prime
example of the harmonious blend of agriculture and biodiversity conservation. The lush green
tea bushes are seamlessly intertwined with shade trees, providing a habitat for various birds
and insects. Assam’s tea is globally renowned for its robust flavor and represents a heritage
deeply rooted in the land and its ecosystems. However, climate and environmental changes
threaten these lush industries, impacting the ecological and socio-economic balance in the
region.

The government has launched several key initiatives to promote development, ecological
conservation, and socio-economic growth across the state. Notable initiatives include the
Assam Budget for Sustainable Development, Assam Tea Tribes Welfare Board, Jal Jeevan
Mission (Har Ghar Jal), Assam Arunodoi Scheme, Assam Green Mission, Assam Skill
Development Mission, and Assam Startup. Effective implementation of these programs aims
to address climate change, promote environmental conservation, and improve the overall
quality of life for the people of Assam. However, the success of these programs depends on
thorough execution at the grassroots level.

What unfolds in the remote corners of Assam reverberates across continents. The lessons
gleaned from this region—on biodiversity conservation, traditional knowledge integration, and
community-led resilience—are universal. They inform global discussions on sustainable
development, emphasizing the need for inclusive approaches that prioritize both people and
the planet.

This World Environment Day, let us heed the call of Northeast India—a call to action for
environmental engagement and climate action involving youth, communities, government
agencies, and non-profit organizations. The region’s youth must understand the challenges
facing their environment and take action to safeguard their communities and natural
surroundings amidst infrastructural growth and development for their own and future
generations. Climate mitigation and adaptation strategies tailored to the region’s unique
context are critical, including afforestation, sustainable agriculture, and flood management
solutions. Youth can lead the way in developing context-specific climate adaptation and
environment restoration strategies that respect local cultures and ecosystems. By immersing
themselves in environmental education, research, and activism, young students can amplify
their voices and influence decision-makers at all levels.

Assam and its neighboring states in India stand out as a distinctive and valuable addition to
the mosaic of Earth’s landscapes. They serve as a beacon of hope and possibility in our
collective journey toward planetary stewardship. The region’s unique natural heritage,
combined with its rich cultural and ethnic diversity, makes it an important site for scientific
research and cultural exchange. As we strive to better understand and protect our planet,
regions like Northeast India offer invaluable insights and opportunities for collaboration.

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This blog is written by Dr Jagannath Biswakarma, School of Earth Sciences, University of Bristol, UK. jagannath.biswakarma@bristol.ac.uk.

Haiku has captured the essence of seasons for centuries – new poems contain a trace of climate change

Posted on March 18, 2024 by amanda.woodman-hardy

A successful haiku could be described as a half-finished poem. Originating in Japan in the 17th century, the haiku uses a combination of sensory language, seasonal references, a sense of contrast and a focus on the present tense to share an experience between writer and reader.

It relies on the reader to “finish” the poem by employing their recollections of sensations and emotions to connect to the moment described as vividly as they do their own experiences.

Haiku often depict moments in a particular season by describing the behaviour of animals, the weather and the appearance of plants. With a new generation of haiku poets, there’s a whole new collection of work that reflects how seasons are changing as a result of rising global temperatures.

Could haiku poetry written more recently contain a trace of the changes wrought by our warming climate? That’s something one of us (Jasmin) set out to investigate by analysing haiku published in English over the last 30 years.

First, let’s learn how to read haiku.

Do the seasons feel increasingly weird to you? You’re not alone. Climate change is distorting nature’s calendar, causing plants to flower early and animals to emerge at the wrong time.

This article is part of a series, Wild Seasons, on how the seasons are changing – and what they may eventually look like.

What enables this brief poetic form to achieve its resonance is its use of negative space. A haiku is a poem in two parts – a fragment (one line) and a phrase (two lines), divided by a pause (signified by a line break or punctuation).

Related to the concept of ma in Japanese visual arts, which perceives empty space in an artwork as a positive entity, the negative space in haiku is a way in to the contemplative experience of the poem.

The following by Japanese poet Matsuo Basho (1644-94) is the most famous haiku ever composed:

old pond –

a frog leaps in

water’s sound

A frog in a pond surrounded by spawn. — Frogspawn is a harbinger of spring in the UK.
Lesley Andrew/Shutterstock

To write a different account of this same event, you could say something like a frog leapt into an old pond and made a sound. But the key distinction between the two is the negative space that follows Basho’s first line. It encourages the reader to pause, breathe and contemplate the old pond before they encounter the frog leaping and the sound of the water.

When our minds become still, and reflective, like the old pond, we witness the action of an animal living simply according to its nature. We perceive things just as they are. The result is an experience of interconnectedness: a realisation that we are not separate from the natural world, but a part of it.

In the following haiku by Basho we experience the season as both a physical setting and as a metaphor for emotional experience:

no-one walks

along this road but I

autumn evening

A tree-lined urban path in the evening. — Autumn’s arrival can be felt in falling leaves and earlier sunsets.
S_Oleg/Shutterstock

In a world of increasing anxiety and distraction, the negative space in a haiku affords us moments of reflection and invites us into a dialogue with the rest of the natural world.

It requires a sensitivity on the part of the reader, but its effect is to instil an appreciation for what surrounds us. Through a meaningful, felt awareness of the seasonal cycles, the reading and writing of haiku inspires a deeper connection to our environment.

How haiku is changing

I spent the summer of 2022 in my home office, consuming decades of haiku journals and anthologies, trying not to leave sweaty fingerprints on their ancient covers in the unnatural 40°C heat. As that year’s researcher-in-residence for the British Haiku Society, working on a project called Twisting Point, I was searching for tell-tale traces of climate change in the English-language haiku archives.

My goal was to contrast present-day haiku against older archival ones, using the differences between them to make readers sensitive to nature’s decline and to suggest how the English-language haiku form might be evolving due to climate change.

I was looking at 30 years’ worth of haiku. In the UK during this time flying insect populations have fallen by over 60%, 41% of wildlife species have decreased in abundance and the frequency of heatwaves, floods and other extreme weather have all increased. More than enough change has occurred in these three decades to manifest in the archives.

Yet, these changes emerge in a strange fashion. It’s hard to write about nature’s losses, and writers tend to do so unconsciously. Rather than tracking population declines in concrete terms, then, the language used around certain species has altered, becoming soaked in grief.

For example, over 25 years numbers of curlews, a wading bird, have halved in the UK. Earlier haiku described their powerful cry “lengthen[ing] the hill[s]”; a poem written in 2022 found them “calling across wintry mudflats, haunting the wind”. Similarly, since 2000, declining butterflies have moved from being a “cloud” common in the background of haiku to lone survivors “pushing against time”.

A wading bird in shallow water with a long, slender, curved beak. — Curlews use their crescent beaks to probe the soft intertidal mud for worms.
Emutan/Shutterstock

The archetypal seasonal words used in haiku are shifting too, disrupting centuries-long traditions of meaning and emotion. As winter has been squeezed into weeks, spring arrives earlier and frosts become tardier, snowdrops have become a symptom of the changing haiku form.

Here is a haiku published in the 1990s in the spring seasonal category (the traditional haiku date for spring’s beginning is February 4):

song of a greenfinch

a ray of sun on cold steps

and a few snowdrops

By 2022, snowdrops are emerging in December in this tanka (a slightly longer poem variety) by Ruth Parker:

Omicron triumphs

and sends Christmas packing – but in the garden

the delicate white hope

of snowdrops

Small white flowers. — Snowdrops are flowering earlier as the climate warms.
Daniel Chetroni/Shutterstock

I was struck by how few haiku seemed to address climate change. Twisting Point became my call to arms for haiku writers. Haiku are about intense moments of perception, in which “the vast is perceived in one thing”. But in addressing climate change so little, are English-language haiku really depicting “the vast”?

Since 2022 the issue has come to the fore, with The Guardian describing how Japanese haiku writers are “lost for words” in the face of climate change. Meanwhile, Twisting Point is to be republished in a journal of the New Zealand Poetry Society. The call to haiku arms is growing: the vast climate crisis is upon us, and we should write about it.

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This blog was written by Jasmin Kirkbride, Lecturer in Publishing, University of East Anglia and Paul Chambers, PhD Candidate in Creative Writing, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘Foul and loathsome’ or jewels of the natural world? The complicated history of human-frog relations

Posted on February 26, 2024 by amanda.woodman-hardy

When was the last time you saw a frog? Perhaps you came across one in your garden and wondered at its little hands, glossy skin and what looked very much like a contented smile.

Maybe you regularly see them on Instagram or TikTok, where “frog accounts” have proliferated in recent years. People share adorable cartoon frogs, coo over crocheted frogs or go gaga for frogs dressed in cute hats.

In fact, our fascination with frogs isn’t new. As our research has found, the history of human-frog relations is long and complicated – and not all of it is nice.

Why we love frogs

There is a rich history of people really loving frogs.

This is interesting, because many people much prefer mammals and birds over reptiles and amphibians.

But the frog is an exception – for a lot of reasons. People tend to be attracted to baby-like faces. Many species of frog have the large eyes characteristic of young animals, humans included.

Having no teeth and no sharp claws, they also do not seem to be immediately threatening, while many of them have beautiful skin colouring and some are improbably tiny.

Frogs are truly among the jewels of the natural world, unlike toads which – with their more mundane colours and “warty skins” – do not usually inspire the same sense of enchantment.

Their beauty connects us to the wider riches of a vibrant nature hidden from most people’s sight in the dense rainforests of the tropical regions.

And they also connect us to nature in our own backyards. At certain times of the year, they spontaneously appear in our gardens and ponds. They can feel like special visitors from the natural world.

Dissecting human feelings for frogs

Yet relationships between people and frogs haven’t always been so positive. In fact, frogs occupy complicated places across cultures all over the world.

In the Western tradition, the legacy of biblical and classical sources was both negative and longstanding.

References to frogs in the Bible rendered them the instrument of divine anger as a swarming plague.

An etching from the late 1700s shows a plague of frogs.
Wellcome Collection

Frogs challenged early modern zoological taxonomies, moving between classification as serpent, insect or reptile.

Perhaps their resistance to easy placement by humans explains the strong emotional language about them used by Swedish naturalist (and “father of modern taxonomy”) Carl Linnaeus.

When he considered the Amphibia in his 1758 Systema Naturae, he noted:

These foul and loathsome animals are abhorrent because of their cold body, pale colour, cartilaginous skeleton, filthy skin, fierce aspect, calculating eye, offensive smell, harsh voice, squalid habitation, and terrible venom.

In modern science, they sit in a branch of zoology, herpetology, that brings frogs together as “creeping animals” with snakes and lizards.

Frogs have also (or perhaps consequently) suffered in the service of science since at least the eighteenth century because it seemed to be possible to easily replicate experiments across multiple frog specimens.

Frogs were particularly crucial to the study of muscles and nerves. This led to ever more violent encounters between experimenters and frog bodies. Italian scientist Luigi Galvani, for example, did experiments in the late 18th century on legs of frogs to investigate what he thought of as “animal electricity”.

Legs of dissected frogs, and various metallic apparatus used to measure what was thought to be electricity flowing in animals — Scientist Luigi Galvani’s 18th-century diagrams of dissected frog legs and various metallic apparatus he used to measure what was thought to be electricity flowing in animals.
Library of Congress

In this sense, frogs were valued as significant scientific objects, their value lying in their flesh, their nervous systems, rather than in their status as living, feeling beings in the world.

In time, experiments with frogs moved beyond the laboratory into the classroom. In the 1930s, schoolchildren were expected to find frogs and bring them to school for dissection in biology classes.

This practice was, however, somewhat controversial, with opponents expressing sentimental attachment to frogs and concerns that such animal cruelty would lead to barbarism.

Recognising the fragility of frogs

So, our relationship with frogs is complicated. From the frogs of Aesop’s Fables to the meme Pepe the Frog, we have projected our own feelings and frustrations onto frogs, and exploited them for science and education.

Frogs have also borne the brunt of our failures as environmental stewards.

By 1990, the world was seeing a global pattern of decline in frog populations due to destruction and degradation of habitat for agriculture and logging, as well as a global amphibian pandemic caused by the chytrid fungus.

Climate change is also making life hard for many species. In 2022, over 40% of amphibian species (of which frogs and toads are by far the largest group) were threatened with extinction. Their vulnerability has seen the frog – especially the red-eyed tree frog – become a symbol for the environment more generally.

So we should delight in frogs and marvel at how beautiful and special they are while we still can, and consider how we might help save them.

Something to reflect on next time you are lucky enough to spot a frog.

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This blog is written by Susan Broomhall, Director, Gender and Women’s History Research Centre, Australian Catholic University; Andrea Gaynor, Professor of History, The University of Western Australia, and Cabot Institute for the Environment member, Dr Andy Flack, Senior Lecturer in Modern and Environmental History, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Labour scaling back its £28 billion green pledge will impact UK housing – and public health

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

The UK Labour party has announced its intention to reduce its £28 billion green investment pledge to less than £15 billion if elected this year. The political fallout has been been largely focused on the party’s fiscal credibility and leader of the opposition Keir Starmer’s seeming proclivity for U-turns.

A crucial question so far overlooked is what impact the cut would have on public health. The initial pledge included a key home-insulation plan to upgrade 72% – 19m homes – of the UK’s housing stock.

The revised plan, however, replaces that ambitious target with the more ambiguous statement that “millions of homes” will be refurbished. Research has long shown that uninsulated homes have consequences for health, especially for those living in poverty and in poor quality housing. This in turn places an extra burden on an already over-stretched health service.

A constructionn site. — Labour plans to build 1.5 million homes.
Shutterstock

Existing government failure

The wider societal cost of poor-quality housing in the UK is estimated at £18.6 billion a year. Such costs, however, are often ignored when housing policy is being developed and implemented.

Labour promises to deliver 1.5 million homes by “blitzing” the planning system, but it has so far ignored the potential consequences for public health.

Of course, the failure to factor in health is by no means unique to Labour policy. It is already embedded in the government’s approach. A recent academic review of government housing and transport policy found that health is notably absent, despite well-established evidence that urban spaces are making us ill. This shows that on the occasions where health is included, it is lower in a hierarchy of priorities compared to other agendas such as growing the economy.

For many years, government housing policy has been shaped by the numeric gap between supply and demand, rather than the type or quality of the housing stock. The mechanisms for delivering have been based on land release and planning reform. Successive housing policies have mentioned involving communities and supporting their health, social, and cultural wellbeing. But there have been no clear targets for ensuring house retrofit and house building positively impact public health.

In his 2010 independent review on how to reduce health inequalities in England, epidemiologist Michael Marmot showed that prioritising health in urban policies, like housing and transport, can have significant health benefits for local populations.

Our research project has shown that health should be made a central factor in all national policy and guidance that shapes urban spaces. The World Health Organization recommends explicitly including health in housing policy – and tracking its impact with recognised metrics. UK politicians have largely failed to respond.

Promising developments

In addition to positive developments in government, such as the Build Back Beautiful Commission, the opposition also has some promising ambitions. Labour is pledging to deliver a “prevention-first revolution”, in which it envisions a pro-active role for government in ensuring that everybody has the building blocks for a healthy life.

In its mission document for health policy, Labour says that retrofitting of millions of homes will “keep families warm rather than living in damp, mouldy conditions that give their children asthma”. The fact that the party is making explicit this link between housing and health signal is a potentially very positive step forward.

However, in all the furore about Labour scrapping its £28 billion pledge, this crucial link to public health has been entirely forgotten. Indeed, while Labour’s environmental policy has been carefully updated to revise and remove various targets, the preventative health agenda retains the now defunct promise to “oversee retrofitting of 19 million homes”. This is perhaps indicative of the extent to which policymakers just don’t think about health when they think about housing.

While the Conservative pledges for the next parliament remain unclear, analysis of their existing policies in government has found a failure to think about or measure the way housing and urban development policis impact health. Instead, it is merely assumed that housing policies will have positive health outcomes. Rather than making such assumptions, policymakers should be putting public health considerations at the centre of all their decision making.

To ensure that the impact any given policy has on public health is measured and acted upon, health needs to be an explicit urban planning policy outcome. It needs to be clearly defined, measurable, and built into policy implementation and political discourse.

It is also important that different government ministries and relevant stakeholders focused on public health, planning and the environment work together more effectively. Unhealthy homes should be a priority for both the housing minister and the health minister.

Healthier people are more economically productive. They have a smaller financial footprint on the NHS. In the long term, better preventative health is a key part of solving some of the UK’s biggest economic challenges, from labour shortages and sluggish productivity growth to stretched public finances.

Too often government policy is not often designed with the long-term in mind. Instead, short-term economic outcomes and political gains are prioritised – to the detriment of public health.

The best way for the government to protect public health is for every department to consider how their work impacts on it. If political and economic calculations about creating, scrapping and rescaling major projects continue to ignore health, however, politicians are likely to continue coming up with the wrong answers.

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This blog is written by Dr Jack Newman, Research Fellow, School for Policy Studies, University of Bristol and Dr Geoff Bates, Lecturer in Social Policy, Research Fellow, University of Bath.

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