Detectable impacts of Climate Change in the UK; a new review for the next Climate Change Risk Assessment

2022 was another year of “unprecedented” weather. Provisional figures indicate that it was the warmest so far recorded, with almost every month hotter than average. Much of the country had a notably mild New Year, despite the cold snap in mid-December. This was preceded by the third warmest autumn on record, and that by a scorching summer, with the hottest day ever recorded in July. But summer’s heat waves were also accompanied by a rise in the number of daily deaths across the country. People around the world are becoming increasingly more aware of events like these, and their impact in the UK is particularly concerning amidst the ongoing cost-of-living, energy, and NHS crises.

Aerial view of the Wennington wildfire, London, 19 July 2022. Source: Harrison Healey, Wikimedia Commons (CC BY 3.0).

Ahead of the Fourth UK Climate Change Risk Assessment (CCRA4), the Climate Change Committee (CCC) are asking what we know about the impact of past and present climate change on natural and human systems here in the UK specifically. At the global level, the 2021 IPCC sixth assessment working group I (AR6 WGI) report concluded: “It is unequivocal that human influence has warmed the atmosphere, ocean and land.” This single sentence has been informed by decades of research by people at the cutting edge of climate science, and the evidence to support it has grown stronger in every IPCC report since they began. The report goes on to say: “Human-induced climate change is already affecting many weather and climate extremes in every region across the globe.” In last year’s follow-up AR6 WGII report on impacts, adaptation, and vulnerability, an extensive assessment of the science led to the conclusion that the magnitude and proliferation of extremes caused by human-induced climate change were having widespread, adverse impacts on both nature and people. Last summer’s heatwaves, and the concurrent dangers to health, homes, and the environment, were a graphic illustration of the nature of such human-induced impacts.

The study of impacts that informed this conclusion is the remit of climate scientists who specialise in “detection and attribution”. This is about looking at what is changing around us and being able to pinpoint the cause(s) – and particularly, whether human-induced climate change is at the root. To inform CCRA4, the CCC have commissioned a joint Bristol and Exeter University team to conduct a comprehensive review of the detection and attribution of climate change in the UK. The first part will cover the detection and attribution of weather and climate changes in the UK, relevant to specific “Climate Impact Drivers”. The second will cover attribution of impacts on societal, infrastructural, economic, and biodiversity sectors. We aim to find out what studies have been done so far, where the gaps are, and whether they can be filled, or if they would require substantial new methodological or data advances. We aim to identify variables which are key drivers of multiple impacts, and, importantly, where further attribution analysis is needed – especially when the impacts are critical for UK risk.

Detection and attribution is a rapidly evolving field, with focus only relatively recently moving from meteorological attribution (e.g., weather extremes) to impact attribution (e.g., consequences for humans and ecosystems). Our systematic review of the literature and final report will be key to tying it all together, especially with the UK focus required by the CCC. But to be able to present the most up-to-date findings, and thus make informed recommendations, we need to ensure that we have considered all relevant studies. So, if you, or someone you know, has published on this topic – whether UK specific or not – we’d like to know about it! Help shape and inform the next UK Climate Change Risk Assessment.

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This blog was written by Regan Mudhar, Professor Dann Mitchell (University of Bristol), Professor Richard Betts and Professor Peter Stott (University of Exeter/UK Met Office).

Hydrological hazards across timescales

University of Bristol – Met Office Academic Partnership Meeting 

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

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

 

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

 

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

 

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

 

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

Cutting edge collaborative research – using climate data to advance understanding

 

Perhaps you saw my recent blog post about an upcoming University of Bristol-led hackathon, which was to be part of a series following the Met Office’s Climate Data Challenge in March. The University of Bristol hackathon took place virtually earlier this month and was opened out to all UK researchers to produce cutting-edge research using Climate Model Intercomparison Project 6 (CMIP6) data. The event themes ranged from climate change to oceanography, biogeochemistry and more, and, as promised, here’s what happened.

An enabling environment

The event wouldn’t have run smoothly without the hard work of the organising team including James Thomas from the Jean Golding Institute who set up all the Github documentation and provided technical support prior and during the hackathon event. The hackathon was also a great opportunity to road test a new collaboration space that the Centre for Environmental Data Analysis (CEDA) have developed to provide a new digital platform, JASMIN Notebook Service.

As part of the introduction to the event, Professor Kate Robson Brown, Jean Golding Institute director, spoke about data science and space-enabled data. This was an excellent talk especially in terms of making connections through data and training events – you can watch her speech here. If you’re interested in more on this, there’s a data week 14-18 June 2021 for University of Bristol and external participants with details here.

Collaborating for results

Altogether there were over 100 participants at the hackathon with people involved from across the Met Office Academic Partnership (MOAP) universities and the Met Office as well as participants from across the world. There were ten project themes for delegates to work around and, as with the Met Office Climate Data Challenge, I was astounded by how far the teams got over the three days. Given the CMIP6 theme, it was great to see many projects advance our understanding by updating and improving previous model evaluation and projection analyses with the new CMIP6 datasets.

Given the work that I am involved in at the Met Office on visualisation and communication, I was particularly impressed by the thought that went into making important Intergovernmental Panel on Climate Change (IPCC) figures interactive. In three days, the team working on this managed to process data and produce a working demonstration that made the results pop out of the page.

Also related to my work on using climate data to understand impacts, another project which caught my eye looked at how the Artic Tern’s migration would be affected by changes in wind regimes and sea ice in the CMIP6 ensemble. Of particular note was the creation of a “digital arctic tern” to simulate their migratory flight path.

What’s next?

There’s lots more I could say about this excellent event, and many thanks to colleagues at the University of Bristol for hosting the hackathon. Now I am looking forward to seeing how some of the work will develop further in terms of journal papers and potentially being showcased at the UN Climate Change Conference (COP26) in Glasgow in November.

#ClimateDataChallenge

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This blog is written by Dr Fai Fung, Science Manager at the Met Office and Senior Research Fellow at the University of Bristol.

Dr Fai Fung

 

 

University of Bristol welcomes five Met Office Research Scientists as part of the new Met Office Academic Partnership

 

Image Credit: Federico Respini on Unsplash

In spring of 2020 the University of Bristol joined a prestigious alliance of the Met Office and six University Research Institutes that brings together expertise in weather and climate science.  The exciting, new Bristol Met Office Academic Partnership (MOAP) is focussed on the theme of “weather and climate hazards for decision making.” The aim is to align research interests through combining the Met Office world-leading ability in weather forecasting and the hazard and impact modelling expertise we have at Bristol.

A core part of the MOAP is to embed Met Office expertise within the University and to develop cross-disciplinary research in our key theme areas. We are, therefore, delighted to announce five new part-time Joint Bristol – Met Office Faculty members of staff who began working with us at the beginning of April.

Our Joint MOAP Chair based at the Met Office, Professor Chris Hewitt commented:

“We were delighted to welcome the University of Bristol to the Met Office Academic Partnership last year, and are excited that there will be five new joint faculty positions for Met Office scientists to cement the collaboration with the University’s experts working on research topics of mutual interest.”

The collaborative research will come under four interchangeable, themes:

  • Weather, climate and environmental hazards (e.g. volcanic hazards, heat waves, storms).
  • Impact and risk-based predictions.
  • Resilience to hazards and weather.
  • Climate services for making decisions.

The theme areas are co-led by eight University of Bristol researchers from Earth Sciences, Geographical Sciences and Civil Engineering and eight Met Office scientists. The new positions will work closely with the theme co-leads and have been strategically placed across the University Faculties to enhance collaboration and develop new research opportunities, particularly in the lead up to COP26.

University of Bristol-based MOAP Joint Chair, Dr Dann Mitchell says:

“We are really excited with the new joint faculty positions starting at Bristol. They represent the full spectrum of our partnership with the Met Office, from fundamental science for weather and climate hazards, to end user engagement. They will sit across three of our faculties and help solidify cross-disciplinary links between weather and climate, and the impacts on society, such as through health and hydrological modelling.”

The Faculty of Science welcomes three of the appointments: Dr Lizzie Kendon, a Science Manager and Met Office Fellow looking at high impact weather events using very high-resolution climate models, Dr Matt Palmer who leads the team at the Met Office who research sea level and ocean heat content and Dr Joseph Daron a Science Manager for International Climate Services at the Met Office.

The Faculty of Engineering welcomes our fourth appointment Dr Fai Fung who is the UK Climate Projections Climate Services Manager.. Our fifth appointment, Dr Dan Bernie, is the Science Manager for the UK Climate Resilience Team at the Met Office and is welcomed by the Faculty of Health Sciences. With regular MOAP meetings underway and events such as the CMIP6 Data Hackathon now open for applications we are excited to begin working with our new colleagues to develop a strong, collaborative relationship between Bristol and the Met Office.

The new appointments will work closely with The Cabot Institute for the Environment, Jean Golding Institute and Elizabeth Blackwell Institute to deliver cutting-edge research in weather and climate science

For further enquiries about the MOAP we can be contacted at bris-moap-coordinator@bristol.ac.uk.

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This blog is written by Dr Emma Stone (Bristol MOAP Project Manager).

Emma’s role as MOAP project Manager, previously with a background in climate science, is to assist with and coordinate MOAP-related activities working alongside the MOAP Joint Chairs, Research Advisory Panel and theme co-leads to identify potential research opportunities between the University and the Met Office and see these through to development. Emma is a key point of contact for internal and external researchers, collaborators, funders and support staff.

Dr Emma Stone

 

 

 

 

 

Image at start of article credit: Federico Respini on Unsplash

Why snow days are becoming increasingly rare in the UK

A snowy start to the day at Watlington station, King’s Lynn. December 18 2009.
Lewis Collard/Wikipedia

Winter frost fairs were common on the frozen River Thames between the 17th and 19th centuries, but they’ve become unimaginable in our lifetime. Over decades and centuries, natural variability in the climate has plunged the UK into sub-zero temperatures from time to time. But global warming is tipping the odds away from the weather we once knew.

These days, people in the UK have become accustomed to much warmer, wetter winters. In fact, winter is warming faster than any other season. This is bad news for those holding out for a white Christmas – the Met Office reports that only four Christmases in over five decades recorded snow at more than 40% of UK weather stations.

Painting of people, tents and horse-drawn carriages on the frozen river.
A frost fair on the River Thames, painted by Thomas Wyke (1683-1684).
Thomas Wyke/Wikipedia

Christmas is a magical day for many, but meteorologically, it’s no different from other winter periods, when snow and ice are also becoming less common. The Met Office definition of a snow day at a given location in the UK is when snow lies on at least 50% of the ground at 9am. Currently, the Cairngorms around Aviemore receive over 70 snow-lying days per year – the most in the UK.

This amount is smaller than in previous decades though. Met Office data shows that, since 1979, the number of snow-lying days has generally decreased by up to five days per decade, and up to ten days per decade in the North Pennines, near Penrith. Around a fifth of the total area of the UK has experienced a significant drop in the prevalence of days with snow lying on the ground.

Two maps of the UK depicting the change in prevalence of snow days throughout the UK from 1971-2019.
Snow days are a rarer occasion in the UK today than they were five decades ago.
Met Office, Author provided

What causes snow days?

Snow days are often the result of a meandering jet stream, the fast-flowing current of air that’s between 9km and 16km above the Earth’s surface. The jet stream normally transports temperate weather from the Atlantic across the UK, but if it’s displaced southwards, it allows persistent high pressure systems of colder air from the north and east, originating in the Arctic or over the Eurasian continent, known as blocking high pressures, to settle over the UK for extended periods.

A number of atmospheric processes can cause the jet stream to meander, but perhaps the most dramatic is when the stratospheric polar vortex, a huge rotating air mass in the middle atmosphere, breaks down. This disruption causes the jet stream to weaken, leading to events such as the infamous 2018 Beast from the East, which brought widespread snowfall to the UK.

The winter of 2018 was not unique in this sense – 2009-2010 and 2013 both brought snowfall because of these dynamic “beasts”. So why is there still a decline in winter snow days in the UK?

The snows of yesteryear

There’s no strong evidence for a long-term trend in polar vortex disruptions, or other atmospheric processes that influence the jet stream. So the fact that people in the UK have fewer snow days to enjoy each year than they did in the past can’t be blamed on the invisible twists and turns above their heads.

But as the concentration of CO₂ in the atmosphere climbs, disruptions that do occur sit on top of increasing background temperatures, reducing the likelihood of the cold spells that bring widespread snowfall. Just as natural climate trends have lowered the severity of winters since the days of the frost fairs, man-made climate change will increasingly keep the UK’s average temperature above zero.

A heavy covering of snow can transform the country and our perception of it. Snow days, with the closures of schools and workplaces that they bring, evoke fond memories and bring out the child in many as hillslopes and parks become sledging highways. More tangibly, in Scotland, the snowsports industry is estimated to be worth over £30 million a year.

But wintry weather can be dangerous too. The cold affects our health, exacerbating heart and lung conditions and the spread of infectious diseases. In extreme cases, heavy snowfall can cause widespread livestock deaths, which happened in Northern Ireland in 2013. The inevitable disruption to travel and businesses can cause economic damage running into billions of pounds, with sectors like the construction industry halted entirely.

While the falling chances of a white Christmas might disappoint many, the current trajectory of less and less snow will at least come as a relief to some.The Conversation

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This blog is written by Cabot Institute members Dr Alan Thomas Kennedy-Asser, Research Associate in Climate Science, University of Bristol; Dr Dann Mitchell, Met Office Co-Chair in Climate Hazards, University of Bristol, and Dr Eunice Lo, Research Associate in Climate Science, University of Bristol.

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

Dann Mitchell
Alan Kennedy-Asser
Eunice Lo

 

Predicting the hazards of weather and climate; the partnering of Bristol and the Met Office

Image credit Federico Respini on Unsplash

When people think of the University of Bristol University, or indeed any university, they sometimes think of academics sitting in their ivy towers, researching into obscurities that are three stages removed from reality, and never applicable to the world they live in. Conversely, the perception of the Met Office is often one of purely applied science, forecasting the weather; hours, days, and weeks ahead of time. The reality is far from this, and today, on the rather apt Earth Day 2020, I am delighted to announce a clear example of the multidisciplinary nature of both institutes with our newly formed academic partnership.

This new and exciting partnership brings together the Met Office’s gold standard weather forecasts and climate projections, with Bristol’s world leading impact and hazard models. Our partnership goal is to expand on the advice we already give decision makers around the globe, allowing them to make evidence-based decisions on weather-related impacts, across a range of timescales.

By combining the weather and climate data from the Met Office with our hazard and impact models at Bristol, we could, for instance, model the flooding impact from a storm forecasted a week ahead, or estimate the potential health burden from heat waves in a decade’s time. This kind of advanced knowledge is crucial for decision makers in many sectors. For instance, if we were able to forecast which villages might be flooded from an incoming storm, we could prioritise emergency relief and flood defenses in that area days ahead of time. Or, if we projected that hospital admissions would increase by 10% due to more major heatwaves in London in the 2030s, then decision makers could include the need for more resilient housing and infrastructure in their planning. Infrastructure often lasts decades, so these sorts of decisions can have a long memory, and we want our decision makers to be proactive, rather than reactive in these cases.

While the examples I give are UK focussed, both the University of Bristol and the Met Office are internationally facing and work with stakeholders all over the world. Only last year, while holding a workshop in the Caribbean on island resilience to tropical cyclones; seeing the importance of our work the prime minister of Jamaica invited us to his residence for a celebration. While I don’t see this happening with Boris Johnson anytime soon, it goes to show the different behaviours and levels of engagement policy makers have in different countries. It’s all very well being able to do science around the world, but if you don’t get the culture, they won’t get your science. It is this local knowledge and connection that is essential for an international facing partnership to work, and that is where both Bristol and the Met Office can pool their experience.

To ensure we get the most out of this partnership we will launch a number of new joint Bristol-Met Office academic positions, ranging from doctoral studentships all the way to full professorships. These positions will work with our Research Advisory Group (RAP), made up of academics across the university, and be associated with both institutes. The new positions will sit in this cross-disciplinary space between theory and application; taking a combined approach to addressing some of the most pressing environmental issues of our time.

As the newly appointed Met Office Joint Chair I will be leading this partnership at Bristol over the coming years, and I welcome discussions and ideas from academics across the university; some of the best collaborations I’ve had have come from a random knock on the door, so don’t be shy in sharing your thoughts.

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This blog is written by Dr Dann Mitchell – Met Office Joint Chair and co-lead of the Cabot Institute for the Environment’s Natural Hazards and Disaster Risk research.
You can follow him on Twitter @ClimateDann.

Dann Mitchell

UK Climate Projections 2018: From science to policy making

On a sunny day earlier this week, I attended the UK Climate Projections 2018: From science to policy making, meeting in Westminster on behalf of the Cabot Institute. Co-hosted by the All-Party Parliamentary Climate Change Group and the UK Met Office, the main purpose of this event was to forge discussions between scientists involved in producing the latest UK Climate Projections (UKCP18) and users from various sectors about the role of UKCP18 in increasing the UK’s preparedness of future climate change.

Many people in my constituency come and ask about climate change every day.

The event began with an opening remark by Rebecca Pow, the MP for Taunton Deane in Somerset. Somerset has seen some devastating floods over the years, and a new land drainage bill was passed a week prior to manage flood risk in the area. Constantly faced with questions from her constituents about climate change, Rebecca is particularly interested in regional climate change, both at present and in the future, and any opportunities that may arise from it.

Everyone would like a model of their back garden.

Prof Sir Brian Hoskins, the Founding Director and Chair of the Grantham Institute for Climate Change and the Environment, and Professor in Meteorology at the University of Reading, gave an overview on climate projection. He listed three main sources of uncertainty in 21st century climate projection: internal variability, model uncertainty, and human activity uncertainty. Climate scientists deal with these uncertainties by using large ensembles of simulations, a range of climate models, and a range of climate scenarios. However, there is always tension between model resolution, complexity and the need for many model runs in global climate projections due to constraints in computer resources. Regional climate models can be embedded in global domains to provide local weather and climate information, but they cannot correct large scale errors. The peer-reviewed UKCP18 provide both the statistics of global climate by combining data from different climate models and runs, and regional daily data for the UK and Europe.

A greater chance of warmer, wetter winters and hotter, drier summers.

This was one of the headline results from UKCP18 shown by Prof Jason Lowe, Head of Climate Services for Government at the Met Office Hadley Centre. UKCP18 is an update from its predecessor, UKCP09, but with constraints from new observations and data from more climate models from around the world. The horizontal resolution of regional climate projections for the UK and Europe has increased from 25 km in UKCP09 to 12 km in UKCP18, with an even higher resolution (2.2 km) dataset coming out in summer 2019. UKCP18 results show that all areas of the UK are projected to experience warming, with greater warming in the summer than the winter. Summer rainfall is expected to decrease in the UK, whereas winter precipitation is expected to increase. However, when it rains in summer it may rain harder. Sea-level rise will continue under all greenhouse gas emission scenarios at all locations around the UK, impacting extreme water levels in the future.

Heat and health inter-connections are complex.

Prof Sarah Lindley, Professor of Geography at the University of Manchester, shared how UKCP18 could be used to study the health effects of climate change and urban heat in the UK. Many of us would remember how hot it was last summer; by 2050, hot summers of that type may happen every other year, even under a low greenhouse gas emission scenario. The most extreme heat-related hazards are in cities due to the Urban Heat Island effect (UHI), i.e. urban areas are often warmer than surrounding rural areas. For instance, Manchester’s UHI intensity (difference between urban and rural temperatures) has increased significantly since the late 1990s. By the end of this century, the city of Manchester is projected to be 2.4ºC warmer than its surrounding rural area in a UKCP09 medium emission scenario. With an aging population, UK’s vulnerability to heat may increase in the future. Both exposure and vulnerability to heat contribute to heat disadvantage. High-resolution UKCP18 data, together with social vulnerability maps of the UK, provide new opportunities to heat disadvantage and adaptation research.

European birds will need to shift about 550 km north-east under 3ºC warming.

The next speaker was Dr Olly Watts, Senior Climate Change Policy Officer for the RSPB, the largest nature conservation charity in the UK. Climate adaptation is an important aspect of nature conservation work, as it should be in everyone’s work. The Climatic Atlas of European Breeding Birds finds that not only will European birds shift 550 km under a likely 3ºC increase in global average temperature, but also a quarter of the bird species will be at high risk. Currently 5000 bird species are changing species distribution, and they face an uncertain future. The UKCP18 data of 2-4ºC warmer worlds could be used to derive qualitative strategies to build wildlife resilience against climate change. Adaptation strategies including informing nature reserve management will be in place across the RSPB conservation programme. The RSPB will also use UKCP18 data to raise public awareness of climate change.

Water demand can increase by 30% on a hot day.

Dr Geoff Darch, Water Resources Strategy Manager at Anglian Water, began his talk by highlighting the inherent climate vulnerabilities in water management in the East of England. It is a “water stressed” region that has low lying and extensive coastline, sensitive habitats, and vulnerable soils. On a hot day, water demand can go up by 30%. Climate change alone is expected to have a total impact of 55 Ml/day on water supplies in the region by 2045. A growing risk of severe drought means an additional impact of 26 Ml/day is expected, not to mention the impacts of population growth. The water industry is proactively adapting to these challenges by setting up plans to reduce leakage and install smart meters for customers. UKCP09 has been used extensively for climate change risk assessment across the water sector; the latest UKCP18 could be used in hydrological modelling, demand modelling, storm impact modelling, flood risk assessment, and sensitivity testing to assess the robustness of water resources management solutions under a range of climate scenarios.

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This blog was written by Cabot Institute member Dr Eunice Lo, from the School of Geographical Sciences at the University of Bristol. Her research focusses on climate change, extreme weather and human health.

Dr Eunice Lo

 

A shower of change with gusts of discontent

“This is 2LO calling, the London station of the British Broadcasting Company calling. This is 2LO calling”

Such was the first broadcast ever issued by the BBC on 14th November 1922 from the organisation’s 2LO Office in London. The message was received by any radio within a 30 mile radius and was the inaugeration of the British Broadcasting Corporation.  Integrated in the announcement was a weather bulletin prepared by the Met Office which marked the beginning of a partnership which has supplied the British public’s appetite for weather-related conversation for 93 years.

Despite the longevity of this relationship, it was not immune to the BBC’s ever-tightening pockets and last month it was announced the Met Office is to become the latest casualty of the corporation’s modernisation. The BBC blames the split on the Met Office’s uncompetitive price, while rumours suggest that the problem runs deeper with a difference of opinion over the way the forecast should be communicated to the public. Those who are hoping the Met Office will be in the running for the re-tendering process are likely to be disappointed. The early rejection of the Met Office’s offer implies that more was at stake than just the money and any hope of a renewal is a low probability.

Whatever the outcome, the BBC weather forecast, which spans local news to the world service, is estimated to reach a quarter of a billion people weekly and the changes are certain to have an impact on how the world watches the weather. The Met Office is ranked as the world’s most accurate forecasting body, so is the BBC sacrificing it’s credibility on the alter of austerity? Or could there be a sunny outlook?

There are plenty of alternatives to the Met Office, with Dutch and New Zealand firms rumoured to be in the running for the £35.2 million contract. This, it seems, is adding insult to injury for some disgruntled members of the British public with cries of discontent along the lines of ‘Heaven forbid a foreign firm should predict the British weather; how could they possibly understand it’s temperamental disposition?’ (the fact that the majority of the UK’s weather is governed by global climate systems seems to be irrelevant in this). Even if the BBC resolves to look closer to home, there is a reasonable list of UK alternatives; The Weather Channel, Net Weather and The Weather Outlook to name a few although whether they have the capability to handling the BBCs expansive demands is a different matter altogether.

As the storm clouds gather over BBC HQ, the new provider will be announced next year after the tendering process. In short, it is uncertain who will be giving Britons their daily weather-fix although there is no doubt the BBC will be battening down the hatches to endure yet another tornado of discontent from license payers when the replacement made. Personally, I’ve never felt the weather pays much attention to the forecast regardless of the provider: In fact, the element of surprise is what makes being caught in the rain in my flip flops and snowed on in my swimsuit part of the paradoxical joy of inhabiting this country. Long may it continue I say.

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This blog is written by Cabot Institute member Keri McNamara, a PhD student in the School of Earth Sciences at the University of Bristol.

Professor Dame Julia Slingo: Modelling climate risk

When Professor Dame Julia Slingo visited the Cabot Institute last week, her message was clear: We need to look at climate risk in real world contexts.

Dame Julia was in the city to receive a Cabot Institute Distinguished Fellowship, which involved giving a talk about her work as a world leading meteorologist and Chief Scientist at the Met Office.

One of the first things she highlighted was that climate change isn’t isolated from other pressures like population growth and limited resources, so we need to understand the risks it poses in a real world context. We need to define the effects it may have on the security of food, water, health and energy around the world, and use the science as a guide to define an evidence-based and cost effective plan of action going forward. This, she said, is “one of the greatest challenges of the 21st century”.

Are we making extreme weather worse?

Today, the huge global population boom is putting an ever increasing strain on limited resources like land and water, which are also at risk from the cyclical climate variations that occur naturally. The big and controversial question is whether climate change caused by human activity has exacerbated the problem.

Dame Julia described an annual report produced by the American Meteorological Society (AMS) that analyses extreme weather events around the world each year, aiming to determine whether the effects were magnified by anthropogenic climate change. As she pointed out, it is important that we recognise that not every bit of bad weather can be attributed to climate change, however the AMS often do find that we have played a role in making the situation worse.

One example she picked out was 2012’s Hurricane Sandy, which killed 233 people across eight countries in central and north America. The AMS report found that if sea level had been at the level that it was 50 years ago, the devastating effects of the storm would not have been as bad. It also suggested that continuing on our current path of climate change will mean minor storms will have increasingly severe impacts, leading to Sandy-level hurricanes more frequently in the future.

“We need a more nuanced discussion”

Last year was the warmest on UK record, making a total of 8 out of 10 of our hottest years having occurred since 2002. While of course there is variability in our climate from year to year and even decade to decade, intricate scientific climate models have shown that these record-breaking UK temperatures are made ten times more likely due to anthropogenic climate change.

While we may prefer a hot summer, temperatures don’t change uniformly across the entire planet. Worryingly, the Arctic is warming twice as fast as the rest of the planet, leading to a huge decrease in the amount of sea ice cover and corresponding sea level rise, which is already threatening communities living on low lying islands. Dame Julia reminded us all that it’s not as simple as trying to prevent a 2°C global temperature increase. The danger that climate change poses depends on who you are and where you live, and we need models to show what the risks will be.

Predicting climate risk

So how can we predict what the effects of climate change will be across the world? It begins with having a sophisticated model of the current global system. The Met Office has led decades of climate modelling, producing incredibly sophisticated simulations of climate systems on both short term (weather) and long term (climate change) scales.

I was absolutely amazed by the intricacy of these models. Millions of lines of computer code recreate the true physical nature of the planet, to the extent where large scale meteorological patterns like El Niño are emergent properties of the model, that is to say that they are a result of the basic physics encoded in the model, rather than being specifically programmed into it.

By altering the model with new data taken from the present extent of climate change or its predicted level in the future, the Met Office can model the global response at incredible resolution, showing the specific risks posed with increasingly detailed clarity (while still incorporating the inherent uncertainties present in all models). These models can then be used to test potential mitigation approaches and of course inform the global communities of the dangers they face.

What can we do?

Dame Julia explained that her role as Chief Scientist is to determine the needs of the people around the world, their risk tolerance and the information they require to make their own decisions. Science, she says, has a lot to offer in enabling governments to make wise, informed and efficient decisions with how best to spend their funds within the wider context of other societal issues, upholding the global securities of food, water, health and energy for the future.

Flooded Pakistan



Image: “There is no evidence to counter the basic premise that a warmer world will lead to more intense daily and hourly rain events” – Professor Dame Julia Slingo


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This blog is written by Cabot Institute member Sarah Jose, Biological Sciences, University of Bristol.

 

Sarah Jose

Do people respond to air pollution forecasts?

In 2010, the House of Commons Environmental Audit Committee published a report on air quality in which they concluded that “poor air quality probably causes more mortality and morbidity than passive smoking, road traffic accidents or obesity”. Concerned that the Government was still not giving air quality a high enough priority, the Committee published another report in 2011. To date, the Committee’s main recommendations have not been implemented. Amidst new evidence on the negative effects of air pollution on health and a court case that found the UK Government guilty of failing to meet EU air quality targets, the Committee published a third report on air quality last week.

One of the Committee’s recommendations is that the Government works more closely with the Met Office, the BBC and other broadcasters to ensure that forecasts of high air pollution episodes are disseminated widely together with advice on what action should be taken. The Committee’s rationale is that information about air pollution allows individuals to take action that reduces exposure. However, avoidance behaviour, such as staying indoors, imposes a cost on individuals that might exceed the perceived gains.

A BBC weather forecast for Bristol showing the commonly
encountered “green” air pollution forecast.

In a paper published this month in the Journal of Health Economics (Link with free access until 22 January 2015) I investigate responses to air pollution warnings in England. I obtained data on the air pollution forecasts issued by Defra from 2002 to 2008. During this period the daily air pollution forecast was freely available via the internet, a Freephone telephone service, Teletext and with the weather forecast on the BBC website. The forecast was disseminated using traffic light colour-coding, with green indicating low levels of air pollution, amber moderate and red high levels. “Red” forecasts were extremely rare (3% of forecasts) and “green” forecasts very common (70% of forecasts), so a change from “green” to “amber” (27% of forecasts) was akin to an air pollution warning. Hence, I define an “amber” or “red” forecast as an air pollution warning.

Air pollution warnings and hospital emergency admissions

First, I looked at indirect evidence of avoidance behaviour by estimating the relationship between air pollution warnings and hospital emergency admissions for respiratory diseases in children aged 5 to 19 years. I controlled for actual air pollution levels and therefore essentially compared days with a certain level of air pollution for which an air pollution warning was issued with days with the same level of air pollution for which no air pollution warning was issued. If parents and children do respond to air pollution warnings by reducing their exposure or taking other preventive measures, we expect fewer emergency hospital admissions on days for which an air pollution warning was issued compared to days with the same level of air pollution but no warning.

Looking at all respiratory admissions I found no effect. Looking at a subset of respiratory admissions – admissions for acute respiratory infections such as pneumonia and bronchitis – I also found no effect. Only when I examined another subset of respiratory admissions, namely admissions for asthma, did I find that air pollution warnings reduce hospital emergency admissions, by about 8%.

Presumably, it is less costly for asthmatics to respond to an air pollution warning. Standard advice for asthmatics is to adjust the dose of their reliever medicine and to make sure they carry their inhaler with them. Other types of respiratory disease require far more disruptive preventive measures such as staying indoors, making the cost of responding to air pollution warnings larger than the perceived gains.

Direct evidence of avoidance behaviour: visitors to Bristol Zoo

To find direct evidence of avoidance behaviour, I examined daily visitor counts to Bristol Zoo Gardens. Zoos are attractive destinations for families with children. Even with some animal houses under cover, most people will consider a zoo visit to be an outdoor activity and therefore susceptible individuals might adjust their plans to the air pollution forecast.  I found that lower temperature, more rain and higher wind speed reduced visitor numbers but found no effect of air pollution warnings on visitor numbers. Only when I looked at members – visitors who have an annual membership that entitles them to unlimited visits for a year – did I find that air pollution warnings reduce visits by about 6%. For members it is less costly to respond to air pollution warnings as they tend to be local residents who can just drop in for a quick visit. Thus, the perceived gains from postponing a visit are more likely to exceed the cost of postponing than for day visitors.

This graph shows monthly means of visitors to Bristol Zoo Gardens, daily maximum temperature and monthly total of air pollution warnings. Day visitors (grey bars) are far more responsive to temperature (yellow line) than to air pollution warnings (purple bars). Members’ visits (green bars) seem to be fewer in months with more air pollution warnings (purple bars).

Overall, my results show that whether individuals respond to air quality information depends on the costs and benefits of doing so: where costs are low and the benefits clear, responses are higher. This finding suggests, that wider dissemination of high air pollution forecasts as recommended by the Commons Environmental Audit Committee may not bring about the desired prevention of adverse health effects from air pollution. The Committee’s other recommendations aimed at lowering air pollution levels are more likely to succeed in preventing ill health.

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This blog is written by Cabot Institute member Katharina Janke, Research Associate in Applied Microeconomics and Health Economics at the Centre for Market and Public Organisation at the University of Bristol.
Katharina Janke