Tag: wind

Limiting global warming to 2℃ is not enough – why the world must keep temperature rise below 1℃

Posted on by amanda.woodman-hardy
Warming of more than 1℃ risks unsafe and harmful outcomes for humanity.
Ink Drop/Shutterstock

The Paris Climate agreement represented a historic step towards a safer future for humanity on Earth when it was adopted in 2015. The agreement strove to keep global heating below 2℃ above pre-industrial levels with the aim of limiting the increase to 1.5℃ if possible. It was signed by 196 parties around the world, representing the overwhelming majority of humanity.

But in the intervening eight years, the Arctic region has experienced record-breaking temperatures, heatwaves have gripped many parts of Asia and Australia has faced unprecedented floods and wildfires. These events remind us of the dangers associated with climate breakdown. Our newly published research argues instead that humanity is only safe at 1℃ of global warming or below.

While one extreme event cannot be solely attributed to global heating, scientific studies have shown that such events are much more likely in a warmer world. Since the Paris agreement, our understanding of the impacts of global heating have also improved.

A fishing boat surrounded by icebergs that have come off a glacier.
Fishing boat dwarfed by icebergs that came off Greenland’s largest glacier, Jakobshavn Isbrae.
Jonathan Bamber, Author provided

Rising sea levels are an inevitable consequence of global warming. This is due to the combination of increased land ice melting and warmer oceans, which cause the volume of ocean water to increase. Recent research shows that in order to eliminate the human-induced component of sea-level rise, we need to return to temperatures last seen in the pre-industrial era (usually taken to be around 1850).

Perhaps more worrying are tipping points in the climate system that are effectively irreversible on human timescales if passed. Two of these tipping points relate to the melting of the Greenland and West Antarctic ice sheets. Together, these sheets contain enough ice to raise the global sea level by more than ten metres.

The temperature threshold for these ice sheets is uncertain, but we know that it lies close to 1.5℃ of global heating above pre-industrial era levels. There’s even evidence that suggests the threshold may already have been passed in one part of west Antarctica.

Critical boundaries

A temperature change of 1.5℃ might sound quite small. But it’s worth noting that the rise of modern civilisation and the agricultural revolution some 12,000 years ago took place during a period of exceptionally stable temperatures.

Our food production, global infrastructure and ecosystem services (the goods and services provided by ecosystems to humans) are all intimately tied to that stable climate. For example, historical evidence shows that a period called the little ice age (1400-1850), when glaciers grew extensively in the northern hemisphere and frost fairs were held annually on the River Thames, was caused by a much smaller temperature change of only about 0.3℃.

A sign marking the retreat of a glacier since 1908.
Jasper National Park, Canada. Glaciers used to grow extensively in the Northern Hemisphere.
Matty Symons/Shutterstock

A recent review of the current research in this area introduces a concept called “Earth system boundaries”, which defines various thresholds beyond which life on our planet would suffer substantial harm. To avoid passing multiple critical boundaries, the authors stress the need to limit temperature rise to 1℃ or less.

In our new research, we also argue that warming of more than 1℃ risks unsafe and harmful outcomes. This potentially includes sea level rise of multiple metres, more intense hurricanes and more frequent weather extremes.

More affordable renewable energy

Although we are already at 1.2℃ above pre-industrial temperatures, reducing global temperatures is not an impossible task. Our research presents a roadmap based on current technologies that can help us work towards achieving the 1℃ warming goal. We do not need to pull a technological “rabbit out of the hat”, but instead we need to invest and implement existing approaches, such as renewable energy, at scale.

Renewable energy sources have become increasingly affordable over time. Between 2010 and 2021, the cost of producing electricity from solar energy reduced by 88%, while wind power saw a reduction of 67% over the same period. The cost of power storage in batteries (for when the availability of wind and sunlight is low) has also decreased, by 70% between 2014 and 2020.

An aerial photograph of a photovoltaic power plant on a lush hillside.
A photovoltaic power plant in Yunnan, China.
Captain Wang/Shutterstock

The cost disparity between renewable energy and alternative sources like nuclear and fossil fuels is now huge – there is a three to four-fold difference.

In addition to being affordable, renewable energy sources are abundantly available and could swiftly meet society’s energy demands. Massive capacity expansions are also currently underway across the globe, which will only further bolster the renewable energy sector. Global solar energy manufacturing capacity, for example, is expected to double in 2023 and 2024.

Removing carbon dioxide from the atmosphere

Low-cost renewable energy will enable our energy systems to transition away from fossil fuels. But it also provides the means of directly removing CO₂ from the atmosphere at a large scale.

CO₂ removal is crucial for keeping warming to 1℃ or less, even though it requires a significant amount of energy. According to research, achieving a safe climate would require dedicating between 5% and 10% of total power generation demand to effective CO₂ removal. This represents a realistic and attainable policy option.

Various measures are used to remove CO₂ from the atmosphere. These include nature-based solutions like reforestation, as well as direct air carbon capture and storage. Trees absorb CO₂ from the atmosphere through photosynthesis and then lock it up for centuries.

A group of people planting a mangrove forest next to the sea.
A mangrove forest being planted in Klong Khone Samut Songkhram Province, Thailand.
vinai chunkhajorn/Shutterstock

Direct air capture technology was originally developed in the 1960s for air purification on submarines and spacecrafts. But it has since been further adapted for use on land. When combined with underground storage methods, such as the process of converting CO₂ into stone, this technology provides a safe and permanent method of removing CO₂ from the atmosphere.

Our paper demonstrates that the tools and technology exist to achieve a safer, healthier and more prosperous future – and that it’s economically viable to do so. What appears to be lacking is the societal will and, as a consequence, the political conviction and commitment to achieve it.

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This blog is written Cabot Institute for the Environment member Jonathan Bamber, Professor of Glaciology and Earth Observation, University of Bristol and Christian Breyer, Professor of Solar Economy, Lappeenranta University of Technology. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Jonathan Bamber
Jonathan Bamber

Energy landscapes and the generative power of place

Posted on by janet.crompton

Spring 2020 will be remembered for the global Covid-19 pandemic. While in Britain people  were ordered to stay at home in a national lockdown, the nation also experienced its longest run of coal-free energy generation since the Industrial Revolution – 68 days of coal-free power. This wasn’t unconnected: as the economy shrunk almost overnight some of the major industrial energy uses stopped; steady low usage meant that the ‘back-up’ coal-fired generators of the national grid weren’t needed. Nor was this fossil-free: oil, alongside nuclear and gas, continued to fuel power plants. But, more than ever before, our energy was produced by renewable sources, and on 26 August 2020, the National Grid recorded the highest every contribution by wind to the national electricity mix: 59.9%.

This shift out of fossil dependence is both a historic moment, and the product of historical processes. The technological and scientific work that underpins the development of efficient turbines has taken decades – and it is what I’ve written about in my article, ‘When’s a gale a gale? Understanding wind as an energetic force in mid-twentieth century Britain’, out now in Environmental History. I look at how interest in the wind as a potential energy source (by the British state, and state scientists), generated the need for knowledge about how wind worked. Turbine technology needs airspace to operate, but it also needs land – to ground the turbines in, to connect to the grid by – and people to install and operate the devices. And so when looking at energy landscapes, we really need to think beyond the technology and consider the people and places with which it interacts,  to understand how energy is produced and used.

Hauling wind measuring equipment up Costa Hill, Orkney. In E.H. Golding and A.H. Stodhart, ‘The selection and characteristics of wind-power sites’ (The Electrical Research Association, 1952). Met Office Archive.

This was certainly the case for understanding wind energy. In 1940s and 50s Britain, scientists surveyed the wind regime at a national scale for the first time. They relied on the help and cooperation of local people to do this. In the brief mentions of this assistance in the archival record, we gain insight into the importance of embodied, localised knowledge in scientific processes which can at first seem detached from the actual landscapes of study.

The surveys determined Orkney as the best place to situate a test turbine. Embodied knowledge, knowledge that is learnt from being in place and from place, is very tangible in accounts of a hurricane which hit Orkney in 1952, during the turbine tests. By looking at how the islanders made sense of a disastrous wind, and brought the turbine technology into their narratives of the storm, we learn that it is not only electricity generated by the development of renewable energy, but also new dimensions to place-based knowledge and identities.

Seeing beyond the technology to consider its interactions with environments and societies is something that the energy humanities considers as essential. I’ll be working on this subject from this perspective for some time to come, and would love to hear your thoughts on the article.

Costa Hill from the coast path. Photograph by Marianna Dudley, 2017.

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This blog has been reposted with kind permission from the Bristol Centre for Environmental Humanities. View the original blog. This blog was written by Cabot Institute for the Environment member Dr Marianna Dudley. You can follow Marianna on Twitter @DudleyMarianna.

Dune: how high could giant sand dunes actually grow on Arrakis?

Posted on by janet.crompton

Frank Herbert first published his science-fiction epic Dune back in 1965, though its origins lay in a chance encounter eight years previously when as a journalist he was tasked to report on a dune stabilisation programme in the US state of Oregon. Ultimately, this set the wheels in motion for the recent film adaptation.

The large and inhospitable sand dunes of the desert planet Arrakis are, of course, very prominent in both the books and film, not least because of the terrifying gigantic sandworms that hunt any movement on the surface. But just how high would sand dunes be on a realistic version of this world?

Before the movie was released, we took a scientific climate model and used it to simulate the climate of Arrakis. We now want to use insights from this same model to focus on the dunes themselves.

Sand dunes are the product of thousands or even tens of thousands of years of erosion of the underlying or surrounding geology. On a simple level, they are formed by sand being blown along the path of the prevailing wind until it meets an obstruction, at which point the sand will settle in front of it.

There is certainly no shortage of wind on Arrakis. Our simulation showed that wind would routinely exceed the minimum speed required to blow sand grains into the air, and there are even some regions where speeds regularly reach 162 km/h during the year. That’s well over hurricane force.

Diagram of sand dune formation
How sand dunes are formed. David Tarailo / US National Park Service / Geological Society of America

Sand dunes in the book are said to be on average around 100 metres high. However, this isn’t based on actual science, more likely it’s what Herbert knew from his time in Oregon as well as the world we live in. But we can use our climate model to predict what the general (and maximum) attainable height might suggest.

Where the wind blows

The size and distance between giant dunes are determined not simply by the type of sand or underlying rock, but by the lowest 2km or so of the atmosphere that interacts with the land surface. This level, also known as the planetary boundary layer, is where most of the weather we can see occurs. Above this, a thin “inversion layer” separates the weather below from the more stable higher-altitude part of the atmosphere.

The growth of sand dunes and theoretical height is determined by the depth of this boundary layer where the wind blows. Sand dunes stabilise above the wind at the altitude of the inversion layer. The height of the boundary layer – usually somewhere between 100 metres to 2,000 metres – can vary through the night as well as the year. When it is cooler, it is shallower. When there is a strong wind or lots of rising warm air, it is deeper.

Arrakis would be much hotter than Earth, which means more rising air and a boundary layer two to three times as high over land compared with ours. Our climate model simulation, therefore, predicts dunes on Arrakis would be as high as 250m, particularly in the tropics and mid-latitudes. That’s about three times the height of the Big Ben clock tower in London. Most regions would have a more modest average height of between 25m and 75m. As the boundary layer is generally higher everywhere on Arrakis the average dune height is in general twice that of Earths.

map with shaded areas
Predicted sand dune height (in metres) on Arrakis. Farnsworth et al, Author provided

We were also able to simulate the space between dunes, which can also be determined by the height of the boundary layer. Spacing is highest in the tropics, a little over 2km between the crest of one giant sand dune to the next. However, in general, sand dunes have a spacing of around 0.5 to 1km crest to crest. Still plenty of room for a sandworm to wiggle through. Scientists looking at Saturn’s moon Titan have run this same process in reverse, using the space between dunes – easy to measure with satellite images – to estimate a boundary layer of up to 3km.

As nothing can grow on Arrakis to stabilise these sand dunes they will always be in a state of constant drift across the planet. Some large dunes on Earth can move about 5m a year. Smaller dunes can move even faster – about 20m a year.

A visualisation of the authors’ climate model of Arrakis. Source: climatearchive.org/dune.

Mountain-sized dunes?

Our simulation can only give the general height that most sand dunes would reach, and there would be exceptions to the rule. For instance, the largest known sand dune on Earth today is the Duna Federico Kirbus in Argentina, a staggering 1,234m in height. Its size shows that local factors, such as vegetation, surrounding hills or the type of local sand, can play an important role.

Given Arrakis is hotter than Earth, has a higher boundary layer and has more sand and stronger winds, it’s possible a truly mammoth dune the size of a small mountain may form somewhere – it’s just impossible for a climate model to say exactly where.

Scientists have recently revealed that as the world warms the planetary boundary layer is increasing by around 53 metres a decade. So we may well see even bigger record-breaking sand dunes as the lower atmosphere continues to warm – even if Earth will not end up like Arrakis.The Conversation

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This blog is written by Caboteers Dr Alex Farnsworth, Senior Research Associate in Meteorology, University of Bristol and Dr Sebastian Steinig, Research Associate in Paleoclimate Modelling, University of Bristol and Dr Michael Farnsworth, Research Lead Future Electrical Machines Manufacturing Hub, University of Sheffield,

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

#CabotNext10 Spotlight on Low Carbon Energy

Posted on by janet.crompton
Dr Paul Harper (left) and Professor Tom Scott (right)

In conversation with Professor Tom Scott and Dr Paul Harper, theme leads at the Cabot Institute

Why did you choose to become a theme leader at Cabot Institute?

T.S: There is no single technology solution for our low carbon energy and net zero ambitions. Therefore, being a theme leader gives me the chance to work and coordinate research from all areas, such as wind, solar, nuclear and hydro, so we can work together to develop solutions.

P.H: I became increasingly inspired by renewable energy during my time at Bristol studying Aerospace Engineering (2000-2004, a long time ago now!). I know this is a real cliche, but I wanted to do something with my career that would help tackle some of the major challenges facing society around climate change and environmental sustainability. After completing my undergraduate degree and a PhD at Bristol in composite materials, I began a postdoc research post linked to tidal energy devices and also became involved in some the early development work of the Cabot Institute, so it has always had a special place in my heart. 10 years on and it is great to look back on so many new research developments in Low Carbon Energy and environmental sustainability more generally that have taken place across the University because of Cabot.

In your opinion, what is one of the biggest global challenges associated with your theme?

P.H: This is biased towards my interests in renewable energy, but I think the following are all major challenges associated with the Low Carbon Energy Theme:

  • Bringing down costs of both mainstream technologies (wind, solar) and more novel, less mature technologies (e.g., wave, tidal).
  • Applying circular design principles to prevent material going to landfill at end-of-life.
  • Designing improved ways of storing energy and integrating many distributed energy supply sources.
  • Electrification of the heating and transport sectors to increase the potential contribution of renewables.

T.S: Replacing fossil fuels with a mixed portfolio of viable and renewable alternatives. This is the fundamental challenge to tackle if the UK is to reach its 2050 Net Zero target, and if we are to provide reliable energy sources for future generations globally.

As we are looking into the future, what longer term projects are there in your theme?

T.S: In my specialist area of nuclear energy, there are several major projects and technologies in development to support low carbon energy production:

STEP – the Spherical Tokamak for Energy Production (STEP) programme will develop the world’s first commercial fusion plant in the UK, with a site set to be selected by the end of 2022. Complementary, large scale international consortia fusion projects ITER and DEMO are already underway.

Geological Disposal Facility (GDF) siting – The UK has begun the search for a site where radioactive waste can be stored permanently in a way that doesn’t burden future populations. We have to show we can deal with the waste produced by nuclear fission energy production to ensure support for nuclear power as a key low carbon energy source.

Advanced Modular Reactors (AMR) – We need to get the most from existing fission power, wherein there is much more value we can get from just producing electricity. Heat, Hydrogen and direct air-capture of CO2 are all viable from nuclear and AMRs, which operate at higher temperatures are the way to best exploit these other opportunities which will provide much more value than the current electricity-only proposition.

What’s more, Hydrogen will be the largest growth commodity in the next few decades. It gives us the opportunity to address issues around energy storage and transfer and especially, decarbonisation of transport, either directly as fuels for cars or indirectly as a precursor substance for making ammonia which can be used in heavy transport e.g., shipping.

Alongside all these technology developments, we will need to see a change in energy transport and storage infrastructure. For example, hydro or battery storage can help mitigate the intermittencies suffered by solar or wind. Equally, we cannot immediately swap methane for hydrogen in our domestic gas network and hence we need to upgrade or replace our infrastructure, with the former being much preferable and affordable.

Bringing the public along on this transitional journey will be incredibly important because they need to understand and support some of the tough technical decisions that need to be made.

P.H: A huge proportion of the world’s population has no existing access to a sustainable electricity supply and working on international development projects is vital to ensure communities can improve quality of life through access to low carbon energy. We currently have a rapidly growing portfolio of projects linked to international development and I think this trend is likely to continue in the future.

We are lucky to have a very large number of projects across a wide variety of different areas. The Cabot website gives a very good flavour of our diversity of projects (Energy | Cabot Institute for the Environment | University of Bristol) and these involve collaborations with a range of multinational companies, SMEs and start-ups, NGOs and policy makers.

Across the portfolio of projects in your theme, what type of institutions are you working with? (For example, governments, NGO’s)

T.S: The Government and its research organisations including National Nuclear Laboratory, UK Atomic Energy Authority.  I am also a member of the Nuclear Innovation & Research Advisory Board (NIRAB).

Working with other Universities in the UK and overseas as well as government research organisations and industry. It’s important that all these parties are talking and working together to ensure that there is both a push and a pull for the research we are doing towards net zero carbon by the middle of the century.

Please can you give some examples and state the relevant project.

T.S: My fellowship awarded earlier this year (Research Chair in Advancing the Fusion Energy Fuel Cycle) has the remit of doing just that. Being funded by the Royal Academy of Engineering and UKAEA, but with the remit to work with (and pull together) other academics with companies across a wide spectrum, from Cornish Lithium, to Rolls-Royce, EDF, Hynamics, Urenco and many others to advance the fuel cycle for future fusion power stations but also to develop spin-off opportunities in hydrogen storage, isotope production and even diamond batteries!

The South West Nuclear Hub provides a focus for civil nuclear research, innovation and skills in the South West of the UK, bringing together a strategic alliance of academic, industrial and governmental members, creating a unique pool of specialist talent and expertise that can be tapped into by industry

What disciplines are currently represented within your theme?

P.H: I’m sure I’ve missed some out but the main ones that spring to mind Engineering (all disciplines), Physics, Chemistry, Geography, Sociology, Economics and Law. We also have particularly close link with Cabot’s Future Cities Theme.

In your opinion, why is it important to highlight interdisciplinary research both in general and here at Bristol?

T.S: It’s quite simply because some of the big societal challenges are so multifaceted that they de facto require a multidisciplinary solution! At UoB we have a wealth of expertise and a wide network of collaborators that we can draw on to address key aspects around energy.

We can’t do everything, but we have been working hard to understand what we’re good at, our USPs and we’ll be concentrating on strengthening these going forwards as well as developing new opportunities.

P.H: In order to implement effective low carbon energy systems in society, interdisciplinary research is vital. You can design the most innovative and technically brilliant energy technologies but if they are not well suited to the social and economic environment where they will be deployed, they are of very limited value. For example, the type of energy system best suited to a UK community can be very different to the best solution for a community in the developing world, which may have no existing electrical grid infrastructure, relatively little access to skilled labour for installation/maintenance and relatively low incomes.

Are there any projects which are currently underway in your theme which are interdisciplinary that you believe should be highlighted in this campaign?

T.S: STEP is a classic example; you’d be forgiven for thinking it was just a big physics project (because this is what it was for many years) but now it is actually a huge interdisciplinary effort involving engineers, computer scientists, materials people (like myself), environmentalists, economists, and social scientists. The Physicists are still there working very hard too, but they are complemented by all this other activity which will help deliver this big scientific ambition into an actual working power station.

Is there anything else you would like to mention about your theme, interdisciplinary research and working as part of Cabot Institute?

P.H: It is essential to remember importance of teaching alongside research; the University are training the next generation of graduates who can address society’s environmental challenges and Cabot can play a key role in this through initiatives such as the Cabot MRes programme. I’m very pleased that within the Low Carbon Energy Theme, our members are playing a very active role in supporting both undergraduate courses and postgraduate study opportunities linked to Low Carbon Energy topics such as renewable energy.

T.S: The Cabot Energy theme is open and inclusive for anyone and any discipline! We enjoy a healthy debate about energy and the pros and cons of how we produce it, distribute it and use it. We’re proud to have different opinions and an open forum for discussion.

Please do come and join us even if you’re the tiniest bit curious and would like to help contribute to our collective efforts.

For more information, visit Low Carbon Energy.

What Europe’s exceptionally low winds mean for the future energy grid

Posted on by janet.crompton

 

Shaggyphoto / shutterstock

Through summer and early autumn 2021, Europe experienced a long period of dry conditions and low wind speeds. The beautifully bright and still weather may have been a welcome reason to hold off reaching for our winter coats, but the lack of wind can be a serious issue when we consider where our electricity might be coming from.

To meet climate mitigation targets, such as those to be discussed at the upcoming COP26 event in Glasgow, power systems are having to rapidly change from relying on fossil fuel generation to renewables such as wind, solar and hydropower. This change makes our energy systems increasingly sensitive to weather and climate variability and the possible effects of climate change.

That period of still weather badly affected wind generation. For instance, UK-based power company SSE stated that its renewable assets produced 32% less power than expected. Although this may appear initially alarming, given the UK government’s plans to become a world leader in wind energy, wind farm developers are aware these low wind “events” are possible, and understanding their impact has become a hot topic in energy-meteorology research.

A new type of extreme weather

So should we be worried about this period of low wind? In short, no. The key thing here is that we’re experiencing an extreme event. It may not be the traditional definition of extreme weather (like a large flood or a hurricane) but these periods, known in energy-meteorology as “wind-droughts”, are becoming critical to understand in order to operate power systems reliably.

Recent research I published with colleagues at the University of Reading highlighted the importance of accounting for the year-to-year variability in wind generation as we continue to invest in it, to make sure we are ready for these events when they do occur. Our team has also shown that periods of stagnant high atmospheric pressure over central Europe, which lead to prolonged low wind conditions, could become the most difficult for power systems in future.

Climate change could play a role

When we think about climate change we tend to focus much more on changes in temperature and rainfall than on possible variations in near-surface wind speed. But it is an important consideration in a power system that will rely more heavily on wind generation.

The latest IPCC report suggests that average wind speeds over Europe will reduce by 8%-10% as a result of climate change. It is important to note that wind speed projections are quite uncertain in climate models compared with those for near-surface temperatures, and it is common for different model simulations to show quite contrasting behaviour.

Colleagues and I recently analysed how wind speeds over Europe would change according to six different climate models. Some showed wind speeds increasing as temperatures warm, and others showed decreases. Understanding this in more detail is an ongoing topic of scientific research. It is important to remember that small changes in wind speed could lead to larger changes in power generation, as the power output by a turbine is related to the cube of the wind speed (a cubic number is a number multiplied by itself three times. They increase very fast: 1, 8, 27, 64 and so on).

World map with dark blue (less wind) in Europe, North America and China
Change in wind speed compared to 1986-2005 if we were to limit global warming to 1.5C. Areas in blue will have less wind; areas in green, more wind.
IPCC Interactive Atlas, CC BY-SA

The reductions in near-surface wind speeds seen in the above map could be due to a phenomenon called “global stilling”. This can be explained by the cold Arctic warming at a faster rate than equatorial regions, which means there is less difference in temperature between hot and cold areas. This temperature difference is what drives large-scale winds around the globe through a phenomenon called thermal wind balance.

With all the talk of wind power being the answer to our energy needs, amid spiralling gas prices and the countdown to COP26, the recent wind drought is a clear reminder of how variable this form of generation can be and that it cannot be the sole investment for a reliable future energy grid. Combining wind with other renewable resources such as solar, hydropower and the ability to smartly manage our electricity demand will be critical at times like this summer when the wind is not blowing.The Conversation

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This blog was written the Cabot Institute for the Environment member Dr Hannah Bloomfield, Postdoctoral Researcher in Climate Risk Analytics, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

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