Tag: IPCC

Climate change: effect on forests could last millennia, ancient ruins suggest

Posted on by janet.crompton

 

Jonathan Lenoir, Author provided

Jonathan Lenoir, Université de Picardie Jules Verne (UPJV) and Tommaso Jucker, University of Bristol

Forests are home to 80% of land-based biodiversity, but these arks of life are under threat. The rising average global temperature is forcing tiny plants like sidebells wintergreen on the forest floor (known as the understory) to shift upslope in search of cooler climes. Forest plants can’t keep up with the speed at which the climate is changing – they lag behind.

The pace at which forests adapt to changing conditions is so slow that species living in forest understories today are probably responding to more ancient changes in their environment. For instance, the Mormal Forest floor in northern France is, in several places, covered by a carpet of quaking sedge. This long grass-like plant betrays the former settlements of German soldiers who used it to make straw mattresses during the first world war.

Changes in how people managed the land, sometimes dating back to the Middle Ages or even earlier, leave a lasting fingerprint on the biodiversity of forest understories. Knowing how long the presence of a given species can carry on the memory of past human activities can tell scientists how long climate change is likely to have an influence.

A forest carpeted with tall grass.
The wind whispering through Mormal’s sedge evokes the region’s wartime past.
Jonathan Lenoir, Author provided

Ecologists are turning to technologies such as lidar to rewind the wheel of time. Lidar works on the same principles as radar and sonar, using millions of laser pulses to analyse echoes and generate detailed 3D reconstructions of the surrounding environment. This is what driverless cars use to sense and navigate the world. Since the late 1990s, lidar has enabled amazing discoveries, such as the imprints of Mayan civilisation preserved beneath the canopy of tropical forest.

In a new paper, I, along with experts in ecology, history, archaeology and remote sensing, used lidar to trace human activity in the Compiègne Forest in northern France back to Roman times – much later than historical maps could ever do.

Illuminating ghosts from the past

Compared to farm fields, which are ceaselessly disturbed, forest floors tend to be well-preserved environments. As a result, the ground below the forest canopy may still bear the imprints of ancient human occupation.

Archaeologists know this pretty well and they increasingly rely on lidar technology as a prospecting tool. It allows them to virtually remove all the trees from aerial images and hunt artefacts hidden below treetops and fossilised under forest floors.

Using airborne lidar data acquired in 2014 over the Compiègne Forest in northern France, a team of archaeologists and historians found well-preserved Roman settlements, farm fields and roads. Long considered a remnant of prehistoric forest, the Compiègne was, in fact, a busy agricultural landscape 1,800 years ago.

A black-and-white aerial photo of a landscape marked by depressions and boundaries.
Lidar can reveal the terrain hidden beneath forests.
Jonathan Lenoir, Author provided

A closer look at these ghostly images of the Compiègne Forest reveals several depressions within a fossilised network of Roman farm fields. Archaeologists excavated numerous depressions like this across many forests in north-eastern France and found that people from the late iron age and Roman era carved them.

These depressions were made to extract marls (lime-rich mud) to enrich farm fields in carbonate minerals for growing crops and to create local depressions where rainwater collects naturally for livestock to drink. Marling is still a widespread practice in crop production in northern France.

A hillside with a large, white crater in.
A pit for extracting marl in Northern France.
Jonathan Lenoir, Author provided

The long-lasting effects of human activity

These signs of Roman occupation in modern forests provide clues to why some plant species are present where we wouldn’t expect them to be.

On a summer day in 2007 in a corner of the Tronçais Forest in central France, a team of botanists found a little patch of nitrogen-loving species – blue bugle, woodland figwort and stinging nettle – nestled among more acid-loving plants.

Nothing special at first sight. Until archaeologists found that Roman farm buildings had once stood in that spot, with cattle manure probably enriching the soil in phosphorous and nitrogen.

A shrub with bright blue flowers.
Blue bugle heralds an ancient Roman farm.
Kateryna Pavliuk/Shutterstock

If a clutch of tiny plants can betray ancient farming practices dating back centuries or millennia, ongoing environmental changes, such as climate change, will have similarly long-lasting effects. Even if the Earth stopped heating, the biodiversity of its forests would continue changing in response to the warming signal, in a delayed manner, through the establishment of more and more warm-loving species for several centuries into the future.

Just as the Intergovernmental Panel on Climate Change has a mission to provide plausible scenarios on future climate change, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services aims to provide plausible scenarios on the fate of biodiversity. Yet none of the biodiversity models so far incorporate this lag effect. This means that model predictions are more prone to errors in forecasting the fate of biodiversity under future climate change.

Knowing about the past of modern forests can help decode their present state and model their future biodiversity. Now lidar technology is there to help ecologists travel back in time and explore the forest past. Improving the accuracy of predictions from biodiversity models by incorporating lagging dynamics is a big challenge, but it is a necessary endeavour for more effective conservation strategies.

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This blog is written by Jonathan Lenoir, Senior Researcher in Ecology & Biostatistics (CNRS), Université de Picardie Jules Verne (UPJV) and Cabot Institute for the Environment member Dr Tommaso Jucker, Research Fellow and Lecturer, School of Biological Sciences, University of Bristol

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

Human health is entwined with the health of our planet

Posted on by janet.crompton

 

It’s a short time since COP26 finished in Glasgow. Many colleagues from the University of Bristol were there to discuss their research and share knowledge with those who are making decisions about policies that impact everyone’s futures. When we think about climate change, we often think about the health of the planet and the natural world, but the health of our planet is entwined to the health of the human population too. Here, Elizabeth Blackwell Institute Director, Rachael Gooberman-Hill, gives a timely update on our research looking at the intersection between climate and health.

We’re already seeing local and global impacts of climate change on human health. The World Health Organization states that in the 20 years from 2030 to 2050 climate change will cause around 250,000 additional deaths per year, which is a timeframe that starts in just eight years from now.

These, arguably preventable, deaths will relate to malnutrition, malaria, diarrhoea and heat. Health impacts of climate change will disproportionately affect people who are already vulnerable in other ways, including people who are young, old, living with other conditions, or living in situations of vulnerability including poverty and other dimensions of disadvantage. Climate change is associated with changes in infectious diseases and non-communicable conditions, such as mental health difficulties. Heat and extreme weather events have major impact on health, cause forced migration and these issues are global in scale. In the UK, extreme weather events and heat are already visible and are likely to become more common and more impactful.

Embedding climate in current research

Broadly speaking, research efforts include work to reduce rise in our planet’s temperature and attempts to address, mitigate, and adapt to the impact of the rises that are already happening. At the Elizabeth Blackwell Institute we are working with the Cabot Institute for the Environment. As researchers, we can change focus of our research, can embed climate in the research that we are already planning or doing, and we can also consider that all of the research that we do is already impacted by climate change and will already have much to add to the evidence base that can underpin change and make a difference.

Mapping activity in climate research

The University of Bristol has a world-leading track record in environment-focused research already. We recently mapped the research activity in this area and identified 39 climate and health related research projects and over 150 members of our research community working in this area. We work on many topics, including extreme weather events, heat, water and sanitation, animal health, crops and nutrition, and social impacts of climate change. The University is an active member of the Met Office Academic Partnership (MOAP), we contribute considerable and internationally recognised expertise to the Intergovernmental Panel on Climate Change (IPCC), including in the crucial assessment reports which provide the scientific evidence base. We’re active in the GW4 Climate Alliance, comprising the Universities of Bristol, Cardiff, Bath, and Exeter.

Potential to pivot

There is real potential now to build this area even more. Many members of our University are deeply concerned about climate change and many are doing work that helps, or want to do so. We are a community whose research is often driven by our sense of social responsibility and we’ve seen before how our desire to make a difference can drive new focus. In the early days of the COVID-19 pandemic we saw large parts of the University’s research community turn skills and attention to the virus and its impact. At the Elizabeth Blackwell Institute we supported over 90 projects that focused on COVID-19 and owe thanks to everyone for the vast effort that has been put into research with real world impact. The effort to focus on COVID-19 showed how our expert researchers can pivot quickly onto new topic areas, although other topics remained urgent and important alongside our pandemic-related work.

Supporting more climate research

The Elizabeth Blackwell Institute wants to support the desire and need to work on climate change and health, whether that’s to enable people to pivot to the area, build on existing work or to encompass climate change into existing workstreams. We’ve already supported projects focused on climate change and health, with particular emphasis on interdisciplinary research. We want to support even more. As we move forward from COP26, please consider how your research can address climate change and health and let us know about your plans and ideas.

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This blog is by Elizabeth Blackwell Institute Director, Rachael Gooberman-Hill . View the original post.

Rachel Gooberman-Hill

Humanity is compressing millions of years of natural change into just a few centuries

Posted on by janet.crompton
The near future may be similar to the mid-Pliocene warm period a few million years ago.
Daniel Eskridge / shutterstock

Many numbers are swirling around the climate negotiations at the UN climate summit in Glasgow, COP26. These include global warming targets of 1.5℃ and 2.0℃, recent warming of 1.1℃, remaining CO₂ budget of 400 billion tonnes, or current atmospheric CO₂ of 415 parts per million.

It’s often hard to grasp the significance of these numbers. But the study of ancient climates can give us an appreciation of their scale compared to what has occurred naturally in the past. Our knowledge of ancient climate change also allows scientists to calibrate their models and therefore improve predictions of what the future may hold.

Recent climate changes in context.
IPCC AR6, chapter 2

Recent work, summarised in the latest report of the Intergovernmental Panel on Climate Change (IPCC), has allowed scientists to refine their understanding and measurement of past climate changes. These changes are recorded in rocky outcrops, sediments from the ocean floor and lakes, in polar ice sheets, and in other shorter-term archives such as tree rings and corals. As scientists discover more of these archives and get better at using them, we have become increasingly able to compare recent and future climate change with what has happened in the past, and to provide important context to the numbers involved in climate negotiations.

For instance one headline finding in the IPCC report was that global temperature (currently 1.1℃ above a pre-industrial baseline) is higher than at any time in at least the past 120,000 or so years. That’s because the last warm period between ice ages peaked about 125,000 years ago – in contrast to today, warmth at that time was driven not by CO₂, but by changes in Earth’s orbit and spin axis. Another finding regards the rate of current warming, which is faster than at any time in the past 2,000 years – and probably much longer.

But it is not only past temperature that can be reconstructed from the geological record. For instance, tiny gas bubbles trapped in Antarctic ice can record atmospheric CO₂ concentrations back to 800,000 years ago. Beyond that, scientists can turn to microscopic fossils preserved in seabed sediments. These properties (such as the types of elements that make up the fossil shells) are related to how much CO₂ was in the ocean when the fossilised organisms were alive, which itself is related to how much was in the atmosphere. As we get better at using these “proxies” for atmospheric CO₂, recent work has shown that the current atmospheric CO₂ concentration of around 415 parts per million (compared to 280 ppm prior to industrialisation in the early 1800s), is greater than at any time in at least the past 2 million years.

chart showing climate changes over history
An IPCC graphic showing climate changes at various points since 56 million years ago. Note most rows show changes over thousands or millions of years, while the top row (recent changes) is just a few decades.
IPCC AR6, chapter 2 (modified by Darrell Kaufman)

Other climate variables can also be compared to past changes. These include the greenhouse gases methane and nitrous oxide (now greater than at any time in at least 800,000 years), late summer Arctic sea ice area (smaller than at any time in at least the past 1,000 years), glacier retreat (unprecedented in at least 2,000 years) sea level (rising faster than at any point in at least 3,000 years), and ocean acidity (unusually acidic compared to the past 2 million years).

In addition, changes predicted by climate models can be compared to the past. For instance an “intermediate” amount of emissions will likely lead to global warming of between 2.3°C and 4.6°C by the year 2300, which is similar to the mid-Pliocene warm period of about 3.2 million years ago. Extremely high emissions would lead to warming of somewhere between 6.6°C and 14.1°C, which just overlaps with the warmest period since the demise of the dinosaurs – the “Paleocene-Eocene Thermal Maximum” kicked off by massive volcanic eruptions about 55 million years ago. As such, humanity is currently on the path to compressing millions of years of temperature change into just a couple of centuries.

Small animals in a forest
Many mammals, like these horse-ancestors ‘Eohippus’, first appeared after a sudden warm period 55 million years ago.
Daniel Eskridge / shutterstock

Distant past can held predict the near future

For the first time in an IPCC report, the latest report uses ancient time periods to refine projections of climate change. In previous IPCC reports, future projections have been produced simply by averaging results from all climate models, and using their spread as a measure of uncertainty. But for this new report, temperature and rainfall and sea level projections relied more heavily on those models that did the best job of simulating known climate changes.

Part of this process was based on each individual model’s “climate sensitivity” – the amount it warms when atmospheric CO₂ is doubled. The “correct” value (and uncertainty range) of sensitivity is known from a number of different lines of evidence, one of which comes from certain times in the ancient past when global temperature changes were driven by natural changes in CO₂, caused for example by volcanic eruptions or change in the amount of carbon removed from the atmosphere as rocks are eroded away. Combining estimates of ancient CO₂ and temperature therefore allows scientists to estimate the “correct” value of climate sensitivity, and so refine their future projections by relying more heavily on those models with more accurate climate sensitivities.

Overall, past climates show us that recent changes across all aspects of the Earth system are unprecedented in at least thousands of years. Unless emissions are reduced rapidly and dramatically, global warming will reach a level that has not been seen for millions of years. Let’s hope those attending COP26 are listening to messages from the past.

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This blog is written by Cabot Institute for the Environment member Dan Lunt, Professor of Climate Science, University of Bristol and Darrell Kaufman, Professor of Earth and Environmental Sciences, Northern Arizona University

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

Dan Lunt

 

 

Read all blogs in our COP26 blog series:

Time for policymakers to make policies (and to learn from those who are)

Posted on by janet.crompton

From a social scientist’s point of view, the recent IPCC report and the reception it has received are a bit odd. The report certainly reflects a huge amount of work, its message is vital, and it’s great so many people are hearing it. But not much in the report updates how we think about climate change. We’ve known for a while that people are changing the climate, and that how much more the climate changes will depend on the decisions we make.

What decisions? The Summary for Policymakers— the scientists’ memo to the people who will make the really important choices—doesn’t say. The words “fossil fuel”, “oil”, and “coal” never even appear. Nor “regulation”, “ban”, “subsidy”, or “tax”. The last five pages of the 42-page Summary are entitled “Limiting Future Climate Change”; but while “policymakers” appear, “policies” do not.

This is not the fault of the authors; Working Group I’s remit does not include policy recommendations. Even Working Group III (focused on mitigation) is not allowed to advocate for specific choices. Yet every IPCC contributor knows the most important question is which emission pathway we take, and that will depend on what policies we choose.

Which is why it’s so odd that big policy issues and announcements get comparatively little airtime (and research funding). For example, in June, the European Union codified in law the goal of reducing its greenhouse gas emissions 55% by 2030 (relative to 1990), and last month the European Commission presented a set of ambitious proposals for hitting that target. As a continent, Europe is already leading the world in emission reductions (albeit starting from a high level, with large cumulative historical emissions), and showing the rest of the world how to organize high-income societies in low-carbon ways. But the Commission’s proposals—called “Fit for 55”—have gone largely under the radar, not only outside of the EU but even within it.

The proposals are worth examining. At least according to the Commission, they will make the EU’s greenhouse gas emissions consistent with its commitments under the Paris Agreement. (Independent assessments generally agree that while a 55% reduction by 2030 won’t hit the Paris Agreement’s 1.5˚ target, it would be a proportionate contribution to the goal of limiting global heating to no more than 2˚.) And they will build on the EU’s prior reduction of its territorial emissions by 24% between 1990 and 2019.

A change of -24% over that period, and -18% for consumption emissions, is in one sense disappointing, given that climate scientists were warning about the need for action even before 1990. But this achievement, inadequate though it may be, far exceeds those of other high per-capita emitters, like the U.S. (+14%), Canada (+21%), or Australia (+54%).

The most notable reductions have been in the areas of electricity generation and heavy industry—sectors covered by the EU’s emissions trading system (ETS). Emissions from buildings have not declined as much, and those from transportation (land, air, and marine) have risen. Several of the Fit for 55 proposals therefore focus on these sectors. Maritime transport is to be incorporated into the ETS; free permits for aviation are to be eliminated; and a new, separate ETS for fuels used in buildings and land transport is to be established. Sales of new cars and trucks with internal combustion engines will end as of 2035, and increased taxes will apply to fuels for transport, heat, and electricity.

The Commission also proposes to cut emissions under the ETS by 4.2% each year (rather than 2.2% currently); expand the share of electricity sourced from renewables; and set a stricter (lower) target for the total amount of energy the EU will use by 2030—for the sake of greater energy efficiency.

All of this is going to be hugely contentious, and it will take a year or two at least for the Commission, the member-states, and the European Parliament to negotiate a final version. Corporate lobbying will shape the outcome, as will public opinion (paywall).

Two of the most interesting proposals are meant to head off opposition from industry and voters. A carbon border adjustment mechanism will put a price on greenhouse gases emitted by the production abroad of selected imports into the EU (provisionally cement, fertiliser, iron, steel, electricity, and aluminium). This will protect European producers from competitors subject to weaker rules. A social climate fund, paid for out of the new ETS, will compensate low-income consumers and small businesses for the increased costs of fossil fuels—thereby preventing any rise in fuel poverty.

No country is doing enough to mitigate emissions. But Fit for 55 represents the broadest, most detailed emissions reductions plan in the world—and, in some form, it will be implemented. Decision-makers everywhere should be studying, and making, policies like this.

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This guest blog is by friend of Cabot Insitute for the Environment and PLOS Climate Academic Editor Malcolm Fairbrother. Malcolm is a Professor of Sociology at Umeå University (Sweden), the Institute for Futures Studies (Stockholm), and University of Graz (Austria). Twitter: @malcolmfair. This blog has been reposted with kind permission from Malcolm Fairbrother. View the original blog.

Top image credit: Cold Dawn, Warm World by Mark McNestry, CC BY 2.0

 

How University-city partnerships can help us tackle the global climate emergency

Posted on by janet.crompton

 

Image credit: Chris Bhan 

Climate scientists have made it clear: we are in a global state of emergency. The International Panel on Climate Change report published late last year was a wake-up call to the world – if we don’t limit warming to 1.5 degrees, 10 million more people will be exposed to flood risk. If we don’t, it will be much, much harder to grow crops and have affordable food. If we don’t, we’ll have more extreme weather, which will undoubtedly impact the most vulnerable. If we don’t, the coral reefs will be almost 100% gone.

And yet… National governments are failing to act with the urgency demanded by our climate crisis. The commitments each country made to reduce emissions under the Paris Agreement won’t get us there – not even close.

How can we make progress in the face of political paralysis?

The answer is local action. Specifically, it’s action at the city-scale that has excited and inspired a plethora of researchers at the Cabot Institute in recent years.  Cities are complex places of contradiction – they are where our most significant environmental impacts will be borne out through consumption and emissions, whilst simultaneously being places of inspirational leadership, of rapid change, and of innovation.

City governments across the world are increasingly taking the lead and recognising that radically changing the way our cities are designed and powered is essential to reducing carbon emissions [ref 1; ref 2]. They are standing against national powers to make a change (see for example We Are Still In, a coalition of cities and other non-state actors responding to Trump’s withdrawal from the Paris Agreement). And they are forming innovative partnerships to galvanise action quickly – both in terms of lowering emissions and planning for adaptation to climate change (see for example C40 Cities or 100 Resilient Cities).

Bristol is among them. It was a combination of grass-roots leadership and City support that led to Bristol being the first and only UK city to be awarded the title of European Green Capital in 2015. In November 2018, Bristol City Council unanimously passed the Council Motion to declare a Climate Emergency in Bristol and pledge to make the city Carbon neutral by 2030. It was the first local government authority to do so in the UK.

Today, the University of Bristol is the first UK university to stand alongside its city and declare a Climate Emergency. Far from being a symbolic gesture, these declarations reflect strong local political will to tackle climate change, and they are backed up by action at all levels of the University – from committing to become a carbon neutral campus by 2030, to making education on sustainable futures available to every student.

What’s clear, and potentially even more exciting, is that Universities and cities have a unique opportunity collaborate to innovate for change in truly meaningful and cutting-edge ways.

Within the Cabot Institute for the Environment, we’ve been fortunate to build research partnerships with the many inspiring individuals and organisations in our city. Whether it’s collaborating with the City Council to evaluate the economics of a low carbon Bristol, or with We the Curious to create street art on the impacts and solutions to climate change, or with Ujima Radio and the Bristol Green Capital Partnership to improve inclusion in the city’s sustainability movement – we’ve seen that we can achieve more when we recognise and value knowledge from within and outside the walls of the institution, and make progress together.

Bristol City Council has been working closely with both academics and students at the University of Bristol to explore ways to deliver the highly ambitious target of carbon neutrality by 2030. Cabot Institute researchers have also been working alongside the City Office to embed the UN Sustainable Development Goals in the recently launched One City Plan, which reflects a unique effort to bring together partners from across the public, private and non-profit sectors to collectively define a vision for the city and chart a path towards achieving it. There are many organisations and citizens working to make Bristol more sustainable. The One City Plan is designed to amplify these efforts by improving coordination and encouraging new partnerships.

The good news is that Bristol has already begun reducing its carbon emissions, having cut per capita emissions by 1.76 tonnes since 2010. However, we need to accelerate decarbonisation to avert a crisis and make our contribution to tackling the climate emergency.

We can achieve this in Bristol if we work together in partnership, and we must. We simply cannot wait for our national governments to act. We look forward to standing with our city to meet this challenge together.

This blog is written by Dr Sean Fox and Hayley Shaw with contributions from Dr Alix Dietzel and Allan Macleod.

Dr Sean Fox, Senior Lecturer in Global Development in the School of Geographical Sciences and City Futures theme lead at Cabot Institute for the Environment.

Hayley Shaw, Manager of Cabot Institute for the Environment.

Courts can play a pivotal role in combating climate change

Posted on by janet.crompton
Calin Tatu/Shuttestock.com
The international community has widely acknowledged the severe threats posed by the impacts of climate change to a series of human rights, including the rights to life, health, and an adequate standard of living. But a stark gap has emerged between this acknowledgement in global climate policy – evidenced by a non-binding clause in the preamble of the Paris Agreement – and their actions to meet promised targets.
How can we hold governments accountable to their human rights duties? A Dutch case recently upheld by the appeals court might hold the answer.
In June 2015, The Hague District Court and a group of 886 concerned citizens, united by the environmental interest group Urgenda Foundation, made history. This, the first successful climate change case brought on human rights and civil law grounds, saw the Dutch government ordered to reduce their greenhouse gas emissions by a minimum of 25% on 1990 levels by the year 2020.
Three years on – against a backdrop of intense scrutiny and after an appeal lodged by the government – The Hague Court of Appeal upheld this decision on October 9. Indeed, it has gone significantly further in affirming the duties of care owed by the state to its people. The court considered the weight of the scientific evidence presented by the Intergovernmental Panel on Climate Change (IPCC) and the recommendations of successive UN conferences to reach an informed conclusion on the required mitigation targets commensurate with the prevention of dangerous climate change.
Marjan Minnesma, director of environmental group Urgenda, arrives at court prior to the appeal. Jerry Lampden/EPA
Significantly, the judges reached this decision by applying the European Convention on Human Rights: the right to private and family life and the right to life more broadly. As such, this case reaffirms the existence of obligations on the part of the state to take concrete measures to prevent the infringement of these rights where the authorities are aware of the existence of a real and imminent threat.
These obligations were held to extend to industrial activities which threaten the rights of people within the state’s jurisdiction. Based on an analysis of the scientific evidence, the court concluded that climate change presents a real and imminent threat to the enjoyment of citizens’ rights as spelled out in the EU convention. They ruled that a 25% emissions reduction is the minimum required to fulfil the government’s duty of care.


Human rights alarm

The Urgenda appeal decision was handed down too early for the findings of the most recent IPCC report on global warming of 1.5ºC, which was published the day before the ruling, to be integrated into the judges’ reasoning. But these findings will significantly strengthen the evidential basis of future claims.
The IPCC report outlines the stark increase in the risks to human health, food and water security, and livelihoods associated with 2ºC of warming, when compared to 1.5ºC. The evidence presented on human health, including the increased risk of heat-related morbidity and mortality, projected with “very high confidence”, is particularly striking. The climate is currently 1ºC warmer than pre-industrial levels, and with the planet projected to reach 1.5ºC as early as 2030 if current trends continue, the alarm on the imminence of the threat to human rights has been sounded.
No legally binding human rights provisions or remedies are provided within the international climate change regime. And so we must turn to the courts to clarify state duties. The Urgenda case sets an encouraging precedent. And there are many more examples of rights-based claims being brought against governments in Belgium, Canada, Colombia, the UK, and even against the EU institutions. This marks a sea change in the use of human rights to hold policymakers to account for their inaction on climate change.


The decision by the Netherlands court of appeals in #Urgenda immediately becomes the most important judicial decision yet on the application of human rights law to climate change. 1/10 https://t.co/8ioKxFEjly

— John H Knox (@JohnHKnox) 9 October 2018


A new approach

In the face of the severity and imminence of the environmental risks we face, the approach to human rights protection adopted by the Urgenda judges is crucial. If courts focus on the imminent risks to human life and health, cases brought forward by particularly climate-vulnerable groups should be prioritised.
Individuals most at risk from rising temperatures and extreme weather events – including those whose livelihoods, socio-economic status, and geographic susceptibility result in them being disproportionately affected – would have the strongest claims. Civil society organisations have a crucial role to play in facilitating access to justice for such individuals, for whom entrenched structural barriers often mean that individual access to the courts remains out of reach.
To effectively accommodate climate risks of this nature the existing legal doctrine will need to be adapted, bringing together environmental principles and human rights. The role of the courts themselves is being called into question by climate litigation: the separation of powers between policymakers and the judiciary is embedded in legal systems around the globe, yet the protection of fundamental rights is intended to transcend this divide. It is the duty of the courts to act as a check on executive action and, in this case, inaction, where the enjoyment of rights is in jeopardy.
Never before has the role of the courts been so significant in influencing the path of global policy. In the face of inadequately ambitious action by policy-makers, civil society movements and the courts are the agents of change securing climate action.The Conversation


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This blog was written by Cabot Institute member Alice Venn, a PhD Candidate in Environment, Energy & Resilience and Unit Coordinator in Environmental Law, University of Bristol.  This article is republished from The Conversation under a Creative Commons license. Read the original article. 
Alice Venn
 
 

The Paris Agreement – where are we now?

Posted on by janet.crompton

Cabot Annual Lecture 2018

This year the Cabot Institute Annual Lecture posed a critical question: where are we with current efforts to tackle global climate change? The event brought together over 800 people to hear from leading Cabot Institute experts in climate science, policy, and justice, Dr Jo House, Dr Dann Mitchell, Dr Alix Dietzel and Professor Tony Payne. It was both an appraisal of the findings of the recently published report of the Intergovernmental Panel on Climate Change (IPCC), and a grounded call to climate action.

Paris commitments

In 2015 world leaders adopted the Paris Agreement committing all parties to limiting global average temperatures to well below 2 °C above pre-industrial levels and to pursue efforts to limit warming to 1.5 °C. All countries undertook to achieve global peaking of greenhouse gas emissions as soon as possible and to enact increasingly ambitious mitigation measures in line with the overarching temperature goals. The Paris Agreement, in contrast to the preceding Kyoto Protocol, is not based on legally binding reductions targets for developed countries, but on a voluntary system of pledges known as ‘nationally determined contributions’ for all parties which will be subject to a stocktake of global progress every five years, beginning in 2023.

Although the Paris Agreement initially offered great promise with pledges being made by both developed and developing countries, a report by the UN Environment Programme in November 2017 examining progress towards the global temperature goals found that even if all current pledges are honoured, we remain on track for some 3 °C of warming by 2100. In light of this, and under the Presidency of Fiji, the first Small Island State to preside over a Conference of the Parties at COP23 last year, the focus has been on building momentum for more urgent action through the facilitative ‘Talanoa dialogue’ and on hashing out the final operating procedures for the Agreement. The findings of the IPCC Report on Global Warming of 1.5°C, published on 8 October represent a further important piece of the picture of global progress, which three of the Cabot speakers shed light upon as contributing authors.

Why 0.5°C of warming matters

The findings of the report are significant in illustrating the projected differences in climate change impacts between the 1.5°C and 2°C temperature thresholds. Dr Dann Mitchell outlined the evidence for increases in regional mean temperatures and for the increasing likelihood of temperature extremes of the kind witnessed during this summer’s European heatwave, which we could see occur almost every year at 2°C of warming. These extremes, together with the projected intensification of storms presented in the report, are closely linked to human risks to health, wellbeing and livelihoods.

Cabot Annual Lecture 2018
Dr Dann Mitchell

Professor Tony Payne echoed these concerns with respect to the findings of the report on sea-level rise which predict an extra 10cm rise between the 1.5°C and 2°C temperature thresholds, equating, in turn, to an additional 10 million people at risk of related impacts including inundation and displacement. The destabilisation of the ice sheets is set to become more likely beyond 1.5°C, entailing risks of much greater sea-level rise in the future. Professor Payne further outlined the strikingly severe consequences for coral reefs of the two temperature thresholds, with projections that at 2°C all coral in the oceans will die, while by limiting temperature to 1.5°C, some 10-30% of coral will survive. Reefs are not only crucial for the maintenance of healthy marine ecosystems, but also for the millions of people around the world who depend upon those ecosystems for their food security and livelihoods.

Cabot Annual Lecture 2018
Professor Tony Payne

A call for action

Against these stark warnings on the significance of limiting global temperatures to 1.5°C, Dr Jo House outlined some key recommendations for how we can get on track. The IPCC report sets out a number of pathways for action, each calling for changes across a broad spectrum of policy sectors with the aim of rapidly reducing greenhouse gas emissions and enhancing the absorption of existing carbon in the atmosphere. These changes include moving away from fossil fuels to renewable sources of energy, greening the transport sector, replanting forests, and investing in carbon capture and storage technologies. Dr House underlined the importance of action at all levels of governance to meet these goals. At the national level in the UK under the provisions of the Climate Change Act we are already committed to an 80% reduction on 1990 levels by 2050, while at the city level in Bristol, the Climate and Energy Security Framework commits to the same target, with a 50% reduction to be achieved by 2025.

Cabot Annual Lecture 2018
Dr Jo House

This action in climate policy is increasingly being driven by sub-state actors and Dr Alix Dietzel highlighted the crucial role that local government, civil society groups, citizens initiatives, corporations, and individuals are playing in this. Dr Dietzel expressed cause for hope in the reaction of sub-state actors to the announcement of the withdrawal of the United States from the Paris Agreement, with the ‘WE ARE STILL IN’ movement garnering support from city mayors, governors, tribal leaders, universities, and businesses for continuing commitment to the Paris goals. At the individual level, the actions we can all take within the boundaries of our own capabilities were discussed, outlining our capacity to affect change through our consumption and lifestyle choices. The need to consider the ethical questions surrounding our responsibilities as individuals and global citizens remains crucial, particularly in light of the disproportionately harmful effects that climate impacts will have upon those who have contributed least to the problem.

Cabot Annual Lecture 2018
Dr Alix Dietzel

The risks of inaction on the 1.5°C threshold were balanced against the opportunities and benefits of action by the panel. The successful lobbying efforts of climate-vulnerable states to embed the 1.5°C threshold within the Paris framework, alongside the commitment of many governments and sub-state actors to meet it, are cause for hope but we still have a long way to go.

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This blog was written by Cabot Institute member Alice Venn, a PhD Candidate in Environment, Energy & Resilience at the University of Bristol’s Law School.

Alice Venn

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Monitoring greenhouse gas emissions: Now more important than ever?

Posted on by janet.crompton

As part of Green Great Britain Week, supported by BEIS, we are posting a series of blogs throughout the week highlighting what work is going on at the University of Bristol’s Cabot Institute for the Environment to help provide up to date climate science, technology and solutions for government and industry.  We will also be highlighting some of the big sustainability actions happening across the University and local community in order to do our part to mitigate the negative effects of global warming. Today our blog will look at ‘Explaining the latest science on climate change’.

The IPCC report

On 8 October 2018 the Intergovernmental Panel on Climate Change (IPCC) [1] published their special report on Global Warming of 1.5 ˚C. As little as 24 hours after the report had been published, the results of the report were already receiving extensive global coverage in the media, with BBC News describing the report as the “final call”. The BBC News article also explicitly mentions that this is “the most extensive warning yet on the risks of rising global temperatures. Their dramatic report on keeping that rise under 1.5 ˚C states that the world is now completely off track, heading instead towards 3 ˚C. Staying below 1.5 ˚C will require ‘rapid, far-reaching and unprecedented changes in all aspects of society’ [2].”

Reading the report has quite honestly been somewhat overwhelming but also necessary to understand exactly what we are in for. And as much as I understand the difficulty one might face either with the technical terms of the report or even the volume of information, I would really encourage you to give it a read. This special report covers a wide range of subjects from oceans, ice and flooding to crops, health and economy. However, if you do find that the chapters themselves are too lengthy or difficult, there is an amazing interactive, and very easy way that will help you explore the impacts of a 1.5 ˚C, 2 ˚C and beyond on Carbon Brief’s website.

There are two distinct parts in the IPCC special report. The full technical report that consists of 5 chapters and a short summary for policy makers (SPM). The SPM clearly states that “Estimated anthropogenic global warming matches the level of observed warming to within ±20 %” which translates into ‘almost 100 % of the warming is the result of human activity’ [3] [4].

We know for a fact that human activity is warming the planet

One outcome of this “human activity” that we often discuss is the emission of greenhouse gases (GHGs). Through various types of activities, whether that is agriculture, deforestation or burning fossil fuels, GHGs are emitted to the atmosphere. Without going too much into the chemistry and physics, what these GHGs do is change the mixing ratios within the atmosphere, resulting in greater absorbance of infrared radiation. And it is this change in the composition of our atmosphere that we refer to as the manmade greenhouse gas effect which also leads to the warming described in the IPCC report. But far more than the warming effect itself, global warming has all sorts of impacts most of which you can explore through the interactive link above.

Greenhouse gases and a long history of monitoring

Some of the ‘usual suspects’ in the discussion of GHG emissions are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) (often described as the ‘major’ greenhouse gases [5]). However, an often-overlooked set of halogenated greenhouse gases are playing an increasingly large role in anthropogenic driven climate change. Gases like perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs) are compounds that are emitted through some form of human activity. In the case of PFCs for example, the GHGs CF4 and C2F6 are two of the most volatile and long-lived gases monitored under the Kyoto protocol [6] and they are both primarily emitted through or during industrial processes. In contrast, HFCs are used widely as coolants in refrigerators and air-conditioning units, as blowing agents in foam manufacture and propellants in aerosols. They were originally introduced to replace ozone-depleting gases such as chlorofluorocarbons (CFCs), but like their predecessors, are potent greenhouse gases. Given the long lifetime of many of these halogenated gases, current emissions will influence the climate system for decades to come.

In order to monitor the accumulation of these gases in atmosphere, high-precision measurements are required. Through projects such as the Advanced Global Atmospheric Gases Experiment (AGAGE) [7] (figure 1 [8]) that has been measuring the composition of the global atmosphere continuously since 1978 and the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory Global Monitoring Division, scientists have tracked the atmospheric concentrations of climate forcing gases from as far back as 1950s [9].

Figure 1: The AGAGE network

The Atmospheric Chemistry Research Group (ACRG) Chemistry Department, University of Bristol

The ACRG carries out research in the UK and worldwide in collaboration with other atmospheric chemistry research centres, universities and third parties. In the UK, the ACRG runs the UK Deriving Emissions linked to Climate Change network (DECC) [10], funded by the Department for Business, Energy and Industrial Strategy (BEIS) to measure atmospheric GHG and ozone depleting substances over the UK. These measurements are used in elaborate mathematical models to create top-down emission estimates for the UK and verify the UK GHG inventories submitted to the United Nations Framework Convention for Climate Change (UNFCCC) as part of the Kyoto protocol. Worldwide, the group is involved in the AGAGE network, monitoring global background levels of a wide range of GHGs. The ACRG runs 2 of the 9 global background stations under the AGAGE programme. One of these is the Mace Head station (Figure 2) on the west coast of Ireland, which is ideally placed for resolving northern hemispheric baseline air amongst European pollution events. The other AGAGE research station managed by the ACRG is the site at Ragged Point, Barbados. This site just north of the tropics, sits on the eastern edge of the island of Barbados and is directly exposed to the Atlantic. The researchers in ACRG study a variety of GHGs and a very large range of topics from maintaining instrument suites to ensuring the quality of the resulting data so that it can be used in modelling studies.

Figure 2: The Mace Head Station (Credit: Dr Kieran Stanley)

Why are measuring stations and networks like AGAGE so valuable and more important than ever?

The answer to this question is straightforward. Without measurement stations and their underlying networks, we would have very few means [11] by which to measure the accumulation of GHGs in the global atmosphere, and consequently no way of evaluating their emissions without relying on statistics from the industries that emit them. The current IPCC report is underpinned by such measurements, which allow scientists to estimate the impact of anthropogenic activity on past, present and future climates.

From Mauna Loa and its 60 -year record of atmospheric CO2 [12], to unexpected growth in emissions of banned substances such as CFC – 11 [13] and monitoring the accumulation of extremely long-lived greenhouse gases in the global atmosphere, atmospheric measurements stations have been our inside man when it comes to keeping track of what is happening in our atmosphere and to what extent human activities are altering its composition.

Perhaps now more than ever, in the light of the IPCC report, we can appreciate the importance of the data that have been collected over decades but also, the efforts of those who have been directly or indirectly involved in this kind of work.  Continuing and expanding the measurement networks for these gases is and will be even more vital for a continued understanding of global and regional GHG emission trends.

References

[1] http://www.ipcc.ch/
[2]  https://www.bbc.co.uk/news/science-environment-45775309
[3]  http://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf
[4]  https://www.carbonbrief.org/analysis-why-scientists-think-100-of-global-warming-is-due-to-humans
[5]  https://www.c2es.org/content/main-greenhouse-gases/
[6]  https://www.atmos-chem-phys.net/10/5145/2010/acp-10-5145-2010.pdf
[7]  https://agage.mit.edu/
[8]  https://agage.mit.edu/
[9]  https://www.esrl.noaa.gov/gmd/about/aboutgmd.html
[10]  http://www.bristol.ac.uk/chemistry/research/acrg/current/decc.html
[11]  https://www.co2.earth/co2-ice-core-data
[12]  https://www.co2.earth/daily-co2
[13]  https://www.theguardian.com/environment/2018/may/16/mysterious-rise-in-banned-ozone-destroying-chemical-shocks-scientists

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This blog is written by Cabot Institute members Eleni Michalopoulou, Dr Dan Say, Dr Kieran Stanley and Professor Simon O’Doherty from the University of Bristol’s School of Chemistry.

Dan Say
Eleni Michalopoulou

 

Read other blogs in this Green Great Britain Week series:
1. Just the tip of the iceberg: Climate research at the Bristol Glaciology Centre
2. Monitoring greenhouse gas emissions: Now more important than ever?
3. Digital future of renewable energy
4. The new carbon economy – transforming waste into a resource
5. Systems thinking: 5 ways to be a more sustainable university
6. Local students + local communities = action on the local environment

Global warming ‘pause’ was a myth all along, says new study

Posted on by janet.crompton

The idea that global warming has “stopped” is a contrarian talking point that dates back to at least 2006. This framing was first created on blogs, then picked up by segments of the media – and it ultimately found entry into the scientific literature itself. There are now numerous peer-reviewed articles that address a presumed recent “pause” or “hiatus” in global warming, including the latest IPCC report.

So did global warming really pause, stop, or enter a hiatus? At least six academic studies have been published in 2015 that argue against the existence of a pause or hiatus, including three that were authored by me and colleagues James Risbey of CSIRO in Hobart, Tasmania, and Naomi Oreskes of Harvard University.

Our most recent paper has just been published in Nature’s open-access journal Scientific Reports and provides further evidence against the pause.

Pause not backed up by data

First, we analysed the research literature on global temperature variation over the recent period. This turns out to be crucial because research on the pause has addressed – and often conflated – several distinct questions: some asked whether there is a pause or hiatus in warming, others asked whether it slowed compared to the long-term trend and yet others have examined whether warming has lagged behind expectations derived from climate models.

These are all distinct questions and involve different data and different statistical hypotheses. Unnecessary confusion has resulted because they were frequently conflated under the blanket labels of pause or hiatus.

 

New NOAA data released earlier this year confirmed there had been no pause. The author’s latest study used NASA’s GISTEMP data and obtained the same conclusions.
NOAA

To reduce the confusion, we were exclusively concerned with the first question: is there, or has there recently been, a pause or hiatus in warming? It is this question – and only this question – that we answer with a clear and unambiguous “no”.

No one can agree when the pause started

We considered 40 recent peer-reviewed articles on the so-called pause and inferred what the authors considered to be its onset year. There was a spread of about a decade (1993-2003) between the various papers. Thus, rather than being consensually defined, the pause appears to be a diffuse phenomenon whose presumed onset is anywhere during a ten-year window.

Given that the average presumed duration of the pause in the same set of articles is only 13.5 years, this is of concern: it is difficult to see how scientists could be talking about the same phenomenon when they talked about short trends that commenced up to a decade apart.

This concern was amplified in our third point: the pauses in the literature are by no means consistently extreme or unusual, when compared to all possible trends. If we take the past three decades, during which temperatures increased by 0.6℃, we would have been in a pause between 30% and 40% of the time using the definition in the literature.

In other words, academic research on the pause is typically not talking about an actual pause but, at best, about a fluctuation in warming rate that is towards the lower end of the various temperature trends over recent decades.

How the pause became a meme

If there has been no pause, why then did the recent period attract so much research attention?
One reason is a matter of semantics. Many academic studies addressed not the absence of warming but a presumed discrepancy between climate models and observations. Those articles were scientifically valuable (we even wrote one ourselves), but we do not believe that those articles should have been framed in the language of a pause: the relationship between models (what was expected to happen) and observations (what actually happened) is a completely different issue from the question about whether or not global warming has paused.

A second reason is that the incessant challenge of climate science by highly vocal contrarians and Merchants of Doubt may have amplified scientists’ natural tendency to be reticent over reporting the most dramatic risks they are concerned about.

We explored the possible underlying mechanisms for this in an article earlier this year, which suggested climate denial had seeped into the scientific community. Scientists have unwittingly been influenced by a linguistic frame that originated outside the scientific community and by accepting the word pause they have subtly reframed their own research.

Research directed towards the pause has clearly yielded interesting insights into medium-term climate variability. My colleagues and I do not fault that research at all. Except that the research was not about a (non-existent) pause – it was about a routine fluctuation in warming rate. With 2015 being virtually certain to be another hottest year on record, this routine fluctuation has likely already come to an end.
The Conversation

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This article was originally published on The Conversation. Read the original article.

This blog is by Cabot Institute member Prof Stephan Lewandowsky, University of Bristol.

Prof Steve Lewandowsky



Read the official press release.

The science of sustainable development, what shall I teach?

Posted on by janet.crompton

Before the lectures

Next week I will teach the first of three lectures which constitute the Science of Sustainable Development within the Sustainable Development course at the University of Bristol. This is an open unit and can therefore be attended by first year undergraduate students from across the university.

The figure below shows how Sustainable Development is considered at the University of Bristol, clearly a hugely interdisciplinary and wide subject area!

Traditionally this unit has attracted a significant fraction of its cohort from Geographical Sciences, which is my current home department. This should make preparation of these three lectures relatively straightforward right? Wrong.A fascinating aspect of the School of Geographical Sciences is its breadth and variety of research and expertise. This is the case not simply because our physical geographers work on everything from past climates to flood inundation modelling but also because there is also the ‘human’ side to geography. My human geography colleagues research and teach on topics as varied as spatial and historical patterns of electoral voting and taxidermy.

This highly varied student body is complicated further by my own personal background. I am a ‘pure’ physicist by training, having studied for my PhD in the nanoscale physics of solar cells and LEDs.  After my PhD I have mostly been a climate modeller, with some time spent in environmental consultancy and so my career has been undeniably ‘environmental’ from start to finish so far. That said, I would struggle to think of more than a few topics in my undergraduate days which were explicitly linked to sustainability. Perhaps this is not surprising however when one considers how large the core of physics is as a university-level subject. How can lecturing staff make quantum mechanics and astrophysics relevant to Sustainable Development? Is it even possible or meaningful? These questions are certainly outside the scope of this short blog post!

Moving back to the subject matter of my lectures, I had to consider what links climate change, climate modelling and environmentalism in such a way that the term Sustainable Development can be introduced scientifically in three parts? When I posed this question to myself in this way, the answer was clear; The Intergovernmental Panel on Climate Change, or IPCC for short, not to be confused with the Independent Police Complaints Commission! This body was founded by the UN and World Meteorological Organisation in the late 1980s to provide a synthesis on the state of knowledge of the climate system and how humans are interfering with it. The IPCC has to date published five of these Assessment Reports and they are split into three Working Groups:

  1. The Physical Science Basis
  2. Impacts, Adaptation and Vulnerability
  3. Mitigation of Climate Change.

The bulk of my work since 2008 (at the Met Office and at Bristol) has concerned climate modelling and therefore fits well within the remit of Working Group one. Theoretically I could have stopped there and taught three lectures on the meteorology and climatology of climate change, this would probably however only really appealed to those students who had taken A Level physics. The natural diversification of the three Working Groups was the only solution and I therefore decided to prepare one lecture on each. This also provided me with an opportunity to improve my own knowledge of Working Groups 2 and 3, something I had been meaning to do for a while! I should state at this point that there is no scientist in the world with an in depth knowledge of every aspect of even one of the Working Groups. Working Group 1 alone has over 1500 pages of fully cited scientific text for example!

After lecture one

As I write this part of the blog post I have just given my first lecture in the series. This lecture tallied well with my research interests and scientific knowledge and I now have a little under a week to finish my preparation for the next two lectures. Crucially, my biggest challenge will undoubtedly be the effective teaching of Working Groups two and three and I will aim to report back with another blog post after my lectures have run their course.

Finally, one aspect of this course which I hope that will come across in my teaching is my aim to emphasise the interdisciplinary nature and breadth of this subject. As I said in my first lecture, I am a physicist working in a geography department and lecturing to students from all five faculties. If this doesn’t illustrate the cross cutting nature of this subject then I don’t know what does!

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This blog is written by Cabot Institute member, Dr Jonny Williams, an environmental physicist working in the School of Geographical Sciences at the University of Bristol.
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