janet.crompton – Page 2 – Cabot Institute for the Environment blog

Insects will struggle to keep pace with global temperature rise – which could be bad news for humans

Posted on October 4, 2022March 29, 2023 by janet.crompton

Animals can only endure temperatures within a given range. The upper and lower temperatures of this range are called its critical thermal limits. As these limits are exceeded, an animal must either adjust or migrate to a cooler climate.

However, temperatures are rising across the world at a rapid pace. The record-breaking heatwaves experienced across Europe this summer are indicative of this. Heatwaves such as these can cause temperatures to regularly surpass critical thermal limits, endangering many species.

In a new study, my colleagues and I assessed how well 102 species of insect can adjust their critical thermal limits to survive temperature extremes. We found that insects have a weak capacity to do so, making them particularly vulnerable to climate change.

The impact of climate change on insects could have profound consequences for human life. Many insect species serve important ecological functions while the movement of others can disrupt the balance of ecosystems.

How do animals adjust to temperature extremes?

An animal can extend its critical thermal limits through either acclimation or adaptation.

Acclimation occurs within an animal’s lifetime (often within hours). It’s the process by which previous exposure helps give an animal or insect protection against later environmental stress. Humans acclimate to intense UV exposure through gradual tanning which later protects skin against harmful UV rays.

One way insects acclimate is by producing heat shock proteins in response to heat exposure. This prevents cells dying under temperature extremes.

A ladybird drinking a speck of water on a narrow leaf. — Insects in warmer environments develop fewer spots to reduce heat retention.
mehmetkrc/Shutterstock

Some insects can also use colour to acclimate. Ladybirds that develop in warm environments emerge from the pupal stage with less spots than insects that develop in the cold. As darker spots absorb heat, having fewer spots keeps the insect cooler.

Adaptation occurs when useful genes are passed through generations via evolution. There are multiple examples of animals evolving in response to climate change.

Over the past 150 years, some Australian parrot species such as gang-gang cockatoos and red-rumped parrots have evolved larger beaks. As a greater quantity of blood can be diverted to a larger beak, more heat can be lost into the surrounding environment.

A colourful red-rumped parrot perched on a branch. — The red-rumped parrot has evolved a larger beak to cope with higher temperatures.
Alamin-Khan/Shutterstock

But evolution occurs over a longer period than acclimation and may not allow critical thermal limits to adjust in line with the current pace of global temperature rise. Upper thermal limits are particularly slow to evolve, which may be due to the large genetic changes required for greater heat tolerance.

Research into how acclimation might help animals survive exceptional temperature rise has therefore become an area of growing scientific interest.

A weak ability to adjust to temperature extremes

When exposed to a 1℃ change in temperature, we found that insects could only modify their upper thermal limit by around 10% and their lower limit by around 15% on average. In comparison, a separate study found that fish and crustaceans could modify their limits by around 30%.

But we found that there are windows during development where an insect has a greater tolerance towards heat. As juvenile insects are less mobile than adults, they are less able to use their behaviour to modify their temperature. A caterpillar in its cocoon stage, for example, cannot move into the shade to escape the heat.

Exposed to greater temperature variations, this immobile life stage has faced strong evolutionary pressure to develop mechanisms to withstand temperature stress. Juvenile insects generally had a greater capacity for acclimating to rising temperatures than adult insects. Juveniles were able to modify their upper thermal limit by 11% on average, compared to 7% for adults.

But given that their capacity to acclimate is still relatively weak and may fall as an insect leaves this life stage, the impact is likely to be limited for adjusting to future climate change.

What does this mean for the future?

A weak ability to adjust to higher temperatures will mean many insects will need to migrate to cooler climates in order to survive. The movement of insects into new environments could upset the delicate balance of ecosystems.

Insect pests account for the loss of 40% of global crop production. As their geographical distribution changes, pests could further threaten food security. A UN report from 2021 concluded that fall armyworm populations, which feed on crops such as maize, have already expanded their range due to climate change.

A damaged corn crop following an attack by fall armyworms. — The fall armyworm is a damaging crop pest which is spreading due to climate change.
Alchemist from India/Shutterstock

Insect migration may also carry profound impacts on human health. Many of the major diseases affecting humans, including malaria, are transmitted by insects. The movement of insects over time increases the possibility of introducing infectious diseases to higher latitudes.

There have been over 770 cases of West Nile virus recorded in Europe this year. Italy’s Veneto region, where the majority of the cases originate, has emerged as an ideal habitat for Culex mosquitoes, which can host and transmit the virus. Earlier this year, scientists found that the number of mosquitoes in the region had increased by 27%.

Insect species incapable of migrating may also become extinct. This is of concern because many insects perform important ecological functions. Three quarters of the crops produced globally are fertilised by pollinators. Their loss could cause a sharp reduction in global food production.

The vulnerability of insects to temperature extremes means that we face an uncertain and worrying future if we cannot curb the pace of climate change. A clear way of protecting these species is to slow the pace of climate change by reducing fossil fuel consumption. On a smaller scale, the creation of shady habitats, which contain cooler microclimates, could provide essential respite for insects facing rising temperatures.

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This blog is written by Hester Weaving, PhD Candidate in Entomology, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Hester Weaving

Three reasons a weak pound is bad news for the environment

Posted on October 3, 2022April 14, 2023 by janet.crompton

The day before new UK chancellor Kwasi Kwarteng’s mini-budget plan for economic growth, a pound would buy you about $1.13. After financial markets rejected the plan, the pound suddenly sunk to around $1.07. Though it has since rallied thanks to major intervention from the Bank of England, the currency remains volatile and far below its value earlier this year.

A lot has been written about how this will affect people’s incomes, the housing market or overall political and economic conditions. But we want to look at why the weak pound is bad news for the UK’s natural environment and its ability to hit climate targets.

1. The low-carbon economy just became a lot more expensive

The fall in sterling’s value partly signals a loss in confidence in the value of UK assets following the unfunded tax commitments contained in the mini-budget. The government’s aim to achieve net zero by 2050 requires substantial public and private investment in energy technologies such as solar and wind as well as carbon storage, insulation and electric cars.

But the loss in investor confidence threatens to derail these investments, because firms may be unwilling to commit the substantial budgets required in an uncertain economic environment. The cost of these investments may also rise as a result of the falling pound because many of the materials and inputs needed for these technologies, such as batteries, are imported and a falling pound increases their prices.

Aerial view of wind farm with forest and fields in background — UK wind power relies on lots of imported parts.
Richard Whitcombe / shutterstock

2. High interest rates may rule out large investment

To support the pound and to control inflation, interest rates are expected to rise further. The UK is already experiencing record levels of inflation, fuelled by pandemic-related spending and Russia’s war on Ukraine. Rising consumer prices developed into a full-blown cost of living crisis, with fuel and food poverty, financial hardship and the collapse of businesses looming large on this winter’s horizon.

While the anticipated increase in interest rates might ease the cost of living crisis, it also increases the cost of government borrowing at a time when we rapidly need to increase low-carbon investment for net zero by 2050. The government’s official climate change advisory committee estimates that an additional £4 billion to £6 billion of annual public spending will be needed by 2030.

Some of this money should be raised through carbon taxes. But in reality, at least for as long as the cost of living crisis is ongoing, if the government is serious about green investment it will have to borrow.

Rising interest rates will push up the cost of borrowing relentlessly and present a tough political choice that seemingly pits the environment against economic recovery. As any future incoming government will inherit these same rates, a falling pound threatens to make it much harder to take large-scale, rapid environmental action.

3. Imports will become pricier

In addition to increased supply prices for firms and rising borrowing costs, it will lead to a significant rise in import prices for consumers. Given the UK’s reliance on imports, this is likely to affect prices for food, clothing and manufactured goods.

At the consumer level, this will immediately impact marginal spending as necessary expenditures (housing, energy, basic food and so on) lower the budget available for products such as eco-friendly cleaning products, organic foods or ethically made clothes. Buying “greener” products typically cost a family of four around £2,000 a year.

Instead, people may have to rely on cheaper goods that also come with larger greenhouse gas footprints and wider impacts on the environment through pollution and increased waste. See this calculator for direct comparisons.

Of course, some spending changes will be positive for the environment, for example if people use their cars less or take fewer holidays abroad. However, high-income individuals who will benefit the most from the mini-budget tax cuts will be less affected by the falling pound and they tend to fly more, buy more things, and have multiple cars and bigger homes to heat.

This raises profound questions about inequality and injustice in UK society. Alongside increased fuel poverty and foodbank use, we will see an uptick in the purchasing power of the wealthiest.

What’s next

Interest rate rises increase the cost of servicing government debt as well as the cost of new borrowing. One estimate says that the combined cost to government of the new tax cuts and higher cost of borrowing is around £250 billion. This substantial loss in government income reduces the budget available for climate change mitigation and improvements to infrastructure.

The government’s growth plan also seems to be based on an increased use of fossil fuels through technologies such as fracking. Given the scant evidence for absolutely decoupling economic growth from resource use, the opposition’s “green growth” proposal is also unlikely to decarbonise at the rate required to get to net zero by 2050 and avert catastrophic climate change.

Therefore, rather than increasing the energy and materials going into the economy for the sake of GDP growth, we would argue the UK needs an economic reorientation that questions the need of growth for its own sake and orients it instead towards social equality and ecological sustainability.

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This blog is written by Cabot Institute for the Environment members Dr Katharina Richter, Lecturer in Climate, Politics and Society, University of Bristol; Dr Alix Dietzel, Senior Lecturer in Climate Justice, University of Bristol, and Professor Alvin Birdi, Professor of Economics Education, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

The night is full of animal life, but scientists know very little about it

Posted on September 30, 2022April 16, 2023 by janet.crompton

Naturalists and life scientists have long debated how insect-eating bats navigate their dark world.
Sarun T/Shutterstock

Human disturbance is rapidly changing the nature of the nocturnal world. Intensive farming, suburban spread, artificially lit cities, and continuously busy road systems mean daytime species are becoming increasingly active throughout the night. Ecologists suggest that the majority of land animals are either nocturnal or active across both the day and night.

Recent research has also shown that the night is warming considerably faster than the day. The stifling night-time heat experienced across Europe this summer is indicative of this, placing nocturnal animals under even greater stress.

The transforming night adds new sensory pressures concerning finding food, a mate, and navigating a world permeated by artificial illumination. Environmental change is severely threatening the ability of nocturnal animals to coexist with humans. The conservation of nocturnal species has therefore become urgent.

Despite the abundance of night-time life, the understanding of nocturnal species has evaded science throughout history. Physical restraints on human navigation in the dark are partially responsible for this. This scientific blind spot is referred to as the “nocturnal problem”.

The legacy of this inaccessibility remains a barrier to our understanding of nocturnal life today. However, given the environmental threat now facing the nocturnal world, this will have profound consequences should it remain unaddressed. A better understanding of nocturnal life is critical to ensure its effective protection.

The origins of the ‘nocturnal problem’

So how did the nocturnal problem arise and why does it still impede science?

Constrained by their own reliance on vision, early scientists struggled to imagine the different ways in which animals might navigate in the dark. The myths that built up around familiar nocturnal creatures, such as hedgehogs, are evidence of historical attempts to fill the scientific gap.

The Greek philosopher Aristotle suggested that hedgehogs poached apples and carried them off on their spines. Such mythology was commonly included within Victorian natural history texts as an introduction to more factual descriptions of hedgehog anatomy, such as their capacity for smell and other bodily adaptations.

A hedgehog passing a road with a car light illuminating the background. — Even the experiences of hedgehogs remain to some degree unknown.
Lukasz Walas/Shutterstock

But even artificial illumination afforded very limited access. Illumination fundamentally changes the nature of the nocturnal world, with impacts on animal behaviour. A good example is the attraction of moths to street lights.

The historical debate surrounding how insect-eating bats navigate their dark world illustrates the problem. Numerous attempts have been made to understand bat senses. However, it was not until the late 1930s, more than 150 years after experimentation on bats had begun, that the scientists Donald R. Griffin and Robert Galambos identified echolocation – the ability to navigate via the emission and detection of sound signals.

Griffin would later describe the secrets of bat senses as a “magic well”, acknowledging the fundamental challenge of comprehending senses so different from our own.

But efforts to understand nocturnal senses could only take scientists so far. In 1940, American naturalist Orlando Park declared that the biological sciences suffered from a “nocturnal problem”, in reference to the continued inability to understand the nocturnal world. This was reflected in the more recent philosophical text of Thomas Nagel, which posed the question what it like is to like to be a bat?

Persistence of the nocturnal problem

Despite technological developments, including the introduction of infrared photography, aspects of nocturnal life continue to elude modern science.

While technology has afforded scientists a much better understanding of echolocation in bats, our way of thinking about bat senses remains limited by our own dependence on vision. When describing echolocation, scientists still suggest that bats “see” using echoes.

The elusive Australian Night Parrot was presumed extinct for much of the 20th century. Although they have been recently rediscovered, scientists remain unable to estimate their population size accurately while questions over the threats facing the species persist.

Despite an improvement in scientific research, nocturnal life remains understudied. In 2019, life scientist Kevin J. Gaston called for an expansion of research into nocturnal life. History shows us that when there are scientific gaps in knowledge about the night, cultures create their own truths to fill those gaps. The consequences of doing so may be significant.

The night is ecologically rich and efforts to fill these gaps in scientific understanding should be prioritised. The nocturnal world is threatened by environmental change, and its future depends on our commitment to getting to know the darkness.

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This blog is written by Cabot Institute for the Environment members, Dr Andy Flack, Senior Lecturer in Modern and Environmental History, University of Bristol and Dr Alice Would, Lecturer in Imperial and Environmental History, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Labour’s Great British Energy is a good start – here’s how to make it work for everyone

Posted on September 29, 2022March 29, 2023 by janet.crompton

In a packed auditorium in Liverpool, Labour leader Keir Starmer stood at a plinth emblazoned with the words “A Fairer, Greener Future”. It was the key theme of this year’s party conference and is evident in Starmer’s landmark policy announcement: the creation of a new publicly-owned energy company, Great British Energy.

The company would effectively be a start-up to grow British renewables. So while Great British Energy is not nationalisation of the electricity sector (or of any one energy company), it would represent a new and different sort of organisation positioned to fund new projects while working to remove the hurdles faced by new wind and solar projects.

This follows calls from various organisations for a new way of generating and providing electricity. For many, the scale of action needed to both reach net zero and address energy poverty is incompatible with the current model of doing things, which focuses on paying shareholders and avoiding riskier investments.

Like EDF in France or Vattenfall in Sweden, Great British Energy would be state-owned. But it would be independent, making its own investment decisions and working closely with private energy companies.

Being backed by the government, the new company can take on riskier investments. This might be in bigger projects or in new, innovative technologies such as tidal energy. Rather than paying shareholders, the profit that this company makes can then be reinvested in new projects, or for cutting bills or insulating homes.

Great British Energy is one part of a broader approach that Labour has put forward, including measures on energy efficiency and an £8 billion national wealth fund to help decarbonise industry.

The public supports public energy

Despite some concerns about how these policies might be sold on the doorstep, there is public support. Polling in May 2022 showed that 60% of UK voters support bringing energy companies into public ownership – and such patterns of support have remained relatively constant.

Popular campaigns have called for nationalising the sector. Others have highlighted how the current system prioritises shareholders over addressing energy poverty.

Offshore wind farm viewed from a beach — Renewable energy has become a national security issue for the UK.
Colin Ward/Shutterstock

When Labour raised a similar policy in the 2019 election, it was treated as foolish by much of the media. Yet Russia’s invasion of Ukraine and its aggressive use of disruptions to its natural gas exports to Europe as a political weapon have changed energy politics in Europe.

Those calling for the expansion of renewable energy used to highlight how they were greener and cheaper than fossil fuels. Events in 2022 have now made renewables the basis for energy security too.

Who makes decisions, and who benefits from them?

While this policy pledges a different type of energy company, being state-owned does not make any organisation inherently “good”. For instance, EDF in France has been caught spying on Greenpeace. Elsewhere, Vattenfall has sold off its coal power stations rather than replacing them with renewables, merely shifting emissions on to somebody else’s balance sheet.

Addressing these issues requires a reflection on who is making decisions. The proposed national wealth fund would include co-investments with private companies. But who would be involved in directing these investments and who might benefit from them?

Hydrogen energy was mentioned in several speeches at Labour’s conference, and the industry’s lobbyists were reported to have been active and hosted meetings. However, recent work has shown that any move to use hydrogen for home heating is likely unviable.

Elsewhere at the conference, climate campaigners accusing Drax, the biggest emitter in the UK, of environmental racism were reportedly removed from a meeting on net zero and green jobs.

A national energy company must also wrestle with where new renewable energy projects, which tend to demand large tracts of land, will be built and who might suffer from the impacts. Compensation payments in the UK have rewarded unfair patterns of land ownership and the monopolisation of land by the rich and the powerful.

In the UK, a small number of landowners stand to gain financially from the expansion of onshore wind, while offshore wind power is permitted by the crown estate which owns the seabed.

Wind turbines in field — Wind and solar farms can use lots of land.
Traceyaphotos2/Shutterstock

Those living nearby often receive limited compensation. In Scotland, communities living near onshore wind turbines get 0.6% of the value of electricity generated.

This does very little to address regional issues of inequality or exclusion. Community-owned projects have a better track record, providing up to 34 times the financial benefits of those built by private energy companies.

Great British Energy is a policy that many voters will support. While there remain questions about the forms it might take and how it might change the energy sector, it represents an opportunity to generate and use energy differently – as long as it is part of a broader, just energy transition.

These policies are coming at a time of spirallling energy costs and energy poverty for millions, and any national energy company must make addressing this a priority. Labour’s energy efficiency plans show that the party is intent on doing so. The cheapest electricity is the electricity that we don’t use, after all.

It is also politically savvy: some of the areas worst affected by energy prices are in marginal seats. A national energy company playing a central role in funding and directing renewable schemes would allow them to be better targeted, would allow funding for unprofitable projects, and any financial returns could be used to further support families and communities.

But there is still room for Labour to be more ambitious. Great British Energy could be the first step towards an inclusive energy transition, but we must think about what comes next.

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This blog is written by Cabot Institute for the Environment member Dr Ed Atkins, Senior Lecturer, School of Geographical Sciences, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Ed Atkins

Why parents shouldn’t be saddled with environmental guilt for having children

Posted on September 23, 2022April 16, 2023 by janet.crompton

The environmental cost of childbearing is central to climate ethics debates.
MJTH/Shutterstock

Whether residents of high-income countries are morally obliged to have fewer children is a growing debate in climate ethics. Due to the high anticipated carbon impact of future population growth, some climate ethicists express support for non-coercive population engineering policies such as reduced child tax credits.

This debate has attracted widespread public attention, making family planning a key issue in climate change prevention.

Much of the debate is underpinned by one influential US study published in 2009 from Oregon State University. The premise of the study is that a person is responsible for the carbon emissions of their descendants, weighted by their relatedness. A grandparent is responsible for one quarter of each of their grandchildren’s emissions, and so on.

By having a child, a cycle of continued procreation over many generations is started. The emissions of future generations are included in the carbon legacy of their ancestors.

The carbon impact of children

Based on this logic, the authors found that having one child adds 9,441 tonnes of carbon dioxide to the carbon legacy of each parent. This equates to more than five times their own lifetime carbon emissions. The potential savings from reduced reproduction are therefore dramatic.

This result is usually taken at face value in both academic debates and popular discussions, while its details and assumptions are rarely scrutinised. Yet the result is contingent on the assumption that all future generations will indefinitely emit at 2005 levels, an assumption that now appears to be wide of the mark.

For example, from 2005–2019, before they were artificially suppressed by the COVID pandemic, US per-capita emissions fell by 21%. And they are likely to fall further in the future.

Large public investments are accelerating the transition towards carbon neutrality. The recent US Inflation Reduction Act allocated US$369 (£319) billion towards fighting climate change.

Net zero has also become a legally binding target in many countries. The European Climate Law, for example, targets net zero carbon emissions across the EU by 2050.

Reconsidering the carbon impact of children

Considering these efforts, the central assumptions underpinning the study need revisiting.

Using the same reasoning that yielded large carbon impact figures for procreation, we instead suggest that having a child today could be far less environmentally harmful than is widely considered.

If high per-capita emitting countries achieve net zero by 2050, then a child born in one of these countries in 2022 would generate emissions only until they are 28 years old. After 2050, they and their descendants would cease to cause any additional emissions. Adding up their lifetime emissions therefore yields a much lower carbon legacy.

A man standing outside a red car while dropping two children at school. — Children will likely cause far fewer emissions than their country’s per-capita rate.
Monkey Business Images/Shutterstock

Assuming emissions decrease linearly to zero until 2050, and that the child does not reproduce in that time, a child born in 2022 will add seven years of carbon emissions to each parent’s lifetime carbon footprint. This is because in the 28 years to 2050, a linear decrease can be modelled as half the total amount on average (14 years) with each parent responsible for half of their child’s footprint (seven years). Subsequent generations add zero emissions to this amount.

The difference between this potential scenario and the accepted “constant emissions” scenario is stark. Yet even this much lower result may still overestimate the carbon impact of having a child.

This figure assumes that a child will cause additional emissions at the per-capita rate of their country of residence. However, children typically engage in fewer high-emission activities than an adult. They share a household with their parents, and will not drive their own car or commute to work for much of the period before 2050.

Particularly in the immediate future, where per-capita emissions are at their highest, a child will likely cause far fewer emissions than their country’s per-person average.

Net zero commitments must be fulfilled

The pursuit of net zero can greatly reduce the climate impact of childbearing in countries with high per-capita carbon emissions. However, this remains dependent on the fulfilment of this commitment.

Progress towards net zero is stuttering, with current climate policy in many countries lagging behind their pledges.

Despite having a net zero strategy, the UK’s progress towards carbon neutrality has been limited. UK emissions rose 4% in 2021 as the economy began to recover from the pandemic – and many other high per-capita emitting countries are in a similar situation. Prime Minister Liz Truss’s cabinet appointments have also raised doubt over the UK’s commitment to climate targets.

So delivering emphatic reductions to the carbon impact of procreation remains distant, despite our reassessment of the 2008 study.

As a society, it is in our power to put ourselves on a credible net zero path. This also means rejecting the popular tendency to assume that climate change should be addressed by individual lifestyle adjustments, rather than by institutional and structural change. Should net zero be achieved, it would be possible to have children without being saddled with environmental guilt.

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This blog is written by Dr Martin Sticker, Lecturer in Ethics, University of Bristol and Felix Pinkert, Tenure-track Assistant Professor, Universität Wien. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cost of living crisis: the health risks of not turning the heating on in winter

Posted on September 20, 2022March 29, 2023 by janet.crompton

People in the UK might be tempted to keep their heating turned off to offset the large increases in energy bills this winter. A recent YouGov poll, revealed that 21% of respondents would not turn their heating on until at least November. Could the health of these people be endangered?

Before COVID, an average of 25,000 extra deaths occurred between December and March compared with any other four-month period of the year. Even if COVID did not exist, the cost of living crisis could result in the toll from the coming winter being worse than usual.

The Marmot review (a report investigating the effects of cold homes and fuel poverty) estimated that 21.5% of all excess winter deaths could be attributed to the coldest 25% of homes in the UK population.

This would suggest that 5,000 extra deaths occur in winter because people live in cold homes. But this does not mean the cold homes cause the deaths. People who live in cold homes may have other disadvantages, making them less able to survive winter.

Would it make any difference whether they leave their heating on or off? Studies suggest temperatures should be kept to at least 18℃ to minimise the risk to health, but how easy is it to maintain this if homes are poorly insulated?

Research into what is best for people’s health ideally relies on randomised controlled trials to tell us about cause and effect. But it would be unethical to conduct a trial where some people were told to leave their heating off and others were told to keep it on to see if it had any effect on mortality. Instead, we have to rely on what are known as “longitudinal studies” where people are followed over many years and respond regularly to questionnaires.

In one such study in the 1970s, the British Regional Heart Study recruited thousands of men, then in middle age, from across Great Britain. In 2014, around 1,400 of these men, then aged 74-96 years, answered a questionnaire that included questions on home heating.

One question asked whether, during the previous winter, the respondent had: “Turned off the heating, even when you were cold because you were worried about the cost?” One hundred and thirty men (9.4%) said yes. These men seemed no more likely to die in the following two years than men who had replied no.

A larger study would have given a more robust answer. And in the absence of other direct evidence, we have to draw conclusions from indirect evidence, such as this.

The most vulnerable

Recently, researchers in Sweden tried to assess a range of questions about the effects of energy use, fuel poverty and energy efficiency improvements on people’s health. They systematically reviewed all the relevant studies on the topic. One of their findings showed consistently across four studies the link between fuel poverty and premature death.

The British Regional Heart Study showed that fuel poverty was more likely to be found among people who were single, poor and working class. This suggests that people who are the most financially vulnerable will be those most likely to leave the heating off. As with climate change, the poorest are hit hardest.

So far I have only discussed effects on health in terms of death, which in the UK concerns mainly older people. The winter deaths that occur are usually the result of heart disease, stroke and respiratory disease. Yet increasing attention has also been paid to the strong effects of the cold on mental health.

The Marmot review quoted studies that drew attention to the depressive effect of living in a cold home. Children in adolescent years may seek respite and privacy away from home, with consequent exposure to mental health risks. The misery caused by financial pressures only add to this burden.

Because the most financially vulnerable people are also the most vulnerable in their health, it should follow that interventions at government level are urgently needed to offset the likely health crisis looming from increased energy costs.

The most vulnerable will need the most help. Yet a common paradox seen in public health is that interventions applying to the whole population will lead to more lives saved than those targeted only to those at greatest risk.

This is because there are far more people in the population at moderate risk than at high risk. Only a modest proportion of people at moderate risk will benefit. Yet because this group is so much larger than the high-risk group, more lives may be saved among those at moderate risk.

Buildings in the UK clearly need to be better insulated, but these sorts of interventions will come too late for this winter. Mitigating the rising costs of energy must be the only way forward to allow homes to be heated to a comfortable level and prevent a tidal wave of excess winter deaths.

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This blog is written by Cabot Institute for the Environment member Richard Morris, Honorary Professor in Medical Statistics, University of Bristol

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

Richard Morris

Watch Richard speak more about this issue in our Cabot Conversations video on Heatwaves and Health.

How energy-saving advice can hurt the most vulnerable households

Posted on September 20, 2022April 16, 2023 by janet.crompton

Households are facing an unprecedented energy crisis, and the most vulnerable will suffer the most.
Solarisys/Shutterstock

With UK households facing a dire energy crisis, there has been no shortage of advice from politicians, experts and journalists about how to save energy. Not all of this advice has been good.

Former prime minister Boris Johnson suggested that buying a new kettle for £20 could save households £10 a year on electricity bills – a comment that was criticised for being unhelpful as well as wildly out of touch with the everyday struggles of Britons.

Prompting similar criticisms, former Conservative MP Edwina Currie said that rather than catastrophising about the 80% increase in the price of energy in October, we should be lining our radiators with tinfoil to save energy.

Some advice, like that provided by Money Saving Expert Martin Lewis and the Energy Savings Trust, can be useful or even obvious. Switching off appliances on standby and draught-proofing your house are two examples. But telling people to rely on tips like drying your hair at the office or burning books for warmth can be unrealistic, absurd or downright dangerous.

In the right setting, energy advice can be beneficial for households and communities. One example is energy cafes, which have demystified energy bills with community events that provide face-to-face advice.

But advice is not a substitute for the government providing the wide-reaching financial support and investments in energy efficiency necessary to assist households at the sharp end of the crisis. Put simply, lining your radiator with tinfoil is not going to fix the scale of energy price hikes anticipated for the coming year.

When energy-saving advice hurts households

A focus on energy-saving advice and “hacks” can perpetuate a misguided and potentially dangerous narrative: that if only low-income households were more prudent, efficient and sensible with their energy use, they would not be struggling to pay their rising bills.

Recent evidence from UCL’s Institute of Health Equity reaffirmed the devastating impacts that being without sufficient energy can have on physical and mental health. Its estimates suggest that 10% of excess winter deaths can be directly linked to fuel poverty – and 21.5% of those deaths are linked to cold homes.

For the most vulnerable households, popular advice can be exclusionary or even insulting. Telling people to shower at the gym, or to plug their phone in at work, assumes that they have a gym membership or work in an office where they can safely leave devices to charge.

And households are already cutting back. Indeed, in the face of the recent price hikes, the charity National Energy Action argued that for millions of low-income households, there is nothing left to cut. They are already being priced out of warmth and power.

Evidence from the Resolution Foundation shows that low-income households will have to cut back spending on non-essentials by three times as much as better-off households to afford their energy bills this winter.

Close-up of a finger turning off a light switch — While some energy-saving advice is useful, it’s no replacement for government action.
eggeegg/Shutterstock

Asking households to reduce or shift energy demand – “energy rationing” – has been widely discussed as a mechanism for managing the potentially limited, expensive and volatile energy supply forecast for the coming winter. While new prime minister Liz Truss has ruled out blackouts, experts warn that the UK should be prepared for both scheduled and unscheduled periods without power due to supply restrictions.

Reductions in demand for energy at the household level need to be carefully designed to target those who can do so safely, without endangering their health. Those with higher energy needs who are often already disadvantaged by the energy system need to be prioritised. This means older people, young children and people with disabilities or long-term health conditions.

Energy demand reductions should be targeting high-consuming affluent households or energy services that might be considered excessive or luxuries.

People living on low incomes are typically very good at managing limited budgets and making resources stretch as far as possible. In fact, low-income households are often much better at reducing energy consumption than their relatively affluent counterparts.

We cannot and should not expect households who are struggling to afford basic necessities – including warmth, hot water, clothes washing and lighting – to “hack” their way out of this unprecedented hike in the cost of energy.

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This blog is written by Cabot Institute for the Environment member Dr Caitlin Robinson, Research Fellow, School of Geographical Science, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Extolling the virtues of a hybrid meeting done well

Posted on September 5, 2022April 16, 2023 by janet.crompton

Following a very successful three-day conference recently, I wanted to write a few words to extol the virtues of a hybrid meeting done really well. Lots of people at the moment are enthusing wildly about getting back to in-person meetings and general socialising, but not all of us are quite so excited about this return to the old world.

If this makes me a miserable old git, then so be it.

The meeting in question was a Galileo Conference, entitled ‘The warm Pliocene: Bridging the geological data and modelling communities’ and held virtually and in-person at the University of Leeds from 24-26 August 2022. It was sponsored by the NERC UK Integrated Ocean Drilling Programme, Past Global Changes (PAGES) and the European Geosciences Union (EGU), and was run by an organising committee led by Dr Aisling Dolan and Dr Heather Ford (from the University of Leeds and Queen Mary University of London, respectively). The conference website can be seen at https://www.egu-galileo.eu/gc10-pliocene/general_information.html. The conference focused on the mid-Piacenzian Warm Period (sometimes also known as the mid-Pliocene Warm Period, mPWP), an interval between approximately 3.3 and 3 million years ago when CO2 levels were roughly equivalent to today, global mean temperatures were 2-3°C higher than today and sea level was approximately 20 m higher than today. This makes it an important analogue for a possible future.

Normally, here, I would continue with the science, but that’s not the purpose of this post. The purpose of this post is the meeting itself. The meeting took a hybrid format, meaning there were approximately 50 people in the room and approximately 50 people joining virtually. I was in the latter group. For ease, I will refer to the former group as ‘reals’ and the latter group as ‘virtuals’; let’s not get into a philosophical discussion over the validity of these terms.

Since the beginning of the COVID pandemic in 2020, and even more so since its ‘supposed’ end in 2022 (not a statement I agree with, but I’m in a minority), I have attended a great number of virtual and hybrid meetings. Almost always, something has gone badly wrong; inadequate technology, glitching, freezing, inaudible lecturers, audio echoes, etc. However, ‘The warm Pliocene…’ meeting demonstrated that with the right technology and, more importantly, the right know-how to use it properly, a hybrid meeting can indeed be done perfectly. Here, I will cover the various elements of the meeting, how they have been done terribly in the past and how they were done flawlessly here.

Firstly, the main lectures (or short presentations), directed at everybody in the audience. This, in theory, should be the easiest part to arrange of any hybrid meeting. All that is needed is a camera (this is usually and most easily a laptop running Zoom, Teams or whatever, but could be a more sophisticated camera/microphone setup) pointing at the podium, a roaming microphone for the reals (so the virtuals can hear them), the slides shared via Zoom and a speaker (so the reals can hear the virtuals). Sounds simple, right?

Wrong.

Without mentioning any names of meetings and their organisers, I have lost count of the number of times I have spent the entire time staring either at the lecturer’s crotch, or the top of their forehead. Neither is particularly desirable. Three things are important here: the direction the camera is facing, the angle (i.e. vertically) the camera is facing and the distance between the camera and the lecturer. Get any of those wrong, and we are into crotch territory. The camera needs to be far enough away to see the whole person behind the podium, but not too far away for them to resemble a matchstick. It is not necessary to see the main screen at which the reals are looking, because the slides can easily be shared. So the reals see a person next to a large screen containing their slides, whereas the virtuals see the slides directly and then the lecturer as a thumbnail in one corner. Ideally, there needs to be a separate person dedicated to moving the camera/laptop; let’s call them the ‘controller’. The controller is not the lecturer or the Chair, but is solely responsible for moving the camera left, right, up or down so that it is always facing the lecturer during the talk and then the audience during the following questions/discussion. When anybody in the audience wants to speak, they use the same microphone that the lecturer was using.

Happily, the organisers of ‘The warm Pliocene…’ meeting got this spot on, constantly moving the laptop to the correct place depending on who was talking. The only thing that might have improved this would be to have a dedicated virtual constantly communicating with the controller (perhaps via the chat), to say whether the camera needs to be moved slightly; but this is only really necessary if the controller cannot see themselves.

As an aside, the concept of being moved around by someone else in order to see properly is unfamiliar to many people but, given my personal circumstances, is very familiar to me. Although most of the time I use an electric wheelchair and can therefore move myself, some of the time I use a manual wheelchair and therefore cannot. Given that I am not really able to turn my head from side to side, in order to see somebody or something I need to be directly facing them. I am therefore very used to asking “Please turn me a bit to the left” or similar. The difference between turning me in person (i.e. turning the wheelchair) and turning me virtually (i.e. turning the laptop) is exactly what?!

Secondly, the poster sessions. If you are at any train station or airport, anywhere in the world, and you see a bunch of nerdy-looking people holding long cardboard or black plastic tubes, you can be sure there is a conference somewhere nearby. Traditionally, the idea is the poster is physically printed and displayed in a large room, and the author stands next to it at the allocated time and talks to people walking by. This, in theory, is not so easy to do in the virtual space; again I have lost count of the number of failures using Zoom, where people haven’t known how to use the breakout room function, people have been lost in virtual space or people have all tried to talk at once.

Or, the now famous “You’re on mute”.

However, again, happily the organisers of ‘The warm Pliocene…’ meeting got it right. There was a combination of traditional and virtual poster sessions; for the former, the reals were able to interact in the old-fashioned way, whereas the virtuals were able to view the posters that had been uploaded, in advance, to Padlet, as well as a two minute introductory talk that had been pre-recorded by the authors. The virtuals could then post questions on Padlet, which could be answered by the author either instantly or later on. For the virtual poster sessions, both the reals and the virtuals operated in virtual space; the reals were told to find a quiet corner of the conference centre and interact virtually using Zoom, whereas the virtuals were already on Zoom. Within this virtual space, every poster presenter was assigned their own breakout room, where they would wait patiently for the audience to drop by. Everybody could see a list of the breakout rooms, and could therefore choose to whom they wanted to talk. If there was more than one person in a given breakout room, they would simply wait their turn to talk to the presenter; much like they would if they were they standing in a crowd around a physical poster and presenter.

As I always tell my students, presenting a poster is actually a lot more hard work than giving a talk, and this is true in both the real and virtual world.

Thirdly, the discussion and breakout groups. Again, in theory, this is not so easy to get right in the virtual world. This is usually because of two reasons. Firstly because of the same problem as above i.e. the breakout room function not being used correctly, and people not knowing whether they were supposed to be in the main virtual room or in a breakout room. But secondly, because of people basically not knowing how to use Zoom. As time goes by this is becoming less of a problem, but at the beginning it was ridiculous. Almost every virtual meeting I attended in the first couple of years of the pandemic – and don’t forget that most of these were academic meetings, so everybody has a brain the size of a planet (except me, obvs, as I am always the dummy in the group) – began with everybody shouting “Can you hear me?” for the first ten minutes.

However, once more, the organisers of ‘The warm Pliocene…’ meeting managed to arrange everything seamlessly. There was in a little bit of confusion, at the beginning of the first day, as to exactly which breakout room the virtuals were supposed to use, but that was quickly resolved and the rest of the days went very smoothly. The reals were divided into groups of four or five, including a member of the organising committee who was responsible for leading the discussion, taking notes and then reporting back to everybody at the end. Likewise the virtuals were divided into similar-sized groups and assigned to a breakout room, again with a member of the organising committee taking the lead. After half an hour or so of discussion, everybody would return to the main room i.e. the reals would stop talking amongst themselves and turn back to the main screen and podium, whereas the virtuals would return to the main virtual room, which was again facing the main screen and podium. People would then report back, either in person or virtually. Given that the reals all used a roaming microphone when speaking, and the virtuals were projected visually on the main screen and audibly via the speaker system, everybody was able to hear everybody and a normal discussion could be had, whether real or virtual.

Lastly, the only part of the conference which, sadly, is almost impossible to translate to the virtual space is the socialising and indeed the scientific conversations had during these times, either over coffee, lunch or during the evenings. I do not doubt that one day we will have Star Wars-style holographic projections on a small floating platform, meaning that in any given setting (such as round the restaurant table, or standing at the bar), there will be a mixture of real people and holograms that can interact as if they were physically present.

But we are not there yet.

In the meantime, this is probably the one and only part of a conference or scientific meeting in which the virtuals cannot fully participate. I have had meetings where there has been an attempt at this, such as after the meeting where the virtuals are told to get a drink and then chat to each other via Zoom breakout rooms. But this never works particularly well; either because there are too many people in one breakout room, meaning everybody talks at once or just a handful dominate the conversation, or because the organiser assigns people randomly to a breakout room, meaning you get stuck with a bunch of people you have never met and would possibly never choose to meet. In the real world, over coffee, you can choose with whom you chat, or you can choose to sit in the corner and be unsociable. In the virtual world, you can do neither.

Chit-chat or small talk always makes me uncomfortable, and this is exaggerated in virtual space.

To summarise, therefore: ‘The warm Pliocene…’ meeting was a masterclass in how to get a hybrid meeting right. I firmly believe that the main reason it was so successful, for both reals and virtuals, is that (like in many aspects of life) it was completely inclusive. I have been to several hybrid meetings where the virtual attendees are treated a little bit like second-class citizens, allowed to say their piece at the appropriate time but otherwise supposed to be quiet, because they are not really there, are they? This is a shame, but common. Sometimes it is completely unintentional, just an artefact of the organisers being too preoccupied with people actually in the room to remember about those who are not. A lot of my friends and colleagues argue that attending a meeting virtually is not the same, but I completely disagree. It is not the same if the hybrid part is done badly, yes. But, as the organisers of ‘The warm Pliocene…’ meeting have shown, when it is done well, a hybrid meeting can be as enjoyable, if not more enjoyable, than being there in-person.

I want to finish with just a few, more general thoughts concerning fully virtual, hybrid or fully in-person conferences and meetings. Moreover, some thoughts on how these principles translate into our university teaching, which was obviously 100% in-person before the pandemic, then out of necessity became 100% virtual and now is moving back towards the old world i.e. 100% in-person.

I should stress that I completely understand the vast majority of people who are very happy to go back to the old world, be that at work attending in-person meetings or generally socialising. Concerning teaching, I completely understand that many students struggled during the various lockdowns of 2020 and 2021, and that many are very happy and indeed keen to go back to the traditional way of teaching. This has resulted in a push, by most universities, to return to 100% in-person teaching as soon as possible. But this university-wide policy has often resulted in a new reluctance, by many university IT departments, to invest in new technology to allow better hybrid meetings. This, in my humble opinion, is very misguided. We know, now, that virtual and hybrid meetings are possible, work well and, when done correctly, can be preferable for some. To abandon this experience and technology in favour of the traditional way is a very big mistake. There are three reasons why I believe this.

Firstly, it doesn’t take a genius to work out that the next global pandemic is only around the corner. This is not being pessimistic, but rather realistic. The scientific community knew, way back in the 1980s, that concerning impact versus likelihood of occurrence, a global pandemic came first amongst all other natural and man-made disasters, as having both the highest impact and the highest likelihood. But, when it did happen almost 40 years later, we were still not ready for it. If we abandon our new experience of virtual and hybrid meetings and teaching, and do not invest in the technology to make this better, we will be caught with our trousers down once again.

Secondly, for the vast majority of the world (or rather, the Western world – much of the Global South is still suffering massively), COVID is over. This is either because most people have had it and it wasn’t too bad, or most people are not vulnerable to it and don’t know anyone who is, or most people have had several doses of the vaccine and therefore (incorrectly) think they are completely shielded from it, or most people became so fed up with the restrictions that they simply don’t care anymore. Either way, the fear (often of the unknown) has gone. However, for some people – not many, but a significant minority – COVID is very much not over. This might be because they are elderly, immunosuppressed or, like myself, have some other underlying condition which means they are still highly vulnerable to any respiratory-related disease. For those people, COVID is still very much a real and present danger. For those people, like myself, who have not yet caught COVID (or, at least, not that I know of) because of their super-cautious behaviour and actions – which is often disapproved of and ridiculed by even close friends and family, “You’ve just got to learn to live with it” – the fear of the unknown is still very much there. Therefore, if we abandon virtual and hybrid meetings and teaching, there is a real risk that this significant minority will feel even more marginalised and excluded than they did before the pandemic.

Likewise, concerning teaching, although most students appear to prefer the traditional way, this is not a constant. Based on my conversations with them, many students quite like a mixture of in-person and virtual lectures, seminars and discussions. This might be for health reasons, or because they quite like the anonymity of being behind a screen. When I was an undergraduate, over 20 years ago, if I had had the option of watching my 9 AM lecture in my pyjamas at home or making the 20 minute, bleary-eyed walk onto campus and into a cold lecture theatre, I know exactly what I would have chosen. Moreover, for those students who need to have difficult conversations with their tutors – possibly bursting into tears because they did not get the grades they wanted – doing that over Zoom is, I would imagine, far more of a safe space than doing it in the tutor’s office. To completely abandon virtual and hybrid communication would, therefore, marginalise these students as well. Instead, the option of doing things virtually should be made available, now that we know it is a viable option.

Lastly, there is the issue of travel, which is more relevant to the scientific meeting or conference than it is to teaching. This is particularly relevant to those in my profession; as somebody once said, climate scientists fly all over the world telling people not to fly all over the world. This is something of which we have all been guilty. Now, however, we don’t need to do this. As long as whatever meeting or conference is prepared to put the technology and know-how to good use, I can attend any meeting I like, anywhere in the world, with minimal effort and zero carbon emissions on my part. I agree, it is not quite the same and you certainly don’t get the change of scenery, but surely it is better, from an environmental perspective, than the old way? Returning to ‘The warm Pliocene…’ meeting, it was not a large international conference involving thousands of people, but rather a relatively small meeting and workshop. It was, however, international, and we had participants from all over the world. For them to fly all the way to the UK for just three days, when they were able to participate fully in virtual space, is nonsense and goes against everything we are trying to preach.

So, in summary, virtual and hybrid meetings are not only possible, but can actually be preferable when done really well, as the recent masterclass demonstrated. To abandon everything we have learnt over the last three years, in the knowledge of what it would do to a significant minority and the knowledge of what is probably going to happen in the future, would be utterly foolish.

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This blog was written by Cabot Institute for the Environment member Dr Charles Williams from the School of Geographical Sciences at the University of Bristol.

Why the aviation industry must look beyond carbon to get serious about climate change

Posted on September 5, 2022March 29, 2023 by janet.crompton

Flying is responsible for around 5% of human-induced climate change.
Wichudapa/Shutterstock

Commercial aviation has become a cornerstone of our economy and society. It allows us to rapidly transport goods and people across the globe, facilitates over a third of all global trade by value, and supports 87.7 million jobs worldwide. However, the 80-tonne flying machines we see hurtling through our skies at near supersonic speeds also carry some serious environmental baggage.

My team’s recent review paper highlights some promising solutions the aviation industry could put in place now to reduce the harm flying does to our planet. Simply changing the routes we fly could hold the key to drastic reductions in climate impact.

Modern aeroplanes burn kerosene to generate the forward propulsion needed to overcome drag and produce lift. Kerosene is a fossil fuel with excellent energy density, providing lots of energy per kilogram burnt. But when it is burnt, harmful chemicals are released: mainly carbon dioxide (CO₂), nitrogen oxides (NOₓ), water vapour and particulate matter (tiny particles of soot, dirt and liquids).

Aviation is widely known for its carbon footprint, with the industry contributing 2.5% to the global CO₂ burden. While some may argue that this pales in comparison with other sectors, carbon is only responsible for a third of aviation’s full climate impact. Non-CO₂ emissions (mainly NOₓ and ice trails made from aircraft water vapour) make up the remaining two-thirds.

Taking all aircraft emissions into account, flying is responsible for around 5% of human-induced climate change. Given that 89% of the population has never flown, passenger demand is doubling every 20 years, and other sectors are decarbonising much faster, this number is predicted to skyrocket.

Aircraft contrails don’t last long but have a huge impact.
Daniel Ciucci/Unsplash

It’s not just carbon

Aircraft spend most of their time flying at cruise altitude (33,000 to 42,000 ft) where the air is thin, to minimise drag.

At these altitudes, aircraft NOₓ reacts with chemicals in the atmosphere to produce ozone and destroy methane, two very potent greenhouse gases. This aviation-induced ozone is not to be confused with the natural ozone layer, which occurs much higher up and protects the Earth from harmful UV rays. Unfortunately, aircraft NOₓ emissions cause more warming due to ozone production than they do cooling due to methane reduction. This leads to a net warming effect that makes up 16% of aviation’s total climate impact.

Also, when temperatures dip below -40℃ and the air is humid, aircraft water vapour condenses on particles in the exhaust and freezes. This forms an ice cloud known as a contrail. Contrails may be made of ice, but they warm the climate as they trap heat emitted from the Earth’s surface. Despite only lasting a few hours, contrails are responsible for 51% of the aviation industry’s climate warming. This means they warm the planet more than all aircraft carbon emissions that have accumulated since the dawn of powered flight.

Unlike carbon, non-CO₂ emissions cause warming through interactions with the surrounding air. Their climate impact changes depending on atmospheric conditions at the time and location of release.

Cutting non-CO₂ climate impact

Two of the most promising short-term options are climate-optimal routing and formation flight.

Left: Climate optimal routing. Right: Formation flight concept.

Climate-optimal routing involves re-routing aircraft to avoid regions of the atmosphere that are particularly climate-sensitive – for example, where particularly humid air causes long-lived and damaging contrails to form. Research shows that for a small increase in flight distance (usually no more than 1-2% of the journey), the net climate impact of a flight can be reduced by around 20%.

Flight operators can also reduce the impact of their aircraft by flying in formation, with one aircraft flying 1-2 km behind the other. The follower aircraft “surfs” the lead aircraft’s wake, leading to a 5% reduction in both CO₂ and other harmful emissions.

But flying in formation can reduce non-CO₂ warming too. When aircraft exhaust plumes overlap, the emissions within them accumulate. When NOₓ reaches a certain concentration, the rate of ozone production decreases and the warming effect slows.

And when contrails form, they grow by absorbing the surrounding water vapour. In formation flight, the aircraft’s contrails compete for water vapour, making them smaller. Summing all three reductions, formation flight could slash climate impact by up to 24%.

Decarbonising aviation will take time

The aviation industry has fixated on tackling carbon emissions. However, current plans for the industry to reach net zero by 2050 rely on an ambitious 3,000-4,000 times increase in sustainable aviation fuel (SAF) production, problematic carbon offsetting schemes, and the introduction of hydrogen- and electric-powered aircraft. All of these could take several decades to make a difference, so it’s crucial the industry cuts its environmental footprint in the meantime.

Climate-optimal routing and formation flight are two key examples of how we could make change happen faster, compared with a purely carbon-focused approach. But there is currently no political or financial incentive to change tack. It is time governments and the aviation industry start listening to the science, and take aircraft non-CO₂ emissions seriously.

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This blog is written by Cabot Institute for the Environment member Kieran Tait, PhD Candidate in Aerospace Engineering, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Kieran Tait

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

Posted on August 16, 2022April 16, 2023 by janet.crompton

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

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

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

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

Why is the Arctic warming so much faster?

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

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

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

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

Blocks of melting sea ice revealing a deep blue sea. — Melting sea ice in the Arctic Ocean.
Nightman1965/Shutterstock

Is Arctic amplification underestimated?

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

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

How concerned should we be?

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

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

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

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

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

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

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

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

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This blog is written by Cabot Institute for the Environment member, Jonathan Bamber, Professor of Physical Geography, University of Bristol.

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