climate change

You are currently browsing articles tagged climate change.

By Phil Newton, Research Dean for Environment, University of Reading

Science is a global business. Very few truly great advances in science happen these days without some level of international collaboration. A quick look at the list of recent Nobel Laureates for Physics tells that story.

But the organisation of science, like many other things, is influenced by politics. Which is how we should view the offer of French President Emmanuel Macron to recruit foreign climate scientists to French institutions.

Macron is riding the wave of populist politics that also helped sweep Donald Trump to victory in the United States. But Macron’s popularity is based on very different foundations to Trump’s. He has wasted little time in opposing the US administration’s policy on pulling America out of the Paris climate change agreement.

What’s really going on here?

Read the rest of this entry »

Tags: , , , , , , , ,

President Donald Trump has indicated an intention to withdraw the US from the Paris accord on climate change.

His announcement, made on Thursday 1 June, means the US will no longer recognise the collective aim of mitigating the impact of climate change.

The University of Reading is a world leader in climate science and research into the physical, economic and social impacts of climate change, helping to provide the strong scientific evidence upon which the Paris agreement was based.

Here, we look at some of this celebrated research, which remains central to the aims of the 194 countries that remain signed up to the Paris Agreement.

Read the rest of this entry »

Tags: ,

By Hannah Parker, Walker Institute, University of Reading

During the wet season of 2012 heavy rainfall across West Africa led to flooding with devastating impacts. More than 3 million people were affected, with hundreds of thousands made homeless (Figure 1). When extreme events such as this occur, it is important to question whether climate change had a role to play. At the Walker Institute we have investigated the impact of climate change on this event, by assessing whether the probability of such high precipitation in the 2012 rainy season was affected by anthropogenic emissions.

Impacts of heavy rainfall-induced flooding across West Africa in 2012

Observations show that there was anomalously high rainfall across much of West Africa during the 2012 rainy season. To look at changes in the probability of such high precipitation, we used hundreds of climate model simulations of the year 2012. By comparing simulations with and without anthropogenic greenhouse gas emissions, we were able to assess whether the probability of the event had been changed.

We found that the probability of such high precipitation in West Africa had been decreased by climate change. This was the case under both general climate conditions (using simulations with the atmosphere coupled to the ocean, therefore including all climate variability), and with conditions specific to 2012 (using atmosphere-only simulations with observed sea surface temperatures (SSTs)). Using different model ensembles, the decrease in probability was found to between a factor of 0 and 16.

However we also found some disagreement between the climate model ensembles. When considering the world without anthropogenic emissions, in the atmosphere-only simulations the effect of anthropogenic emissions had to be removed from the SSTs as well as the atmosphere. We estimated the effect on SSTs using coupled climate model simulations, which showed a decrease in the probability of high precipitation in 2012. However we also used an estimate based on the observed trend in SSTs, and in this case the probability of high precipitation was shown to have been decreased by anthropogenic emissions. Further analysis showed that this discrepancy was likely due to the climate models having much greater warming trends than observations did in the Niño3.4 region in the Pacific Ocean.

Understanding how individual events such as this have been affected by climate change is relevant for policymakers to better understand climate change impacts on extremes. In particular, comparing results from different climate model ensembles is important if we are to better understand such attribution results and their uncertainties, to characterise whether or not they are robust. Few event attribution studies have done this to date, but this will be key if results are be used appropriately in climate policy to address the impacts of such events.


Tags: , ,

By Paul Williams, University of Reading Department of Meteorology

‘As important as political leadership is, individual people and companies will have to make key decisions to deal with the impacts of climate change’

Climate change is never far from the news headlines – but often it’s not because of the science.

As much as I think that complicated mathematical calculations about the circulation of air and water around the globe should make people stop in wonder, I fear my beliefs are not widely shared by most other people.

And they would have a point. Most people don’t talk maths over the water cooler or when down the pub, beyond adding up the cost of their drinks.

So if it’s not the science, what makes climate change so appealing to journalists? Often, it’s the politics.

News media love to observe a good old-fashioned fight, and politics is the arena where disagreements get aired every day. Not only that, but politics tends to have a bearing on how we live our lives, too.

So while the basic facts of human-caused climate change are agreed by just about all scientists working in the field, a handful of doubting politicians often hog the headlines.

Read the rest of this entry »

Tags: , , , , , , ,

By Professor Catriona McKinnon (Director, Leverhulme Programme in Climate Justice)

Later this week, a climate denier will become the President of the United States. Donald Trump claims that ‘nobody really knows’ whether climate change is happening, and has asserted in the past that climate change is a hoax. To make things worse, Trump has filled his cabinet with several climate deniers, and his transition team have raised fears of a ‘witch hunt’ of climate experts in the Department for Energy.

170116 MCKINNON Trump CNN

Today, a letter to the Prime Minister Theresa May, signed by leading figures in the UK climate research community – including some at the University of Reading – expressed fears about what this could do to the evidence base for global climate policy making. If the new Trump administration follows up on his campaign pledges to tear up existing US climate policies, the future could be bleak for the Paris Agreement, which may be the best and last hope for global action on climate change.

Many people in the climate research community are appalled by the climate denial of Trump and his incoming cabinet. But what, exactly, is wrong with it?

The climate denial of Trump and his cabinet is not bad science: it is not science at all

One thought might be that Trump’s climate denial is outrageously bad science. The essence of science is contestation and disagreement, and science in a state of health makes space for mavericks who strike out with bold new hypotheses, sometimes enabling great leaps forward. Should we be horrified by Trump’s denial because he does not fit this mould? This would be a serious mistake. The climate denial of Trump and his cabinet is not bad science: it is not science at all.

Such views  have grown from a set of organised, well-funded, strategic, deceptive, ideological practices undertaken by a range of conservative think tanks in the US, funded by those with fossil fuel interests, and which have perverted climate legislation in America. The tactics these deniers employ include claims of conspiracy among climate scientists, appeal to fake experts, cherry-picking data, and outright deception.

High stakes of climate risks

So he says he doesn’t believe the experts. So what? To understand why Trump’s climate denial is so heinous we must be alive to the severity of the climate crisis and how little time is left to take meaningful action to contain it.

Read the rest of this entry »

Tags: , , , ,

On world food day Professor Richard Tiffin from the University’s Centre for Food Security discusses the challenges faced when meeting the global demand for food.

The present debate around how best to meet the global demand for food has a tendency to polarise into two camps.  First there are those who argue that the food system is broken and what is required is a return to more ‘traditional’ ways in which food is produced on labour intensive small farms and distributed locally.  In the opposite corner are technologists who argue that the only way that we will be able to meet the predicted increase in demand for food of between fifty and one hundred per cent, is to continue the process of intensification that characterised the development of agriculture during the twentieth century.  Instead of this polarisation however perhaps some cross fertilisation is necessary.

A return to a more traditional agriculture has some appeal.  There is no denying that small scale production gives a better looking countryside and increased rural employment.  Its diversified products also provide a nice contrast to the commoditised food products that dominate the supermarket shelves.  In a more subtle way the greater diversity of the farming system employed on these units may provide us with a greater degree of resilience in the face of increased risk of extreme weather events which climate change brings.  

This is all logical but the problems arise when attempts are made to scale the approach up to meet a much larger part of our food needs.  Increased labour intensity demands more labour and we have to ask where this will come from.  ‘New-lifers’ can only go so far, farms will need to reverse the reality of the labour market in which non-agricultural jobs have better conditions and therefore draw people out of the sector.  It is sometimes overlooked that farm employment is often dangerous, cold, wet, depressing and poorly paid. 

The argument becomes much more dangerous, however, when we apply it to developing countries.  Here the small scale sector is often vital in ensuring short term food security, but to argue that it should remain so risks consigning these countries to a permanently less developed state.  The process of agricultural intensification must be seen as one component of the process of economic development.  Blocking agricultural development will stop the release of labour (and other resources) from agriculture which drives growth in other sectors of the economy.  Without this, growing populations may or may not have enough food, but they will be without the services that are necessary to support their inevitably more urban lifestyles.

So, we are left with a situation in which ‘intensification’ must continue, but we must also learn from the practitioners of ‘traditional’ agriculture.  These farmers are acutely aware of the fact that food production is not an industrial process.  Food is, at least in part, a product of nature.  This is a fact that seems not have escaped the food consumer, where all the evidence points to the fact that ‘natural’ food is valued.  The implication is that we cannot divorce our food production from the ecosystem which supports it.  Changes in our farming system have implications for the other things which our ecosystem gives us, for example biodiversity and carbon cycling.  Equally changes in the ecosystem, for example reductions in the population of pollinators, have implications for food production.

There are some encouraging signs that a middle way may become our focus.

The concept of sustainable intensification is on the agenda.  This recognises that we must not stop the search for new ways of producing food but that we should do so in ways which work with nature rather than in a box apart from it.  We should learn from our traditions but not harp back to them.  By 2050 there will be 2bn more people in the world, 1.9bn of whom will be in developing countries.  We owe it to them.

Professor Richard Tiffin is Director for the Centre for Food Security at the University of Reading. Richard is an Agricultural Economist and his current research is focused on diet and health policy, in particular the impacts of fiscal policies with the objective of improving dietary health, such as so-called ‘fat tax’.


Tags: , , ,

Peter Gregory is Professor of Global Food Security and contributes to building research programmes in the University’s Centre for Food Security. One of his research focuses is in global environmental changes and food security. Throughout his career Professor Gregory has been engaged with issues of increasing crop yields especially in drought-prone, rainfed environments.

After many decades in which food security has not been an issue of much interest to many in the developed world, suddenly it’s back on the political and scientific agendas. The sudden spike in food prices in 2008/09 awakened interest once again in the issue, and the realisation that our insatiable demand for more food in response to a growing population with higher average incomes provides many social and scientific challenges.

This was some of the background to the session on food security that I organised with my co-organisers Mike Bushell of Syngenta and Ken Cassman from the University of Nebraska at the Planet Under Pressure conference held from 26-29 March in London as the scientific prelude to the Rio+20 Conference which will commence later this month. The session explored how the agronomic yield gap interacts with economic and nutritional ‘gaps’ to produce food insecurity and what interventions might correct this.

The session attracted the second largest number of contributions in the conference, but the limited time meant that we could hear only five oral contributions with the remaining forty or so as posters. Dr Marianne Banziger of the International Maize and Wheat Improvement Center gave the opening keynote in which she outlined the global challenges facing producers. She noted that publicly-funded agricultural research in developed countries is now only 25% of its level in the 1980s despite the threats posed by a changing climate and the increasing scarcity or costs of natural resources such as land, water and energy.

Other presentations demonstrated the nutritional paucity of many current crops produced in sub-Saharan Africa especially for vitamins A and C, potassium and other minerals, and the skipping of meals, especially by females, as a means of adapting to hardships such as flooding. In many parts of sub-Saharan Africa and South Asia, livestock are an essential component of the agricultural system. A village-level survey in 96 villages across nine different countries in these two regions confirmed that crop residues are valuable sources of animal feed, fuel and construction materials; this limits their use for longer-term ecological services such as mulch for soil protection, water conservation and potential carbon sequestration. Households were most vulnerable where pressure on biomass was greatest. In Indonesia, a study of food availability and incidence of malnutrition showed that the two were not directly related; rather malnutrition was determined by food intake pattern which was a reflection of socio-cultural behaviour.

The session elicited a great deal of discussion about how the vulnerability of groups at risk of malnutrition might be alleviated. Three interesting observations were: i) the more we delay investment in food research, the steeper the challenge of meeting demands will become; we have to increase production of wheat, rice and maize by about 30-40% faster than we currently are; ii) cell phones provide a new possibility for getting locally targeted and up-to-date information to farmers and markets in rural areas; and iii) food security needs to pay greater attention to the nutritional value of food and not focus so much on the yield and calorific value of cereals.

I shall be following up these presentations and other food-related sessions at the conference as we develop the international programme of work associated with the Centre for Food Security at Reading. I am currently writing a paper on Soils and Food Security as part of a special publication by The Royal Society of Chemistry that arose from the London meeting, and am working with a colleague at Oxford University to take forward a potential international programme of work on sustainable intensification of food systems in temperate regions. There’s much to be done!

Tags: , , ,

The cost of a flight

Dr Emma Irvine is a post-doctoral research assistant in the Department of Meteorology at the University of Reading.

In January this year a new measure to tackle climate change came into force. Designed by the European Union, it targets the 220 million tonnes of CO2 emitted annually on flights departing from or arriving to a European airport (figure from 2006).  The new measure is to include aviation CO2 emissions in the EU’s emissions trading scheme; the aim is to achieve real reductions in the CO2 emitted by this fast-growing industry. Put simply: the cost of a flight, for both airline and passenger, now includes CO2.

Why is there a need for such a scheme in the first place? In 2006, globally, aircraft emitted around 700 million tonnes of CO2 into the atmosphere, 30% of which was from flights originating or departing Europe. Putting this into context, global aviation contributed approximately 2% of man-made CO2 emissions (in that year).aeroplane

This is a small proportion; the UK’s share of aviation CO2 emissions is much less than the contribution from, for example, heating our homes (14.8%) or generating electricity (about 26%).  So, why all the fuss? First, the aviation industry is growing by around 5% per year, meaning that its share of CO2 emissions could rapidly increase. Second, the climate impact of aviation, a topic of research at the University of Reading, is not just from CO2 emissions. The non-CO2 climate effects of aviation, like water vapour, ozone creation and contrails, increase aviation’s total contribution to human-induced climate change to up to 15%.

The good news is that the aviation industry isn’t sticking its head in the sand. It has set its own stringent targets that new aircraft entering service in 2020 should produce 50% less CO2 (per passenger kilometre) than aircraft in 2000. The question is, left to its own devices, will the aviation industry really be able to make a significant dent in its CO2 emissions? The EU thinks not.

Now for the technical bit: the Emission Trading System (ETS) limits (‘caps’) overall CO2 emissions in Europe from certain industries; under this cap and trade scheme, companies buy carbon credits to cover their CO2 emissions up to the cap, and may trade surplus carbon credits on the carbon market.  So how does this work for airlines? The total amount of CO2 that can be emitted by aviation is now capped at 97% of the annual average emitted in 2004-2006; this includes CO2 emissions from all flights which arrived at or departed from a European airport (i.e. it counts the total CO2 from the flight, not just the portion of the flight that was in European airspace).  85% of this cap is distributed to airlines as free allowances, proportional to that airline’s share of the emissions in 2010.  The remaining 15% of the cap will be auctioned.

At the end of April 2013, each airline must surrender sufficient carbon credits to cover their 2012 CO2 emissions. Therefore if an airline wishes to expand its operations in Europe, it must either buy carbon credits at auction (or trade from other airlines who have reduced their emissions and thus have surplus credits) or from another industry sector. The implementation is fairly complicated but the rationale behind the scheme is simple: the less CO2 you emit, the smaller your costs, and in a competitive market this should effectively drive CO2emission reductions.

So far so good. But that’s not the end of the story. Internationally, the inclusion of aviation into the EU ETS has been highly controversial; the EU’s decision to introduce a regional scheme is seen by many as taking unilateral action that is both unfair and counterproductive. Legal action, brought by US airlines, was defeated by the European courts in December, however the US government may still make it illegal for US airlines to comply with this new EU law (interestingly, Delta has coincidentally introduced an unspecified $3 per passenger surcharge, ‘just in case’). China doesn’t want its airlines to pay, and has both suspended a large order of (the European-based) Airbus aircraft, and refused to allow its airlines to comply. UK airlines, with the noted exception of Ryanair, have been mostly supportive; BA has previously voluntarily participated in a UK-based ETS.  It is expected that airlines will pass on the costs of participating in the ETS to its passengers in the form of surcharges. So far surcharges have been at the bottom end of the range of estimates of 2 Euros to 3% of the ticket price, and in any case will be insignificant compared to UK air passenger duty (currently £60 for a flight to New York).

It is unclear how this story will end. At a debate I attended at British Airways last December, the overwhelming majority agreed that market-based measures are the best way to tackle CO2 emissions, even if few people believed that the EU would manage to implement the aviation ETS without some concessions or modifications. Some concessions seem likely as international opposition to the scheme is not only increasing but becoming more organised: a coalition of countries (including the US, China, India and Russia) recently met to decide on ‘retaliatory action’ against the EU, threatening to escalate the situation into a full-scale trade war. Meanwhile, aviation’s governing body ICAO says it is accelerating efforts to design a global ETS-style measure for aviation and will present its proposals by summer (full story at

Even the EU acknowledges that a global solution is clearly the best way forward. The EU ETS could just be the catalyst to make that happen.

Tags: , , , ,