Search site

School of Geography

Research news

Vanishing glaciers of Everest

‘Most of the glaciers on Everest are covered in debris,’ says Duncan Quincey, a glaciologist at the Scgool of Geography, University of Leeds. ‘This layer of rock and detritus, which at the terminus can be the height of a room, can affect how the glaciers grow and retreat.’

Since 2003, a collaboration of researchers from the Universities of Aberystwyth, Sheffield and Hertfordshire have been improving data about debris-covered glaciers in the Himalayas. Debris-free (clean ice) glaciers grow forwards and melt backwards seasonally and are generally seeing a net retreat as the climate warms up. ‘Debris glaciers, on the other hand,’ says Quincey, ‘go up and down. But not a lot is known about how fast they will recede as the climate changes.’

Find out more

Why Carbon Is the Best Marker for the New Human Epoch

Fire ranks among humanity's oldest and most powerful tools. Now the residue from all the oil and coal burned to power modern civilization may provide the best marker for the start of a new geologic epoch that highlights Homo sapiens’s world-changing impact, known as the Anthropocene, or "new age of humans."

"We're actually changing and continuing to change how the Earth system functions and leaving markers that could still be found in a million years time," says Earth scientist Karen Bacon of the School of Geography, University of Leeds in England. "That's quite incredible to think about."

Find out more

Volcanic ash found in Yorkshire could help to improve flight safety forecasts

Predictions of where planes can safely fly following volcanic eruptions could be improved, thanks to fresh discoveries about ash clouds.

To study the size of ash grains and how far they can travel, scientists at the Met Office and the Universities of Leeds, Edinburgh and Iceland, compared grains recovered from recent Icelandic eruptions – including samples recovered in Yorkshire –  with satellite measurements of ash clouds.

Their findings, published today in Atmospheric Measurement Techniques, will help to improve methods of mapping ash concentration in order to identify zones where it is safe to fly during future eruptions.  Hundreds of flights were cancelled in 2010 and 2011 following volcanic activity in Iceland because of the danger that volcanic ash posed to aircraft and their engines.

In the new study, researchers studied volcanic ash recovered in the UK from the recent Eyjafjallajökull and Grímsvötn eruptions, as well as prehistoric samples from peat bogs in Yorkshire, Scotland and Ireland. Another sample, from an 1875 eruption, had been in a museum for 140 years.  The researchers found that grains were much larger than what had been typically estimated by satellite measurements of ash clouds – even moderately-sized eruptions could disperse large grains as far as the UK.

Study co-author Dr Graeme Swindles, from the School of Geography at the University of Leeds, said: “Microscopic volcanic ash layers preserved in Yorkshire peat bogs and mud at the bottom of lakes, far from volcanoes, are providing much needed information on the characteristics of ash clouds. These records show us that Europe was hit by volcanic ash clouds very frequently in the past.”

Find out more



Amazon: 1% of tree species store 50% of region's carbon

About 1% of all the tree species in the Amazon account for half of the carbon locked in the vast South American rainforest, a study has estimated.Although the region is home to an estimated 16,000 tree species, researchers found that just 182 species dominated the carbon storage process. Amazonia is vital to the Earth's carbon cycle, storing more of the element than any other terrestrial ecosystem. The findings appear in the journal Nature Communications.

"Considering that the Amazon is massively important for the global carbon cycle and stores so much of the planet's biomass, finding out just how that carbon is stored and produced is very important if we want to understand what might happen in the future in different environmental conditions," explained co-author Sophie Fauset from the School of Geography, University of Leeds.

The tropical forest covers an estimated 5.3 million sq km and holds 17% of the global terrestrial vegetation carbon stock.The findings build on a study published in Science in October 2013 that found that despite being home to an estimated 390 billion trees - made up by 16,000 species - just 227 "hyperdominant" species accounted for half of Amazonia's total trees.

Dr Fauset observed: "If you then take abundance into account and then analyse the data again, then maximum size is very important as well. Trees that are able to reach a large size contribute more to the carbon cycle." As trees grow larger, they develop more biomass, which contains carbon. So the larger the tree, the greater quantity of carbon locked within its wood. As trees are long-lived organisms, this means the carbon is removed from the atmosphere for decades, if not centuries.

Find out more



Fairytale frog: London Zoo breeds bizarre amphibian for the first time thanks to geography PhD student,Thomas Doherty-Bone

Article courtesy of The Guardian

In a world first, the Zoological Society of London hatches and rears Lake Oku clawed frogs as an insurance population against extinction.

It could be the opening of a children’s story: in a great forest on a mountaintop lies a tiny lake, and in that tiny lake lives a tiny frog. But this isn’t just any frog. No, this frog is different. Very, very different. It has big webbed feet, no tongue at all, and (here’s where we leave typical children’s book territory) a whole bunch of chromosomes. The vast majority of the world’s animals, including humans, have two sets of chromosomes. But the Lake Oku clawed frog has twelve sets, which is a high number even for chromosome abundant organisms like plants.

The Lake Oku clawed frog is “[one] of the most genetically unusual creatures in the world,” said Carly Waterman, the Programme Manager for the Zoological Society of London’s (ZSL) EDGE group

The chromosome-happy frog is a member of an ancient lineage of amphibians known as pipids, which are only represented today by about 30 species that lack tongues and stick solely to water. Pipids first split off from other frogs 130 million years ago during the age of dinosaurs, but still some 60 million years before Tyrannosaurs Rex came on the scene. Scientists think the frog attained so many chromosomes through hybridising with similar species over millions of years.

Find out more



Credit: Kuo-Jung Chao
Credit: Kuo-Jung Chao

Amazon’s carbon uptake declines as trees die faster

The most extensive land-based study of the Amazon to date reveals it is losing its capacity to absorb carbon from the atmosphere.  From a peak of two billion tonnes of carbon dioxide each year in the 1990s, the net uptake by the forest has halved and is now for the first time being overtaken by fossil fuel emissions in Latin America.  

The results of this monumental 30-year survey of the South American rainforest, which involved an international team of almost 100 researchers and was led by the University of Leeds, are published in the journal Nature.

Over recent decades the remaining Amazon forest has acted as a vast ‘carbon sink’ – absorbing more carbon from the atmosphere than it releases – helping to put a brake on the rate of climate change. But this new analysis of forest dynamics shows a huge surge in the rate of trees dying across the Amazon.

Lead author Dr Roel Brienen, from the School of Geography at the University of Leeds, said: “Tree mortality rates have increased by more than a third since the mid-1980s, and this is affecting the Amazon’s capacity to store carbon.”

Initially, an increase in carbon dioxide in the atmosphere – a key ingredient for photosynthesis – led to a growth spurt for the Amazon’s trees, the researchers say. But the extra carbon appears to have had unexpected consequences.

Study co-author Professor Oliver Phillips, also from the University’s School of Geography, said: “With time, the growth stimulation feeds through the system, causing trees to live faster, and so die younger.”

Find out more


Nature / Alberto Seveso
Nature / Alberto Seveso

Epoch-defining study pinpoints when humans came to dominate planet Earth

The human-dominated geological epoch known as the Anthropocene probably began around the year 1610, according to new research published today in Nature.

Previous epochs began and ended due to factors including meteorite strikes, sustained volcanic eruptions and the shifting of the continents. The researchers behind the new study have concluded that humans have become a geological power and suggest that human actions have produced a new geological epoch.

Lead author Dr Simon Lewis, a geographer at the University of Leeds and UCL, said: “In a hundred thousand years, scientists will look at the environmental record and know something remarkable happened in the second half of the second millennium. They will be in no doubt that these global changes to Earth were caused by their own species.

“Today we can say when those changes began and why. The Anthropocene probably began when species jumped continents, starting when the Old World met the New. We humans are now a geological power in our own right – as Earth-changing as a meteorite strike.”

The paper ‘Defining the Anthropocene’ appears in the 12 March edition of Nature.

Find out more


Human trafficking and slavery in the UK

Louise Waite and Hannah Lewis were invited to speak at Parliament on Tuesday 10 March 2015. They addressed the All Party Parliamentary Group on Global Uncertainties on the topic of ‘Human Trafficking and Slavery in the UK’, chaired by John Glen MP. They spoke alongside Kevin Hyland; the UK’s first Independent Anti-Slavery Commissioner. The audience comprised MPs and Lords together with representatives from the National Crime Agency, the Home Office, and many NGOs and think-tanks including Anti-Slavery International, Refugee Council, Joseph Rowntree Foundation, CentreForum, Chatham House and the Centre for Social Justice.

Hannah & Louise profiled their ESRC funded research on the Experiences of forced labour among refugees and asylum seekers and a follow on project, also funded by ESRC, on Tackling forced labour among refugees and asylum seekers. Their presentation communicated their key message that amidst the burgeoning amount of research on forced labour and unfreedom in recent years, there is a missing focus on the particular experiences of asylum seekers and refugees living in the UK. Their research reveals for the first time that refugees and asylum seekers are a group of migrants vulnerable to exploitation in various forms of severely exploitative and, in some cases, forced labour in the UK. Hannah and Louise closed their presentation by outlining their key recommendations to tackle forced labour among refugees and asylum seekers:

  • End the enforced destitution of asylum seekers by restoring their right to work.
  • Ensure all workers irrespective of immigration status are protected from forced labour through universal access to basic employment rights.
  • Stop criminalising asylum seekers and undocumented migrants for working to meet basic survival needs by ending criminal prosecutions for new cases and wiping previous convictions from existing records.
  • Allow all refugees to exercise their rights to family reunion without the pressure to take up exploitative work by reinstating legal aid.

Find out more

Most carbon dense ecosystem in Amazonia mapped for first time

Amazonian forests are known to harbour large stores of carbon locked up in their trees. However, results from a new study show surprisingly that the parts of Amazonia with the highest concentration of carbon store most not as wood, but below the ground, as peat.

The study was undertaken by researchers from the Universities of Leeds, St Andrews, Edinburgh (UK), and Turku (Finland), in collaboration with the Research Institute of the Peruvian Amazon (IIAP) and is published today in the journal Environmental Research Letters. The authors mapped and quantified the carbon stored in the largest area of peatland forest in Amazonia within a geological basin almost the size of England (120,000 km2). The researchers estimated that over three billion tons of carbon are stored within this ecosystem, with 90 % stored below the ground as peat.

“Peatland forests are different from other Amazonian forests as they are typically dominated by small-statured trees or palms. We can see these differences not only on the ground but also from space using satellite imagery. These differences allowed us to map the extent of the peatlands and distinguish the different types of peatland forest. Crucially this approach allowed us to distinguish a type of forest dominated by small trees, or ‘pole’ forest – the most carbon-dense peatland type” explains lead author Freddie Draper, a PhD student at the University of Leeds. “Combining this satellite data with extensive field data we have been able to provide spatially explicit estimates of the amount of carbon stored in these ecosystems for the first time”.

Ordinarily in tropical forests, the vast majority of carbon is emitted back to the atmosphere as carbon dioxide, as trees die and decompose. However, waterlogging in peatlands means that decomposition is very slow so the carbon accumulates as peat.

Dr Tim Baker, co-author and Associate Professor at the School of Geography, University of Leeds presented the results to policymakers at ’Voices for Climate’ on the margins of the recent UN Climate Change Conference COP20 in Lima, Peru. “Mapping and quantifying the amount of carbon stored in these ecosystems is an important part of prioritising national strategies to mitigate climate change. For example, these peatlands occupy just 3 % of the forested area of Peru, but contain almost 50 % of the total amount of carbon stored above the ground in all Peruvian forests”.

“The peatlands we studied are largely intact, in contrast to tropical peatlands in Southeast Asia that have been exposed to decades of destruction, leading to huge carbon emissions and biodiversity losses” added co-author Dr Katherine Roucoux, lecturer at the University of St Andrews. “However, most of the peatland area, including the most carbon-dense peatland type, currently lies outside of the protected areas and threats are increasing. If these carbon-rich forests could be protected too, then large emissions of carbon to the atmosphere could be prevented.”

Funding for the project came primarily from the UK Natural Environment Research Council (NERC).

Climate change was not to blame for the collapse of the Bronze Age

Scientists have proven definitively that climate change could not have been responsible for a huge population collapse in Europe at the end of the Bronze Age.

Archaeologists and environmental scientists from the University of Leeds, the University of Bradford, University College Cork and Queen’s University Belfast have shown that the changes in climate that scientists believed to coincide with the fall in population in fact occurred at least two generations later.

Their results, published today in the Proceedings of the National Academy of Sciences, show that human activity starts to decline after 900 BC, and falls rapidly after 800 BC, indicating a population collapse. But the climate records show that colder, wetter conditions didn’t occur until around two generations later.

Dr Graeme Swindles, from the School of Geography, University of Leeds and a co-author of the study, said: “We found clear evidence for a rapid change in climate to much wetter conditions, which we were able to precisely pinpoint to 750 BC using statistical methods.”

Fluctuations in human activity levels through time are reflected by the numbers of radiocarbon dates for a given period. The team used new statistical techniques to analyse more than 2000 radiocarbon dates, taken from hundreds of archaeological sites in Ireland, to pinpoint the precise dates that Europe’s Bronze Age population collapse occurred.

Find out more

Archived news

  • View archived news here.