Monday, 29 September 2014

Flu study offers unique insight into our drug habits during a pandemic

New research led by CEH’s Dr Andrew Singer provides the first evidence of how the use of antibiotic and antiviral drugs became elevated during the 2009-2010 influenza pandemic in the UK. The study, published in PLOS One, offers a unique look at public health practice, human behaviour and drug adherence in the country.

Andrew’s study, carried out at 21 locations within the river Thames catchment, was the first to provide actual measurements of antibiotics, antivirals and decongestants in sewage effluent and receiving rivers during an influenza pandemic, an event only likely to happen every 30 years or so. The aim was to quantify the pharmaceutical response to the pandemic and compare this to drug use during the late pandemic and the inter-pandemic periods. The findings helped to quantify the risk to wastewater treatment plants, as they will be sensitive to the amount of antimicrobials in sewage and could potentially fail to meet water quality standards during high drug use events such as an influenza pandemic.

Dr Andrew Singer at work in one of CEH's laboratories.

The study also provides evidence that environmental concentrations of the antiviral Tamiflu would be sufficiently high to select for antiviral-resistance in influenza viruses within wildfowl inhabiting the river Thames. Future research will need to focus on the minimum concentration of antibiotics needed to ‘knock out’ a wastewater treatment plant, and whether this concentration could be achieved during a more severe pandemic. It remains an open question as to the extent to which exposure to high concentrations of Tamiflu have actually selected for antiviral resistance in wildfowl—as this has been shown to occur in laboratory studies. Lastly, it also remains unclear as to the lasting impact of an increase in antibiotic use during a severe influenza pandemic on the environmental reservoir of antibiotic resistance and its relevance to human health. Will we need to limit antibiotic use during a pandemic in order to spare our wastewater treatment plants as well as the long term efficacy of antibiotics?

Read more about the background to the study in an article on Andrew’s blog and read the freely available study in PLOS One.

Additional information

Staff page of Dr Andrew Singer, CEH

Andrew led a previous study estimating how much prescribed Tamiflu went unused during the 2009-2010 pandemic. More details in a CEH news story.

Thursday, 25 September 2014

What emission profiles aid remaining below two degrees of global warming?

In recent days multiple marches have taken place around the world, timed to coincide with the UN Climate Change summit in New York (23 September 2014). The many protestors have urged more action by governments to reduce greenhouse gas emissions.

CEH climate modeller Dr Chris Huntingford commented:

“There is still significant debate as to what constitutes safe levels of global warming. This almost certainly depends on the different impacts which can result from varying levels of warming. For example, meteorological changes affecting crop productivity detrimentally could be produced by a different level of climate change to that causing unwelcome sea-level rise. Yet despite this, the 2009 climate conference in Copenhagen pushed for the single threshold of no more than two degrees of global warming. There is a persuasive argument that this was a major achievement, as a single easy to understand temperature threshold will probably gain more traction in policymaker circles than debating a range of possible climatic futures.

The immediate question then became: “What emissions profiles can keep us below two degrees of global warming?” Working with colleagues from Met Office Hadley Centre, University of Oxford, Manchester Metropolitan University and the Committee on Climate Change, we carried out a study using a relatively simple coupled climate-carbon cycle model, but one capturing uncertainty based on differences between the fully complex climate models, as operated by various research centres across the world. The resultant paper provided “look-up” diagrams, where different emissions levels of years 2020 and 2050 can be related to the probability of remaining below two degrees. The paper also linked these 2020 and 2050 levels to both year of maximum emissions and required year-on-year emission cuts for the decades thereafter, in order to fulfil them.

The paper was published in 2012 in the journal Environmental Research Letters, but its message still stands. Namely that to have a reasonable chance of constraining warming to two degrees then emissions need to peak in the next few years, followed by year-on-year cuts of at least 3%.”

Chris Huntingford

UN Secretary General Ban Ki-Moon (front row, second from right) at the People's Climate
March in New York, held ahead of the Climate Summit he hosted at UN headquarters in
September 2014. Photo: UN / Mark Garten

Additional information

The paper can be read on the Environmental Research Letters website. It is "open access" allowing circulation of the document, and can be found here (doi: 10.1088/1748-9326/7/1/014039).

Chris Huntingford is a climate researcher at the UK Centre for Ecology & Hydrology, and also long-term visiting scientist at the Oxford University Centre for the Environment.

Information on the UN Climate Summit 2014

Thursday, 18 September 2014

Developing the new CEH-Gridded Estimates of Areal Rainfall dataset

Watch a presentation by Dr Maliko Tanguy of the Centre for Ecology & Hydrology about the new CEH-Gridded Estimates of Areal Rainfall dataset (GEAR). The talk explores the motivations behind development of the dataset, including user and data management needs, explains how the data was derived, and provides some example uses. CEH-GEAR provides 1km gridded estimates of daily and monthly rainfall totals for Great Britain and Northern Ireland from 1890 to 2012, with yearly updates. Precipitation totals from the UK raingauge network are used.

The CEH-GEAR dataset will be available via the CEH Information Gateway by the end of the year.

Additional information

The presentation above was made to an internal CEH audience in September 2014.

CEH Information Gateway

View slides from the presentation made at the British Hydrology Society 2014 National Symposium

Thursday, 11 September 2014

Potential influences on the United Kingdom's floods of winter 2013/14

Last winter severe flooding affected large parts of the UK. In a recent paper published in Nature Climate Change, scientists at the Centre for Ecology & Hydrology, working with colleagues from the Met Office and a number of universities, looked at the possible drivers behind the floods.

Dr Chris Huntingford, the lead author of the paper, explains:

In this paper, along with my co-authors, we have tried to provide a summary document that collates and discusses all possible drivers behind the major flood events that affected the UK last winter. It has three themes.

First, a very brief overview of the large-scale meteorological events leading up to the storms is presented. None of the individual rainfall events was unprecedented, but the weather patterns behind them persisted for three months causing a near-continuous succession of Westerly storms. This had the cumulative effect that for much of the Southern UK, the total winter rainfall was record-breaking. Preliminary analysis suggests that particularly warm ocean conditions and heavy rainfall in and around Indonesia triggered wind patterns across the Pacific that travelled northwards before ultimately drawing cold air down across the USA. This in turn forced a particularly strong and persistent Jet Stream across the Atlantic and towards the UK. The Met Office is now studying this sequence of events in significantly more detail. In our paper, we show how the winter storms affected river flows, and place the events within a historical context.

Flooding in Oxfordshire, February 2014. Photo: Julia Lawrence

Second, questions mount as to whether fossil fuel burning could have a role. We have reviewed existing research literature for Earth system factors that may be both changing through global warming, and additionally are identified as influences on storm features for the UK. As expected, this confirms how complex and inter connected the climate system is. Multiple possible UK rainfall drivers are identified that link to the state of the oceans, the atmosphere and sea-ice extent. Interestingly the recent rapid decrease in Arctic sea-ice that is widely attributed to global warming, for the UK at least is often portrayed as likely to bring more Easterly winds and colder conditions. The previous three winters had these features for some of the time, in marked contrast to winter 2013/14. Although the precise details of linkages between changing large-scale features of the climate system and UK rainfall intensity are still not fully understood, we hope our review article is a complete list of such connections. To apply that frequently used expression, we trust there are no “unknown unknowns” lurking out there we have yet to consider.

Third, we provide some thoughts on how best to proceed. Assuming that we do have a pretty good idea of all drivers expected to affect rainfall, and that require on-going computer modelling, three challenges are noted. These are: (1) the need for continued enhancement of physical process representation via ever better parameterized differential equations of the oceans, atmosphere and ice sheets, (2) increase further the numerical grid resolution of climate models, on which these equations are calculated and (3) undertake significantly higher numbers of simulations, all with slightly different initial conditions, creating a large ensemble of projections. The call for better resolution is because some characteristics of storms occur on fine spatial detail, thus needing small spacings between gridpoints on which calculations are updated. The request for large ensembles is because extremes, by definition, are rare events, and so we need to ensure that all heavy rainfall “return times” are fully sampled. This is both for pre-industrial and for raised levels of atmospheric greenhouse gases.

During the major flood events affecting much of Southern England from December 2013 to February 2014, it was inevitable that questions would be asked as to whether fossil burning could have a role. It is always (and correctly) stated that no single observed extreme event can be formally attributed to human-induced changes to atmospheric composition. But a statistic can be derived that assesses any changing probability of a particular extreme event occurring, a quantity sometimes referred to as “Fractional Attributable Risk”. By satisfying the three challenges we listed above, we will get near to stating if humans are increasing, decreasing or leaving invariant the chances of rainfall events of the type witnessed. However, even now limitations remain on computer speed and resource, and expenditure on climate research can only ever be finite. Hence an especially lively debate will now occur as to what constitutes the optimal balance between pursuing these three challenges, in order to get us most quickly towards the required answers.

Anyone studying meteorological systems, or the full Earth system, soon realizes of course how tightly coupled all features are of the climate system. In this review, by trying to collate in to a single paper the main factors affecting UK rainfall, this did though provide a timely reminder of such comprehensive interconnections. Understanding these further suggests a very interesting time lies ahead for climate change research.

Chris Huntingford

Chris Huntingford is a climate modeller based at the Centre for Ecology & Hydrology in Wallingford, Oxfordshire.

Additional information

Full paper reference: Chris Huntingford, Terry Marsh, Adam A. Scaife, Elizabeth J. Kendon, Jamie Hannaford, Alison L. Kay, Mike Lockwood, Christel Prudhomme, Nick S. Reynard, Simon Parry, Jason A. Lowe, James A. Screen, Helen C. Ward, Malcolm Roberts, Peter A. Stott, Vicky A. Bell, Mark Bailey, Alan Jenkins, Tim Legg, Friederike E. L. Otto, Neil Massey, Nathalie Schaller, Julia Slingo and Myles R. Allen (2014) Potential influences on the United Kingdom’s floods of winter 2013/14. Nature Climate Change, doi:10.1038/NCLIMATE2314

Staff page and research interests of Chris Huntingford 

New scientific review investigates potential influences on recent UK winter floods  (CEH News, 27 August 2014)

Wednesday, 3 September 2014

CEH at the British Hydrological Society National Symposium

Several CEH scientists are in Birmingham this week at the 12th British Hydrological Society National Symposium. This year’s theme is “Challenging hydrological theory and practice.”

The symposium, which takes place from 2-4 September 2014, is one of the main meetings for the UK’s hydrological community, a community in which CEH plays a key role, through both our research on issues such as water resources, floods and droughts, and our extensive hydrological data management remit.

CEH has a stand at the conference. Visitors are being shown this video highlighting the wide range of hydrological research we carry out:

Ten CEH staff are speaking at the conference on a wide range of subjects. Their presentations are as follows:

1. Natural or designer environmental flows for a changing world? Prof Mike Acreman

2. Predicting physical habitat sensitivity to abstraction. Cedric Laizé

3. Overdispersion in peak over threshold (POT) flow data and its effect on flood frequency practice.
Dr Ilaria Prosdocimi

4. The new FEH rainfall depth-duration-frequency model: results,
comparisons and implications. Lisa Stewart

5. What do we talk about when we talk about drought? Jamie Hannaford

6. Real-time modelling of surface water flooding hazard and impact at
countrywide scales. Dr Steven Cole

7. Presentation of the new CEH-GEAR dataset: fine resolution daily and monthly
areal rainfall estimates for the UK for hydrological use Dr Maliko Tanguy

8. Can land use and land management make a difference to water
availability? Helen Houghton-Carr

9. How do we want to access hydrological data over the web? Matt Fry

10. Ensuring UK hydrometric data is fit-for-purpose through a national
Service Level Agreement. Katie Muchan

Conference attendees are tweeting using the hashtag #BHS2014


Conference website

Conference programme