End personal attacks on scientists – regardless of their views

19 05 2014

The Met Office’s Chief Scientist, Professor Dame Julia Slingo, is appealing for an end to personal attacks on scientists – no matter what their viewpoint on the climate debate.

Her call follows recent articles in the media claiming that some scientists have felt pressured due to their views.

Professor Lennart Bengtsson, a research fellow at the University of Reading, featured in the articles after saying he was worried by a wider trend that science is being ‘gradually influenced by political views’. You can read a statement from him and other climate scientists in response to the articles on the Science Media Centre’s website.

In a letter, published in The Times today, Professor Dame Slingo says scientists should be free to review and debate their research without fear of personal attacks.

You can read the full letter below:

Sir

Your articles on the recent events surrounding Prof. Lennart Bengtsson are not a true reflection of the way the climate community conducts its research. My position, and my passion, is that all scientists – no matter what their viewpoint – must be free to review and debate their research unfettered and without personal attacks.

Science is about seeking the truth and acknowledging the uncertainties in what we currently know; it cannot be about subjective, unscientific beliefs and personal attacks of the kind that some of us have had to endure.

Just as we are very clear that climate models do not give us a definitive answer about the possible magnitude of future warming, neither do the estimates from observations as some in the climate sceptic community would claim.

I welcome scientific debate with those whose research challenges my understanding of climate change and scientists have a well established and robust peer review process for doing this. This process is there for good reason because it ensures the debate is rigorous but never personal.

Professor Dame Julia Slingo
Chief Scientist
Met Office





Winter so far – 18th February rainfall update

18 02 2014

As the UK heads into a period of more normal unsettled winter weather weather, the Met Office’s National Climate Information Centre has looked at statistics for this winter so far (from 1 December 2013 to 13 February 2014).

These add to previous facts and figures we put out earlier this month, and show a picture of continuing exceptional rainfall across many areas.

Looking at regions around the UK, these provisional figures show the region of central southern and southeast England has already exceeded its record winter rainfall in the series back to 1910. Rainfall here currently at 459.3mm*, 22mm above the previous record of 437.1mm set in 1915 with two weeks still to go to the end of the season. This winter also currently ranks as the 4th wettest winter (if there is no further rain) for southwest England and south Wales combined and the 3rd wettest for England South.

Both the UK as a whole and Wales are fairly close to exceeding their respective record wettest winter levels in the national series dating back to 1910 (see table below). Average rainfall for the rest of the month could see those records broken.

All countries across the UK have already exceeded their typical average rainfall for the whole winter (according to the 1981-2010 long-term averages). Normally at this stage of the season, you’d expect to have seen only around 80% of that whole season average.

All areas are also on target for a significantly wetter than average winter, with typically around 130-160% of normal rainfall if we get average rainfall for the rest of February.

All countries and areas are also on target for a warmer than average winter.

Current record wettest winters:

Country Year Rainfall Winter 2014 to date*
UK 1995 485.1mm 452.6mm
ENGLAND 1915 392.7mm 345.6mm
WALES 1995 684.1mm 645.1mm
SCOTLAND 1995 649.5mm 590.4mm
NORTHERN IRELAND 1994 489.7mm 386.2mm

*These are provisional figures from 1 December 2013 to 13 February 2014 and could change after final quality control checks on data.





Met Office in the Media: 16 February 2014, response by Professor Mat Collins and the Met Office

17 02 2014

An article by David Rose appeared yesterday in the Mail on Sunday entitled: ‘No, global warming did NOT cause the storms, says one of the Met Office’s most senior experts’

In it he says that Mat Collins, Professor in Climate Systems at Exeter University, ‘appears to contradict’ the report released by the Met Office last weekend and that he ‘declined to comment on his difference in opinion’ with one of the report’s authors, Dame Julia Slingo.

This is not the case and there is no disagreement.

The report by the Met Office states that “As yet, there is no definitive answer on the possible contribution of climate change to the recent storminess, rainfall amounts and the consequent flooding. This is in part due to the highly variable nature of UK weather and climate.”   This agrees with the latest IPCC Report that states: “Substantial uncertainty and thus low confidence remains in projecting changes in Northern Hemisphere storm tracks, especially for the North Atlantic basin.”

This is the basis for Prof Collins’ comment and means that we are not sure, yet, how the features that bring storms across the Atlantic to the UK – the jet-stream and storm track – might be impacted by climate change. As the Met Office report highlights for this year’s extreme conditions, there are many competing factors – from changes in the winds of the upper atmosphere to disturbed weather over Indonesia.

What the Met Office report – and indeed the IPCC – does say is that there is increasing evidence that extreme daily rainfall rates are becoming more intense. It is clear that global warming has led to an increase in moisture in the atmosphere – with about four per cent more moisture over the oceans than in the 1970s – which means that when conditions are favourable to the formation of storms there is a greater risk of intense rainfall. This is where climate change has a role to play in this year’s flooding.

With respect to changes in storminess, the good news is that recent advances in climate science are starting to pay dividends. Improved spatial resolution in models – that means that they can model weather and climate in more spatial detail – is allowing the models to represent some of the key factors that drive regional weather patterns. As the Met Office report states ‘With a credible modelling system in place it should now be possible to perform scientifically robust assessments of changes in storminess, the degree to which they are related to natural variability and the degree to which there is a contribution from human-induced climate change.’





The 2013 global mean temperature

29 01 2014

In December 2013 we published an estimate of the global mean temperature up to the end of October 2013, based on an average of the three main global temperature datasets – Met Office and University of East Anglia (HadCRUT4), NOAA National Climatic Data Center (NOAA NCDC) and NASA Goddard Institute of Space Studies (NASA GISS).

The United Nations’ World Meteorological Organisation (WMO) and the IPCC’s provisional estimate global mean temperature for 2013 is 0.5 °C ± 0.1 °C above the long-term (1961-1990) average.

For HadCRUT4, the provisional estimate for the whole of 2013 is between 0.39 °C and 0.59 °C above the long-term (1961-1990) average of 14.0 °C, with a central estimate of 0.49 °C.

This means 2013 is in the top ten warmest years on record and we continue to see near record global temperatures like those which resulted in 2000-2009 being the warmest decade in the instrumental record.

As always the latest figure has generated interest in the media, which focuses on how it relates to previous forecasts from the Met Office.

The global mean temperature is just one of many indicators – including sea level rise, shrinking glaciers and reducing Arctic sea ice – that give even more confidence that the world is warming. Climate models are an invaluable tool in helping us to understand past changes and predict how temperatures may change in the future; they have provided overall good advice capturing and representing the warmer world we now live in.

We can see from the IPCC AR5 report figure below how global temperatures have risen since 1860 and how the latest provisional observational estimates still lie within the range of the forecast models. This figure also shows that, looking back over the entire observational record there are a number of occasions where the observations lie close to both the upper and lower bounds of the model simulations, so what we are seeing at the moment is nothing new.

Time series of global and annual-averaged surface temperature change from 1860 to 2012 showing results from two ensemble of climate models driven with natural forcings and human-induced changes in greenhouse gases and aerosols compared to observations of global mean temperature from three different datasets relative to 1880-1919. CMIP3 relates to the suite of climate models used in IPCC AR4 and CMIP5 those models used in IPCC AR5.*

Time series of global and annual-averaged surface temperature change from 1860 to 2012 showing results from two ensemble of climate models driven with natural forcings and human-induced changes in greenhouse gases and aerosols compared to observations of global mean temperature from three different datasets relative to 1880-1919. CMIP3 relates to the suite of climate models used in IPCC AR4 and CMIP5 those models used in IPCC AR5.*

So, why might the global mean temperature be different from forecasts? Well, we know that, due to the lack of long-term observing sites in polar latitudes, HadCRUT4 underestimates the contribution from Arctic warming which has accelerated in recent years.

There is also increasing scientific evidence that the current pause in surface warming is associated with natural variability in the global oceans, as they absorb heat from the atmosphere. Changes in the exchange of heat between the upper and deep ocean appear to have caused at least part of the pause in surface warming, and observations suggest that the Pacific Ocean may play a key role. You can find out more about the recent pause in warming here.

*Figure modified from Bindoff, N. L., P. A. Stott, K. M. AchutaRao, M. R. Allen, N. Gillett, D. Gutzler, K. Hansingo, G. Hegerl, Y. Hu, S. Jain, I. I. Mokhov, J. Overland, J. Perlwitz, R. Sebbari and X. Zhang, 2013: Detection and Attribution of Climate Change: from Global to Regional. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T. F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P. M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, in press.





Climate change continues to impact UK waters

2 12 2013

The Marine Climate Change Impacts Partnership (MCCIP) has published its latest Report Card, detailing a comprehensive assessment on how climate change is affecting UK waters. MCCIP is a partnership between scientists, government and the marine community which enables clear communication and engagement across a range of key marine topics. The Met Office has contributed scientific expertise to a range of these topics, as well as being a partner organisation of MCCIP.

For the first time, Arctic sea-ice coverage is considered by the report’s authors. The report states that a long-term decline is clearly apparent, with Arctic sea-ice extent retreating and the ice becoming thinner as temperatures rise. This may provide opportunities for European and Asian commercial ships to cross the globe via northern polar routes.

The report card explains how short term variability means some years will be cooler than others. However, long term records clearly demonstrate an overall warming trend in recent decades, which is expected to continue in the future.

In addition, the 2013 report’s regional maps highlight differences across the UK’s seas and show the importance of local-scale impacts. For instance, the movement of fish species – important to commercial and recreational fishermen – and how non-native species are expanding their range are both covered.

Some key findings in the 2013 MCCIP Report Card include:

• Temperature records continue to show an overall upward trend despite short-term variability. For example, in the last decade, the average UK coastal sea surface temperature was actually lower in 2008-2012 than in 2003-2007.

• The seven lowest Arctic sea-ice extents in the satellite era were recorded between 2007 and 2013. The continuing downward trend is providing opportunities for the use of polar transit routes between Europe and Asia by commercial ships.

• Changes to primary production are expected throughout the UK, with southern regions (e.g. Celtic Sea, English Channel) becoming up to 10% more productive and northern regions (e.g. central and northern North Sea) up to 20% less productive; with clear implications for fisheries.

• There continue to be some challenges in identifying impacts of climate change.  These are due to difficulties distinguishing between short-term variability and long-term trends, and between climate drivers and other pressures.

Dr Matthew Frost of the Marine Biological Association and Chair of the MCCIP Report Card Working Group said:

“The marine environment is subject to a wide range of man-made pressures but can also change in response to natural processes. Disentangling these factors to enable identification of current and potential future impacts of climate change continues to be one of the greatest challenges facing marine scientists today. We have sought to clearly explain these challenges whilst continuing to report on the rapid and significant impacts of marine climate change.”

Marine Environment Minister George Eustice said:

“This report improves our understanding of how UK seas are already influenced by climate change and of potential changes in the future. Understanding these impacts, threats and opportunities is an essential basis for managing our marine environment.”

The report card highlights how little is known about climate change impacts on the “marine economy”, despite its importance for food (fish and aquaculture), energy (oil, gas and renewable energy), transport and coastal tourism and marine recreation. Coastal tourism and marine recreation is a key economic sector that could be highly sensitive to climate change (e.g. the threats of flooding, coastal erosion and opportunities for increasing visitor numbers), but little is known about future social and economic impacts.





Arctic sea ice reaches minimum extent for 2013

24 09 2013

Arctic sea ice has been in the media quite a bit this month and we looked at the issue in a blog a couple of weeks ago.

Late last week there was an update to the continuing story, as the National Snow and Ice Data Center (NSIDC) in the US announced that Arctic sea ice extent had reached its summer minimum.

Figures from the NSIDC show this year extent fell to 5.10 million square kilometres on 13 September, and the ice cover  is now increasing as we head into the northern hemisphere winter.

It’s possible that a shift in wind patterns or a late season melt could push ice extent lower, but – assuming the current figure remains – this year’s minimum extent is the sixth smallest since satellite records began in late 1970s.

The five lower seasonal minimum ice extents all happened from 2007 onwards, with the record set last year. That record low was just 3.41 million square kilometres, a notably low figure that was likely to have been influenced by weather conditions over the region which accelerated ice loss.

While a detailed analysis is required to understand the exact causes of the seasonal minimum this year, the weather conditions during the summer have been less conducive to ice loss than those experienced last year.

From late May to late June a stream of storms entered the Arctic Ocean, creating cloudy conditions at the time when the sun was at its strongest.

Relatively high ice cover during June and July (compared to recent years) was likely to have delayed the warming of the upper ocean and reduced melting at the base of the ice towards the end of the melt season.

We do expect a year to year variability in sea ice extent precisely because it can be so heavily influenced by weather patterns, but there is a long-term picture of decline – as you can see in the graph of August ice extents below.

August Arctic sea ice extent

August Arctic sea ice extent

New ice thickness data from the Cryosat satellite has also been released recently, and this shows a continuing shrinkage of winter ice volume.  This provides a timely reminder that despite the modest recovery in seasonal minimum ice extent this year, the ice continues to thin and the volume of sea ice continues to shrink.





Met Office in the Mail on Sunday

15 09 2013

An article appears in the Mail on Sunday today focusing on the Intergovernmental Panel on Climate Change’s (IPCC) forthcoming Fifth Assessment Report (AR5) which it bills this as the ‘world’s most authoritative climate study’.

It’s fair to say that AR5 is expected to be the most comprehensive review of climate change science to date. The first part of the report, from its Working Group I (WGI), has been worked on by more than 800 scientists from around the world who have assessed more than 9,000 scientific publications and taken into account more than 50,000 comments from over 1000 expert reviewers.

The WGI report is now in its final stages and the major conclusions will be finalised and released on 27 September. It is at that point that we should debate its findings and their implications.

Further parts of the report, from its Working Group II and III, as well as a final version of the whole report will be published next year.

The Mail article also discusses the recent pause in warming, which the Met Office looked at in a series of papers, released in July. Many of the issues raised in the article are addressed in those reports, which you can see on our website.

The article also goes on to mention some of the claims made in a commentary published by Nic Lewis yesterday. This is a lengthy and technical commentary covering several topics and will require time to provide as helpful a response as possible, so further comment will be released in due course.

There are a couple of points raised in the Mail story which should be addressed now, however.

The article states that the Met Office’s ‘flagship’ model (referring to our Earth System Model known as HadGEM2-ES) is too sensitive to greenhouse gases and therefore overestimates the possible temperature changes we may see by 2100.

There is no scientific evidence to support this claim. It is indeed the case that HadGEM2-ES is among the most sensitive models used by the IPCC (something the Met Office itself has discussed in a science paper published early this year), but it lies within the accepted range of climate sensitivity highlighted by the IPCC.

Equally when HadGEM2-ES is evaluated against many aspects of the observed climate, including those that are critical for determining the climate sensitivity, it has proved to be amongst the most skilful models in the world.

Finally, in our aim to provide the best possible scientific advice to the UK Government, the Met Office draws on all the scientific evidence available to us. This includes many other physically based climate models from leading research centres around the world, which provide a range of climate sensitivities and a range of potential future warming.





A response on statistical models and global temperature

31 05 2013

Over a period of several months the Met Office has been involved in dialogue and answered a series of questions on the subject of the use of statistical models in relation to the global temperature record.

The Met Office’s Chief Scientist, Julia Slingo, has written a discussion paper on the subject – you can now view the Executive Summary and a link to the full paper in an article on our Research News pages.

Publication of this paper follows a guest article recently published on the Bishop Hill blog site, where one of the people with which the Met Office has been speaking with – Doug Keenan – makes a series of accusations about the Met Office and its science.

Professor Slingo’s paper answers many of the points Mr Keenan makes, and the Met Office has already directly addressed many of the points Mr Keenan raises through considerable previous correspondence we have had with him on this issue. However, here we directly address a few of the key points in Mr Keenan’s article:

1)       Mr Keenan says that there is “no basis” for the claim that the increase in global temperatures since the late 1800s is too large to be reasonably attributed to natural random variation. He goes on to argue that this is because we haven’t used the right statistical model.

However, the claim that the increase in global warming is larger than could be explained by natural variability has a clear and well understood grounding in fundamental physics and chemistry. There is very high confidence (using the IPCC’s definition) that the global average net effect of human activities since 1850 has been one of warming. The basis for this claim is not, and never has been, the sole use of statistical models to emulate a global temperature trend. Instead it is based on hundreds of years of scientific advancement, supported by the development of high-quality observations and computational modeling.

2)       Mr Keenan suggests that Met Office scientists have been ‘trying to cover it [point 1, above] up’.

The Met Office has entered into email discussion at the working scientific level and responded promptly and transparently on all parliamentary matters and questions. We have also responded to numerous emails from Mr Keenan and invited him to come to the Met Office to discuss statistical modeling in climate science. As he points out in his article, so far those invitations have been declined or unanswered. The invitation still stands.

3)       Mr Keenan then goes on to argue that you can only use a statistical model to determine whether the warming we have seen is statistically significant. He argues that the Met Office has used the wrong statistical model and, therefore, our science is flawed.

The study of climate variability and change is broader than the domain of statistics, most notably due to the importance of the underpinning science of the climate system. Our judgment that changes in temperature since 1850 are driven by human activity is based on information not just from the global temperature trend, or statistics, but also our knowledge of the way that the climate system works, how it responds to global fossil fuel emissions and observations of a wide range of other indicators, such as sea ice, glacier mass, sea level rise, etc.

Using statistical tests in the absence of this other information is inappropriate, particularly when it is not possible to know, definitively, which is the most appropriate statistical model to use. In particular, a key test of an appropriate statistical model is that it agrees with everything we know about the system. Neither of the models discussed by Mr Keenan is adequate in this regard. On that basis, this conversation on statistical modelling is of little scientific merit.

4)       Mr Keenan details his argument to say that various different statistical models can emulate the global temperature record better and worse than others.

This is something the Met Office has already spoken about and shown analysis on (such as in an answer to a parliamentary question (PQHL62)). However, this assessment of relative likelihood does not ensure that any of the statistical models are scientifically valid. Because the Met Office does not make an assessment of global warming solely on statistics – let alone the statistical models referred to in Mr Keenan’s article, this exercise is of very little, if any, scientific use.

5)       Mr Keenan also makes repeated accusations that the Met Office did not, or was not willing to respond to Parliamentary Questions.

This is not the case. The Met Office answered every request for input to Parliamentary Questions and answered them in the most scientifically appropriate way to the best of its knowledge. There has never been a refusal to provide information to answer a Parliamentary Question.





Recent climate research in the news

21 05 2013

A research paper published in Nature Geoscience (Otto et al, 2013) led to a fair amount of media coverage yesterday, including articles in the Guardian, BBC and an opinion piece by Matt Ridley in The Times (this article is behind a pay wall).

The research paper looked at a ‘best estimate’ of the warming expected when the concentration of carbon in the atmosphere is doubled over pre-industrial levels (known as the Transient Climate Response).

Alexander Otto, Research Fellow in Climate Decisions at the Environmental Change Institute, University of Oxford, was the lead author of the research.

He has written an article discussing the science and the implications of the research which can be seen on the Research News pages on our website.

Here is a short extract from Alexander Otto’s article :

“We published a paper in Nature Geoscience on Sunday giving a new best-estimate of 1.3°C for the Transient Climate Response, or the warming expected at the time carbon dioxide reaches double its pre-industrial concentration, using data from the most recent climate observations.

This best-estimate is lower than the HadGEM2 [one of the Met Office climate models] TCR value of 2.5°C and it is also 30% lower than the multi-model average of 1.8°C of the CMIP5 models used in the current IPCC assessment. Does this mean that the Met Office’s advice to government is based on a flawed model? Certainly not.

It is well acknowledged by all that the HadGEM2 model is at the top end of the range of TCR values in CMIP5, but we need a diverse range of TCR values to represent the uncertainties in our understanding of climate system processes. And the Met Office’s advice to government, like any solid policy advice, is based on the range of results from different models, not just their own.

The ‘warming pause’ over the recent decade does not show that climate change is not happening. And it certainly does not mean that climate scientists are “backing away” from our fundamental understanding.

Every new decade of data brings new information that helps reduce uncertainties in climate forecasts. In some ways, the picture changes surprisingly slowly for such an intensely scrutinised problem… This study highlights the importance of continued careful monitoring of the climate system, and also the dangers of over-interpreting any single decade’s worth of data.”





Fascination and forecasting – guest blog by Siân Lloyd

5 03 2013
Siân Lloyd

Siân Lloyd

Here in the UK we’re famous for being obsessed with the weather, and I’m no exception to that. My fascination with the weather started from a young age because my father had a passion for the outdoors, so we were always out in all weathers.

Coming from Wales, where we get continually walloped by fronts spinning off the Atlantic, you certainly see a great variety of weather and you soon get used to coping with whatever gets thrown at you. I remember eating egg and marmite sandwiches on Gower beaches, sat in a kagool with my father saying the rain would clear soon – he was always an optimist.

It’s not just my own experiences that captured my fascination, but also the myths and legends of the Celtic landscape I grew up in. Virtually every story has weather in it – from violent storms, to great floods, or the tranquil calm of a summer’s day. So for me, weather represents the drama of life and is the very stuff of our literature.

So it doesn’t surprise me that, wherever I go, people are always keen to talk about the weather and what’s in the forecast. I know I may be biased, but I really do believe that forecasting is hugely important. From protecting people from the harshest conditions our climate has to offer, to helping fashion conscious ladies like myself decide what to wear, forecasts help us in so many aspects of our day to day lives.

In many ways we take forecasting for granted, but to me the ability to predict the weather days ahead is a true feat of human ingenuity and one of the great triumphs of science. In 1922, mathematician Lewis Fry Richardson estimated you’d need 64,000 people doing endless calculations to get a forecast in time to make it useful – looking just a few hours ahead. Today we take observations from all over the world, from the top of the atmosphere to the depths of the oceans, put them in a supercomputer that does trillions of calculations a second to make forecasts, then people like me interpret that output to put together tailored forecasts which can be transmitted around the world in seconds. Truly amazing stuff.

I’ve been in weather forecasting for 20 years and things have changed a lot. One of the biggest changes is the huge strides in accuracy that have been made. Even from my personal experience I can tell how much better forecasts are and the statistics bear that out. The Met Office’s four-day forecasts are as accurate as its one day forecasts were 30 years ago, and things are still improving all the time as we understand more about the way the atmosphere works and technology improves.

The other big thing that I’ve noticed is that the weather used to follow the news, but now it very often is the news. So often these days I get asked to speak on air during bulletins about floods or droughts and why we’re seeing them. So, from my personal experience, it seems like the weather is changing and that our warming climate is playing a part. As we go forward then, science once again will have an important role to play in helping us understand how and why things are changing, and ever more accurate forecasting will help keep everyone prepared for whatever the weather has in store.

If you want to learn more about our weather and climate, as well as how it all works, you can read about it in ‘An Essential Guide to the Weather’ – a two part guide which will be free in The Telegraph this weekend on the 9th and 10th of March. Part 1, in Saturday’s paper, explains the causes of our weather and provides a comprehensive guide to clouds and other types of weather. Part 2 looks at how weather forecasting is done, extreme weather, and climate zones around the world.








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