So what happened to our summer?

28 08 2015

Our Chief Scientist Professor Dame Julia Slingo OBE FRS reflects on this summer’s weather and what has influenced it:

No-one can deny that we have had a pretty disappointing summer with a lot of unsettled weather and only a few warm spells, especially through July and August. Our weather has been dominated by low pressure over and to the west of the country that has brought us periods of heavy rain from the south – what we call the Spanish Plume. So what has been happening?

If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather.

So could all this have been anticipated? Seasonal forecasts for this summer suggested that temperatures and rainfall would be near normal. However, as the season progressed all the leading models around the world failed to capture the signal for unsettled weather over the UK. We all know that forecasting months and seasons ahead is still in its infancy and much more research needs to be done. On the other hand our day-to-day forecasts have been really successful in allowing us to warn of bad weather, highlighting yet again the benefits of our research that has delivered year-on-year and decade-by-decade improvements in forecasting skill. Our 5-day forecast is now as accurate as our 1-day forecast was when I started my career. This enables us to make so many decisions that keep us safe, protect our property, keep our infrastructure running and even when to go out and enjoy the sunshine!

All of this cannot happen without improvements to research and technology, and this week the first phase of our new supercomputer went live, five weeks ahead of schedule. This will enable us to provide even more accurate and relevant weather and climate forecasts to all of us, our government, emergency responders, and our many other customers at home and abroad.

The news that the BBC has decided that the Met Office won’t be their main weather provider when the current contract ends has raised the question of where will the new provider get their information from. It’s important to understand that no weather forecasting organization, whether it is a National Met Service like the Met Office or an independent company, can provide a service without a forecast, and that it is the leading meteorological agencies, like the Met Office, that build and deliver those forecasts. So whoever the BBC chooses to deliver their weather services in future, you can be sure that Met Office observations and forecasts will continue to be at the heart of them. We are committed to driving forward the skill and usefulness of our forecasts and ensuring that all of us benefit from the advances the Met Office makes in the coming years with our new supercomputer.





Met Office in the Media – 7 August 2015

7 08 2015

Earth from space

An article published today makes a number of claims about Met Office weather and climate science.

It would be difficult to cover all the points raised in this blog, but here we look at the science and facts behind a few of the assertions.

The first decadal forecast issued in 2007

We did indeed publish the first groundbreaking decadal forecast in 2007. It had two headline statements:

  1. that half of all years after 2009 would be warmer globally than the record year at that time (1998) – This is doing well so far with two out of five years (2010 and 2014) warmer than 1998 and given current temperature levels, it’s likely this will be 3 out of 6 by the end of this year, consistent with our forecast for 2015
  2. that 2014 would be 0.3 °C ± 0.21 °C warmer than 2004 (giving a range of 0.09 °C to 0.51 °C) – WMO figures show the global temperature for 2014 was 0.13 °C higher than that in 2004; which is within the range of the forecast

Adjustments to global temperature data

The article says we adjust our temperature figures ‘without justifying why it is scientifically appropriate’. In fact, numerous peer-reviewed science papers from research centres across the world provide detailed explanations of how and why datasets are adjusted to ensure they are as accurate as possible. This is available for anyone to view and analyse.

The conclusion that the world has warmed is supported by independent analysis of global temperature data.

European heatwaves

We published a paper stating heatwaves like that seen across Europe in 2003 would become more frequent under climate change. Subsequent observations back up these conclusions; 2006 saw comparable heat in the UK, 2010 saw intense heat across eastern Europe, and there’s been a prolonged heatwave across much of Europe this year (although not in the UK).

Weather extremes

Met Office research supports climate research centres around the world which concludes we expect more extremes of heat and rainfall as the world continues to warm. The article says this ‘simply hasn’t happened’ but in fact, research shows there has been an increase in both. While here in the UK, we have also seen an increase in the number of temperature and rainfall records.

The article also states ‘the Met Office did all it could to claim the rain that caused last year’s exceptional flooding… was the worst ever recorded.’ We’ve done studies (here and here) of the exceptional rainfall in winter 2013/14., which across southern England was one of the, if not the most, exceptional periods for winter rainfall in around 250 years. Here’s a fuller research piece about the winter 2013/14 storms.

Greenland ice

The article says that we claimed Greenland ice would melt in future due to global warming. We did, and we were clear that it would take thousands of years to happen, not ‘any time soon’. Observations show Greenland has been losing 300 gigatonnes (1 gigatonne is 1000,000,000 tonnes) of ice a year over the last 12 years and research shows surface temperatures have clearly risen.

Other claims

A series of other claims are made in the article, mostly focusing on our forecasts over seasonal to decadal timescales. The Met Office is at the forefront of this pioneering area of research and we are increasing skill in this area.

According to standards set by the World Meteorological Organization the Met Office is ranked as the most accurate global met service in the world. We will continue our research in collaboration with our global scientific partners to improve this vital area of science.





Annual State of the Climate Report for 2014 published

16 07 2015

A report which looks at all the climate variables that can be measured for 2014 has been released today.

The annual ‘State of the Climate’ report has been published by the American Meteorological Society, presenting summaries for all so-called Essential Climate Variables (ECVs).

These include various types of greenhouse gases, temperatures throughout the atmosphere, ocean, and land, water cycle variables, ocean variables such as sea level and salinity, sea ice extent, permafrost temperatures and others. The majority of these reflect a planet that is continuing to warm.

The exceptional warmth of 2014 occurred against a backdrop of neutral to marginal El Niño conditions. Europe was especially warm and all land regions apart from North America showed above average frequency of warm extremes.

Annual average anomalies (difference to normal) for 2014 for surface temperature from the Met Office’s global temperature dataset, HadCRUT4 relative to a 1981-2010 climatology period.

Annual average anomalies (difference to normal) for 2014 for surface temperature from the Met Office’s global temperature dataset, HadCRUT4 relative to a 1981-2010 climatology period.

Over oceans, global sea surface temperatures and ocean heat content were also observed to be exceptionally warm and sea level exceptionally high.

The significant warmth is reflected strongly in regions of snow and ice. Arctic sea ice was well below average but above the exceptional lows seen in 2007, 2011 and 2012. Glacier volume is declining year on year – preliminary results for 2014 make it the 31st consecutive year of decline.

Long-lived greenhouse gases continued to increase, primarily owing to rising carbon dioxide (CO2) concentrations, in addition to methane (CH4), nitrous oxide (N2O) and other minor trace gases.

The Met Office’s Kate Willett, a lead chapter editor on the new report, said: “The comprehensive view of the different variables in the report enables a better understanding of the interconnectedness of our climate system.”

‘State of the Climate in 2014’ is the 25th consecutive instalment of the report, which is lead by scientists from NOAA’s National Centers for Environmental Information, along with 413 scientists from 58 countries.

Met Office scientist Kate Willett leads the Global Climate chapter and several other Met Office scientists contribute, using Met Office Hadley Centre climate data. All reports are freely available online.





Met Office awarded for its collaborative work overseas

15 05 2015

The International Development team at the Met Office has won a prestigous award for its work helping increase the access, use and benefits of climate information services to 2.4 million people in Kenya.

The British Expertise International Award for ‘Outstanding International Collaboration’ was given to the Met Office for its work with the Adaptation Consortium delivering the ‘Mainstreaming Climate Adaptation into Planning’ project.

Other partners in the consortium are Christian Aid, the International Institute for Environment and Development, Kenya Meteorological Services and the National Drought Management Authority Kenya.

The project aims to address the underlying causes of vulnerability to climate change while strengthening adaptation to future extreme events. It has improved access to climate and other information, integrated climate change adaptation into development plans, developed better water infrastructure and training in water governance, and improved disease surveillance.





Has there been a recent increase in UK weather records?

17 12 2014

There have been a striking number of temperature and rainfall records broken in recent years, according to an analysis by the Met Office which is published in the journal Weather.

The paper examines whether recent decades have seen an unusually high number of records broken in the UK. It looks at the number of records over time in the UK national statistics compiled by the Met Office’s National Climate Information Centre (NCIC).

Records were collated from long-running national and regional series of monthly, seasonal and annual temperature, rainfall, and sunshine.

The analysis counts records by decade and weights them according to their relative importance. More weight is given to national records compared to regions, and more weight to annual records compared to individual months.

The UK’s climate shows a large variability and this is bound to also be reflected in weather records. Even so, the analysis does reveal some interesting patterns.

Temperature records:

  • Since 2000, there have been 10 times as many hot records as cold records.
  • Taking into account the weighting, the period since 2000 accounts for two-thirds of all hot records in a national series from 1910, but only 3% of cold-records.
  • The longer Central England Temperature (CET) series, which dates back to 1659, reveals a similar trend – with seven out of a possible 17 records set since 2000 but no record cold periods.
  • The increase in hot records and decrease in cold records seen in recent decades is consistent with the long-term climate change signal. Seven of the warmest years in the UK series from 1910 have occurred since 2000.

Rainfall records:

  • Since 2000 there have been almost 10 times as many wet records as dry records.
  • Taking into account the weighting, the period since 2000 accounts for 45% of all wet records in a national series from 1910, but only 2% of dry records.
  • Remarkably, period since 2010 accounts for more wet records than any other decade – even though this only a 5 year period. The most prominent wet records in this period were winter 2013/2014 and April, June and year 2012.
  • The longer England & Wales Precipitation (EWP) series, which dates back to 1766, shows a similar trend – with six out of a possible 17 records set since 2000, but no record dry periods.
  • The large number of recent wet records may be indicative of trends in underlying rainfall patterns. We would expect an increase in heavy rainfall with climate change and this is an area of active research within the Met Office Hadley Centre.

Sunshine records:

  • In contrast with the other measures, there are no clear trends apparent in the sunshine records.

Exactly why we have seen these records is an ongoing area of research. You can see some discussion points related to this theme in a Met Office research paper on the drivers and impacts of our seasonal weather.

You can explore the Met Office’s climate data for the UK on our climate pages.





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.








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