Weatherwise

Times Educational Supplement - 30 November, 2000 - John Harris

Is global warming responsible for the recent spate of floods?

Head of Geography, Radley College taps into a vast array of websites to help students judge

"These floods and gales; it must be global warming!" my Year 10 class proclaim as they scan the latest press cuttings. Geography and science teachers have been inundated by a deluge of questions from students eager to seek out explanations for the recent extreme weather which has affected the lives of so many people in Britain and Europe.

The debate alone has already produced sufficient heat to make a major contribution to the already overcharged state of the atmosphere. Is there any real evidence for man-induced global climatic change or are we simply witnessing part of a natural and ongoing cycle of weather variation? As teachers, I believe that it is our duty to present unbiased information and to provide an opportunity for informed discussion rather than jumping aboard the global warming balloon and soaring away on a rising thermal of misinformation.

There is no doubt that extreme weather is a catalyst which can be used to promote a greater awareness and understanding of the complexities of the atmosphere. Most students have had first-hand experience of the problems that such weather can create. The gales of mid October brought wind speeds up to 120 mph and a band of devastation across much of southern England. Severe flooding occurred, initially in Kent and Sussex and then across many parts of the country brought widespread damage, disruption and misery. A tornado ripped through the seaside town of Bognor Regis.

It is important for students to have some frame of reference to judge the scale and impact of such events. They also need to appreciate the underlying scientific processes and to discuss possible solutions. How for instance do recent events compare to the gales of October 1987 or the floods of 1947 or 1953? I have found it useful to direct my students to the excellent Met Office website on historic UK weather events

http://www.metoffice.gov.uk/climate/uk/

at http://www.metoffice.gov.uk/climate/uk/extremes/index.html.

Other useful information on weather extremes can be found at the BBC Weather Centre website at http://www.bbc.co.uk/weather/weatherwise/factfiles/extremes/floods.shtml

Students then raise many important questions. Is man to blame through the burning of fossils fuels and increasing atmospheric levels of greenhouse gases? Are present climatic fluctuations greater and more rapid than those experienced previously? What can be done to reduce future hazards? What part can we all play in limiting our future vulnerability? Such questions are highly relevant and cut across many parts of the school curriculum.

There is an enormous amount of weather data freely and instantly available on the worldwide web. The role of the teacher is increasingly one of "navigational assistant" and "discussion moderator". The BBC Weather Centre http://www.bbc.co.uk/weather/ and UK Met Office http://www.metoffice.gov.uk/index.html websites provide an array of live weather satellite images and maps of wind speed and rainfall intensity, accompanied by expert analysis and comment. The Met Office has published a detailed set of synoptic charts and data on the recent UK floods and storms at http://www.metoffice.gov.uk/climate/uk/interesting/oct2000storm.html

Students can use online news and media such as BBC News Online http://news.bbc.co.uk/ to follow events in "real-time" with frequently updated weather warnings, live audio and video reports and web links to background information There is also great deal of archived material on flooding, gales, hazards and global climatic change with widely contrasting views and interpretations. This allows student to put recent events into perspective.

The following websites provide useful sources of information, and students can appreciate the widely differing evidence and environmental interpretations:

Environmental Protection Agency http://www.epa.gov/globalwarming/index.html

CSIRO Atmospheric Research http://www.dar.csiro.au/

NOAA http://www.solcomhouse.com/globalwarming.htm and http://www.cpc.ncep.noaa.gov/

Friends of Earth http://www.foe.co.uk/

DETR "Climate change and its impacts" Oct 1999 published by the Met Office and online at

http://www.metoffice.gov.uk/sec5/CR_div/pubs/brochures/B1999/index.html

Students can enhance their own knowledge and understanding of the complex processes and issues involved. I have found that the resulting classroom discussion and presentations allow more informed judgments and conclusions to be made.

At Key Stage 3 I encourage students to investigate and discuss some of the following:

1 When does a natural event become a natural disaster?

2 Discuss how the impact of natural disasters can be measured eg cost of damage, loss of life, disruption of everyday life?

3 Research a variety of recent natural disasters eg earthquakes, volcanic eruptions and hurricanes:

Volcano World: eruptions http://volcano.und.nodak.edu/vw.html

Discovery Online: earthquakes http://www.discovery.com/exp/earthquakes/hits.html

Hurricanes: http://weathereye.kgan.com/expert/hurricane/basics.html and http://www.discovery.com/stories/science/hurricanes/future.html

4 Map the distribution of disasters on a world map. Do any patterns emerge? If so, how can they be explained and what are the implications?

5 How does the scale of recent flooding and storm damage in the UK compare with other natural disasters worldwide.

6 Contrast the impact of disasters in LEDC's (less economically developed countries) compared to MEDC's (more economically developed countries).

7 Discuss the short, medium and long term impact of disasters.

8 Discuss the role of emergency aid and the need for longer-term aid and planning.

At A Level students are expected to undertake more specific research:

1 Study the Meteosat weather images and Met Office wind charts for October 30 and then describe and explain the distribution of the areas of a) highest rainfall intensity rainfall and b) highest wind speeds.

2 With reference to the synoptic charts and wind gust maps for October 29th and 30th explain why the gales did most damage in southern England

http://www.metoffice.gov.uk/climate/uk/interesting/images/GustValue29-30Oct-00.gif

Study the UK rainfall radar animation of rainfall for October 29th and 30th and describe the pattern of most intense rainfall. How helpful is such information in issuing flood warnings?

http://www.metoffice.gov.uk/climate/uk/interesting/radar30-10-2000.html

http://www.metoffice.gov.uk/climate/uk/interesting/images/PrecipValue29-Oct-00.gif

3 Plot rainfall-intensity graphs and contrast these with the timing of the most severe flooding in the catchments of the River Severn, Ouse or Derwent. What other factors could explain the lag-time in flood response?

4 How unusual are the recent gales and heavy rainfall? Study the UK map of return period and % of long-term average rainfall. How is such data calculated? What is its value?

5 Apart from climatic reasons why else may flooding and its effects have increased in the last 100 years be increasing. Investigate the increase in building in flood plain areas and explain what impact this may have on flood plains.

6 What impact may recent flooding have on local planning decisions and national housing strategies.

7 How accurate are weather forecasts? Why is forecasting so complex?

8 Do recent weather events really provide evidence of man-induced climatic change?

This leads on to further research into weather and climatic variation in the UK, Europe and worldwide. The Radley College Geography Department has designed and administered several interactive web-based weather projects. In 1987 I set up MetLink International http://atschool.eduweb.co.uk/radgeog/metlink/metlink.html to promote the study of meteorology. UK schools exchange weather data with other schools, worldwide, using the internet. Students report first-hand on their own weather experiences and upload material to the weather news website at http://atschool.eduweb.co.uk/radgeog/metlink/news/news.html. Their reports include record low temperatures in Scandinavia, heatwaves and bushfires in Australia, choking smog in Bombay and cyclones and tragic flooding in Southern Africa. MetLink is sponsored and supported by the Royal Meteorological Society. Such projects bring weather studies to life and students participate in valuable first-hand data collection and analysis.

And as for global warming and current weather extremes? I hope that students will make their own final judgment based on a range of scientific evidence. "It's and ill wind that blows no good" and there is no doubt that recent events have greatly enhanced the scope for students to investigate the exciting and ever changing world of weather.

Links

BBC Weather Centre http://www.bbc.co.uk/weather/

UK Met Office http://www.metoffice.gov.uk/index.html

Royal Meteorological Society http://www.royal-met-soc.org.uk/

MetLinkInternational http://atschool.eduweb.co.uk/radgeog/metlink/metlink.html