0:00:03 > 0:00:05Rain -
0:00:05 > 0:00:06it spits,
0:00:06 > 0:00:08it drizzles
0:00:08 > 0:00:10and it pours.
0:00:12 > 0:00:15In English it rains cats and dogs.
0:00:15 > 0:00:18In Welsh it rains old women and sticks.
0:00:18 > 0:00:21Rain nurtures the grass for our sports grounds,
0:00:21 > 0:00:24it gives us green countryside
0:00:24 > 0:00:26and the sliding tackle.
0:00:26 > 0:00:30As you can see, we're in the middle of summer
0:00:30 > 0:00:32and we are here in the rain.
0:00:32 > 0:00:36You really witness this a lot of the time -
0:00:36 > 0:00:38water, water, water.
0:00:38 > 0:00:42So how has our frustration and fascination with rain
0:00:42 > 0:00:46driven our attempts to understand it?
0:00:46 > 0:00:49How did we learn to predict it?
0:00:49 > 0:00:52And protect ourselves from it?
0:00:52 > 0:00:55Rain has been a spur to scientific breakthroughs
0:00:55 > 0:00:57and revolutionary inventions.
0:00:57 > 0:01:01We once hoped these would allow us to master it.
0:01:01 > 0:01:06Now science tells us our rain is likely to become wilder
0:01:06 > 0:01:08and less predictable.
0:01:08 > 0:01:12How will that affect this very British obsession?
0:01:12 > 0:01:14We're going to have to reckon with the fact
0:01:14 > 0:01:19that rain is back as a threat to us
0:01:19 > 0:01:24in a way that the Victorians and the scientists of the 20th century
0:01:24 > 0:01:27thought they might eliminate.
0:01:37 > 0:01:40FEET STAMP IN PUDDLES
0:01:40 > 0:01:43BAND PLAYS A JAZZ TUNE
0:01:45 > 0:01:49If there's one thing the British know about it's rain.
0:01:49 > 0:01:51But there's a paradox.
0:01:51 > 0:01:55It's an essential ingredient for what we love about Britain.
0:01:55 > 0:01:59Yet we love to complain about it. That's what makes us British.
0:02:02 > 0:02:05We want it to be out of the picture
0:02:05 > 0:02:10and rain comes along and spoils that party. We're not happy.
0:02:10 > 0:02:13We're anxious, we're fretful, we're cross.
0:02:16 > 0:02:20Trying to plan our lives around rain is an exasperating business.
0:02:20 > 0:02:24It has a tendency to disrupt our national life.
0:02:25 > 0:02:30We sort of quite irrationally think it should always happen at night,
0:02:30 > 0:02:32or it should happen some other time,
0:02:32 > 0:02:37and when it happens during Wimbledon it seems unreasonable - unfair.
0:02:37 > 0:02:40SPECTATORS GROAN AND MUTTER
0:02:40 > 0:02:43# Into each life
0:02:43 > 0:02:46# Some rain must fall
0:02:46 > 0:02:52# But too much is falling in mine... #
0:02:52 > 0:02:57All our efforts to calculate around it are in vain and we know that.
0:02:57 > 0:03:01It's regarded as devious and tricksy.
0:03:01 > 0:03:05# ..Some day the sun will shine... #
0:03:07 > 0:03:11I think about the rain probably seven or eight times a day.
0:03:11 > 0:03:15For instance, this year's final. I only watched a couple of minutes.
0:03:15 > 0:03:19Most of the time I was looking at the clouds.
0:03:19 > 0:03:24When it rains, it's the referee's responsibility to stop play.
0:03:24 > 0:03:27Most of the time it's a very easy decision
0:03:27 > 0:03:29because if it's hard, that's it.
0:03:29 > 0:03:31Suspend play.
0:03:31 > 0:03:35We've stopped matches on match point before now.
0:03:35 > 0:03:38The criteria being when it gets dangerous for the players.
0:03:38 > 0:03:42If it comes on very heavy, then you've got to stop it immediately.
0:03:46 > 0:03:51Eddie Seaward has been head groundsman here for 15 years.
0:03:51 > 0:03:55What he doesn't know about rain in this corner of South London isn't worth knowing.
0:03:55 > 0:03:59And he's noticed that the pattern of rainfall has changed.
0:04:00 > 0:04:05At one time we used to come in and if we got 2mm overnight,
0:04:05 > 0:04:07that was considered a lot of rain.
0:04:07 > 0:04:11Now we get 10-12mm without thinking too much of it overnight.
0:04:11 > 0:04:16I think that's the biggest thing. When it does rain it rains more and there's greater volume.
0:04:18 > 0:04:22Trying to understand rain - its changing patterns, its origins,
0:04:22 > 0:04:25has always fascinated British scientists.
0:04:31 > 0:04:34Clive Saunders has studied rain for over 40 years.
0:04:34 > 0:04:38In his laboratory at the University of Manchester,
0:04:38 > 0:04:42he injects water into an air stream to simulate a rain drop as it falls to earth.
0:04:42 > 0:04:45It's taking the natural shape
0:04:45 > 0:04:49that it would have if it was a rain drop falling inside a cloud.
0:04:49 > 0:04:53And you can see that it has a flat base,
0:04:53 > 0:04:55is oval in shape,
0:04:55 > 0:04:58and it certainly doesn't have the teardrop shape
0:04:58 > 0:05:02that is sometimes drawn in cartoons.
0:05:07 > 0:05:12I think there's this fallacy that a rain drop is the same shape as a tear drop
0:05:12 > 0:05:14and so it's an interesting metaphor.
0:05:14 > 0:05:18So you can have a thing like - "My tears fell like rain"
0:05:18 > 0:05:19or "rain fell like tears".
0:05:19 > 0:05:23But I think it's much more of a bodily function than that
0:05:23 > 0:05:27because rain makes cold and clammy and wet and that feels miserable.
0:05:28 > 0:05:30The true shape of a rain drop
0:05:30 > 0:05:34was discovered by scientist Philip Lenard in 1898.
0:05:35 > 0:05:38He saw that as rain drops fall they become flat,
0:05:38 > 0:05:42resulting from the tug-of-war between the surface tension of water
0:05:42 > 0:05:44and the air pushing up from below.
0:05:46 > 0:05:49Lenard's experiment also shows how rain drops combine.
0:05:51 > 0:05:54So this would be quite a large rain drop,
0:05:54 > 0:05:57falling at several metres per second in the atmosphere.
0:05:57 > 0:06:01But it can collect other drops as it falls.
0:06:01 > 0:06:04Then two rain drops collide together to make a bigger one.
0:06:04 > 0:06:06So that will fall faster,
0:06:06 > 0:06:10which is how they grow - smaller ones collected by bigger ones.
0:06:10 > 0:06:15These water droplets are between one to two mm in diameter -
0:06:15 > 0:06:17the size of an average rain drop.
0:06:18 > 0:06:21But away from the lab, rain drops can be much larger.
0:06:24 > 0:06:27The largest drops of rain ever recorded
0:06:27 > 0:06:29were nearly one cm in diameter.
0:06:38 > 0:06:42So we know what it looks like but where does rain come from?
0:06:45 > 0:06:47The Greeks were among the first
0:06:47 > 0:06:50to give us a scientific explanation of rain.
0:06:50 > 0:06:53Their investigations into the natural world
0:06:53 > 0:06:56convinced them rain was part of a cycle.
0:06:56 > 0:07:01Water evaporates into the atmosphere and falls back to earth as rain.
0:07:04 > 0:07:06The Greeks were remarkable
0:07:06 > 0:07:09because they were the first to think of the natural world
0:07:09 > 0:07:11as having an integrity of its own -
0:07:11 > 0:07:15not necessarily just gods and goddesses doing their tricks.
0:07:15 > 0:07:17That was present in the Greek world as well
0:07:17 > 0:07:21but on the other hand you start to find people like Aristotle
0:07:21 > 0:07:25with the idea that the natural world has its own physical integrity.
0:07:25 > 0:07:29The realisation that in the heat of the summer water goes up
0:07:29 > 0:07:33and it comes down and you have the basis of the hydrological cycle.
0:07:36 > 0:07:38Aristotle doubted that rain alone
0:07:38 > 0:07:41could account for all the water on earth.
0:07:43 > 0:07:49He believed that our rivers and lakes must be fed by a series of vast underground seas.
0:07:50 > 0:07:56It wasn't until the 17th Century that a new theory challenged this idea.
0:08:00 > 0:08:04European scientists argued that evaporation and rain was sufficient
0:08:04 > 0:08:06to supply all our rivers and lakes.
0:08:08 > 0:08:13It took a young British genius to prove it.
0:08:13 > 0:08:16In 1687, Edmond Halley, of comet fame,
0:08:16 > 0:08:18devised a simple experiment
0:08:18 > 0:08:21that transformed our understanding of rainfall.
0:08:21 > 0:08:25Halley is an IMMENSELY significant thinker
0:08:25 > 0:08:27in the history of the study of rain.
0:08:28 > 0:08:30Now, what he does is this.
0:08:30 > 0:08:35He says, "I took a brass pan of eight inches in diameter
0:08:35 > 0:08:37"and four inches deep
0:08:37 > 0:08:42"and filled it perfectly brimful on a normally warm summer's day
0:08:42 > 0:08:44"and weighed it.
0:08:44 > 0:08:49"Two hours later I re-weighed it and I noticed how much had gone."
0:08:52 > 0:08:54Using this rate of evaporation as a measurement,
0:08:54 > 0:08:59he calculated how much evaporates from one degree of the ocean -
0:08:59 > 0:09:02an approximate area of 69 square miles -
0:09:02 > 0:09:06during the course of just one day.
0:09:06 > 0:09:09And then he gets a STAGGERING figure.
0:09:09 > 0:09:11In every single day -
0:09:11 > 0:09:17in the temperate latitudes of the globe, let alone the tropics -
0:09:17 > 0:09:20every single degree is yielding
0:09:20 > 0:09:2333 million tons of water into the air.
0:09:26 > 0:09:31Halley's astonishing calculation showed millions of tons of water
0:09:31 > 0:09:36move in a constant daily cycle of evaporation and rain
0:09:36 > 0:09:39in what we now call the hydrological cycle.
0:09:39 > 0:09:42The total amount of the Earth's water does not change
0:09:42 > 0:09:47but the distribution of rain varies enormously across the planet.
0:09:47 > 0:09:52It's a distribution that can play havoc with our most treasured cultural traditions.
0:09:56 > 0:10:01Nothing captures the essence of the British summer more than cricket.
0:10:01 > 0:10:06But cricket suffers more from the impact of rain than any other sport.
0:10:07 > 0:10:09It's a typically British game.
0:10:09 > 0:10:11It's a fantastic game -
0:10:11 > 0:10:15influenced by the weather sometimes in a negative way by stopping play.
0:10:15 > 0:10:18TV COMMENTATOR: Ground staff have got to be quick here.
0:10:18 > 0:10:20It's absolutely hammering down.
0:10:20 > 0:10:24Just look at this! Who'd be a groundsman?
0:10:24 > 0:10:29A dreadful day for everybody concerned. It's bucketing down.
0:10:29 > 0:10:33Cricket is played during this wonderful thing called the English summer.
0:10:33 > 0:10:37Unfortunately, we've had a record-breaking spell of rain
0:10:37 > 0:10:40here in South Wales in the last week.
0:10:40 > 0:10:43The average rainfall in September in Cardiff
0:10:43 > 0:10:45is somewhere in the region of 10cm.
0:10:45 > 0:10:49We've, in the last week, already had 12. Very, very unusual.
0:10:49 > 0:10:54The ground has literally become saturated just by the sheer volume.
0:10:54 > 0:10:57It's always a very colourful scene when rain drops
0:10:57 > 0:10:59but it's not the scene everybody wants.
0:10:59 > 0:11:01We are optimistic.
0:11:01 > 0:11:07The forecast here for the rest of the day and for tomorrow is for reasonable weather,
0:11:07 > 0:11:09so we should have some play later.
0:11:09 > 0:11:16# ..It's a lovely day tomorrow
0:11:16 > 0:11:18# Tomorrow is a lovely... #
0:11:18 > 0:11:19But this optimism was confounded.
0:11:19 > 0:11:23For the first time ever at this ground,
0:11:23 > 0:11:27not a single stroke was played over the course of a four-day match.
0:11:27 > 0:11:30# ..Just forget your troubles
0:11:30 > 0:11:33# And learn to say
0:11:33 > 0:11:37# Tomorrow is a lovely day... #
0:11:41 > 0:11:45In Britain, rain can do far more than disrupt our sport.
0:11:45 > 0:11:48It can threaten lives and destroy homes.
0:11:48 > 0:11:51In the summer of 2004,
0:11:51 > 0:11:56an entire village - Boscastle in Cornwall - was devastated by rain.
0:11:56 > 0:12:00Any flood which happens in the West Country during the summer
0:12:00 > 0:12:05is a collusion of meteorology and geography.
0:12:05 > 0:12:08You need the heavy rainfall first of all
0:12:08 > 0:12:12but because the river catchments are, generally speaking, very small
0:12:12 > 0:12:16they respond very quickly to rain which falls on them.
0:12:16 > 0:12:20If the cloudburst happens exactly over that catchment,
0:12:20 > 0:12:23then all the water will find its down the river
0:12:23 > 0:12:25and out to sea in a matter of hours.
0:12:29 > 0:12:33Monday 16th August 2004.
0:12:33 > 0:12:37Visitors in Boscastle are enjoying the morning sun.
0:12:41 > 0:12:45At midday, just a few miles away in the hills above the village,
0:12:45 > 0:12:48heavy rain begins to fall.
0:12:48 > 0:12:52At the end of the main street is a 14th-century building.
0:12:52 > 0:12:57Now a shop, it's one of the most popular attractions in the village.
0:12:57 > 0:13:01The owner is Trixie Webster.
0:13:01 > 0:13:05The day started off quite warm and sunny
0:13:05 > 0:13:09but round about midday we had this sort of ominous black cloud
0:13:09 > 0:13:11and it started raining.
0:13:13 > 0:13:17The first showers took visitors by surprise.
0:13:17 > 0:13:19THUNDER RUMBLES
0:13:19 > 0:13:24But much heavier rain was falling on the slopes above the village.
0:13:24 > 0:13:27This water was being rapidly funnelled down the narrow valley...
0:13:30 > 0:13:33..and heading straight towards Boscastle.
0:13:35 > 0:13:37Just before three o'clock in the afternoon,
0:13:37 > 0:13:39it came up to the top of the old bridge
0:13:39 > 0:13:43and I realised then we were going to have a flood.
0:13:47 > 0:13:51A huge torrent surges through the centre of Boscastle.
0:13:53 > 0:13:58Many don't realise their lives are at risk from the fast-flowing water.
0:14:01 > 0:14:06But soon people call the emergency services for help.
0:14:06 > 0:14:10RADIO: 'We do need assistance urgently. We need police certainly.
0:14:10 > 0:14:13'The roads are all blocked now and it's absolute chaos here.'
0:14:15 > 0:14:18'..reportedly cut off by the cafe.
0:14:18 > 0:14:21'Roger. We'll go and investigate.'
0:14:26 > 0:14:32The surging river is fuelled by one of the most extreme downpours ever experienced in Britain.
0:14:33 > 0:14:37Eight inches of rain falls on the hills in one day.
0:14:37 > 0:14:40Well, we did everything we could.
0:14:40 > 0:14:42We put up storm boards,
0:14:42 > 0:14:46sand bags on all the buildings that we thought might be flooded.
0:14:48 > 0:14:53In Boscastle, 3.5 inches of rain fell in one hour
0:14:53 > 0:14:55and events escalated rapidly.
0:14:55 > 0:14:58The sewage system collapses.
0:14:58 > 0:15:02Hundreds of tons of thick, dark sewage mix with the flood water.
0:15:02 > 0:15:06And the sheer power of the water -
0:15:06 > 0:15:11the volume of it. It was muddy, it was smelling.
0:15:11 > 0:15:14The river burst its banks
0:15:14 > 0:15:18and flood waters threaten Trixie Webster's shop.
0:15:18 > 0:15:22The first thing was the volume of water I saw -
0:15:22 > 0:15:25it just dismissed the sandbags and everything else
0:15:25 > 0:15:26and just broke open the door.
0:15:26 > 0:15:30And we have three windows at the back and it burst through those windows.
0:15:30 > 0:15:35The flood destroyed the contents of Trixie's shop
0:15:35 > 0:15:38and swamped many other buildings in the village.
0:15:39 > 0:15:43The emergency services are now inundated with calls.
0:15:44 > 0:15:49'This is serious flooding, we are talking three foot deep down the main road.'
0:15:49 > 0:15:52'You're through to the police. What's your emergency?'
0:15:52 > 0:15:55'We've got a road flooded and people in danger.
0:15:55 > 0:15:56- 'How many people are trapped? - DIAL TONE
0:15:56 > 0:16:01'There's a flood here. A really bad flood and people are getting injured.
0:16:01 > 0:16:07- 'We need some emergency services down here.- Whereabouts are you?
0:16:07 > 0:16:11'In the car park.' SCREAMING IN BACKGROUND
0:16:11 > 0:16:15The noise was just colossal.
0:16:15 > 0:16:18You literally couldn't hear yourself shout.
0:16:18 > 0:16:23It turned into a ballistic scene of just utter carnage.
0:16:28 > 0:16:31Water cascades through the centre of Boscastle
0:16:31 > 0:16:34at a rate of 140 tonnes per second.
0:16:37 > 0:16:41A wall of water sweeps cars through the village
0:16:41 > 0:16:44and smashes them into buildings.
0:16:44 > 0:16:47WATER RUSHES
0:16:47 > 0:16:50METAL CRUNCHES AGAINST STONE
0:16:55 > 0:16:57Trixie's shop is battered.
0:16:58 > 0:17:03Every car that came down smashed into it. It didn't stand a chance.
0:17:06 > 0:17:09Trixie Webster's 14th-century shop,
0:17:09 > 0:17:12at the end of the main street, simply disappears.
0:17:12 > 0:17:15HELICOPTER WHIRRS OVERHEAD
0:17:24 > 0:17:26It was only the next day,
0:17:26 > 0:17:28when the waters had subsided
0:17:28 > 0:17:32and we saw the devastation. That was the shock, really.
0:17:32 > 0:17:37The 400-year-old building was gone.
0:17:38 > 0:17:41It was like a bereavement, actually.
0:17:46 > 0:17:48If you look through the records,
0:17:48 > 0:17:53you can find examples of previous floods in Boscastle -
0:17:53 > 0:17:55probably once every 15 or 20 years -
0:17:55 > 0:18:00not to the same extent as the 2004 event but the same pattern.
0:18:00 > 0:18:04The weather can always throw you something worse than before.
0:18:04 > 0:18:06Records are there to be broken.
0:18:09 > 0:18:14The unpredictable nature of rain reveals the British character.
0:18:16 > 0:18:20When it rains too much, we complain bitterly.
0:18:20 > 0:18:23And when the sun comes out, we celebrate.
0:18:23 > 0:18:27# Wow! We're having a heat wave
0:18:27 > 0:18:29# A tropical heat wave... #
0:18:29 > 0:18:32MUSIC: "You Sexy Thing" by Hot Chocolate
0:18:32 > 0:18:34A tropical heat wave in 1976
0:18:34 > 0:18:38became the longest dry spell in over two centuries.
0:18:38 > 0:18:42The British abandoned their normal reserve, soaked up the sun
0:18:42 > 0:18:44and swarmed to the seaside.
0:18:47 > 0:18:49# ..I believe in miracles
0:18:50 > 0:18:53# Where you from?
0:18:53 > 0:18:54# You sexy thing
0:18:54 > 0:18:57# Sexy thing, you... #
0:18:57 > 0:18:59The holiday spirit blossomed
0:18:59 > 0:19:03and a new, uninhibited culture took hold of the nation.
0:19:11 > 0:19:14But the 1976 heat wave soon became a drought
0:19:14 > 0:19:17and we badly missed the rain.
0:19:17 > 0:19:20TV: Save or suffer, it's up to you.
0:19:20 > 0:19:24The country was thrown into turmoil as water was restricted
0:19:24 > 0:19:26and reservoirs ran dry.
0:19:29 > 0:19:32A similar drought 100 years earlier, in the 1850s,
0:19:32 > 0:19:35lasted for several years.
0:19:35 > 0:19:39The Victorians worried that there wouldn't be enough water
0:19:39 > 0:19:41to supply their industrial revolution
0:19:41 > 0:19:44and the rapid growth of towns and cities.
0:19:44 > 0:19:47But this drought led to a great step forward in meteorology
0:19:47 > 0:19:51and our understanding of British rainfall.
0:19:51 > 0:19:55In the late 1850s, there was a crisis of drought
0:19:55 > 0:19:59and, as it happened, in the late 1850s,
0:19:59 > 0:20:02there was a young man with a fascination for the weather -
0:20:02 > 0:20:06a young Londoner, George James Symons.
0:20:06 > 0:20:10He saw that all the talk about this crisis of drought lacked something,
0:20:10 > 0:20:12there was something missing,
0:20:12 > 0:20:14and it was a scientific basis for discussion.
0:20:14 > 0:20:17Everybody knew there wasn't enough rain
0:20:17 > 0:20:20but nobody knew how much less rain there had been than before.
0:20:20 > 0:20:23Nobody knew how the patterns across the country worked.
0:20:23 > 0:20:26Nobody knew the longer-term picture.
0:20:26 > 0:20:29How often does a drought like this happen?
0:20:29 > 0:20:34And he set himself the task of answering those questions
0:20:34 > 0:20:37and it's a great threshold in the history of meteorology.
0:20:37 > 0:20:41Here was somebody who said,
0:20:41 > 0:20:45"Look, let's not rely on the sayings of shepherds
0:20:45 > 0:20:48"to inform our understanding of rain, let's measure it."
0:20:50 > 0:20:55The drought of the 1850s ended with a welcome return of the rain.
0:20:55 > 0:20:58George Symons began to take rainfall measurements.
0:20:58 > 0:21:01These are some of his early handwritten records.
0:21:03 > 0:21:06He understood that only with accurate data,
0:21:06 > 0:21:09collected from all over the country and over many years,
0:21:09 > 0:21:13would it possible to discover a pattern to British rainfall.
0:21:13 > 0:21:15It was a giant undertaking
0:21:15 > 0:21:18that consumed Symons for the rest of his life.
0:21:20 > 0:21:24He took out advertisements in local newspapers saying,
0:21:24 > 0:21:28"Would anybody care to measure rain?"
0:21:28 > 0:21:30And there was a craze.
0:21:32 > 0:21:36The response to Symons's advertisement was staggering.
0:21:36 > 0:21:38From prisoners to admirals of the fleet,
0:21:38 > 0:21:41people signed up in their scores to become rain collectors.
0:21:45 > 0:21:48Symons asked them to send in their rainfall measurements
0:21:48 > 0:21:51and he standardised the way rain should be collected,
0:21:51 > 0:21:54so everyone could use the same type of rain gauge.
0:21:56 > 0:21:59This museum piece is a traditional rain gauge.
0:21:59 > 0:22:01It's the same sort of instrument
0:22:01 > 0:22:04that Symons would have used 150 years ago.
0:22:04 > 0:22:06It works very, very simply.
0:22:06 > 0:22:10The rain falls into the funnel, which is exactly five inches across.
0:22:10 > 0:22:14The water finds its way down through the tube
0:22:14 > 0:22:16and into a collecting bottle
0:22:16 > 0:22:20and there we see the rain which fell last night, which we can measure.
0:22:25 > 0:22:31And it tells us that the rainfall last night was exactly 6.2mm.
0:22:39 > 0:22:42Rainfall collectors throughout the country
0:22:42 > 0:22:46sent their readings back to George Symons.
0:22:46 > 0:22:50He was a bit of an anorak, really. He liked playing with numbers.
0:22:50 > 0:22:54Symons painstakingly transcribed the numbers
0:22:54 > 0:22:56and produced annual statistics.
0:22:58 > 0:23:02And such was the demand for regular updates from the British public
0:23:02 > 0:23:06that from 1866 he issued monthly rainfall reports
0:23:06 > 0:23:10in Symons's Monthly Meteorological Magazine.
0:23:11 > 0:23:13I think when you hear that phrase,
0:23:13 > 0:23:16"since records began", when people talk about the rain,
0:23:16 > 0:23:19everybody should think then about George James Symons
0:23:19 > 0:23:24because he was when records began. He started it.
0:23:24 > 0:23:28Until he came along there was a sense that this was just so big,
0:23:28 > 0:23:30it was un-measurable,
0:23:30 > 0:23:33nobody could imagine how you would nail down
0:23:33 > 0:23:37enough information about rainfall for it to be useful.
0:23:37 > 0:23:43Here was somebody who was prepared to think big and be ambitious
0:23:43 > 0:23:45and, you know, he's a marvel.
0:23:48 > 0:23:54Symons died in 1900 after 40 years of studying British rainfall.
0:23:56 > 0:24:00His data sets give us the oldest rainfall records in the world.
0:24:00 > 0:24:03And he never received a penny of public money.
0:24:06 > 0:24:09He was buried in Kensal Green cemetery
0:24:09 > 0:24:12amongst the great and good of London society.
0:24:12 > 0:24:16The Times reported on the large crowd of distinguished scientists
0:24:16 > 0:24:18who gathered here to send him off.
0:24:21 > 0:24:25Well, this is the grave of George James Symons -
0:24:25 > 0:24:29the great pioneer of the study of British rainfall.
0:24:29 > 0:24:32There isn't a headstone. There's a stone there
0:24:32 > 0:24:36but there seems to be nothing on it. There's no record here.
0:24:36 > 0:24:40Nothing to help us remember this man
0:24:40 > 0:24:43who told us more than anyone about the rainfall in Britain.
0:24:43 > 0:24:48If we really were obsessed with the weather, as the legend has it,
0:24:48 > 0:24:49surely he'd be a hero
0:24:49 > 0:24:53and surely he wouldn't be there in an unmarked grave like some pauper,
0:24:53 > 0:24:55a forgotten pauper.
0:24:55 > 0:25:00I suppose he would be consoled with the idea
0:25:00 > 0:25:03that he's left us his fantastic data sets
0:25:03 > 0:25:05and he has left us the ability to say,
0:25:05 > 0:25:09"The wettest July since records began".
0:25:09 > 0:25:14There's the man who made those words possible.
0:25:14 > 0:25:17I'd just like to think it was possible to come
0:25:17 > 0:25:20and remember him in some way.
0:25:20 > 0:25:25That a passer-by might have a chance to say, "Oh, see what he did!"
0:25:36 > 0:25:39Over time, Symons's collection of measurements
0:25:39 > 0:25:42revealed the pattern of British rainfall.
0:25:42 > 0:25:45It showed a Britain divided in two.
0:25:45 > 0:25:49Most of our rain falls in the north and west of the country,
0:25:49 > 0:25:52leaving the south and east relatively dry.
0:25:52 > 0:25:56And he discovered one of the most stunning areas of Britain
0:25:56 > 0:25:58is also the wettest.
0:26:05 > 0:26:07The Lake District.
0:26:07 > 0:26:12This lush, green landscape draws thousands of tourists each year
0:26:12 > 0:26:16and it largely owes its beauty to the rain.
0:26:19 > 0:26:22Green grass, rivers and lakes.
0:26:22 > 0:26:25All a result of regular rainfall.
0:26:26 > 0:26:31No surprise then that Seathwaite, in the valley of Borrowdale,
0:26:31 > 0:26:34is arguably the wettest inhabited spot in Britain.
0:26:37 > 0:26:39Showered by rain all year round,
0:26:39 > 0:26:43Seathwaite has an average yearly rain fall of 120 inches.
0:26:43 > 0:26:45# The sun is out
0:26:45 > 0:26:48# The sky is blue
0:26:48 > 0:26:52# There's not a cloud to spoil the view... #
0:26:52 > 0:26:56Mark Weir has lived in the area all his life.
0:26:56 > 0:26:58# ..Raining in my heart... #
0:26:58 > 0:27:01I've witnessed this weather for 42 years.
0:27:01 > 0:27:02When you've been born here
0:27:02 > 0:27:06and you understand the weather patterns, you get on with it.
0:27:06 > 0:27:09I'm incredibly happy when I leave Borrowdale
0:27:09 > 0:27:12because there's always sunshine everywhere else.
0:27:12 > 0:27:15You really witness this a lot of the time,
0:27:15 > 0:27:19which is water, water, water.
0:27:19 > 0:27:23I would like a little bit of sun, please!
0:27:23 > 0:27:27# ..The weather man says clear today... #
0:27:27 > 0:27:31At the top of a hill pass in the Borrowdale valley
0:27:31 > 0:27:33is Mark Weir's slate mine -
0:27:33 > 0:27:37one of the few underground slate mines still working in Britain.
0:27:37 > 0:27:41A conscious decision when I bought this 12 years ago
0:27:41 > 0:27:44was do I want to work outside and be rained off most of the time,
0:27:44 > 0:27:46or do I want to go underground?
0:27:46 > 0:27:49I think the origin of mining began here
0:27:49 > 0:27:53because underground everybody can continue to work
0:27:53 > 0:27:56regardless of the weather on the surface.
0:27:56 > 0:28:02The Lake District has something to offer even in the wet. You know?
0:28:02 > 0:28:06It is quite beautiful being at one, on the mountains,
0:28:06 > 0:28:08in the driving rain.
0:28:08 > 0:28:10It seems to be getting more tropical now,
0:28:10 > 0:28:14more heavier rain than we used to have.
0:28:14 > 0:28:18And we seem to have more tourists visiting here when it's wet.
0:28:18 > 0:28:21They're treating the mine as a wet-weather experience,
0:28:21 > 0:28:25which is good for my business because it continues to grow.
0:28:25 > 0:28:30So if global warming is a situation where we have more rain,
0:28:30 > 0:28:32that's good for my business.
0:28:32 > 0:28:35So you really need to get your shares in now!
0:28:37 > 0:28:41# ..Oh, misery
0:28:41 > 0:28:44# Misery
0:28:46 > 0:28:53# What's gonna become of me...? #
0:28:58 > 0:29:01So why does the Lake District get more rain
0:29:01 > 0:29:03than other parts of Britain?
0:29:05 > 0:29:09When winds full of moisture from the Atlantic hit the Lake District,
0:29:09 > 0:29:12hills force the air upwards.
0:29:12 > 0:29:14When air rises it cools
0:29:14 > 0:29:18and the moisture condenses into water droplets to form clouds.
0:29:18 > 0:29:24If these water droplets are large enough, they will fall as rain.
0:29:26 > 0:29:29It's the western side of the British Isles that gets this
0:29:29 > 0:29:32and that's because it's where the air that has come from the Atlantic -
0:29:32 > 0:29:37it's blown over all that ocean, it's picked up lots of water -
0:29:37 > 0:29:41and this is the first land it's reached for thousands of miles.
0:29:41 > 0:29:46So it says, "Thank you, I can release my water over the Lake District."
0:29:47 > 0:29:51Clouds are much more complicated than people think.
0:29:51 > 0:29:54They are a manifestation, if you like,
0:29:54 > 0:29:56of the moisture in the atmosphere.
0:29:56 > 0:29:58Most clouds actually don't produce rain.
0:29:58 > 0:30:01They're fair weather clouds and they just stick around
0:30:01 > 0:30:04and block the sun out and don't do anything else.
0:30:04 > 0:30:08But certain sorts of clouds, especially the thicker ones,
0:30:08 > 0:30:11and especially if there is upward motion in them -
0:30:11 > 0:30:14in other words the air is rising in the cloud system -
0:30:14 > 0:30:16they will produce rain.
0:30:16 > 0:30:18It is our understanding of which clouds
0:30:18 > 0:30:21are likely to produce rain and which are not
0:30:21 > 0:30:26that marks our ability to forecast the weather accurately.
0:30:26 > 0:30:30It was in 1803 that clouds were first classified
0:30:30 > 0:30:33into the different types that we know today,
0:30:33 > 0:30:35by Englishman Luke Howard.
0:30:35 > 0:30:39Luke Howard was a London Quaker and businessman
0:30:39 > 0:30:42who had two business premises in different parts of London
0:30:42 > 0:30:44and walked between the two.
0:30:44 > 0:30:48As he walked, he looked up into the sky and he saw clouds
0:30:48 > 0:30:51and he started to think about clouds.
0:30:51 > 0:30:55And he began to see, well, I could sort these.
0:30:55 > 0:30:58That's a fluffy one that seems to go up very high.
0:31:01 > 0:31:03That's a sort of flat grey one...
0:31:03 > 0:31:07and that one's a sort of streaky thin looking one
0:31:07 > 0:31:08that I can almost see through.
0:31:11 > 0:31:15So, if I give these names and then work out what's between those,
0:31:15 > 0:31:17what other kinds are there?
0:31:17 > 0:31:20And he started to classify the clouds
0:31:20 > 0:31:24and he gave them Latin names.
0:31:24 > 0:31:28Puffy white cumulus that look like cotton wool.
0:31:30 > 0:31:35Stratus that form in layers and cover the sky in a blanket of cloud.
0:31:35 > 0:31:40Cirrus and altocumulus that form high in the sky.
0:31:42 > 0:31:46And the ominous cumulonimbus - dark grey clouds
0:31:46 > 0:31:51that can stretch all the way to the ground, bringing rain.
0:31:51 > 0:31:53It's such a simple idea and yet it is,
0:31:53 > 0:31:56as he put it, the key of analysis.
0:31:56 > 0:32:01Up to that point, the knowledge that was accumulated about clouds,
0:32:01 > 0:32:06by individuals, was lost because it was not possible to exchange it.
0:32:06 > 0:32:08Here he had given the clouds types
0:32:08 > 0:32:12which could be standardised throughout the world and were.
0:32:12 > 0:32:14The understanding of clouds and their behaviour,
0:32:14 > 0:32:16their likelihood of bringing rain,
0:32:16 > 0:32:19all that is suddenly much more clear.
0:32:21 > 0:32:25The 19th century advanced our understanding of the water cycle
0:32:25 > 0:32:28but a great challenge remained.
0:32:28 > 0:32:32What happened to water vapour as it rose into the atmosphere?
0:32:32 > 0:32:38It was a challenge embraced by James Glaisher, one of the leading scientists of the day.
0:32:40 > 0:32:42The atmosphere was uncharted territory
0:32:42 > 0:32:46and the only way for Glaisher to get there was in a balloon.
0:32:46 > 0:32:50Balloons were well established by the 1860s, when he's doing his work.
0:32:50 > 0:32:56And the first place you go for a balloon ascent is the entertainments industry
0:32:56 > 0:33:00because balloons in the Victorian period were not used scientifically,
0:33:00 > 0:33:04they were used for spectacular thrills and spills.
0:33:04 > 0:33:07Glaisher realised that balloons could be used
0:33:07 > 0:33:10for scientific experiments
0:33:10 > 0:33:14and he approached a celebrity aeronaut of the day, Henry Coxwell.
0:33:14 > 0:33:18In 1862, they planned a series of balloon flights
0:33:18 > 0:33:21to study the moisture content of the air.
0:33:21 > 0:33:25The classic was the ascent he makes on the 5th September
0:33:25 > 0:33:28from Wolverhampton Gas Works.
0:33:31 > 0:33:35Glaisher gathers together scientific instruments,
0:33:35 > 0:33:37fills the balloon basket and lifts off.
0:33:40 > 0:33:42And what he was after was this.
0:33:42 > 0:33:44At what altitudes will the air carry
0:33:44 > 0:33:47what particular quantities of moisture?
0:33:47 > 0:33:52This he realises is crucial for rain and for evaporation.
0:33:52 > 0:33:54He takes up these 17 instruments
0:33:54 > 0:33:59and is monitoring them literally second by second.
0:34:01 > 0:34:06They rose into the cloud, passed through the cloud.
0:34:06 > 0:34:12And then Glaisher tells us they broke through onto a plateau of cloud.
0:34:13 > 0:34:17And you could see this brilliant white cloud below you.
0:34:17 > 0:34:21Glaisher took regular readings of temperature and humidity
0:34:21 > 0:34:23but there was danger ahead.
0:34:23 > 0:34:27At 29,000 feet, their lives were in peril.
0:34:27 > 0:34:31Now, that is nearly five miles.
0:34:31 > 0:34:35Up at that altitude, he seems to have lost his senses.
0:34:38 > 0:34:42This was the highest manned balloon flight ever attempted.
0:34:42 > 0:34:46And at this height, there was not enough oxygen to breathe.
0:34:47 > 0:34:52Glaisher's hands went numb and he soon passed out.
0:34:52 > 0:34:55The adventure seemed sure to end in death for James Glaisher
0:34:55 > 0:34:57and his pilot, Henry Coxwell.
0:35:00 > 0:35:05Coxwell had got so cold and so paralysed,
0:35:05 > 0:35:09he claims his hands had not only completely failed to function,
0:35:09 > 0:35:11they'd gone black from lack of oxygen.
0:35:11 > 0:35:15They would almost certainly have been doomed to die.
0:35:15 > 0:35:17The balloon would have ascended and ascended
0:35:17 > 0:35:20until the gas pressure became so great it just burst
0:35:20 > 0:35:22and down you would have come!
0:35:23 > 0:35:29Coxwell claims he held the ripcord of the balloon with his teeth,
0:35:29 > 0:35:31pulled it three times,
0:35:31 > 0:35:35until he felt there was sufficient fall coming down.
0:35:35 > 0:35:38Then he let more gas out
0:35:38 > 0:35:41and slowly the great balloon starts to come down.
0:35:41 > 0:35:44It was a narrow escape.
0:35:45 > 0:35:47Undeterred by his brush with death,
0:35:47 > 0:35:51Glaisher resumed his experiments and observations.
0:35:51 > 0:35:53These are determined scientists
0:35:53 > 0:35:57and once he starts getting his senses back,
0:35:57 > 0:36:00Glaisher then starts to re-monitor the instruments
0:36:00 > 0:36:02as soon as he's regained consciousness.
0:36:02 > 0:36:05That whole flight took about two-and-a-half hours.
0:36:05 > 0:36:08Glaisher thought they'd got to 37,000 feet...
0:36:08 > 0:36:11seven miles!
0:36:11 > 0:36:16This was a prodigious feat and scientifically significant.
0:36:16 > 0:36:19Glaisher found that the higher he went,
0:36:19 > 0:36:21the less moisture there was in the atmosphere.
0:36:21 > 0:36:23This discovery alone
0:36:23 > 0:36:27advanced our understanding of how and where clouds form.
0:36:27 > 0:36:30These Victorians were astonishing figures.
0:36:30 > 0:36:32On the 5th September 1862,
0:36:32 > 0:36:36one of the greatest Victorian journeys of exploration took place,
0:36:36 > 0:36:40and Glaisher and Coxwell rose seven miles
0:36:40 > 0:36:43to study the moisture content of the air.
0:36:45 > 0:36:50Victorian scientists not only advanced our understanding of rain,
0:36:50 > 0:36:53they invented ways to protect us from its ill effects -
0:36:53 > 0:36:57inventions that would transform British life forever.
0:37:03 > 0:37:05People were afraid of the rain, in an odd way.
0:37:05 > 0:37:10There was an absolute conviction that getting wet you would,
0:37:10 > 0:37:13to use the phrase, catch your death.
0:37:15 > 0:37:19Posh ladies didn't go out and get wet, unless,
0:37:19 > 0:37:20as in Sense and Sensibility,
0:37:20 > 0:37:23they were in terrible emotional turmoil.
0:37:31 > 0:37:35- She's gone out walking. - The devil knows which way she went.
0:37:35 > 0:37:37THUNDER RUMBLES
0:37:37 > 0:37:41The first waterproof fabric in this country is eternally associated
0:37:41 > 0:37:44with Macintosh, a Scottish inventor,
0:37:44 > 0:37:47a Scottish chemist who found a way of sandwiching rubber
0:37:47 > 0:37:49between two sheets of cloth
0:37:49 > 0:37:52and was therefore able to make waterproof clothing,
0:37:52 > 0:37:54which was a revelation.
0:37:54 > 0:37:57People didn't have to get soaked and stay soaked.
0:37:57 > 0:37:59You could go for a ride in the country.
0:37:59 > 0:38:02You could ride through a shower, arrive at your destination,
0:38:02 > 0:38:04take your coat off and you were dry.
0:38:04 > 0:38:08This was a novelty at the beginning of the 19th century
0:38:08 > 0:38:12and through the 19th century these materials developed enormously,
0:38:12 > 0:38:14right up to the present day.
0:38:18 > 0:38:21Macintosh's amazing invention
0:38:21 > 0:38:25led to a booming industry for rainwear.
0:38:25 > 0:38:26Let it rain, let it blow.
0:38:26 > 0:38:30When you outdoor-type dolls doll up in Aquatogs,
0:38:30 > 0:38:33you are snugly stylish and stylishly snug.
0:38:33 > 0:38:37With waterproof clothing, people no longer needed to fear the rain,
0:38:37 > 0:38:39they could celebrate it in style.
0:38:39 > 0:38:41# Pitter patter patter
0:38:41 > 0:38:44# Pitter patter patter It feels like rain
0:38:44 > 0:38:47# Let it pitter patter Let it pitter patter
0:38:47 > 0:38:49# Don't mind the rain... #
0:38:49 > 0:38:52Around this time there was an invention
0:38:52 > 0:38:55that had even more impact on daily life in Britain
0:38:55 > 0:38:57and indeed around the world.
0:38:57 > 0:39:01It came from another Scottish pioneer, John McAdam.
0:39:02 > 0:39:05By the late 18th century,
0:39:05 > 0:39:09British roads were in a state not much different than,
0:39:09 > 0:39:14or perhaps notably worse than, when the Romans left.
0:39:14 > 0:39:15So that journeys,
0:39:15 > 0:39:19you would have to budget twice as long in winter
0:39:19 > 0:39:24to make any journey than you would in summer because of the rain.
0:39:24 > 0:39:27The roads would simply decay into swamps.
0:39:27 > 0:39:32At the end of the 18th century, McAdam, a Scottish businessman,
0:39:32 > 0:39:36had the leisure to experiment with a thing that fascinated him -
0:39:36 > 0:39:37how do you make a good road surface?
0:39:37 > 0:39:42And laid a road, which was a huge success.
0:39:42 > 0:39:45It was built on very simple principles.
0:39:45 > 0:39:46You banked up the road
0:39:46 > 0:39:50and then you created a surface of tiny chips of stone,
0:39:50 > 0:39:54which would, with the action of the carriages passing over it,
0:39:54 > 0:39:57be broken down into a very fine hard surface,
0:39:57 > 0:40:01which in fact was relatively waterproof and that's rainproof.
0:40:01 > 0:40:03That's the key here.
0:40:06 > 0:40:09McAdam's roads were so successful
0:40:09 > 0:40:12that we still use the same principles today.
0:40:12 > 0:40:17Small chips are pressed together to form a rainproof layer.
0:40:20 > 0:40:24These days we use bitumen and tar to increase waterproofing.
0:40:24 > 0:40:29McAdam's road designs were one of the great accelerators of the economy.
0:40:29 > 0:40:32They transformed life in the 19th century.
0:40:34 > 0:40:38You were no longer trapped, as it were, behind a barrier of mud.
0:40:38 > 0:40:42And that may sound like an exaggeration
0:40:42 > 0:40:46but it's easy to find letters from the 18th century of people saying,
0:40:46 > 0:40:49"Well, I'd love to come and visit you
0:40:49 > 0:40:53"but the two miles from here to there are so muddy
0:40:53 > 0:40:54"I couldn't possibly do it."
0:40:54 > 0:40:58This is a way of beating the rain
0:40:58 > 0:41:00and by laying a good road surface,
0:41:00 > 0:41:03you're pushing the rain to one side,
0:41:03 > 0:41:06you're eliminating it as a factor in your road
0:41:06 > 0:41:08and that was a great leap.
0:41:08 > 0:41:11He patented it and the world ignored it.
0:41:11 > 0:41:13It was just too damn good.
0:41:13 > 0:41:15It was copied everywhere.
0:41:15 > 0:41:17If he'd got a penny, as it were,
0:41:17 > 0:41:20for every yard of road he was responsible for,
0:41:20 > 0:41:23he would have been the Bill Gates of his time.
0:41:25 > 0:41:28We may not give it a second thought
0:41:28 > 0:41:31but in Britain many of our great inventions
0:41:31 > 0:41:34have been ways to protect ourselves from the rain.
0:41:34 > 0:41:37Rain is certainly the mother of invention in Britain.
0:41:37 > 0:41:41It's one of the big drivers for change.
0:41:41 > 0:41:43People wanted to get out of the rain.
0:41:43 > 0:41:47We have a huge variety of inventions -
0:41:47 > 0:41:51from the car, which incidentally keeps us out of the rain,
0:41:51 > 0:41:54the covered railway carriage keeps us out of the rain.
0:41:54 > 0:41:56They're partly to keep water out.
0:41:56 > 0:42:00It's a very big driver for modernity.
0:42:01 > 0:42:05While we need protection from the worst rain can throw at us,
0:42:05 > 0:42:10scientists today continue to research the mysterious process
0:42:10 > 0:42:11that produces rain drops in clouds.
0:42:11 > 0:42:14In the late 19th century,
0:42:14 > 0:42:17scientists made a crucial breakthrough.
0:42:17 > 0:42:20They realised that a key ingredient
0:42:20 > 0:42:24essential for the production of rain drops is dust.
0:42:24 > 0:42:26In warm climates,
0:42:26 > 0:42:30water droplets condense around specks of dust in the atmosphere.
0:42:30 > 0:42:35These are the seeds around which rain drops grow.
0:42:35 > 0:42:39As water droplets collide with each other, they grow in size
0:42:39 > 0:42:43until eventually they are heavy enough to fall as rain drops.
0:42:48 > 0:42:52In the tropics, this is how rain usually forms and grows.
0:42:55 > 0:42:58But in cooler climates, like ours in Britain,
0:42:58 > 0:43:00rain forms in a very different way.
0:43:02 > 0:43:04Dust particles are still the seed
0:43:04 > 0:43:08but rain drops start their life as tiny ice crystals.
0:43:10 > 0:43:13It's known as the cold rain process.
0:43:15 > 0:43:17At Manchester University,
0:43:17 > 0:43:21Clive Saunders conducts research into this cold rain process.
0:43:21 > 0:43:23He uses a 40 foot chamber
0:43:23 > 0:43:27to recreate conditions in a typical British rain cloud.
0:43:27 > 0:43:30First, he fills the chamber with steam.
0:43:30 > 0:43:34So this is the cloud generator
0:43:34 > 0:43:41and we're going to use it to fill our chamber with cloud droplets,
0:43:41 > 0:43:45which will take several minutes to fill up the chamber.
0:43:45 > 0:43:48Then it will be simulating the inside of a cloud,
0:43:48 > 0:43:51which is really rather like being in a fog.
0:43:56 > 0:44:00Three floors up, Clive seals the top of the cloud chamber.
0:44:01 > 0:44:05The temperature inside is now reduced to -15 degrees Centigrade
0:44:05 > 0:44:09to simulate conditions inside a cloud.
0:44:10 > 0:44:12Within the chamber are dust particles,
0:44:12 > 0:44:15just as there would be in the atmosphere.
0:44:15 > 0:44:20But because the temperature of the water vapour inside the chamber
0:44:20 > 0:44:25is below freezing, ice crystals form around the dust particles.
0:44:27 > 0:44:30As these ice crystals move around,
0:44:30 > 0:44:34they attract more and more water vapour and grow in size.
0:44:34 > 0:44:38Falling out of this chamber are millions of little ice crystals
0:44:38 > 0:44:41and the whole of the cold room is full of ice crystals.
0:44:41 > 0:44:46So they're growing now from me talking and breath producing vapour.
0:44:46 > 0:44:48They're growing like snow.
0:44:48 > 0:44:52So you can see diamond dust floating around.
0:44:53 > 0:44:57In a real cloud the ice crystals grow into snow flakes
0:44:57 > 0:45:00and begin the descent to earth as snow.
0:45:02 > 0:45:05But unless the air temperature remains cold,
0:45:05 > 0:45:10the flakes melt as they fall and become rain.
0:45:10 > 0:45:14Most of the rain we experience in Britain starts its life as snow.
0:45:17 > 0:45:19When scientists discovered
0:45:19 > 0:45:22that dust particles are the key to growing rain drops,
0:45:22 > 0:45:24they realised it might be possible
0:45:24 > 0:45:27to artificially seed clouds to produce rain.
0:45:29 > 0:45:34The breakthrough came in 1946, when American scientists found
0:45:34 > 0:45:37that the chemical silver iodide produced particles
0:45:37 > 0:45:40suitable for growing rain drops in clouds.
0:45:42 > 0:45:48Cloud seeding works on the basis of the way rain drops
0:45:48 > 0:45:51coalesce around small particles -
0:45:51 > 0:45:54small, solid particles - in a cloud.
0:45:54 > 0:45:56They're called condensation nuclei.
0:45:56 > 0:46:03What you need to make rain drops is small pieces of dust, or pollen,
0:46:03 > 0:46:06or salt and the more of those that you have in a cloud,
0:46:06 > 0:46:10the more likely it is that you're going to get rain drops.
0:46:10 > 0:46:14So the idea of cloud seeding was to artificially seed the cloud.
0:46:14 > 0:46:19A rain cloud can contain more than eight million tonnes of water,
0:46:19 > 0:46:24so the power to control when and where rain falls
0:46:24 > 0:46:28has greatly interested governments and the military.
0:46:28 > 0:46:30Could rain be used as a weapon of war?
0:46:32 > 0:46:33In 1952,
0:46:33 > 0:46:39the RAF conducted a cloud seeding experiment above Bedfordshire.
0:46:39 > 0:46:41The results were inconclusive.
0:46:41 > 0:46:44Cloud seeding was abandoned as a military option.
0:46:46 > 0:46:51The American airforce seized on the potential of seeding in the '60s
0:46:51 > 0:46:53and poured money into research.
0:46:56 > 0:46:58During the Vietnam War,
0:46:58 > 0:47:02the Pentagon was keen to use anything to give them an advantage
0:47:02 > 0:47:05in the fight against the Vietcong, an elusive guerrilla army.
0:47:06 > 0:47:09Their aim was to trigger rain
0:47:09 > 0:47:13to fall on the Vietcong's key strategic supply routes
0:47:13 > 0:47:19and in March 1967 this new weapon was put to the test
0:47:19 > 0:47:23in operation Project Popeye.
0:47:25 > 0:47:29Experiments continued for five years until 1972,
0:47:29 > 0:47:32when a document was leaked to the press.
0:47:32 > 0:47:37The public were outraged and the experiments were halted.
0:47:37 > 0:47:41Yet today cloud seeding is carried out throughout the world.
0:47:41 > 0:47:45The Chinese did it during the Olympic Games.
0:47:45 > 0:47:49But scientists disagree about the effectiveness of cloud seeding.
0:47:49 > 0:47:52It's been extremely difficult to show this works.
0:47:52 > 0:47:56In fact, the random trials have shown -
0:47:56 > 0:47:58as best we can see - that it doesn't work.
0:47:58 > 0:48:02But in some countries of the world it still goes on
0:48:02 > 0:48:07and in China there's more people trying to modify the weather
0:48:07 > 0:48:10than there are trying to forecast it.
0:48:11 > 0:48:14Despite our attempts to manipulate the rain,
0:48:14 > 0:48:17we will never truly be the masters of it.
0:48:17 > 0:48:22And climate change is cruelly exposing our lack of control.
0:48:22 > 0:48:26Wild weather may not be a punishment from the gods
0:48:26 > 0:48:29but we look to the heavens with increasing anxiety
0:48:29 > 0:48:33as the character of British rain changes.
0:48:33 > 0:48:37The existing forecasts about what climate change will do to Britain
0:48:37 > 0:48:42tell us that we will have a lot of concentrated very bad weather.
0:48:42 > 0:48:44How will we cope with that?
0:48:44 > 0:48:47I think that we will struggle.
0:48:49 > 0:48:51We need to overcome this idea
0:48:51 > 0:48:56that we shouldn't have to accommodate ourselves to weather.
0:48:56 > 0:49:00With climate change, the one prediction that we can make
0:49:00 > 0:49:06with real confidence is that we expect rainfall to become heavier.
0:49:06 > 0:49:10When it rains, we'll get more large precipitation events.
0:49:10 > 0:49:16The warmer air will actually be able to hold more water vapour,
0:49:16 > 0:49:18so we can expect heavier rainfall.
0:49:21 > 0:49:26Lewes, in East Sussex, thought they had a solution to heavy rain.
0:49:27 > 0:49:31Sitting on the flood plain of the River Ouse,
0:49:31 > 0:49:35the town centre had flooded in the past,
0:49:35 > 0:49:39but since then defences had been built, banks strengthened,
0:49:39 > 0:49:42and walls were put in place along the river.
0:49:42 > 0:49:48But in the year 2000 it became clear that people of Lewes
0:49:48 > 0:49:52had been enjoying a false sense of security.
0:49:52 > 0:49:58Lewes had a very big flood in the 1960s and the response then was,
0:49:58 > 0:50:02"We'll build up our defences so that can't happen again."
0:50:02 > 0:50:07And yet along comes a pretty freaky series of weather events
0:50:07 > 0:50:12and the whole valley above the town floods
0:50:12 > 0:50:17and this water is then forced through Lewes.
0:50:23 > 0:50:27Well, we had a month's rainfall in 48 hours
0:50:27 > 0:50:31and then suddenly all hell broke loose
0:50:31 > 0:50:32because it came through the ground.
0:50:34 > 0:50:39It came up through the tarmac, through the drains,
0:50:39 > 0:50:42and we were six foot under water in the space of 15 minutes.
0:50:42 > 0:50:46I don't think we were prepared for the magnitude of the flood.
0:50:46 > 0:50:51What happens is that the water gets over the flood barriers,
0:50:51 > 0:50:53inundates the town and can't get out again.
0:50:53 > 0:50:55And worse than that, of course,
0:50:55 > 0:51:00because of this conviction you could defend yourself against flooding,
0:51:00 > 0:51:05the Fire Service installed their headquarters behind the defences.
0:51:05 > 0:51:09These were now flooded and the water was trapped for days.
0:51:12 > 0:51:14TV: The town is completely cut in two.
0:51:14 > 0:51:19Waters rose so fast, even the emergency services were caught out.
0:51:19 > 0:51:22Ambulances and police cars have been replaced with boats.
0:51:27 > 0:51:31Emergency services struggled to cope with the rain.
0:51:34 > 0:51:36At Harvey's Brewery,
0:51:36 > 0:51:40Miles Jenner was working hard to salvage the business.
0:51:41 > 0:51:45The brewery itself we evacuated by lifeboat
0:51:45 > 0:51:50because we'd stayed to the bitter end and they sent in a life raft
0:51:50 > 0:51:53and our staff were ferried out through the casks
0:51:53 > 0:51:57that were bobbing in the water and up to dry land.
0:52:02 > 0:52:04No-one died in these floods
0:52:04 > 0:52:09but over 800 homes and businesses were devastated.
0:52:09 > 0:52:12More than £80 million of damage was caused
0:52:12 > 0:52:15by one of the heaviest rainfalls in the area.
0:52:15 > 0:52:18Flood plains are there for a purpose.
0:52:18 > 0:52:22They're to allow rivers to flood, as the name suggests,
0:52:22 > 0:52:26when there's a lot of rainfall, and that's why they're flat.
0:52:28 > 0:52:32That means developers like to build on them because it's easy,
0:52:32 > 0:52:34until a flood comes along.
0:52:34 > 0:52:38I think the lessons learned in Lewes are very hard ones
0:52:38 > 0:52:41because Lewes faced a choice. It was expanding.
0:52:41 > 0:52:45It could build up onto the South Downs.
0:52:45 > 0:52:49Well, who wants that? Or it could build down onto the flood plain.
0:52:49 > 0:52:54It built down onto the flood plain with big flood barriers
0:52:54 > 0:52:56and still it was caught.
0:52:56 > 0:52:59So the lesson from that is,
0:52:59 > 0:53:04do you build ever bigger flood defences at enormous cost,
0:53:04 > 0:53:08or do you try and plan to expand your populations somewhere else,
0:53:08 > 0:53:10because it is a natural bottleneck.
0:53:10 > 0:53:13There will always be a danger of flooding.
0:53:13 > 0:53:17MUSIC: "I Can't Stand The Rain" by Ann Peebles
0:53:29 > 0:53:31If we ever believed we could master the rain,
0:53:31 > 0:53:35then recent summers have shattered our complacency.
0:53:35 > 0:53:38In 2007, extreme rainfall led
0:53:38 > 0:53:42to the wettest May to July since 1766.
0:53:42 > 0:53:45Tewkesbury in Gloucestershire was deluged.
0:53:45 > 0:53:48There have always been floods here -
0:53:48 > 0:53:50a fact taken into account
0:53:50 > 0:53:54when the builders constructed the town around the abbey.
0:53:54 > 0:53:57They knew that Tewkesbury floods and so they were very clever,
0:53:57 > 0:54:00particularly the monks, of building the abbey
0:54:00 > 0:54:04exactly where it should be built, which is on dry land.
0:54:05 > 0:54:10The lessons of the past were forgotten or ignored.
0:54:10 > 0:54:14And in 2007, when rain flooded the town centre,
0:54:14 > 0:54:19one building to remain above the waterline was the medieval abbey.
0:54:19 > 0:54:22It looked like an ark. And it was treated as an ark.
0:54:22 > 0:54:26People actually came and sought sanctuary here,
0:54:26 > 0:54:29which is what a church should be able to offer - sanctuary.
0:54:31 > 0:54:37I think when the rains come, people are looking over their shoulder.
0:54:37 > 0:54:42There's a sense of fear around that all this could happen again.
0:54:42 > 0:54:45The weather that we're experiencing at the moment
0:54:45 > 0:54:50is reminding us that we are not above nature
0:54:50 > 0:54:52but we're an essential part of it.
0:54:53 > 0:54:58I think, especially over the last two decades,
0:54:58 > 0:55:01we've become increasingly disconnected from the weather
0:55:01 > 0:55:03and from the climate as well.
0:55:03 > 0:55:08We no longer know, as a nation, what normal British weather is.
0:55:09 > 0:55:13And every time something unusual comes along,
0:55:13 > 0:55:15though we may have had it many times in the past,
0:55:15 > 0:55:20everybody wants an explanation. They want to point the finger.
0:55:20 > 0:55:24If it impinges on their lives and interrupts their day-to-day lives,
0:55:24 > 0:55:27they want somebody to blame for it.
0:55:27 > 0:55:30Somebody has to do something about this.
0:55:30 > 0:55:35There's gotta be some precaution they can take about this flooding.
0:55:35 > 0:55:37It's happened three times this year.
0:55:37 > 0:55:40We were always a bit too complacent about rain.
0:55:40 > 0:55:42I think we did get an idea
0:55:42 > 0:55:46that we were above weather and we never were.
0:55:46 > 0:55:50With the arrival of global warming,
0:55:50 > 0:55:55we're now slipping back into a time of greater uncertainty about it
0:55:55 > 0:56:00and a fear that we will have to alter our behaviour.
0:56:00 > 0:56:03We're going to have reckon with the fact that rain is back,
0:56:03 > 0:56:08as a threat to us, in a way that the Victorians
0:56:08 > 0:56:11and the scientists of the 20th century
0:56:11 > 0:56:14thought they might eliminate.
0:56:14 > 0:56:18# In each and every life
0:56:18 > 0:56:22# Some rain has got to fall
0:56:22 > 0:56:27# But too much of that stuff has fallen into mine
0:56:28 > 0:56:36# Some folks can lose the blues in their heart
0:56:36 > 0:56:43# But when I think of you another shower starts
0:56:43 > 0:56:49# Into each life some rain must fall
0:56:49 > 0:56:57# But too much has fallen in mine. #