Friday, 25 June 2010

China: An Empire Risen from the Dust

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First published: National Geographic June 2010

Written as part of the TV series 'How Earth Made Us'. This series is also known as 'How The Earth Changed History' on National Geographic, USA.

Paul Williams, Assistant Producer

Winds of Change
China’s civilisation is one of the oldest and largest in the world, and you could say that it built much of its success on something delivered by the wind. Fifty million years ago, India collided with Asia and pushed up the Himalayas. They were pushed up so high that they had a profound effect on the winds across much of this part of the world, strengthening the Asian westerlies and forcing upwards the wet air flowing north from the Indian Ocean. This ocean air forms clouds and rain which intensifies the monsoon that India relies upon each year. Every drop is squeezed from the air so that, by the time it reaches China on the far side of the mountains, it’s bone dry. The Himalayas form a rain-shadow, creating some of the driest and dustiest places on Earth — the Taklimakan and the Gobi deserts.

The prevailing westerly winds act like a huge conveyor belt that blows this dust all the way to central China. Here it's deposited and mixed with rotten plant matter to become a light, fertile soil — perfect for farming. As early as 10,000 years ago, this slab of fertile dust became a seed for the Neolithic revolution and was one of the first sites of rice cultivation in the world. This dust is better known as loess, and the slab it forms is the Loess Plateau, over a thousand feet thick and covering an area almost the size of France.
The Loess Plateau at the heart of China, flanked on the North & West by great sources of dust

Revolution to Empire 
It’s so vast that farming could develop here on an enormous scale. That meant surplus food. And surplus food is the first and most important pre-requisite of any self respecting empire. Farmers produced the food and paid taxes. Their labour freed priests to organize the worship of gods, armies to protect the city, and it allowed rulers and governments to become wealthy and ambitious. Three thousand years ago, this transition led to the rise of the Shang dynasty, the first of China’s famous dynastic empires — the Loess Plateau had become the ‘Cradle of Chinese Civilisation.' All of the early Chinese empires, the Qin, the Han and the Tang, built their strongholds here, and the Great Wall of China was built across the northern edge of the plateau to safeguard the Empire’s heartland. But the crowning glory of the Loess Plateau is the 8000-strong Terracotta Army, built as a Mausoleum to China's first emperor — Qin Shi Huang. It is not only buried in the loess, but the terracotta from which they were created is itself made from loess.
Image: Platoons of Loess soldiers were buried with China's first emperor, Qin Shi Huang Di, to accompany him during his eternal rest. These life-size figures, shown here during excavation at the emperor's burial complex near the city of Xi'an in China's Shaanxi Province, are more than 2,200 years old. Photograph by O. Louis Mazzatenta

The importance of the Loess Plateau has also shaped China’s cultural heritage. In the 5th century, the Wei dynasty carved the Yungang Grottoes — a honey comb of 250 man-made caves carved beneath the Loess Plateau, the walls covered with over fifty thousand Buddhist statues. It was a symbol of the empire’s wealth and of the new philosophies and religion of Buddhism spreading across the land.

Caves in the Loess Plateau were not only constructed as a testament to religion and power, but for centuries they have provided insulated shelter from the cold winters of the region. Even today it is estimated that over a million people still live in the man-made caves known as Yaodong. In the 1930s, they provided the headquarters and home for Chairman Mao Zedong and his communist party — once again the Loess Plateau was the focal point for great change in China.

What began with loess led to empires and dynasties, art and religion. And it was all made possible by the winds. China was lucky. It found itself at the end of a wind pattern that delivered some of the finest quality soil in the world. But that's not the end of the story...

Chinas Sorrow
As China's population boomed and prospered, the pressure on the land grew. Centuries of over-grazing and deforestation have reduced the once lush and fertile plateau to an almost barren desert-like landscape. Without vegetation to anchor the loess in place, the land has been eroded. What has taken millions of years to be blown in by the wind is stripped away by the mighty Yellow River, a raging torrent which washes up to 1.6 billion tonnes of soil downstream every year. Here the loess tightens its grip on the fate of China. It periodically clogs up the arteries of the Yellow River, causing widespread flooding on the lowlands. Dykes and levees are continuously built in defence, but these cannot contain the beast. Flooding and breaching of these dykes have been responsible for some of the highest death tolls in human history. Up to 2 million people lost their lives to this flooding in 1887, and, in 1931, an estimated 4 million succumbed to the waters as it flooded the North China Plain. It’s no wonder that the river is known by man as 'China's Sorrow.'

In 1938, during a war with Japan, Chinese troops were ordered to break the levees holding back the river in order to stop the encroaching Japanese. This flooding of an area of 54,000 square kilometres did destroy its intended target, but, along with the Japanese army, it also killed an estimated 9 million Chinese.

The Loess Plateau, which was once the treasured heart of the empire, is now a major issue for the Chinese government. In the 1990s, they launched the Loess Plateau Watershed Rehabilitation Project in a bid to reverse centuries of neglect. Local people have been educated about sustainable farming practice, and thousands of trees have been planted. Nature is now reclaiming a portion of the Loess Plateau and slowly returning it to its former glory. It is hoped that, with time, more of the land will be made arable, and the load on 'China's Sorrow' will be lessened.
Image: China's Loess Plateau was once covered with natural forests, but high winds and thousands of years of clear-cutting for agricultural purposes have created one of the world's worst soil-erosion problems. Here, a government tree-restoration project aimed at stabilizing the soil and reducing erosion covers miles of hillside on the plateau. Photograph by Jim Richardson

Wednesday, 23 June 2010

The Browning of Australia & The First Revolution

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First published: National Geographic June 2010

Written as part of the TV series 'How Earth Made Us'. This series is also known as 'How The Earth Changed History' on National Geographic, USA.

Paul Williams, Assistant Producer

The First Revolution

Between 10 and 7 thousand years ago a revolution swept across the world which would lay the foundations for the development of human civilization. It was the Neolithic revolution - the age of farming. While China ploughed rice and millet in the fertile soils of the Loess Plateau, Mesopotamia grew along the banks of the Tigris and Euphrates. In Australia, on the other other side of the planet, a very different story was playing out.

Australia did have one thing in common with these 'cradles of civilisation' - well crafted stones tools. Used for grinding seeds they can be found scattered across the continent, some dating back 30,000 years - 20,000 years earlier than anywhere else on Earth. In most civilizations these tools seem to be a prerequisite for the Neolithic transition but here, given a head-start, farming never took off.

You might think that’s because it’s parched and dry. But it’s just as much to do with the wind.

The Eternal Joy Ride

The Australian continent sits right atop the Indo-Australian tectonic Plate, on an eternal joy ride around the planet. It is placed neatly at the plates centre, far away from the edges where a destructive regime of earthquakes and volcanoes operate. Because of this positioning Australia remains tectonically stable, solid as a rock. Geologically it is rather a boring continent - and it has been for more than 400 million years.

65 million years ago, while dinosaurs where breathing their last, Australia was commencing a slow northward journey leaving behind the cool chill of the polar region and eeking its way towards warmer climes snugly situated between 10 and 43o latitude. This led Australia straight into the hands of one of the planets most powerful phenomena - The Hadley Cell, a giant powerful circulation of air which wraps around the entire globe.

These cells have a grasp on the planet which begins at the equator. Here the sun is at its hottest – so the air is continually rising, as it rises over the tropics any moisture condenses and falls on the rainforests below - an equatorial band of thunderstorms mark out its ascension. At a height of 10 to 15kms the dry air cools as it continues to spread away from the equator, until between 20 and 30 degrees latitude it sinks back to Earth, heating up again in the process.

Image: The Hadley Cell, At the surface the descending air flows back towards the equator. These are the trade winds. They close the loop and form what's known as an atmospheric cell. It's the spin of the earth that deflects these surface winds so they move towards the Americas. Each hemisphere has 3 giant atmospheric cells which define the prevailing surface winds around the entire Earth. East-West Movements of the atmospheric Cells.

The Browning of Australia

This pattern of winds creates a band of hot, dry deserts around the world on either side of the equator, including the Sahara and Arabian deserts in the northern hemisphere. In the Southern Hemisphere it meets Australia. During its interminable progression northwards the climate of Australia became ever more variable as it slowly coincided with this atmospheric hotspot. The red continent essentially found itself sitting beneath a huge atmospheric hairdryer which for the past two and a half million years has blasted dry hot air onto it, creating half a million square miles of desert and leaving a continent parched and dry - what Mary E White described as the Browning of Australia.

To really appreciate this browning it helps to be in the centre of Australia, and to be up high. Mount Connor, Attila to the aborigine people, is a monolithic giant standing proud in an otherwise flat and featureless landscape. It lies at the geographical and spiritual centre of Australia, and it also lies at the heart of an incredible circular wind system. The descending air is influenced by a myriad of atmospheric protuberances, and deflected by the spin of the earth, to create a giant anticlockwise swirl around most of the continent.
 Image: Mount Connor 'Atilla', central Australia

A Continent Laid Bare

These swirling winds have a profound effect at ground level. Australians are familiar with a landscape they call Gibber - the 12,000 square miles of the Stoney Desert is almost nothing but Gibber. More commonly known as desert pavement, it forms when winds strip away fine material leaving behind larger rocks which interlock to look like crazy paving. This acts like an armoured cap to the landscape preventing vegetation from taking root. With minimal vegetation to anchor sediment in place fertile dust and nutrients continue to be blown away. On other continents this fertility may be continuously replenished by material washed down river from mountains - the Euphrates in the middle east, the Ganges in India, the Yellow River in China, but on a tectonically stable and flat continent such as Australia the mountains have long since dissapeared and there is very little left from which to replenish the fertility. While the winds brought fertile dust to China, in Australia it simply whips it away, so much so that across vast expanses of the continent all that remains is sand and stone. Where Gibber isn't formed the sand has been shaped into vast fields of long parallel dunes which circle Australia – all lined up with the path of the winds...

 Australian Gibber 'Desert Pavement'

It’s a process that continues to this day. Giant dust storms regularly engulf Eastern Australia. In 2009 a dust plume more than 500 kilometres (310 mi) in width and 1,000 kilometres (620 mi) in length swept over New South Wales and Queensland loaded with more than 16 million tonnes of dust blown from the deserts of Central Australia. At its peak the Australian continent was estimated to be losing 75,000 tonnes of dust per hour, most of it is deposited at sea where its nutrients provide an essential part of the marine food chain.

Over millions of years the winds and the planets tectonic forces conspired to deal a tough hand to the ancient peoples of Australia. With large areas of the continent bare and arid, continuing with a hunter gatherer lifestyle made more sense than taking up farming. Rather than relying on one or two intensive crops, they diversified into a wide range of wild food sources. And instead of living in permanent settled communities they lived in small, mobile groups, always able to move in search of food.

A dust storm obscures the Sydney Opera House at sunrise Sept 2009. REUTERS/Tim Winborne

Friday, 18 June 2010

BBC Wild Night In: YOUR chance to help Save Wildlife

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I'm lucky to work for the BBC Natural History Unit and I'm very proud of our rich heritage. For more than 50 years we've brought you the most awesome natural spectacles and revealed the intimate lives of everything from the smallest insect to the largest whale. Now more than one third of all known species are under threat - do they have more than a future on film? The BBC Wildlife fund was created as an opportunity to give something back and help wildlife around the world. We've been doing all we can to help raise money and awareness and now its CRUNCH time, we need to raise over two million pounds to keep the fund going. Every single penny will be given to a wildlife project. On Sunday night I'll be down at London Zoo with the Springwatch crew helping with the Live Broadcast of  'BBC Wild Night In' on BBC Two. It's like 'Children in Need' for Wildlife. This is your chance to do something positive and to help organisations who are working to save some of the planets most endagered species. 

"We owe it not only to the wildlife but to the next generation, to create a healthier planet for all."

Here's a few things you can do right now to help get the night started with a BANG...

DONATE: Click here 

Bid for 'money can't buy' items like the Springwatch sofa or a Wildlife Walk with BBC Radio 2's Jeremy Vine in the Wild Auction. This will take you to the charity auction section of eBay. The BBC Wildlife Fund will receive 100% of the proceeds.

 You could own the Springwatch Sofa!
The BBC Wildlife Fund's official single is available to download now!
'Sunchyme 2010' by Dario G will help raise funds for the BBC Wildlife Fund appeal this year.
40p or more from the sale of this single will be donated to the BBC Wildlife Fund so why delay, get your dancing shoes on and get down to Dario G's 'Sunchyme 2010' 

Tell your friends, Twitter, email, spread the word. Use the official Facebook App - Do you have more friends than there are Tigers in the wild?

Why should YOU help...
Click here to watch a short film & find out more. 

From the BBC Wildlife Finder:
"We've unearthed footage of some remarkable animals, plants and habitats that are facing an imminent threat to their survival. The unique selling point of our planet is life. From the deepest trenches of the Pacific Ocean to Africa’s inhospitable deserts, it has demonstrated a knack for hanging on in there. However, the challenges for many species now seem to be too great. Watch, before they fade out."

Sir David Attenborough holds an image of a Panamanian golden frog, now thought to be extinct in the wild.
We filmed these frogs in 2007 for Life in Cold Blood. Soon after filming, the chytrid fungus (which kills amphibians) was discovered in the area. In order to keep these frogs safe from the fungus, scientists removed them from the wild. For the time being the frogs live in captivity.

Tuesday, 15 June 2010

10 Steps to create a Greenscreen Adventure

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At last weekends festival of nature we were really proud of our presence as the BBC Natural History Unit. The theme of our tent was to give people and insight into the technologies used to make Natural History TV, including mini-cams, thermal cameras, IR-cams and parabolic reflectors for recording sound. We couldn't take people to exotic and remote locations and so we decided that we would bring some of these locations to them. I created a greenscreen adventure to do just that. It was a very successful activity with more than 500 children (and a few adults) having a go at presenting from one of three locations; Polar Bears in the Arctic, Orangutan in the rainforest and Great White Sharks under the sea. The shark adventure was by far the most popular - giving our intrepid presenters the opportunity to swim with, and escape, this formidable predator! I've had lots of people calling and requesting information on how to create a live greenscreen and so I've put together this basic guide to get you started...

Step 1. Hire or make your greenscreen
I used two 2x1 metre strips of lime green fabric bought from a craft shop and sewed together. For best results use a single continuous piece of material as any 'joins' will create lines through your green screen image. A nice bright lime green material works best but blue has also been traditionally used in television.

Step 2. Find a location 
For best results you will need a location that is not influenced by natural light. As we were creating a greenscreen experience for the Bristol Festival of Nature 'The BBC Adventure Screen', we had to work within a white festival tent. On the first day the lighting was even and so once the chroma-key had been set (i.e. the green removed so that you can insert your custom backdrop) it did not need to be recalibrated. On the second day the sky was intermittently cloudy and the lightning conditions frequently changed. I created a chroma-key setting optimised for both light conditions so I could switch between the two as the natural light changed.

Step 3. Stretch the material
Ensure the greenscreen is pulled tight and flat, any creases could distort the greenscreen image.

Step 4. Use even lighting
As already mentioned lighting is of the most important factors to consider. For best results it's important that the greenscreen is lit evenly and is much brighter than the 'presenter'. I used two kenoflo lights, which produce a nice soft white light. I did not use hot-heads as the light produced by these tend to be concentrated at a central focal point, they also tend to become 'hot' which is not a good idea when working in tents at a public event.

Step 5. Connect Camera
You can use any camera device including the inbuilt webcam on a macbook pro. For a much better image, and to optimise the chroma-key effect, I used a Z1 camera connected to my Macbook Pro via firewire.

Step 6. Connect Sound
For sound I connected a directional microphone to the camera, and had the audio playing from external speakers connected to the cameras minijack port. These speakers where situated away from the presenter and oriented towards the audience. The video that I created to play behind the presenter as the 'video layer' had sound effects and music. To create a more immersive experience I fed this audio directly from the laptop into a second pair of speakers which were placed facing the presenter.

Step 7. Connect view screen
I connected the laptop to a plasma screen onto which the final greenscreen composite was played full-screen. The control deck of the software was visible on the laptop screen so the public could see how it all worked. Due to the limitations of the plasma screen that I was using there was a short delay in image playback. This was because I had to convert from a digital output from the mac to an analogue input into the TV. I would recommend using a digital output to digital input such as a DVI to HDMI cable.

Step 8. Create a greenscreen layer
I used BoinxTV but this is quite a pricey package, so if you just want a simple greenscreen there's plenty of free software such as: Chroma Key Live

Once the greenscreen is in place and the lighting has been set it's time to launch the chroma-key software and calibrate the image. With Chroma Key Live it's a simple case of clicking on the green within the image displayed in the software window. If all has worked well the green of the greenscreen will be replaced by a grey and white chequerboard. If the lighting is not even some of the green material may still be visible through the chequers (as in the image on the left). You can adjust hue, brightness and saturation until the greenscreen has been completely highlighted (most software will have an auto button to make this process even simpler!).

Step 9. Create a video layer

Upload a video to use as a backdrop. This will form the layer which sits beneath the greenscreen layer. This 'video layer' will be visible and should completely replace the chequers in the chroma-key layer. Using BoinxTV I was able to line up all videos as separate layers ready to be switched on depending on which 'adventure' the presenter wished to do. Most Chroma-key software only allows one background video to be loaded at a time meaning a new video has to be uploaded with each presenter.

Step 10. Added Glitz

We gave the 'presenters' clothing to suite the locations they were visiting, e.g. polar gear or a rainforest hat - children also really enjoyed using binoculars in their search for wildlife! If the presenter is wearing a green T-shirt it may appear transparent with the background, so its handy to have something that they can wear over the top... however, many children enjoy the chance to be partially invisible. We did keep an extra piece of green material so they could play with it - like Harry Potters invisibility cloak!

An added feature of BoinxTV was that I was able to create additional layers to overlay onto the composite image. The 'video layer' was the bottom layer, the presenter chroma-key layer was the middle layer and then I created a snow or rain layer as the top layer. I used an additional layer which showed their name and location e.g. 'Charlie LIVE from the Arctic'.

Hope this helps. Have fun. - Paul