Tourists walk the ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

Watchtower arch of the Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

Detail of the ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking) , China

Hoar frost on barbed wire fence and dry-stone wall, Oxfordshire, England, United Kingdom

Chinese boy walking up steps of the Great Wall of China at Mutianyu, north of Beijing, China

The ancient Great Wall at Mutianyu, north of Beijing (formerly Peking)

Two men walk along the side of the Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

Tourist couple walk the ancient Great Wall of China at Mutianyu, north of Beijing, China

Father with his daughter on the Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

Chinese boy walking the Great Wall of China at Mutianyu, north of Beijing (formerly Peking)

The ancient Great Wall of China snaking through mountains at Mutianyu, north of Beijing (formerly Peking)

The ancient Great Wall of China snaking through mountains at Mutianyu, north of Beijing (formerly Peking)

Father with his daughter on the Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

The ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking)

The ancient Great Wall of China snaking through mountains at Mutianyu, north of Beijing (formerly Peking)

Tourists walk the ancient Great Wall of China at Mutianyu, north of Beijing, China

The ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking)

Barbed wire fence in Oxfordshire field, Bruern, The Cotswolds, United Kingdom

Statue among palm trees of Dunk Island Resort, Great Barrier Reef, Mission Beach, Queensland, Australia, Pacific

Looking out from lounge of Dunk Island Resort into Pacific Ocean, Great Barrier Reef, at twilight, Mission Beach, Queensland, Australia, Pacific

Dunk Island beach with islands offshore, palm leaves, Great Barrier Reef, UNESCO World Heritage Site, Queensland, Australia, Pacific

Passengers hurrying through automatic ticket wickets on their way to bullet train platforms at Tokyo Station, Japan, Asia

Passengers passing through automatic ticket wickets upon entering the JR Ueno railway station in Tokyo, Japan, Asia

Thames Barrier, Woolwich, London, England, United Kingdom, Europe

Thames Barrier and Canary Wharf at dawn, London, England, United Kingdom, Europe

Beautiful colonial railway station of Oran, Algeria, North Africa, Africa

Western-style modern gated housing development with security guard and barriers, Yichang, China

Tourists walk the ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

The ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking)

The ancient Great Wall of China snaking through mountains at Mutianyu, north of Beijing (formerly Peking)

Tourist takes a photograph on the ancient Great Wall of China at Mutianyu, north of Beijing (formerly Peking), China

Storm Barriers, Netherlands

People snorkelling on Outer Great Barrier Reef near Cairns, North Queensland, Australia, Pacific

Traditional dry stone wall, stones laid flat, in field in The Burren, County Clare, West of Ireland

People snorkelling on Outer Great Barrier Reef near Cairns, North Queensland, Australia, Pacific

Restored section with watchtowers of the Great Wall (Changcheng), northeast of Beijing, Mutianyu, China, Asia

Car waits at railway crossing in Ascott-Under-Wychwood, Oxfordshire, United Kingdom

Restored section of the Great Wall, UNESCO World Heritage Site, Mutianyua, (Changcheng), northeast of Beijing, China, Asia

Western tourists walk the ancient Great Wall of China at Mutianyu, north of Beijing, China

Thames Barrier, Woolwich, London, England, United Kingdom, Europe

The Thames Flood Barrier, Woolwich, near Greenwich, London, England, United Kingdom, Europe

Boat moored in Hamilton harbour, Whitsundays, off the Great Barrier reef, Queensland, Australia, Pacific

Nuclear waste reprocessing plant at Cap de la Hague in Normandy, France

Thames Barrier, Woolwich, London, England, United Kingdom, Europe

Thames Barrier, O2 Arena, Canary Wharf, London, England, United Kingdom, Europe

A boat moored on the beach on Green Island, Great Barrier Reef, Queensland, Australia, Pacific

Railings, Scottish Parliament Building, Edinburgh, Scotland, United Kingdom, Europe

The Thames Barrier with Canary Wharf behind, London, SE18, England, United Kingdom, Europe

The Thames Flood Barrier, Woolwich, near Greenwich, London, England, United Kingdom, Europe

The Thames Barrier, Woolwich, London, SE18, England, United Kingdom, Europe

The Thames Barrier, Woolwich, London, SE18, England, United Kingdom, Europe

Barriers of palm leaves to control sand, to stop it from drifting onto road, near Tinejdad, Morocco, North Africa, Africa

Barriers erected to prevent sand drifting onto road, near Tinejdad, Morocco, North Africa, Africa

The Thames Barrier, Woolwich, London, SE18, England, United Kingdom, Europe

Thames Barrier floodgates, Woolwich, London, England, United Kingdom, Europe

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia

The Hartbeespoort dam wall in South Africa's Noth West Province.

The Hartbeespoort dam wall in South Africa's Noth West Province.

Concrete sea defences at Beach Bank Caravan Park in Ulrome near Skipsea on Yorkshires East Coast, UK. The coast is composed of soft boulder clays, very vulnerable to coastal erosion. This section of coast has been eroding since Roman times, with many villages having disappeared into the sea, and is the fastest eroding coast in Europe. Climate change is speeding up the erosion, with sea level rise, increased stormy weather and increased heavy rainfall events, all playing their part.

A Second world War lookout post leaning alarmingly and about to tumble over the edge of the cliff near Aldbrough on Yorkshires East Coast, UK. The coast is composed of soft boulder clays, very vulnerable to coastal erosion. This section of coast has been eroding since Roman times, with many villages having disappeared into the sea, and is the fastest eroding coast in Europe. Climate change is speeding up the erosion, with sea level rise, increased stormy weather and increased heavy rainfall events, all playing their part.

The Thames barrier on the River Thames in London. It was constructed to protect the capital city from storm surge flooding. Recent predictions show it will probably be redundant in around twenty years due to increased stormy weather and sea level rise driven by climate change.

The Thames barrier on the River Thames in London. It was constructed to protect the capital city from storm surge flooding. Recent predictions show it will probably be redundant in around twenty years due to increased stormy weather and sea level rise driven by climate change.

The Thames barrier on the River Thames in London. It was constructed to protect the capital city from storm surge flooding. Recent predictions show it will probably be redundant in around twenty years due to increased stormy weather and sea level rise driven by climate change.

The Remains of the Godwin battery on the beach at Kilnsea at the head of Spurn point on Yorkshires East Coast, UK. Initially constructed during the First World War, the Godwin Battery was added to during the Second World War. It comprised of gun emplacements, search light, barracks, officers’ mess, and a hospital. This section of coastline is the fastest eroding coastline in Europe. The soft boulder clay cliffs are easily eroded and have been eroding since Roman Times, but recently the climate change impacts of increased stormy weather, increased heavy rainfall events and sea level rise have accelerated the rate of erosion. The average rate of attrition is 1.5metres per year, last year it was 5 metres.

The Remains of the Godwin battery on the beach at Kilnsea at the head of Spurn point on Yorkshires East Coast, UK. Initially constructed during the First World War, the Godwin Battery was added to during the Second World War. It comprised of gun emplacements, search light, barracks, officers’ mess, and a hospital. This section of coastline is the fastest eroding coastline in Europe. The soft boulder clay cliffs are easily eroded and have been eroding since Roman Times, but recently the climate change impacts of increased stormy weather, increased heavy rainfall events and sea level rise have accelerated the rate of erosion. The average rate of attrition is 1.5metres per year, last year it was 5 metres.

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia, Pacific

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

Anti-terrorist road barriers to prevent a vehicle attack, Sellafield nuclear power station near Seascale in West Cumbria, England, United Kingdom, Europe

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

Victoria Station in London, UK.

Thames Barrier, London, England, United Kingdom, Europe

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

Thames Barrier, London, England, United Kingdom, Europe

The Thames Flood Barrier on the River Thames, Woolwich, London, England, United Kingdom, Europe

Netherlands, Rotterdam, The Keringhuis (Moving Barrier On River Meuse)

Thames Barrier, London, England, United Kingdom, Europe

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Tourists on a semi submersible, viewing the Great Barrier Reef off Cairns in Queensland, Australia, Pacific

Tourists snorkelling from a dive and snorkel platform anchored to the Great Barrier Reef off Cairns in Queensland, Australia, Pacific

Avalanche protection defences above Iceland's most northerly town, Siglufjordur, Iceland, Polar Regions

Queen conch storage trap, Belize Barrier Reef, Caribbean

Liitter and mangrove roots, Belize Barrier Reef, Caribbean

English key, Belize barrier reef

coral key, Belize barrier reef

Person sitting in wooden chair watching sunset, Belize Barrier Reef, Caribbean (rr)

Tourists parasailing off Green Island on The Great Barrier Reef near Cairns in Queensland, Australia, Pacific

A householder's attempt to hold bavk the flood waters near Cockermouth's Main street, after the water receded, Cumbria, England, United Kingdom, Europe

Police protecting the House of Parlaiment from climate change protestors on a rally in Parliament Square in December 2008, London, England, United Kingdom, Europe

A large section of road collapsed betwwen Skelwyth and Elterwater in the Langdale Valley, Lake District, Cumbria, England, United Kingdom, Europe

Large rocks placed on the shore of the west coast of Walney Island, to prevent coastal erosion, Cumbria, England, United Kingdom, Europe

Giant clam amongst the soft coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

A Green turtle (Chelonia mydas) swimming over the Great Barrier Reef off Cairns, Queensland, Australia, Pacific

Sand dunes spreading across a highway in Inner Mongolia, China, Asia

A coral atoll from the air, part of the Great Barrier Reef near Cairns, Queensland, Australia, Pacific

Dead and broken coral on the sea bed, Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

A barrier surrounding a hole in the pavement, Ambleside, Lake District, Cumbria, England, United Kingdom, Europe