A David Cameron look-alike poses with a polar bear model outside the Houses of Parliament as part of a Greenpeace protest on May 13, 2011 in London, England. The environmental charity Greenpeace arranged the protest to highlight the first anniversary of David Cameron’s speech when he pledged to make his new government the greenest ever. In April 2006 Mr Cameron traveled by huskie-drawn sledge when he visited the island of Svalbard in Norway to witness the effects of climate change. (Photo by Oli Scarff/Getty Images)

Kit Cox wears a mustache umbrella in the Hendrick's Unusual Umbrella Emporium at the launch of London Cocktail Week on October 12, 2011 in London, England. The Unusual Umbrella Emporium is a pop-up bar in Seven Dials which will open for the duration of London Cocktail Week until October 15, 2011. The venue will showcase obscure umbrellas alongside a selection of cocktails and cocktail umbrellas designed by the top bartenders in the UK. (Photo by Oli Scarff/Getty Images)

An employee of the British Museum examines a silver coin dating from 900 AD which is part of the Silverdale Viking Hoard on December 14, 2011 in London, England. The hoard, which was discovered by local metal-detectorist Darren Webster in North Lancashire, comprises of 201 silver objects including arm-rings, coins, finger-rings, ingots, brooch fragments and fine wire braid. (Photo by Oli Scarff/Getty Images)

A protester uses his laptop computer in the “Occupy LSX” camp outside St. Paul's Cathedral ahead of a demonstration against higher tuition fees and privatisation in universities on November 9, 2011 in London, England. Around 4000 police officers are on duty and are to be allowed to deploy baton rounds if needed. The march is expected to finish at London Wall in the heart of the capital's financial district. (Photo by Oli Scarff/Getty Images)

Model Bianca Gavrilas wears a a hand-embroidered cape made from the silk of the Golden Orb Spider in the V&A Museum's Medieval and Renaissance Gallery on January 23, 2012 in London, England. The cape is one of two golden spider silk textiles that exist in the world, it was made in Madagascar over a period of 8 years and using the silk of silk of 1.2million spiders. (Photo by Oli Scarff/Getty Images)

A woman walks past a painting by Jenny Saville entitled “Red Stare Head IV” on display in the Royal Academy of Arts' Summer Exhibition on June 2, 2011 in London, England. The Summer Exhibition is the world's largest open submission contemporary art show, now in its 243rd year, with over 12,000 entries received from 27 countries. The exhibition features over 1100 works of art including: painting, sculpture, photography, architecture and film, it officially opens to the public on June 7, 2011. (Photo by Oli Scarff/Getty Images)

Meerkats are weighed and measured during the ZSL London Zoo 's annual weigh-in on August 22, 2012 in London, England. The height and mass of every animal in the zoo, of which there are over 16,000, needs to be recorded. The measurements are collated in the Zoological Information Management System, from which zoologists can use the data to compare information on thousands of endangered species. (Photo by Oli Scarff)

Members of the public admire trees displaying their autumn colours at the Royal Horticultural Society Garden Wisley on October 26, 2011 in Wisley, England. Many deciduous trees have now changed colour as they begin to shed their leaves for Autumn. An extended period of leaf colour change has come about this year due to a warm, dry Spring prompting an early growth spurt and a premature colour change. (Photo by Oli Scarff/Getty Images)