A hole has opened in the ozone layer above the Arctic and looks set to become the largest on record for the region. The hole looks set to break up in the coming weeks but not before setting a new record in ozone layer depletion at the North Pole.
The ozone layer is a protective shield in the Earth’s stratosphere which absorbs some of the ultraviolet radiation reaching us from the sun. Without the ozone layer, it would be nearly impossible for anything to survive on the planet. In Antarctica, the thickness of the ozone changes with the season. The freezing winters lead to high- altitude clouds combining with ozone-damaging chlorofluorocarbons (CFCs), which have been lingering in the atmosphere for decades, to thin out the layer. The North Pole region is different, where the weather is typically warmer and doesn't create high- altitude clouds.
This year, unusually cold temperatures and powerful winds formed a "polar vortex" in the Arctic, creating the frigid conditions that have led to a vast ozone depletion, about three times the size of Greenland. Scientists are watching and waiting to see what happens next but it appears the new ozone layer depletion in the Arctic will surpass smaller holes recorded in 1997 and 2011. Marcus Rex, an atmospheric scientist at the Alfred Wegener Institute in Germany, told Nature that the Arctic ozone hole didn’t threaten human health but over the next month, there was a possibility it might drift over more populated areas. In that case, he recommended more sunscreen. Last month there was good news for the ozone layer, when a study found that the hole in the southern hemisphere had significantly shrank due to a 1987 international treaty, the "Montreal Protocol", which banned the use of CFCs.
Antara Banerjee, a CIRES Visiting Fellow at the University of Colorado Boulder, who also works at the National Oceanic and Atmospheric Administration (NOAA), led the study. "The emissions of ozone-depleting substances that were responsible for the ozone hole - the CFCs from spray cans and refrigerants - started to decline around 2000, thanks to the Montreal Protocol," she told The Independent.
(Adapted from IELTS by Cambridge)

1. Undersea turbines which produce electricity from the tides are set to become an important source of renewable energy for Britain. It is still too early to predict the extend of the impact they may have, but all the signs are that they will play a significant role in the future.
2. Operating on the same principle as wind turbines, the power in sea turbines comes from tidal currents which turn blades similar to ship’s propellers, but unlike wind, the tides are predictable and power input is constant. The technology raises the prospect of Britain becoming self-sufficient in renewable energy and drastically reducing its carbon dioxide emissions. If tide, wind and wave power are developed, Britain would be able to close parts of Europe. Unlike wind power, which Britain originally developed and then abandoned for 20 years allowing the Dutch to make it a major industry, undersea turbines could become a big export earner to island nations such as Japan and New Zealand.
3. Tidal sites have already been identified that will produce one sixth or more of the UK’s power - and at prices competitive with modern gas turbines and undercutting those of the already ailing nuclear industry. One site alone, the Pentland Firth, between Orkney and mainland Scotland, could produce 10% of the country’s electricity with banks of turbines under the sea, and another at Alderney in the Channel islands three times the 1,200 megawatts of Britain's largest and newest nuclear plant, Sizewell B, in Suffolk. Other sites identified include the Bristol Channel and the west coast of Scotland, particularly the channel between Campbelttown and Northern Ireland.
4. Work on designs for the new turbine blades and sites are well advanced at the University of Southampton’s sustainable energy research group. The first station is expected to be installed off Lynmouth in Devon shortly to test the technology in a venture jointly funded by the department of Trade and Industry and the European Union. AbuBakr Bahaj, in charge of the Southampton research, said: "The prospects for energy from tidal currents are far better than from wind because the flows of water are predictable and constant..”
(Adapted from IELTS by Cambridge)

Extraordinary people
There are people in this world who have incredible abilities that seem to break the laws of nature. Here are three real-life superheroes who have amazed the world with their talents.
Wim Hof, also known as ‘The Iceman’, is a Dutch man who has broken the limits of what humans can do in low temperatures. He has set several world records for his ability to deal with freezing temperatures, including the longest ice bath and longest full-body contact with ice, although those records have been broken many times. Wim has developed a method of breathing that allows him to control his body temperature and survive extreme cold. He has run a full marathon in the Arctic Circle and almost reached the peak of Mount Everest in just shoes and shorts in 2007!
Daniel Tammet, from the UK, is often called ‘The Human Calculator’, due to his incredible abilities to do maths. Daniel can solve complicated mathematical problems in his head at lightning speed. Daniel also has an amazing language learning ability. He can speak a wide variety of different languages, including Icelandic, which he took just one week to learn! He has even written three books about his life and talents.
Stephen Wiltshire. aka. 'The Human Camera’, is a British artist with an incredible ability to draw detailed pictures of cities from memory. Wiltshire can take a brief helicopter ride over a city and perfectly recreate the view in his drawings. He has drawn famous cities like New York. Rome, and Tokyo, and his artwork has appeared in galleries around the world.
(Adapted from BRIGHT 12 SBT)
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