Presentation on theme: "What is antarctica? Antarctica is earths southernmost continent, containing the south pole. It is in the southern hemisphere, entirely south of the."— Presentation transcript:
What is antarctica? Antarctica is earths southernmost continent, containing the south pole. It is in the southern hemisphere, entirely south of the Antarctic circle, and its surrounded by the southern ocean. It is the fifth largest continent, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice and on some places it can be up to 7 miles thick.
Antarctica is the coldest, driest and windiest continent. It is considered a desert, the temperature in Antarctica has been known to reach -89 degrees Celsius. There are no permanent human residents, but thousands of people go to research stations across the continent. Only cold adapted organisms survive there, which include, some types of algae, penguins, seals, bacteria, fungi, plants...
What is global warming? Global warming is the rising temperature of the earth’s atmosphere and oceans. The rise in temperature is caused by greenhouse gases produced by human activities like deforestation and the burning of fossil fuels. An increase in global temperature will cause sea levels to rise which will change weather patterns and could cause catastrophic floods.
But why is Antarctica in Danger? It’s in danger because Antarctica is solid ice, scientists worry that global warming will cause the ice shelves to melt. This will result in loss of habitats for some creatures and the rising of sea levels.
The Filcher – Ronne Ice shelf The Filcher-Ronne ice shelf is predicted to have dissapeared by the end of the century which will accelerate rising sea levels by a big amount. This ice shelf is on the eastern side of Antarctica and hasn’t been so badly affected by global warming, but new research says the 450,000 square kilometres ice shelf is under threat. Scientists predict the melting of the Filcher-Ronne shelf could add up to 4.4mm per year to rising sea levels.
What else can damage Antarctica? Another greenhouse gas is methane, which also traps the radiated heat from the earth and heats up the planet, methane is a threat to Antarctica. Sulphur dioxide and nitrogen oxides are given off by coal-fired power stations and car exhausts. They cause acid rain, which if blown near Antarctica can make waters ‘dead’. Lead and heavy metals are found in vehicle exhausts and the smoke released by factories. They can become trapped in the polar ice sheets. In Antarctica there are traces of heavy metals and organic toxins. Which have been carried from the inhabited parts of the Earth. These could be returned to the environment if the ice melts.
The other big problems are CFCs and ozone. Ozone is a poisonous substance which causes pollution at ground level. But in the stratosphere, it is vital for controlling the amount of incoming ultra-violet radiation. Gases like chlorofluocarbons (CFCs) break down this protective shield. The effect is worse in areas of intense cold. The destruction of ozone in the upper atmosphere above Antarctica is one aspect of the pollution.
The hole in the Ozone layer
The loss of ice shelves In the ice sheets around antarctica, large cracks have started to appear. Scientists are debating over whether it is part of a natural process or an effect of Global warming. No one can predict what will happen but many suggestions have been made:
Because the Ross and Ronne ice shelves support the ice on the main part of antarctica, if they melt the whole of the sheet will become unstable If loads of cold water is suddenly released into the oceans, it may affect the pattern of ocean currents. If the ocean currents are affected, it could mean that the currents can no longer transfer heat from the equator to the poles to stop the world from overheating.
There are also other stresses on the environment, such as tourism, Antarctica cruises are being offered to tourists who want to explore the wonders of this continent. There is a risk that tourists will cause pressure on the fragile environment and disturb the breeding grounds of animals. The impact of scientists is also causing stress, scientists can leave rubbish or waste which is very expensive to remove and in such cold temperatures, the natural processes of decomposition are very slow.
Scientists in Antarctica Animals loose their habitats.
So what can we do? To help do our bit for the preservation of Antarctica there are various things we can do: Instead of using cars all the time, Walk! Or ride a bike! Or use enviromentally friendly measures of transport. Gases from our car exhausts are one of the main reasons Antarctica is in danger!
We need to reduce the burning of fossil fuels. To do this we need to save our electricity. Share car journeys Instead of using coal-burning factories for our electricity, we should use renewable energy sources such as solar power of wind turbines! Recyclying!
We need to stop releasing harmful gases into our precious atmosphere…
Or antarctica could be gone sooner than we think!