Term3_ English _ Part 4- Part 10. Our Changing Planet

The Upsala glacier in Argentina used to be one of the biggest glaciers in South America. In 1928, it was covered in ice and snow, but now the glacier is melting at an annual rate of about 650 feet (about 200 meters), so the area is covered in water. This is evidence of global warming. 1 In the last 100 years, the global temperature has gone up by around 1.33°F (0.75°C). This may not sound like much, but such a small increase is causing sea levels to rise and threatening the habitat of many species of plants and animals. An increase of 3.6°F (2°C) in global temperatures could result in extinction for 30% of the world’s land species.

2 The Northwest Passage is a sea route that runs along the northern coast of Canada between the Atlantic and the Pacific Oceans. In the past, it was often difficult to use because the water was frozen; however, increasing temperatures and the subsequent deglaciation have made it easier for ships to travel through this route. The trouble is that the melting of the ice will lead to loss of habitat for the polar bears and other species that live in this area.

3 Experts predict that global sea levels could rise by 12 to 48 inches (30.5 to 122 centimeters) by the end of the century. Consequently, some areas that were land a few hundred years ago are now underwater, and many low-lying islands may be underwater in the future.

4 As a result of the changing climate, the world’s ecosystems are also changing faster than ever before. More than one-third of the world’s mangrove forests and around 20% of the world’s coral reefs have been destroyed in the last few decades. Forests are being cut down to provide land for food, because the human population is growing at such a rapid rate. Approximately a quarter of the land on Earth is now used for growing food. As a result of the higher temperatures and higher levels of carbon dioxide in the atmosphere, plants are producing more pollen, which could lead to more cases of asthma, a medical condition that makes it hard to breathe.

5 What is causing climate change? The main cause is the huge amount of greenhouse gases, such as methane and carbon dioxide (CO2), in the atmosphere, but the reason for the high levels is the world’s population. As the population increases, more land is needed to provide food and energy. Burning fossil fuels for heating, lighting, transportation, electricity, or manufacturing produces CO2. Furthermore, humans breathe out CO2 while trees “breathe in” CO2 and produce oxygen, so by cutting down trees, we are increasing the amount of CO2 in the atmosphere and reducing the amount of oxygen. As a result of human activities, CO2 levels are at their highest in 800,000 years.

6 The biggest challenge we all face is to prevent further environmental disasters. We must do something before it is too late. We need to reduce the amount of CO2 in the atmosphere. We need to stop burning fossil fuels and start using renewable energy. We can get enough energy from renewable fuels such as solar energy, hydroelectric energy, or wind power to be able to stop using fossil fuels completely.