When scientists scan the global horizon, over-fishing, loss of species habitat, water shortage, climate change, and invasive1 species look to be the biggest threats to the earth. What will our world be like in 2050?
Population Decrease and Increase There are two features in the growth of world population. First, the annual increase in population in 15 European countries, in the past few years, has been only 300,000. The United Nations estimates that by 2050, the population of European countries will decrease from the current 0.72 billion to 0.63 billion. Second, the population in developing countries is growing rapidly. Over the past 50 years, the rate of increase in population has been fastest in the least developed countries. By 2050, the population of Africa is expected to reach 1.8 billion, 0.9 billion more than its current population.
Global Warming A recent research report published by the United Nations indicates that it is quite possible that the Earth's temperature is rising well above the previous estimate. Such an outcome2 would have severe consequences, such as the collapse of the Greenland ice sheet and disruption3 of the Gulf Stream ocean current. The Antarctic ice sheet, which contains 90% of the world's ice, has lost significant mass in the past few years. The discovery comes as a surprise to scientists, who thought that the continent would gain ice this century because of increased snowfall in a warming climate. A research team from the University of Colorado used satellite data to estimate that the ice sheet will lose up to 48 cubic miles by 2050. In comparison, a city the size of Los Angeles uses one cubic mile of fresh water every year. Ice shelves in the Antarctic will have decreased by more than 7,200 square miles in the next four decades. At twice the size of Australia, Antarctica is the Earth's fifth largest continent and contains 70% of its total fresh water resources.
Water Shortage Africa's rivers face dramatic change that will leave a quarter of the continent severely short of water by the middle of the century, according to a global warming study published today. Even modest decreases in rain in western Africa will see rivers lose as much as 80% of their water, triggering a surge of what the scientists call “water refugees. ” “In those areas where there is already a water shortage, it's going to have a devastating4 affect,” the study says. “If you're already walking 5 km to the nearest stream to get water, by 2050, it's going to mean walking 30 km or moving your whole household closer to the water source.”
Four Wheels Good, Four Wheels Dad The car has transformed the lives of people, but the planet is paying too high a price. It is almost incredible to think that when our grandparents were born cars were a rarity. Today there are 620 million private cars worldwide, to say nothing of buses, vans and lorries. With current growth trends, that number is expected to reach a staggering5 three billion cars worldwide by 2050. If we continue to burn fossil fuels6 at current rates, levels of carbon dioxide7 in the atmosphere will reach 550 ppm (parts per million)—double pre-industrial levels—by around 2050. This will increase global temperatures between 1.4 and 4.8℃ by 2050, and sea levels will rise between 0.09 and 0.78 meters. 研究者们环视全球,发现过度捕捞、物种栖息地缺失、水资源缺乏、气候变化和外来物种入侵是对地球最大的威胁。 到2050年的时候,我们的世界会是什么样子?