Scientists say that something very serious is happening to the earth. It will begin to get 【B1】 in the following years. There will be major changes in 【B2】 in the new century. Coastal waters will have a 【B3】 temperature. This will have a 【B4】 effect on agriculture. In northern areas, the 【B5】 season will be ten days longer by the year 2010. However, in warmer areas, it will be too dry. The 【B6】 of water could 【B7】 by eighty percent. This would 【B8】 a large decrease in agriculture production. World temperature could 【B9】 two degrees centigrade by the year 2040. However, the increase could be three times as great in the Arctic and Antarctic areas. This could cause the 【B10】 sheets to melt and raise the 【B11】 of the oceans 【B12】 one to two meters. Many coastal cities would be 【B13】 water. Why is this happening? There is too 【B14】 carbon dioxide in the air. 【B15】 oil, gas and coal burn, they create large amounts of carbon dioxide. This carbon dioxide lets 【B16】 enter the earth's atmosphere and 【B17】 the earth. However, it doesn't let as much heat 【B18】 the atmosphere and enter space. It's like a blanket. The heat 【B19】 the sun can pass through the blanket to warm the earth. The heat 【B20】 there and can't escape through the blanket again. Scientists call this the green-house effect. 【B1】