The Pollution Of The Oceans
Large quantities of wastes are dumped into the worlds oceans every year, including the runoff of excess fertilizer from farmland, and 2 million tonnes of oil which affects photosynthesis and the amount of sunlight reflected from the planet. In the early 1980s the North Sea was receiving every year 49 tonnes of cadmium, 20 tonnes of mercury, 12 tonnes of copper, 9 tonnes of lead, 34 tonnes of arsenic, and 20 million cubic metres of sewage. THE LOSS OF FORESTS Around 16 − 20 million hectares of rainforest are being lost each year and most of the remaining 14 might have been destroyed by early in the 21st century. In addition about-4 million ha of other forest types are being lost every year. This destruction not only reduces the rate at which carbon is taken out of the atmosphere, but the rotting of cleared vegetation and exposed soil humus is also putting carbon into the atmosphere, possibly equal to 40% of the input from fossil fuel burning. The loss of the rainforest could also reduce the planets cloud cover and therefore greatly increase its temperature. Tropical forest loss is the main cause of the loss of species.