Unit4Globalwarming课件（新人教选修6）.ppt

Global warming 在过去的一百年里，由于人类活动二氧化碳的排放量不断增加。卫星数据有助于我们了解全球气候变暖，预测未来气候的变化。;Every time we breathe out，we release carbon dioxide gas into the atmosphere.Carbon dioxide is one example of greenhouse gases—a gas that traps heat. Over the last 100 years，the amount of carbon dioxide in the atmosphere has been steadily increasing.Most of this increase has been due to human activity，such as burning of oil and coal，or clearing of forests. Forests remove a lot of carbon dioxide from the air. However，this stored carbon is released into the atmosphere when trees are cleared or burnt.;Satellite data show that the world seems to be growing warmer. Most scientists think that there is a link between global warming and the rise in greenhouse gases.This is commonly known as the “Greenhouse Effect”．Satellites such as ESA’s Envisat help us learn more about global climate change and to predict what will happen in the future.Some instruments on Envisat produce daily global maps of greenhouse gases such as methane. Others show changes in temperature，snow，ice，lakes and forests. Such information is vital in enforcing international agreements to cut back on greenhouse gases output.;You Can Help! The problem seems so enormous that it may be hard for you to imagine that anything you do can really help.But it can.Here are some things you can do to help slow down global warming.;? Plant trees. ? Take shorter showers. ? Use only energy-saving bulbs in your lights. ? Wear lighter clothing when it’s hot instead of turning on a fan. ? Turn your lights，computers and chargers (充电器) off，and unplug (拔去……插头) them when they’re not in use. ? Skip car rides and take your bike，walk，or take the bus instead.