Unit 22 Environmental Protection Lesson 1 Global Warming

Can we take the heat?In the last few decades, environmentalists have reported that human beings are causing changes in the Earth's climate-something previously seen as beyond our control. They claim that since the Industrial Revolution (1750)and especially in the last 50 years, gases pumped into the Earth's atmosphere by our factories and vehicles have been speeding up the process of global warming and there by affecting our climate. Scientists believe that global warming could be one of the biggest environmental problems facing the 21st century, but what exactly is global warming and why is it seen as a threat? Global warming refers to an average increase in the Earth's temperature that, in turn,leads to climate change. Scientists found that the temperature of the Earth is controlled by greenhouse gases such as carbon dioxide, that trap heat from the sun in the Earth's atmosphere. Without these naturally occurring gases, the sun's energy would be radiated back into space leaving the earth could and unsuitable for life.
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