Choose the best answer.________is the gradual warming of the earth because of heat trapped by carbon dioxide and other gases in the atmosphere.

Choose the best answer. A strong greenhouse effect will warm the oceans and partially melt glaciers, increasing ______.

Choose the best answer. Ocean water also will expand if it warms, _______further to sea level rise.

Choose the best answer. The clearing of land for agriculture, industry, and other human activities have increased ______ of greenhouse gases.

Choose the word or phrase that is CLOSEST in meaning to the underlined part in the following questions. Pollution can have disastrous effects on the delicately balanced ecosystem.

Choose the best answer. The destruction of the rain forests is an______disaster.

Choose the best answer. Greenpeace works to promote public_______of the dangers that threaten our planet today.

Choose the word or phrase that is CLOSEST in meaning to the underlined part in the following questions. Environmental groups want a substantial reduction in the emission of greenhouse gases.