(1) Today, the amount of carbon dioxide released into the atmosphere is about twice the amount that remains in the atmosphere. .
. . (2) The increased amount of carbon dioxide (and other gases) in the atmosphere is causing a rise in temperature called global warming. (3) These gases allow the sun's rays to pass through, but they absorb and radiate heat back to Earth, a phenomenon called the greenhouse effect. (4) Global warming is contributing to climate change, which is causing significant changes in many of the Earth's ecosystems. Source: Mader, Sylvia, and Michael Windelspecht. Essentials of Biology. 4th ed., WCB-McGraw, 2015.
Which sentence from the passage uses a coordinating conjunction to join two independent clauses?
