The Increase in Greenhouse Gases During the Last 130 Years

Multiple Choice

The increase in greenhouse gases during the last 130 years is primarily a result of ________.

A) the excessive burning of fossil fuels by humans.
B) the escape of these gases from plate boundaries and volcanoes.
C) increased sunspot activity that accelerates plant photosynthesis rates.
D) the release of excessive amounts of carbon from the oceans.
E) widespread use of chemical fertilizers in agriculture.