The levels of atmospheric greenhouse gases (Carbon Dioxide, Methane) have raised and lowered over the planet's history. However, they have been fairly constant for the few thousand years. Over this...

Extracted text: The levels of atmospheric greenhouse gases (Carbon Dioxide, Methane) have raised and lowered over the planet's history. However, they have been fairly constant for the few thousand years. Over this time, the average temperature of the planet has also been constant, until the last 150-200 years, after hurmans began to burn fossil fuels and emit large amounts of these gases which trap excess solar radiation in the atmosphere. All of this increased heat is referred to as: O 1. Climate Change O 2. The Troposphere Effect O 3. None of the Above O 4. Global Warming