This comic is a timeline on how the temperature of the Earth has changed from 20,000 BCE (Before Common Era) to the present day (2016), with three predictions for the rest of the 21st century depending on what actions are taken (or not taken) to stop C02 emission.
Over the past 100 years, human action has produced a large amount of CO2 emissions, which have caused a rise in average global temperature through the greenhouse effect. This is called global warming and is a very real part of climate change. There are still many people who claim that this is not happening, or at least that it is not caused by any human actions, called climate change deniers. One argument of theirs is that global warming is happening for natural causes, summarized with the phrase “temperature has changed before”.
The title text compares the saying that “the temperature has changed before” comparing temperature changes over thousands of years to the rapid global warming over the last century with saying that the “small” changes to the temperature a car experiences over the years of normal usage should not make you worried over the rapid temperature increase that happens when someone sets your car on fire (comic via xkxd)..
…if you know of any climate change deniers, perhaps sharing this comic might help them come to a more logical conclusion as to the leading cause of climate change.
