This new video produced by NASA shows the pattern of global temperatures over the last 50 years. And yes, there has been considerable warming. Earth's average temperature increased 1.1 degrees Fahrenheit in 63 years, reaching 58.3 degrees.

More than 97 percent of climate scientists agree that this warming has been caused by human activity, specifically the large quantities of greenhouse gases that human industry has emitted since the industrial revolution.

Atmospheric carbon dioxide levels are now above any point in the past 400,000 years:


And although solar activity this cycle has been unusually weak, global temperatures have still been way above the historical norm. In the Southern hemisphere, for example, Australia recorded its highest average temperature last year, according to NASA. The frequency of extreme weather events has also increased globally, a pattern that many climate scientists believe is explained by rising temperatures.