Last week, NASA and NOAA announced that 2014 was the hottest year in Earth's recorded history. Bloomberg animated it to show the monthly records for each year overlaid on top of each other with a new time series in each frame. The dotted line which represents the year's average moves each year too, while old records fade into the background (it's cooler looking on their site which you can find here: http://goo.gl/mcYwzd).
In short, it shows the Earth’s warming climate, recorded in monthly measurements from land and sea over 135 years. Temperatures are displayed in degrees above or below the 20th-century average. Thirteen of the 14 hottest years are in the 21st century.