A key observable (and important effect) of global climate change is the extent of the Arctic ice sheet, which varies seasonally but also has a significant downward secular trend, presumably tied to global temperature increase.
The total extent of the sheet as a function of time is tracked in detail via a combination of satellite data, and can be seen here as an image, and here as a function of time. (A second interactive chart is here.)
Will the extent of the Arctic ice sheet reach its lowest yet recorded value in 2016?
Resolution will be positive if the 2016 curve dips below the lowest point on the 2012 curve at the ADS website.