To better understand how climate change will impact our future, we have to know more about the weather patterns of the past. Historical whaling logs hold decades worth of untapped weather records, and now amateur scientists from around the world are working hard to make sure that data gets put to use.

Many commercial whaling ships of the mid-19th century sailed far north into the Pacific Arctic—an area that's especially important to our understanding of global warming. It was the responsibility of the first mate of each ship to keep a meticulous logbook detailing information like latitude and longitude, temperature, weather patterns, icebergs, and the locations of ice shelves. Extracting this data will help scientists build more accurate climate pattern models that chart data from before the rise of weather satellites.

But before this data can be used, it needs to be transcribed. The online citizen-science project Old Weather—which in the past transcribed the logbooks of both British and American ships—is now focusing on 500,000 handwritten pages from whaling logs. In order to make the job easier, they’ve enlisted the help of amateur scientists and historians to transcribe the mountain of information. Participants choose a ship and decipher the handwriting.

Screenshot from Old Weather: Whaling

Once it’s finished, the researchers behind the project believe they’ll have assembled the most comprehensive documentation possible of that place and time. Even with the help of crowd-sourced volunteers, they still estimate the project won’t be completed for about another year.

[h/t: City Lab