The Collapse Of Arctic Sea Ice [Greg Laden's Blog]

Andy Lee Robinson started the recent trend of making compelling graphics about climate change that move. He did a version of the Arctic Ice Death Spiral (a term coined by Joe Romm), which was highly acclaimed but that did not go as viral as it should have at the time. Then, a version with additive ribbon graphs about three years ago. He called that the “waterfall diagram” and it was picked up and used by the BBC at the time. Not long after, he came up with the disappearing block of ice motif. And now, Andy has an updated version, here:

This is ice VOLUME, not the oft cited surface area. Surface ice will always reform and melt in the Arctic, but long term there used to be a lot of thick ice that never melted during the summer. This long term thick ice would survive the summer melt, and allow new winter time surface ice to form more easily each year. As that ice disappears from various coastal areas in the high Arctic, new winter surface ice takes longer to get going.

The first version of this graphic, using ice blocks, was requested by Joe Romm, for Think Progress, in 2013, and appears here. Joe just wanted two ice cubes, side by side, and that is what Andy provided.

But Andy got thinking about the presentation of this very important climate change related metric. “After a while I thought it would be a nice challenge to try to animate it,” he told me. “To accomplish this, I started from the same camera angle, zooming in, following the line to the minimum and then returning to the original location. This required a way to create hundreds of script files to describe each frame.”

Andy told me that he is fluent in Perl, so he used that to calculate parameters for the objects he wanted to manipulate and substitute them in a povray script template. “At a resolution of 1920×1080, it takes between 15 minutes and 2 hours to make one, depending on what computer is working on it. I wrote spline and easing routines to calculate the smooth motions of the camera and cube sizing, and to interpolate the progression of the graph series.” The MySQL is a shared database that each server has access to, in order to check out a frame, render and return the results over NFS to a shared directory.

“The same perl program is run on each server and therefore knows which frame to render next, and after a few days the finished frames can be assembled together using ffmpeg with music, in a wav file.”

Andy, who is a gifted musician, composed the music himself.

“This uses 8 machines in total, including a linux laptop at 2 hours per frame! It was very painstaking work, writing all the code and parameters, but once done the images can be replicated automatically as new data appears. If only it would pay the rent!”