I made this animation to visualize climate change based on the HadCRUT 4 data (specifically the ensemble median gridded data) from the Met Office Hadley Centre.

HadCRUT 4 provides temperature anomalies in a five degree grid by month and year from January 1850 to November 2018 (as of this post). Anomaly here means deviation from the 1961-1990 average.

In the animation I wanted to capture the full timespan of the data but also show long term trends. Each frame is a month of data and each five degree grid of longitude and latitude is colored based on the maximum cumulative anomaly (positive or negative) for each decade. The range for color is 0 to +/- 20.85 degrees, red for warmer and blue for cooler. This means there is a reset at the start of each decade, the first few years are mostly random noise but by the end of each decade you're seeing the range of extremes.

Spoiler alert - you can spot something happening in the last three decades.

As well as the change in temperature it's interesting to watch the increase in global coverage over time. It's surprising that even the most recent years have no readings for Antarctica. Here's a paper (PDF) discussing the impact of the missing data. The HadCRUT 4 FAQ has more detail on how the temperature anomalies were assembled.

(Previously)

Here's an animation showing a year of global cloud cover (from July 2017 to July 2018) :

The clouds are sourced from the free daily download at xplanet. I run a Google apps script that saves a copy of the image to Google Drive every day (basically the same as this script to save Nest cam images). The hard part was waiting a year to get enough frames. Xplanet combines GEOS, METEOSAT and GMS satellite imagery with some reflection near the poles. Although I didn't need to for this project note that you can subscribe to higher quality / more frequent downloads.

As well as the clouds you can also see the terminator between day and night change shape over the course of the year. This video starts and ends with the Summer equinox when days are longest in the Northern hemisphere.

Where it's nighttime the image is based on NASA's Black Marble. The daytime is based on Blue Marble, but blended with a different older image which has better ocean colors and interpolated daily between twelve monthly Blue Marble satellite images. The result of this is that you can see snow and ice coverage changing over the course of the year. If you look closely you'll also notice vegetation growing and dying back with the seasons.

Rendered in a slightly modified build of Catfood Earth (the main release doesn't know how to access my private cache of xplanet cloud images). As well as combining day, night and cloud images Catfood Earth can also show you earthquakes, volcanoes, US weather radar, political borders, places and time zones. It has been enlivening Windows desktop wallpaper for fifteen years now (as shareware back when that was a thing, these days it's a free download for Windows and Android).