By JAMES CHESHIRE Aug. 23, 2021, 9:43 a.m.
Why good graphics are essential for reporting on climate change Like many people, the first graph I ever saw explaining climate change was in a school geography textbook. It showed the “hockey stick” curve of the Earth’s surface temperature over time, which has become one of the world’s most recognizable line graphs.
Despite relatively minor fluctuations, the line on the graph depicting global surface temperature remains almost horizontal across centuries, before suddenly inclining to an almost vertical trajectory over the past 50 years. Since 1970 the rate of global temperature increase has hit an unprecedented 3.06°F (1.7°C) per century.
One challenge of understanding the information contained in this hockey stick graph — and this is a gift to climate-change deniers — is the inclusion of the grey fuzz of “uncertainty data”: outlying data points that can be cherry-picked to raise doubts about the mass of evidence supporting a general warming trend.
Uncertainty is a complex thing to communicate in a single chart. In 2018, the UK-based climate scientist Ed Hawkins chose to omit it altogether when he presented his “warming stripes” graphic to help clearly visualize key trends in climate data. Hawkins explained that the warming stripes were designed to remove all superfluous information, leaving behind only the undeniable scientific evidence of a steadily warming world.
If getting to grips with all the data and complexity in the hockey stick required a long read, Hawkins’ climate stripes give us the headline. The stripes are now a global phenomenon, having appeared on the lapels of U.S. senators, the ties of TV weather presenters, and on the front cover of The Economist.
As calls for change grow louder in light of the latest IPCC (Intergovernmental Panel on Climate Change) report and in the run-up to the COP26 conference in Glasgow this November, it’s time to focus on how data visualization can help people grasp the challenges that lie ahead.
The power of maps
This intriguingly named “Peirce quincuncial” projection, which you can see below, is a type of 2D map that flattens the Earth into a grid of 130 mini maps called tiles. Like all projections, it’s not a perfect representation of the 3D Earth, since some areas are stretched more than others. But it lets us create a series of tiles representing the planet in each year from 1890 to 2019, colored by how and where temperatures deviated from a reliable baseline measured between 1961 and 1990. Blue areas represent temperature anomalies between -3.6°F and 0°F (-2°C and 0°C), while red areas represent anomalies between 0°F and 5.4°F (0°C and 3°C) and gray represents insufficient data.
Reading the images from left to right reveals that while heatwaves and cold spells speckle the grid, tiles representing the current century are increasingly filled with warm tones. For example, compare the few pink splotches in 1976 when the UK experienced its famous heatwave to years later in 2006 and 2016 when ruddy hues spanned the globe. I
n fact, the 10 hottest years on record have occurred since 2005.Full article:
https://www.niemanlab.org/2021/08/why-good-graphics-are-essential-for-reporting-on-climate-change/