Inspirations Behind the IPCC 6th Assessment Graphic

Yesterday the IPCC 6th Assessment published its Synthesis Report (SYR) which included this graphic (SYR.1c) which has been a popular way to discuss future warming in the context of different generations.
What were the inspirations for this graphic?
A thread... 🧵 pic.twitter.com/TToDC7J9kn

— Ed Hawkins (@ed_hawkins) March 21, 2023

Within the formal IPCC process there are (at least) two other relevant figures from the WGI report.
From the Technical Summary, Figure TS.6 used a similar concept but focussed the future projections component on communicating the time of reaching different global warming levels. pic.twitter.com/ztTzq8lMk7

— Ed Hawkins (@ed_hawkins) March 21, 2023

As an aside, here is Figure SYR.2 which also borrows some concepts from WGI TS.6 to discuss impacts at different global warming levels. pic.twitter.com/NZFFkytWxF

— Ed Hawkins (@ed_hawkins) March 21, 2023

But, the more obvious link for SYR.1c is with Figure 1.25, the development of which was led by @meinshausen. This shows warming stripes back to 1750 and out to 2100, including inter-annual variations, the uncertainty in projections & emission reduction concepts. pic.twitter.com/wsJUQ0OTHC

— Ed Hawkins (@ed_hawkins) March 21, 2023

Obviously, Figure 1.25 was itself inspired by the original warming stripes, but... pic.twitter.com/wbYiycIj2l

— Ed Hawkins (@ed_hawkins) March 21, 2023

... perhaps more importantly, was also inspired by @alxrdk, who has published various versions of his 'warning stripes' here on twitter.
The IPCC WGI Chapter 1 authors, with encouragement from @valmasdel & @SISeneviratne, saw @alxrdk's graphics and decided to include a version. pic.twitter.com/qBQS89C9fe

— Ed Hawkins (@ed_hawkins) March 21, 2023

And, going further back, the warming stripe graphics themselves took inspiration from a knitted blanket by @EllieHighwood https://t.co/hnR4e1x9QV

— Ed Hawkins (@ed_hawkins) March 21, 2023

But graphics also need underlying data. The observations come from the various international groups producing global temperature estimates, assessed in Chapter 2. The assessed projections are in Chapter 4, based on lots of model simulations & research on how to constrain them.

— Ed Hawkins (@ed_hawkins) March 21, 2023

Last, the development of the graphic used in the SYR was led by @BckgrndStories & @AlexRuane who introduced the generational icons which have helped make this version of the graphic so powerful. pic.twitter.com/eljNRtQM6s

— Ed Hawkins (@ed_hawkins) March 21, 2023

The development of this figure took place over several months, with numerous discussions about what aspects to include. Personally I would have liked the inclusion of some historical events for extra context, as in an earlier version I made, but these were not added in the end. pic.twitter.com/EkSyc3r2zV

— Ed Hawkins (@ed_hawkins) March 21, 2023

I hope this thread gives some insight into how visuals like SYR.1c are developed. There is no single point of inspiration. There is no single inventor. It is a deeply collaborative & iterative process, relying on inspiration from a wide collection of people over several years.

— Ed Hawkins (@ed_hawkins) March 21, 2023