Finally, Lord Stern's PR guy got back to me
Of course, this claim was absurd (it was the *total* costs of weather, not the possible, incremental cost of climate)
and they've removed the video
gao.gov/assets/690/687…
Everyone knows you should correct for GDP, and then the trend is downwards (but of course not scary)
tandfonline.com/doi/full/10.10…