My web presence

Wednesday, 5 February 2025

London Thames Barrier update

Two weeks ago I recreated Sea Level Rise (SLR) and Risk of Flooding (RoF) maps for the lower Thames River near the Thames Barrier (blog) for a WhatsApp Group considering the future of its ageing infrastructure w.r.t. recent climate extremes. This week came a global and urgent update affecting Sea Level Rise, by James Hansen who sounded the alarm ~ 35 yrs ago (go to 1981 & 1988 in Medium): a paper incl. supplementary materials "Global Warming Has Accelerated" (Columbia) c/w companion webinar (Columbia).

I mapped conservatively up to 6 m. SLR in my previous blog. But as Extinction Rebellion Scientist in Cambridge UK, I mapped up to 12 m. SLR from increased polar ice melt before the Pandemic. The recent discussion by Hansen above led not only to further upgrade that to 15 m. SLR, but also to shorten IPCC anticipated end-century timeframe to mid-century!


PDF here


Here is the original SLR & RoF map blogged recently based on Ordnance Survey (OS) topography; as a reminder, SLR is a simple model intersecting incremental elevations against topography:

click to enlarge (full A0 plot here)

Here is the updated SLR & RoF map with two key differences:

  • the topography used here is Climate Central's on a no-cost non-commercial license (75 m. resolution slightly down from 50 m. OS): it removes infrastructure and vegetation for better ground-truthing - see the consequence here at a global level of those new calculations published in 2019
  • the timeframe is moved up from 2100 to 2050 due to the combined factors discussed above
click to enlarge (full A0 plot here)

If risk of inundation looks more severe here, it's because it is... for two reasons:

  • SLR is modelled via incremental elevations against topography: the latter, lowered by an avg. 2m. globally, vastly increases the affected areas as discussed by Climate Central above
  • SLR increment is raised to 15 m.: warmer El Niño, accelerated polar ice-melt, lesser cloud albedo and potential AMOC reversal discussed in the opening paper / video caused this upward revision

Here is what the difference looks like, using the same map plotting trick for SLR as for RoF:
  • the original RoF opaque blues are now the original SLR opaque rainbow colors
  • the original up-to-6 m. SLR halftones atop are now the up-to-15 m. SLR halftones to show the wider affected areas
click to enlarge

The stark contrast between the original mustard color overlays against the new rainbow color extents, shows the significant range increase due to this update. Even without running statistics, it underscores Climate Central's estimates of increased areal impact. 

An update will be run on CoastalDEM v.3 licensed this year, against v.2.1 used in 2020 and currently shown. All sources and attribution appear on A0 maps linked above.
To recap, what was a "far-tail" scenario at 12 m. SLR ca. 2150, is now drastically brought forward to 2050, due to newly studied and combined accelerated climate effects. In addition, the targeted 1.5°C annual increase has already been reached and replaced by possible 4°C annual increase that is not sustainable. 

Thursday, 30 January 2025

A brief web history of mine

As I wind down my blog posts and I quit socials, perhaps this may be a good time to reflect on my Web journey that started almost 40 years ago (a recap of my IT journey is here)...

But wait... Tim Berners-Lee didn't invent it til just over 35 years ago (Wikipedia)! That's because I had a site dubbed HTTP in 1986, see inset below:  "world wide web" hadn't been coined yet, but I knew as a student at late 70's University of Calgary of Ted Nelson's failed Project Xanadu (Wikipedia), to try and link all forms of knowledge via hypertext; it failed partly due to Nelson's eccentricity,  partly because there was no global network to carry it. 

Tuesday, 21 January 2025

London Thames Barrier revisited

Update 2: see renewed Sea-level Rise extents according to new information here 

Update 1: see addition at bottom... thanks to our indefatigable London climate activists!

Further to my original blog post 3½ yrs. ago here, I was asked to share maps of the area surrounding the Thames Barrier (Wikipedia): A WhatsApp group considered the necessity for a second barrier under Climate Change that increases both flooding and sea level seasonal elevations. 

Saturday, 4 January 2025

Exhuming my thesis ... an update

Update 2:  ... aaaand I didn't plan on having yet another one here!

Update 1: this is my last post as I move on. Didn't plan it that way, but ending where I began  _is_ satisfying.

Wednesday, 1 January 2025

New Years Eve 2000 racing by Greenwich Meridian

Update: note a dash of AI mixed in at the bottom for fun

Our TV rung in 2025 live in Paris in my time zone, and six hours later in NYC dropping its ball in Times Square; nothing matches however this cracking event in London to usher in the New Millennium: barges were aligned in the middle of the River Thames, spaced exactly 1 s. apart as the earth rotated past midnight GMT in London, from the Meridian at the Millennium Dome to the east, to Vauxhall Bridge to the west.

Thursday, 26 December 2024

Exhuming my thesis area over 40 years later

Update: see here papers a decade later that point also to precambrian terranes.

My 1982 M.Sc. thesis, Regional cross section of the Southern Province adjacent to Lake Huron, Ontario: implications for the tectonic significance of the Murray Fault Zone (ResearchGate) proposed a plate-tectonic (Wikipedia) setting around 1.9 billion years ago, in the Proterozoic (late Pre-Cambrian). I presumed there was another buried land mass south of what I called the Manitoulin Island Discontinuity. While plate tectonics was well established in the later Phanerozoic (Wikipedia) record, it took a lot longer to be accepted earlier in the geologic time scale with lot scanter rock record to go by (more at the bottom).

Monday, 16 December 2024

Senegal delta sea level rise map

Five friends at Arts & Metiers engineering school in Paris took a ten month leave to sail around the North Atlantic: Lez'Arts Marins (here) sail south from Britanny past the Azores & Madeira to Senegal for a moth humanitarian aid project, west across to Martinique and northeast N of Scotland to Scandinavia and back.

Sunday, 24 November 2024

Arctic Urban Legends

An update to a Northwest Passage blogpost posted to the Facebook Rememberig Frankline Expedition group, elicited a response from @aaron.spitzer. I post his comment below, which I thanked him for citing the fact my stories were from conversations that weren't fact-checked. That in turn got me to fact-check another story from the same 1986 summer in the Arctic Islands from my now-defunct original website reposted at bottom.

Tuesday, 12 November 2024

Cumbria classic revisited, Appleby-in-Westmoreland

Almost four years ago, a story map here showed the Skelworth Fold area of the Lake District for a friend, using advanced mapping and Environment Agency digital elevation.

Tuesday, 5 November 2024

"AI for the rest of us", Part VII

Note: the last post on my personal Medium channel shows how I used Copilot AI to good effect for fact-checking. 

Last we showed here how to create "quick & dirty" graphs while chatting on ur mobile. Now we'll see how we can create summaries, not from "text to hand", but from that cribbed off the internet. 

Having left socials, I'm down to corresponding at Extinction Rebellion "Media Tell the Truth" WhatsApp group. Jon Fuller there is also at "Climate Genocide Act Now" here. I was a scientist for Extinction Rebellion, and blogged here about the pandemic against the lies of the British government, as well as about floods and rising sea levels in East Anglia. I didn't know GCAN, however, as I'm no longer active.