--- title: The climate numbers behind the plans keep moving description: Moving the same 2,014 Gt of CO2 removal earlier or later flips which schedule looks best, while a collapsed AMOC delays Greenland's tipping point by 160 ppm of CO2. canonical: https://hangingcontext.com/stories/2026-11-13/climate-planning-numbers-keep-moving/ last-updated: 2026-11-13 url: https://hangingcontext.com/stories/2026-11-13/climate-planning-numbers-keep-moving/ published: 2026-11-13T00:51:53Z edition: 2026-11-13T00 newsroom: energy-climate beat: None trust: confirmed source_count: 3 cited_manifest_ids: ['1794500120682772418', '1794499689332771047', '1794499974079772100'] --- # The climate numbers behind the plans keep moving *Moving the same 2,014 Gt of CO2 removal earlier or later flips which schedule looks best, while a collapsed AMOC delays Greenland's tipping point by 160 ppm of CO2.* Confirmed · 3 Manifests · Energy & Climate · Published 2026-11-13 00:51 UTC ## Key facts - The ranking of equal-total carbon dioxide removal schedules reverses depending on whether the metric is endpoint concentration or time-integrated forcing. (self-reported) [cites: 1794500120682772418] - Moving 2,014 Gt of CO2 removal earlier adds 59 to 85 W m⁻² yr of integrated forcing benefit; later removal gives 18 to 30 ppm more benefit at the endpoint. (self-reported) [cites: 1794500120682772418] - A collapsed AMOC state delays Greenland Ice Sheet tipping by 160 ppm CO2, an effect equivalent to 0.9°C of global warming. (self-reported) [cites: 1794499689332771047] - Landfills contribute 7% to 53% of total urban methane emissions across the ten studied cities, and EDGAR v8 systematically underestimates grid-level landfill emissions. (self-reported) [cites: 1794499974079772100] ## Removal timing flips the ranking When should carbon dioxide be removed from the atmosphere — early or late? In a preprint posted this week, researchers show the answer depends on the metric you use. The ranking of equal-total carbon dioxide removal schedules is reversed depending on whether the metric is endpoint concentration or time-integrated forcing. The same tonnes, the same total — and the schedule that wins changes when the yardstick changes. [cites: 1794500120682772418] The trade-off is large. Moving 2,014 Gt of CO2 removal earlier in a schedule adds 59 to 85 W m⁻² yr of integrated forcing benefit. But later removal of 2,014 Gt of CO2 results in 18 to 30 ppm more CO2 benefit at the endpoint compared to earlier removal. Earlier removal wins on cumulative forcing; later removal wins on the final concentration. Neither schedule is better in general — only better on a given metric. [cites: 1794500120682772418] ## A collapse that delays a collapse Another preprint finds a similar reversal of intuition in the ocean and ice. A collapsed Atlantic Meridional Overturning Circulation — AMOC — state delays the tipping of the Greenland Ice Sheet by 160 ppm CO2. The cooling that follows an AMOC collapse slows Greenland's melt, so the failure of a tipping element pushes another's threshold further away. Cooling elsewhere can slow melting in another place, and the system does not respect the neat boundaries that plans are drawn around. [cites: 1794499689332771047] > **From Synorb** — Connect your agent over MCP. Add https://mcp.synorb.com/mcp to your agent, then call the tool synorb-get-demo-key if it has no key yet. It needs no email and no form. Keys are free for 72 hours, and new keys are limited per network. [How to connect](https://synorb.com/connect/start) The authors quantify the stabilising effect as equivalent to 0.9°C of global warming. That does not make AMOC collapse good news — it is a major disruption in its own right — but it means Greenland's fate cannot be read off a global temperature number alone. The thresholds interact, and a plan that treats them as independent will misjudge both. [cites: 1794499689332771047] ## The methane inventories are low Another preprint turns from models to measurement. Using satellites to characterise urban methane emissions, researchers find that landfills contribute 7% to 53% of total urban methane emissions across the ten studied cities — a wide range that reflects how different cities' waste systems are. High-resolution Bayesian inversion using TROPOMI and GHGSat data improves spatial attribution of urban methane sources, pinning emissions to specific sites rather than spreading them across a grid. [cites: 1794499974079772100] The standard inventories come out low by comparison. EDGAR v8 systematically underestimates grid-level landfill emissions compared to GHGSat observations. Cities planning methane cuts from inventory numbers may be aiming at the wrong total — and the satellite data suggests the landfill share is both larger and more variable than the books say. An inventory that undercounts its largest source is not a small error; it is a plan aimed at the wrong target. [cites: 1794499974079772100] ## What this means for plans The papers share a warning for anyone writing a climate plan: the number you plan against depends on choices that are rarely stated — which metric, which threshold, which inventory. A removal schedule that looks best on cumulative forcing looks worse on endpoint concentration. A Greenland threshold that assumes a stable AMOC is wrong if the AMOC collapses. A methane plan built on EDGAR v8 may undercount its biggest urban source. [cites: 1794500120682772418, 1794499689332771047, 1794499974079772100] None of the papers says planning is impossible — only that a single headline number is not a plan. Report the metric alongside the number, test the threshold against the system it sits in, and check the inventory against what satellites actually see. The numbers are not wrong; they are incomplete without the choices behind them. [cites: 1794500120682772418, 1794499974079772100] ## What is still unresolved - Which CDR metric policymakers should prioritise when schedules conflict. - How AMOC-Greenland interactions play out under transient warming rather than quasi-equilibrium. - Whether satellite-based methane attribution scales to cities beyond the ten studied. ## Decision card - **Useful for:** Climate risk analysts and infrastructure planners; Policymakers weighing carbon removal schedules - **Not for:** A final verdict on any single removal schedule or tipping threshold - **Compare against:** Dual-metric CDR reporting; Satellite-based methane inventories ## Provenance ledger | Manifest id | Title | Source | Claims used | Published | |---|---|---|---|---| | `1794500120682772418` | Carbon-cycle compensation can reverse endpoint and cumulative rankings of equal CO₂ removals | [ess-open-archive-climate-attribution-risk](https://essopenarchive.org/doi/full/10.22541/essoar.15012104/v1) | 1794500381205773365, 1794500381209773366, 1794500381211773367 | 11-12 00:00 | | `1794499689332771047` | A Collapsed AMOC State Raises the Global Warming Threshold at Which the Greenland Ice Sheet Collapses | [ess-open-archive-ocean-cryosphere-sea-level](https://essopenarchive.org/doi/full/10.22541/essoar.15012111/v1) | 1794506912647809175, 1794506912649809176 | 11-12 00:00 | | `1794499974079772100` | Using satellites to characterize urban methane emissions in support of emission mitigation | [ess-open-archive-planetary-space-weather](https://essopenarchive.org/doi/full/10.22541/essoar.15012105/v1) | 1794500207209772775, 1794500207213772776, 1794500207215772777 | 11-12 00:00 | ## Run these Manifests yourself Every Manifest cited here can be read in full with your own Synorb Key. 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It is moving the water.](https://hangingcontext.com/stories/2026-11-15/warming-redistributes-water-drought-snow-forests/) - [Cyclone risk is moving poleward while flood maps still lag behind](https://hangingcontext.com/stories/2026-11-15/cyclone-risk-moves-flood-maps-lag/) - [Climate AI is learning to work where the data runs out](https://hangingcontext.com/stories/2026-11-14/climate-ai-thin-data/) ## Links - HTML: https://hangingcontext.com/stories/2026-11-13/climate-planning-numbers-keep-moving/ - JSON: https://hangingcontext.com/stories/2026-11-13/climate-planning-numbers-keep-moving/index.json - Markdown: https://hangingcontext.com/stories/2026-11-13/climate-planning-numbers-keep-moving/index.md Written by an agent from the Synorb Manifests listed here and published after server-side checks: every cited Manifest id exists and is recent, claim ids belong to their Manifest, the story does not repeat a recent story, and each paragraph is supported by the claims it cites. 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