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Research sweep · deep · 1970 – 2026

Climate Change - Evidence, Attribution, Projections and Remedies

Climate change from the 1970s to June 2026: the measured surface-temperature record (HadCRUT5, NASA GISTEMP, NOAA, Berkeley Earth) and cryosphere proxies (NSIDC sea-ice, snow cover, glacier mass balance, ocean heat content), biodiversity feedbacks, attribution to fossil-fuel carbon, and forward projections under current-trend and modelled scenarios (IPCC AR6, CMIP6 SSPs), through to the evidence base for remedies from ocean and land carbon sinks to solar geoengineering, weighting recent authoritative sources (IPCC, PNAS, Nature Climate Change, Copernicus/ECMWF) over older ones.

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Synthesised 2026-06-26

Climate Change 1970–2026: The Measured Record, the Money, and the Remedies

Overview

The climate story split into two registers over the past eighteen months. The physical science kept producing records, and the financial system started pricing them. In 2024 the planet crossed 1.5°C above pre-industrial for a full calendar year for the first time, confirmed by five independent science agencies, and the financial press treated this not as a forecast but as an accounting fact with balance-sheet consequences.

Sources: Bloomberg (2025) (↗); WTW (2025) (↗)

The defining shift is the move from scenario planning to damage measurement. Global climate-driven losses topped $1.4 trillion in 2024, roughly ten times the 2000 total, and insured losses exceeded $140 billion for the fifth straight year. At the same time, capital flows decoupled from rhetoric: clean technology drew $2.2 trillion of the IEA's record $3.3 trillion in 2025 energy investment, double the fossil-fuel figure, even as US banks fled the Net-Zero Banking Alliance and the SEC abandoned its disclosure rules.

Sources: BloombergNEF (2025) (↗); WTW (2025) (↗); International Energy Agency (2025) (↗); Bloomberg (2025) (↗)

The science itself converged and sharpened. Five datasets agree 2024 was the warmest year in 175 years at 1.55 to 1.62°C, while the cryosphere proxies (Arctic sea-ice minima, ocean heat content, Svalbard glacier loss) all broke records in lockstep. The remaining carbon budget for a coin-flip chance at 1.5°C is now measured in single-digit years.

Sources: Berkeley Earth (2026) (↗); Copernicus Climate Change Service / ECMWF (2025) (↗); Global Carbon Project (2025) (↗)

What separates this moment from prior alarm cycles is that the genuine disagreements are now between scientists, not between scientists and deniers. Hansen versus Dessler on committed warming, and the AMOC tipping-debate, are live empirical questions inside the consensus framework. Organised "scepticism" has retreated to attacking solutions and scientist integrity, a shift the Christian Science Monitor labelled the move from old denial to new denial.

Sources: Climate Uncensored (Substack) - James Hansen, Pushker Kharecha, Dylan Morgan, Jasen Vest (2025) (↗); The Climate Brink (Substack) - Andrew Dessler, Texas A&M (2024) (↗); Christian Science Monitor (2024) (↗)

Timeline

Key milestones, 1970-2026

1970

Climate models begin making testable temperature projections

2006

Stern Review frames climate as the greatest market failure

2017

TCFD splits climate risk into physical and transition

2021

HadCRUT5 closes polar coverage gap
AR6 WG1 narrows ECS to 2.5-4C

2022

16 tipping elements mapped against warming thresholds
US Inflation Reduction Act passes

2023

AR6 Synthesis Report
Hansen warming-in-the-pipeline debate opens

2024

First full calendar year above 1.5C
Climate-tech VC funding falls 40 percent
SCoPEx geoengineering experiment cancelled

2025

SEC repeals climate disclosure
US banks exit Net-Zero Banking Alliance
Arctic sets record-low sea-ice maximum

2026

Carbon budget for 1.5C down to roughly four years
Higher cloud-feedback sensitivity estimates published

Key Findings

The instrumental record is now boringly consistent, which is the point. HadCRUT5, GISTEMP, NOAA, Berkeley Earth, and ERA5 all place 2024 as the warmest year on record at 1.55 to 1.62°C above 1850 to 1900, with the eleven warmest years all falling in the last eleven. Berkeley Earth's 2025 figure of 1.44 ± 0.09°C combined 23 million station readings with around 500 million ocean observations. The convergence of methodologically independent products is the strongest single defence against the homogenisation complaints that dominated earlier debate.

Sources: Berkeley Earth (2026) (↗); Berkeley Earth (2026) (↗); NASA Goddard Scientific Visualization Studio (2026) (↗); NCAR Climate Data Guide (2025) (↗)

Cryosphere proxies corroborate the surface record without relying on it. Arctic sea-ice maximum extent in March 2025 hit 14.33 million km², the lowest in the 47-year satellite record and 1.31 million km² below the 1981 to 2010 average, with ice older than four years down more than 95% since the 1980s. NOAA's Arctic Report Card 2025 found the last ten years are the ten warmest on record there, and glaciers losing ice three times faster than in the 1990s. Upper-2000m ocean heat content set new records in both 2024 and 2025, rising 16 zettajoules between 2023 and 2024, roughly forty times annual global electricity generation.

Sources: National Snow and Ice Data Center (NSIDC) (2025) (↗); NOAA Arctic (2025) (↗); Advances in Atmospheric Sciences (2026) (↗); Advances in Atmospheric Sciences (2025) (↗)

Attribution is settled even as climate sensitivity stays open. AR6 attributed 0.8 to 1.3°C of the observed warming to human activity, and isotopic fingerprinting (falling ¹³C/¹²C ratios) ties the CO₂ rise to fossil combustion unambiguously. The live question is equilibrium climate sensitivity: CMIP6 spans 1.8 to 5.6°C, AR6 narrowed the likely range to 2.5 to 4°C, and 2026 cloud-feedback analyses point towards the higher end. This is the genuine uncertainty, distinct from the industry-funded attacks on attribution that the science has long closed out.

Sources: IPCC (2023) (↗); IPCC (2021) (↗); Geophysical Research Letters (2026) (↗)

Old climate models held up. RealClimate's January 2026 model-observation update confirmed that projections published since 1970 have been skillful, and a Geophysical Research Letters review of 25 annual forecasts found they captured the record warmth of 2023 and 2024. This matters for the projection sections: the tools sceptics dismissed for decades have a track record.

Sources: RealClimate - Gavin Schmidt et al. (2026) (↗); Geophysical Research Letters (2025) (↗)

The carbon-cycle buffer is weakening. A November 2025 Nature paper revised the natural land sink downwards and increased net land-use-change emissions, shrinking the apparent buffer on remaining budgets. The Global Carbon Budget 2025 logged fossil CO₂ emissions rising 1.1% to a record 38.1 billion tonnes, with the budget for a 50% chance of staying under 1.5°C down to roughly four years. Atmospheric CO₂ reached 423 ppm in 2024, far above the 180 to 280 ppm band of the past 800,000 years recorded in ice cores.

Sources: Nature (2025) (↗); Global Carbon Project (2025) (↗); Earth System Science Data (Copernicus) (2025) (↗)

Money moved towards adaptation while mitigation stalled. McKinsey's January 2026 tracking found global emissions up 9% since 2015, with under 15% of the low-emissions technology needed for Paris-aligned 2050 deployed. Bain's 2025 survey found only 32% of energy executives still expect net zero by 2050, down from nearly 40% a year earlier, and only 3% of climate capex going to adaptation despite operations chiefs ranking resilience top priority. The investment thesis flipped from green premium to green discount.

Sources: McKinsey & Company (2026) (↗); Bain & Company (2025) (↗); Bain & Company (2025) (↗)

Carbon removal is real but five orders of magnitude short. Carnegie Endowment noted BECCS removes 0.00051 GtCO₂ per year against 37.4 GtCO₂ of fossil emissions. Bain found 2025 durable CDR purchases projected at 14 million tonnes but deliveries under half a million, and CDR.fyi logged just $3.6 billion of private capital into removal companies across 2021 to 2025, peaking in 2023. The IAM dependence on removal at scale is not matched by any deployment curve.

Sources: Carnegie Endowment for International Peace (2025) (↗); Bain & Company (2025) (↗); CDR.fyi (2026) (↗)

Climate-tech venture funding contracted hard, with exceptions. CB Insights recorded a 40% year-on-year fall in 2024 funding, mega-rounds down 47%, EV deals off 61%. Sightline's H1 2025 data showed $13.2 billion across 653 deals, down 19%, with seed funding off 26%. Gartner's 2024 Hype Cycle placed no sustainability technology on the slope of enlightenment, a striking signal that the field remains pre-validation even after a decade of attention.

Sources: CB Insights (2025) (↗); Sightline Climate (2025) (↗); Gartner (2024) (↗)

Tipping-point science hardened into the policy mainstream. Armstrong McKay et al. (Science, 2022) identified 16 tipping elements, five already possible at current warming and four more likely above 1.5°C. AMOC remains the most contested: CMIP6 medium scenarios show no 21st-century collapse, but van Westen et al. (2024) provide physics-based early-warning signals of a tipping trajectory, and independent estimates on the EA Forum range from the IPCC's "very unlikely" to a 59% mid-century probability in unpublished work.

Sources: Science (2022) (↗); Science Advances (2024) (↗); EA Forum (independent analysis) (2025) (↗)

Evidence & Data

The temperature anchors: 2024 at 1.55 to 1.62°C across five datasets, 2025 at 1.44 ± 0.09°C (Berkeley Earth) and effectively tied with 2023 for second warmest (Carbon Brief). Human-induced warming sat at 1.36°C in the 2024 Global Carbon Budget. CO₂ reached 423 ppm in 2024 and emissions hit 38.1 billion tonnes in 2025.

Sources: Berkeley Earth (2026) (↗); Carbon Brief (2026) (↗); Earth System Science Data (Copernicus) (2025) (↗); Global Carbon Project (2025) (↗)

The economics: $1.4 trillion in 2024 climate losses, $140 billion insured, $350 billion total economic damage. A 10-point rise in modelled asset-damage risk adds 22 basis points to weighted average cost of capital. NGFS revised 2°C damages to 15% of global GDP by 2050, three times its earlier figure, while the CBO offered a much narrower 3 to 4% GDP hit by 2100. McKinsey Global Institute put the cost of protecting all exposed people at 2°C at $1.2 trillion annually.

Sources: BloombergNEF (2025) (↗); Bloomberg Professional Services (2026) (↗); CEPR / VoxEU (2024) (↗); Congressional Budget Office (2025) (↗); McKinsey Global Institute (2025) (↗)

The capital picture: $3.3 trillion total energy investment in 2025, $2.2 trillion clean versus $1.1 trillion fossil, a ratio reversed from a decade ago. Yet the top 65 banks channelled $429 billion to fossil-fuel expanders in 2024, up $84.8 billion. Climate finance funds raised a record $92 billion across 179 vehicles in 2025. BloombergNEF's base case sees carbon-credit supply growing from 243 million tonnes in 2024 to 2.6 billion in 2030 only if governance holds.

Sources: International Energy Agency (2025) (↗); Oil Change International (2025) (↗); Bloomberg (2026) (↗); BloombergNEF (2025) (↗)

The geoengineering numbers: the Simons Foundation committed $50 million over five years to SRM research in 2024, UKRI and NERC a £10.5 million programme. A 2026 Earth System Dynamics paper modelled SAI raising global land carbon storage by 5.9% under SSP585, while npj Climate Action estimated SAI side-effect harms at zero to $809 billion annually.

Sources: Solar Geoengineering Updates (Substack) (2025) (↗); Earth System Dynamics (Copernicus) (2026) (↗); npj Climate Action (2025) (↗)

Signals & Tensions

Damage functions are unstable and everyone knows it. The Potsdam Institute's 2024 Nature paper projecting 19% committed income loss by 2050 was retracted by December 2025 and resubmitted for review, after wide citation in investor briefings. The spread between NGFS (15% of GDP) and the CBO (3 to 4%) is an order of magnitude. The financial press now covers this methodological fragility explicitly rather than reporting headline figures as settled.

Sources: Potsdam Institute for Climate Impact Research (2024) (↗); Euronews (2026) (↗); CEPR / VoxEU (2024) (↗)

Committed warming is a genuine scientist-versus-scientist split. Hansen's team projects underlying warming accelerated to roughly 0.31°C per decade via aerosol unmasking, arguing the IPCC understates sensitivity. Dessler argues very little warming is in fact locked in. Both accept the forcing framework; the disagreement is real and bears directly on SSP2-4.5 projections.

Regulatory divergence is now an arbitrage, not a debate. The SEC repealed disclosure rules in March 2025 and US banks exited the Net-Zero Banking Alliance, while the EU's CBAM went fully operational and the ECB embedded physical risk in supervision. This split is a material factor in cross-border capital allocation, not a normative side-show.

Sources: Bloomberg Professional Services (2026) (↗); Bloomberg (2025) (↗)

SST homogenisation is the last serious measurement uncertainty. Menemenlis et al. (2025) show satellite-era SST trends differ by dataset, MERRA2 at 0.176°C per decade versus ERA5 at 0.142°C. This propagates into global trend estimates and is the one place where the "contested measurement" framing carries weight, distinct from the discredited station-siting complaints.

Sources: NCAR Climate Data Guide (2025) (↗); Geophysical Research Letters (2026) (↗)

Geoengineering moved from lab to legislature. The SCoPEx cancellation and over 16 US state legislatures introducing SRM bans in early 2025 shifted the debate from scientific governance to politics, while research funding rose. The signal is that deployment pressure may arrive before the science can constrain monsoon and ozone side-effects.

Sources: Science News (2025) (↗); Oxford Open Climate Change (2024) (↗)

The contracted-versus-delivered CDR gap is underreported. Bain's 14 million tonnes contracted against under half a million delivered is the kind of structural shortfall that undermines corporate net-zero accounting built on durable removal credits.

Sources: Bain & Company (2025) (↗)

Open Questions

Where does equilibrium climate sensitivity actually sit? CMIP6 spans 1.8 to 5.6°C and 2026 cloud-feedback work pushes towards the high end, but marine low-cloud feedback remains unresolved despite CERES constraints. Sources: Geophysical Research Letters (2026) (↗); IPCC (2021) (↗)
Is the AMOC on a tipping course this century? Physics-based early-warning signals say yes, CMIP6 medium scenarios say not before 2100, and probability estimates range from "very unlikely" to 59% by mid-century. Sources: Science Advances (2024) (↗); Environmental Research Letters (2025) (↗); EA Forum (independent analysis) (2025) (↗)
How fast is the natural land sink weakening, and how much budget does that erase? The November 2025 Nature revision cut the buffer, but carbon-cycle feedback rates span an order of magnitude. Sources: Nature (2025) (↗)
Can durable CDR close a five-order-of-magnitude gap in time to matter for IAM pathways that assume it? Nothing in the deployment or funding data suggests yes. Sources: Carnegie Endowment for International Peace (2025) (↗); CDR.fyi (2026) (↗)
What is the true distribution of economic damage? An order-of-magnitude spread between empirical and IAM approaches, plus the Potsdam retraction, leaves the central estimate genuinely open. Sources: Euronews (2026) (↗); Congressional Budget Office (2025) (↗)
Will SAI's modelled benefits survive contact with monsoon, ozone, and termination-shock risks? The Oxford Open systematic review found scenario, model, and natural-variability uncertainties all poorly quantified for policy. Sources: Oxford Open Climate Change (2024) (↗); Earth System Dynamics (Copernicus) (2026) (↗)
Does the high-emissions pathway still deserve weight? Hausfather argues SSP5-8.5 has reduced plausibility given current policy, which would reshape both physical projections and damage modelling. Sources: Environment and Planning - Zeke Hausfather (2025) (↗)

The measurement is no longer the argument. The argument is what the numbers cost, who pays, and whether the remedies in the models exist anywhere outside them.

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Sources

Summary: ↑ Back to summary

Financial Press

ID	Title	Outlet	Date	Significance
f1	Record Heat Pushed 2024 Above Global Warming Threshold of 1.5C	Bloomberg	2025-01	Bloomberg's primary news report confirming five science agencies' verdict that 2024 was the hottest year on record and the first to breach the 1.5°C Paris threshold.
f2	Ten data insights showing the continued rise of climate risk and what investors should look out for in 2026	Bloomberg Professional Services	2026-04	Quantifies the direct cost-of-capital impact of physical climate risk on companies and tracks outperformance of climate-adaptation equity indices in 2025.
f3	Climate Finance Funds Attract Record Inflows in 'Feast or Famine' Year	Bloomberg	2026-04	Reports the record $92 billion raised by 179 climate finance funds in 2025, doubling from 2024, while noting the structural shift away from early-stage bets towards infrastructure.
f4	Climate Finance Finds Itself at a Pivotal Moment in History	Bloomberg	2025-04	Documents the withdrawal of US banks, led by Goldman Sachs, from the Net-Zero Banking Alliance following Trump's re-election, and analyses the long-run financial costs of that reversal.
f5	Investing in Carbon Markets As Climate Policy Shifts	Bloomberg	2025-08	Examines the gap between voluntary carbon markets' projected and actual scale, and profiles private-sector attempts to introduce standardised credit-rating frameworks.
f6	Long-Term Carbon Credit Supply Outlook 2025	BloombergNEF	2025-08	Projects carbon credit supply from 243 million tonnes in 2024 to 2.6 billion tonnes by 2030 in the high-quality scenario, with direct air capture as the cost driver, providing the canonical supply-side baseline.
f7	Canada, Singapore and UK Among Countries Most Prepared for Climate Change, BloombergNEF's New Ranking of Climate Adaptation Preparedness Finds	BloombergNEF	2025-10	Provides the first investor-facing country-level climate adaptation scorecard, reporting that global climate-driven losses exceeded $1.4 trillion in 2024, nearly tenfold the figure from 2000.
f8	What a New Model of Climate Finance Can Look Like	Bloomberg	2025-11	Covers pre-COP30 Sao Paulo discussions between bankers on restructuring climate finance models, with EU Commissioner Ribera commentary on European regulatory pressures.
f9	June 2026 Global Regulatory Brief: SEC climate disclosure repeal, transition finance and carbon market rules	Bloomberg Professional Services	2026-06	The most recent regulatory snapshot, documenting SEC abandonment of climate disclosure rules, EU CBAM operation, and Article 6 carbon market developments as of June 2026.
f10	Banking on Climate Chaos 2025: Fossil Fuel Finance Report	Oil Change International	2025-06	The 16th annual edition documenting $429 billion in fossil-fuel-company financing by the world's 65 largest banks in 2024, an $84.8 billion increase from 2023 despite net-zero pledges.
f11	World Energy Investment 2025 – Executive Summary	International Energy Agency	2025-06	Authoritative annual benchmark showing clean energy attracting $2.2 trillion versus $1.1 trillion for fossil fuels in 2025, the first year fossil fuel investment declined since 2020.
f12	Global energy investment set to rise to $3.3 trillion in 2025 amid economic uncertainty and energy security concerns	IEA	2025-06	Official press release quantifying solar's $450 billion single-year investment and the 50% premium of electricity-sector investment over total fossil fuel supply spending.
f13	With 2024 the first year to exceed 1.5°C warming, the insurance protection gap for natural catastrophes stands at 60%, according to WTW Natural Catastrophe Review	WTW	2025-01	Establishes the 60% insurance protection gap for natural catastrophes alongside the fifth consecutive year of insured losses exceeding $100 billion, directly linking 1.5°C breach to financial exposure.
f14	How boards can use insurance to fully manage climate risk	World Economic Forum	2025-10	Cites NGFS 2024 revised estimates that climate damages could reach 15% of global GDP by 2050 under 2°C warming, three times earlier NGFS assessments, with relevance for corporate risk governance.
f15	Global climate predictions show temperatures expected to remain at or near record levels in coming 5 years	World Meteorological Organization	2025-05	WMO's decadal forecast showing a 70% chance the 2025–2029 five-year average will exceed 1.5°C, providing the forward temperature baseline used in financial stress-testing.
f16	Climate change: global temperature	NOAA Climate.gov	2025-05	NOAA's authoritative summary confirming the ten warmest years in the 175-year record all occurred 2015–2024, with warming rate tripling since 1975, underpinning financial risk modelling baselines.
f17	Economic losses from climate change are probably larger than you think: New NGFS scenarios	CEPR / VoxEU	2024	Synthesises the new NGFS damage scenarios showing the range of potential GDP loss from 2% to 45% by end of century depending on damage function, a directly investor-relevant spread.
f18	The Risks of Climate Change to the United States in the 21st Century	Congressional Budget Office	2025-02	Official US government probabilistic assessment of climate's GDP impact, central estimate –3% to –4% by 2100, providing the legislative anchor for US fiscal and financial planning.
f19	38 trillion dollars in damages each year: World economy already committed to income reduction of 19% due to climate change	Potsdam Institute for Climate Impact Research	2024-04	The widely cited Nature study estimating $38 trillion annual damages by 2050, subsequently revised and retracted in December 2025 for peer re-review, illustrating the methodological fragility of headline damage figures.
f20	Economic models 'fail to capture' severity of climate damages. Is a global financial crash looming?	Euronews	2026-02	Synthesises University of Exeter and Carbon Tracker analysis warning that standard damage functions create a 'false sense of security', with ECB work quantifying immediate EU losses at 0.26% of output in 2024 alone.
f21	AMOC: Is global warming tipping key Atlantic ocean currents towards 'collapse'?	Carbon Brief	2026-04	Comprehensive explainer on AMOC tipping-point evidence and media coverage patterns, directly relevant to financial stress-testing of tail risks given the implications for European and North American weather systems.
f22	Physics-based early warning signal shows that AMOC is on tipping course	Science Advances	2024	Peer-reviewed study finding reanalysis products indicate the present-day AMOC is on a tipping trajectory, the underlying science behind financial risk of AMOC-related systemic disruption.
f23	How mitigating and adapting to climate change can create investment opportunity	Bloomberg Professional Services	2024-07	Bloomberg's own practitioner-oriented analysis of physical and transition risk modelling, explaining how sector-by-sector climate risk feeds into portfolio construction and net-zero investment strategies.
f24	Five Lessons From the IEA's 2025 World Energy Outlook for the Transition Away from Fossil Fuels	IISD	2025	Analyses IEA scenario divergence between current-policy and net-zero pathways, including oil price trajectories from $65 today to $104 under continued fossil-fuel expansion, key for energy-sector equity and bond valuation.
f25	Increasing climate change losses threaten insurance industry financial stability	Green Central Banking	2024-12	Quantifies climate-attributed insured losses at $600 billion over 2002–2022 growing at 6.5% annually, and identifies the systemic financial-stability risk from insurers' market withdrawal.

Academic & arXiv

ID	Title	Outlet	Date	Significance
a1	Global Temperature Report for 2025	Berkeley Earth	2026-03	Definitive annual surface temperature synthesis combining 57,685 stations and 500 million ocean observations, placing 2025 as third warmest year at 1.44 degrees C above pre-industrial baseline.
a2	Global Temperature Report for 2024	Berkeley Earth	2026-01	Establishes 2024 as the warmest year on record at 1.62 degrees C above pre-industrial, cross-referenced against GISTEMP, NOAA and HadCRUT5.
a3	Record Temperature Years: 2025, 2024, and 2023 (GISTEMP v4)	NASA Goddard Scientific Visualization Studio	2026-02	NASA GISTEMP v4 confirmation that 2023, 2024, 2025 are the three warmest years in the 146-year instrumental record, with full data lineage to Lenssen et al. 2024.
a4	An Updated Assessment of Near-Surface Temperature Change from 1850: The HadCRUT5 Data Set (Morice et al. 2021, referenced via comparison pages)	NCAR Climate Data Guide	2025-12	Expert guidance on HadCRUT5 methodology, infilling approach, and comparison to GISTEMP, Berkeley Earth and NOAA, including discussion of the 200-member ensemble uncertainty structure.
a5	Global Temperature Data Sets: Overview and Comparison Table	NCAR Climate Data Guide	2025-12	Systematic comparison of NOAA GlobalTemp, GISTEMP, Berkeley Earth, HadCRUT5, and the newly released DCENT dataset, detailing methodological differences and SST bias concerns.
a6	A Review of 25 Annual Forecasts of Global Mean Surface Temperature Including the Record Warm Years 2023 and 2024	Geophysical Research Letters	2025-09	Evaluates forecast skill across six surface temperature datasets including HadCRUT5, Berkeley Earth, and ERA5; finds both statistical and dynamical models underestimated the 2022-2023 warming jump by around 0.29 degrees C.
a7	Global Climate Highlights 2024	Copernicus Climate Change Service / ECMWF	2025-01	Copernicus ERA5-based official record confirming 2024 as the first year clearly exceeding 1.5 degrees C annual average, with record SST, atmospheric water vapour, and correlated extreme events.
a8	Ocean Heat Content Sets Another Record in 2025	Advances in Atmospheric Sciences	2026-01	Documents 23 ZJ increase in upper 2000-metre ocean heat content in 2025, confirmed by three independent datasets, with the rate of heat gain accelerating from 0.14 to 0.32 W per square metre per decade since 2005.
a9	Record High Temperatures in the Ocean in 2024	Advances in Atmospheric Sciences	2025-01	Led by Lijing Cheng with 54 co-authors; quantifies 16 ZJ increase in 0-2000 m OHC from 2023 to 2024, confirming continued ocean warming despite El Nino to neutral transition.
a10	Arctic Sea Ice Sets a Record Low Maximum in 2025	National Snow and Ice Data Center (NSIDC)	2025-03	Reports lowest Arctic sea ice maximum in 47-year satellite record at 14.33 million square kilometres, 1.31 million below the 1981-2010 average, as a key cryosphere proxy.
a11	Arctic Report Card 2025	NOAA Arctic	2025-12	Comprehensive multi-variable assessment showing that all 19 lowest September Arctic sea ice extents have occurred in the last 19 years, and oldest ice has declined more than 95 per cent since the 1980s.
a12	Svalbard's 2024 Record Summer: An Early View of Arctic Glacier Meltdown?	PMC / peer-reviewed journal	2025-06	Quantifies unprecedented 2024 Svalbard glacier mass loss using in situ, remote sensing, and modelling; finds its sea-level rise contribution comparable to the entire Greenland ice sheet that year.
a13	Global Carbon Budget 2024	Earth System Science Data (Copernicus)	2025-03	Friedlingstein et al.; definitive annual accounting of fossil fuel emissions, land-use change, and ocean and land sinks, finding atmospheric CO2 at 423 ppm in 2024 with emissions continuing to rise.
a14	Emerging Climate Impact on Carbon Sinks in a Consolidated Carbon Budget	Nature	2025-11	Revises the natural land sink substantially downward and raises net land-use emissions; finds tropical forest regions in Southeast Asia and parts of South America have shifted from sinks to sources.
a15	AR6 Synthesis Report: Climate Change 2023	IPCC	2023-03	Definitive inter-governmental assessment attributing 0.8-1.3 degrees C of observed warming to anthropogenic emissions; formalises remaining carbon budgets and SSP pathway requirements for 1.5 and 2 degrees C limits.
a16	IPCC AR6 WG1 Chapter 7: The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity	IPCC	2021	Canonical assessment of climate feedbacks, equilibrium climate sensitivity, and greenhouse gas metrics including revised GWP values for methane and nitrous oxide.
a17	Detection, Attribution, and Modeling of Climate Change: Key Open Issues	arXiv / Gondwana Research	2025-05	Minority-position peer-reviewed paper arguing ECS may be considerably below mainstream CMIP6 range; provides a structured account of genuine uncertainties around natural variability, solar influence, and station siting that the synthesis must address.
a18	Recent Cloud Controlling Factor Analyses Indicate Higher Climate Sensitivity	Geophysical Research Letters	2026-01	Uses observational cloud-controlling factor methodology to constrain low-cloud and high-cloud feedbacks, finding implied ECS towards the higher end of the assessed range.
a19	Exceeding 1.5 degrees C Global Warming Could Trigger Multiple Climate Tipping Points	Science	2022-09	Armstrong McKay et al.; landmark systematic assessment of 16 tipping elements finding five already possible at current warming and four likely above 1.5 degrees C, highly cited foundational paper for tipping-point risk.
a20	Two Decades of Climate Tipping Points Research: Progress and Outlook	Earth's Future (SAGE)	2024	Armstrong McKay (2024) reviews the evolution of tipping-point science, updating threshold estimates, interaction cascades, and early-warning signal research across the post-2022 literature.
a21	Physics-Based Early Warning Signal Shows That AMOC Is on Tipping Course	Science Advances	2024	Van Westen et al. use a physics-based freshwater transport indicator to show a robust 40-year negative trend consistent with the AMOC approaching a tipping threshold, contrasting with CMIP6 model biases.
a22	Shutdown of Northern Atlantic Overturning After 2100 Following Deep Mixing Collapse in CMIP6 Projections	Environmental Research Letters	2025-08	Drijfhout et al. show that CMIP6 extended projections beyond 2100 exhibit deep convection collapse under SSP585 and sometimes under SSP245, representing a significantly higher AMOC risk than previously assessed.
a23	Uncertainties and Confidence in Stratospheric Aerosol Injection Modelling: A Systematic Literature Review	Oxford Open Climate Change	2024	Systematic review identifying scenario, model, and natural variability uncertainty as the three insufficiently quantified pillars of SAI modelling, providing a structured evidence base for policy use.
a24	Stratospheric Aerosol Injection Geoengineering Has the Potential to Increase Land Carbon Storage and to Protect the Amazon Rainforest	Earth System Dynamics (Copernicus)	2026-04	Parry et al. (2026) find SAI under G6sulfur scenario produces 15.6 per cent higher net primary productivity and 5.9 per cent more land carbon storage compared to SSP245, and could protect the Amazon from dieback under high-emission scenarios.
a25	The Social Costs of Solar Radiation Management	npj Climate Action	2025-07	First systematic economic estimate of SAI side-effect harms, ranging from zero to 809 billion USD annually for stratospheric aerosol injection, with marine cloud brightening likely higher, critical for cost-benefit analysis of SRM.

VC & Analyst Reports

ID	Title	Outlet	Date	Significance
v1	State of Climate Tech 2024 Report	CB Insights	2025-07	Provides headline figures on the 40% YoY decline in global climate tech funding in 2024, the 47% drop in mega-rounds, and a 61% collapse in EV tech deal activity, establishing the quantitative baseline for the market downturn.
v2	State of Climate Tech Q3'24 Report	CB Insights	2024-10	Records climate tech funding hitting a four-year low of $4.8 billion in Q3 2024, with CCUS companies continuing to secure capital against the broader decline, and identifies grid tech and nuclear as the highest-momentum markets by CB Insights Mosaic score.
v3	State of Climate Tech Q2'24 Report	CB Insights	2024-08	Documents the absence of new climate tech unicorns for two consecutive quarters in 2024 and the divergence between declining late-stage deal sizes and rising early-stage median sizes, indicating selectivity among investors.
v4	Climate Tech Investment Trends H1 2025	Sightline Climate	2025-07	Quantifies the continued contraction in H1 2025 at $13.2 billion across 653 deals, down 19% from H1 2024, and articulates the emerging thesis that energy security and domestic supply chains are supplanting green premiums as the primary investment rationale.
v5	Investment Landscape in Carbon Removal 2026	CDR.fyi	2026-01	Provides the most granular public data on private CDR investment, tracking approximately $3.6 billion across 2021 to 2025, peak in 2023, DACCS dominance, and the structural gap between early-stage fundraising and late-stage delivery.
v6	Global Energy Perspective 2024	McKinsey & Company	2024-09	McKinsey's flagship scenario modelling report, covering 68 sectors and 78 fuels, finding that CO2 emissions will not peak until around 2025 and that 2050 emissions remain above net-zero targets in all three bottom-up pathways, with the fossil fuel plateau superseding the previously anticipated peak.
v7	Tracking the Energy Transition: Where Are We Now?	McKinsey & Company	2026-01	January 2026 update showing that less than 15% of low-emissions technologies required for Paris-aligned targets have been deployed, that global emissions rose 9% since 2015, and that geopolitical pressures are now redirecting capital away from decarbonisation.
v8	The Energy Transition: Where Are We, Really?	McKinsey & Company	2024-08	Detailed assessment of the execution gap between announced and FID-stage decarbonisation projects in Europe and the United States, finding that fewer than 15% of US green hydrogen projects announced since 2015 had reached final investment decision.
v9	Advancing Adaptation: Mapping Costs from Cooling to Coastal Defenses	McKinsey Global Institute	2025-12	Quantifies the adaptation funding gap, estimating $1.2 trillion annually needed at 2°C warming versus current global spending of $190 billion, and finds that benefits of adaptation far outweigh its costs.
v10	Climate Resilience Technology: Capturing Value in a $1T Market	McKinsey & Company	2025-09	Sizes the climate resilience technology opportunity at $1 trillion, documenting that 2024 saw 27 billion-dollar climate disasters in the US (three times the 44-year annual average) and tracking nascent private capital mobilisation into resilience and adaptation technologies.
v11	The CEO Playbook for Climate Resilience (CEO Sustainability Guide 2025)	Bain & Company	2025-09	Documents that only 3% of climate capital expenditure targets adaptation and resilience despite operations executives ranking physical climate risk as their top strategic priority, and finds only 25% of corporate Scope 1 and 2 emissions can be mitigated through ROI-positive levers today.
v12	Why Leaders Must Focus on Carbon Removal Markets Now (CEO Sustainability Guide 2025)	Bain & Company	2025-09	Highlights the structural supply shortfall in durable CDR: 2025 purchases projected at 14 million tonnes CO2 but actual deliveries under half a million tonnes, with demand already outstripping supply and early movers securing prices through multiyear offtake agreements.
v13	Embracing the Do-Say Gap (CEO Sustainability Guide 2025)	Bain & Company	2025-09	Tracks CEO sustainability rhetoric and action, finding that only 32% of energy executives now expect net zero by 2050 (down from ~40% in 2024) and that 44% project net zero will not arrive until 2070 or later, indicating material downward revision in decarbonisation ambition.
v14	Decarbonization That Works: Five Key Actions in Private Equity (CEO Sustainability Guide 2025)	Bain & Company	2025-09	Based on a study of 824 PE-owned companies, finds median 26% reduction in Scope 2 emissions and documents that the number of PE-owned companies disclosing climate impact via CDP rose 55% between 2021 and 2023.
v15	Climate Week NYC 2025: Sustainability Integrates into the Core	Bain & Company	2025-09	Records the shift in private equity toward adaptation and resilience as an investment theme, documents that climate physical risk is increasingly affecting company valuations and insurance costs, and notes AI-driven electricity demand as a durable structural force reshaping energy planning.
v16	Hype Cycle for Environmental Sustainability, 2024	Gartner	2024-07	Maps 38 sustainability technologies and innovations, concluding that none has yet reached the slope of enlightenment or plateau of productivity, and urges enterprises to pivot from mitigation to adaptation strategies as the 1.5°C target slips out of reach.
v17	Hype Cycle for Low-Carbon Energy Technologies, 2024	Gartner	2024	Tracks maturity and adoption of hydrogen, nuclear, grid storage, and decarbonised consumption technologies, noting that AI-driven energy demand is simultaneously pressuring systems while driving demand for clean firm power solutions.
v18	Hype Cycle for Environmental Sustainability, 2025	Gartner	2025-07	2025 update of Gartner's sustainability technology radar, covering AI-driven sustainability, net-zero data centres, and climate risk analytics, aimed at executive leaders embedding responsible practices into investment decisions.
v19	Investing in Flowcarbon	Andreessen Horowitz (a16z)	2023-05	States a16z's thesis that on-chain carbon credits represent critical financial architecture for a net-zero future, illustrating how the firm attempted to merge Web3 and voluntary carbon markets before subsequent structural challenges in both sectors.
v20	Mitigating Climate Change	McKinsey & Company	2024-02	McKinsey analysis projecting that average warming is likely to exceed 1.5°C by 2035 under current emissions trajectories, and that current path toward approximately 3°C could activate feedback loops including Greenland glacier collapse.
v21	The Visionary CEO's Guide to Sustainability 2025	Bain & Company	2025-09	Hub for Bain's full 2025 CEO Sustainability Guide, synthesising fresh survey data from 150 major companies and proprietary market intelligence to frame climate strategy as an execution challenge rather than a pledge-making exercise.

Blogs & Independent Thinkers

ID	Title	Outlet	Date	Significance
b1	Global Temperature in 2025, 2026, 2027	Climate Uncensored (Substack) - James Hansen, Pushker Kharecha, Dylan Morgan, Jasen Vest	2025-12	Hansen's Substack projects a 2027 global temperature record of +1.7°C and argues that an aerosol-masking shift has accelerated underlying warming, directly contesting the IPCC central estimate of climate sensitivity.
b2	State of the climate: 2025 in top-three hottest years on record as ocean heat surges	Carbon Brief	2026-01	Synthesises eight independent temperature datasets - including HadCRUT5, GISTEMP, NOAA and Berkeley Earth - placing 2025 as second or third warmest and documenting record ocean heat content, making it the single most comprehensive recent cross-dataset comparison.
b3	Climate change: from top to bottom	Climate Lab Book (Substack) - Ed Hawkins and colleagues	2026-02	Extends the warming-stripes methodology from ocean floor through troposphere to stratosphere, providing accessible evidence for the human fingerprint across all atmospheric layers.
b4	RealClimate: 2025 Updates	RealClimate - Gavin Schmidt et al.	2026-01	Annual update of model-observation comparisons with 2025 data by the blog co-founded by NASA GISS director Gavin Schmidt, confirming continued model skill and updated sea-ice comparisons.
b5	RealClimate: Much ado about acceleration	RealClimate - Gavin Schmidt	2024-04	Documents the live scientific debate between Hansen's aerosol-acceleration hypothesis and the mainstream CMIP6/AR6 framework, providing a primary source for where genuine expert disagreement sits.
b6	Global Temperature Report for 2025	Berkeley Earth - Zeke Hausfather and colleagues	2026-03	Berkeley Earth's authoritative independent annual analysis, documenting that land-warming exceeded 2°C above pre-industrial in 2025 and that CO₂ emissions hit a new record high, with greenhouse gas emissions as the underlying cause.
b7	An assessment of current policy scenarios over the 21st century and the reduced plausibility of high-emissions pathways	Environment and Planning - Zeke Hausfather	2025	Hausfather's peer-reviewed assessment of SSP scenarios argues the central estimate for 21st-century warming is now likely below 3°C under current policies, directly informing the SSP pathway debate.
b8	The Climate Brink - Andrew Dessler (Substack)	The Climate Brink (Substack) - Andrew Dessler, Texas A&M	2024	High-signal Substack by an atmospheric scientist with tens of thousands of subscribers; a December 2024 post arguing that very little warming is locked in directly counters Hansen's pipeline framing, illustrating a genuine expert disagreement.
b9	Should EAs pay more attention to Climate Tipping Points? AMOC Collapse as a Case Study	EA Forum (independent analysis)	2025-06	Detailed independent synthesis of AMOC tipping-point science surveying the full probability range from IPCC AR6 to Ditlevsen (2023), mapping genuine empirical uncertainty rather than political disagreement.
b10	From Climate Reports to Security Planning	Strategic Climate Risks (Substack)	2025-12	Documents the shift in governmental framing of AMOC risk from physical science to national security, covering Iceland's 2025 ministerial statement and the UK ARIA tipping-points programme.
b11	Solar Geoengineering in 2024: Rays of Hope, Clouds of Doubt	Solar Geoengineering Updates (Substack)	2025-01	Annual survey of SRM research and funding landscape, documenting the Simons Foundation $50 million commitment and UKRI £10.5 million programme, providing the most comprehensive independent tracker of the field.
b12	Monthly Solar Geoengineering Updates (November 2025)	Solar Geoengineering Updates (Substack)	2025-12	Tracks emerging SRM research including bipartisan US political backlash, governance challenges, and the latest SAI modelling studies, illustrating the rapid politicisation of solar geoengineering in 2025.
b13	Geoengineering: Assessing Risks in the Era of Planetary Security	Carnegie Endowment for International Peace	2025-07	Provides the critical quantitative anchor for BECCS: current removal capacity of 0.00051 GtCO₂ per year against 37.4 GtCO₂ annual fossil emissions, exposing the scale gap in negative emissions claims.
b14	Fossil fuel CO₂ emissions hit record high in 2025	Global Carbon Project	2025-11	Authoritative primary source for 2025 emissions (38.1 GtCO₂, +1.1%), the carbon budget (four years to 50% probability of staying below 1.5°C), and the weakening of natural land sinks, directly relevant to attribution and budget analysis.
b15	Global Carbon Budget 2025	Earth System Science Data - Copernicus	2026-05	Peer-reviewed 2025 edition of the definitive annual carbon accounting exercise, confirming fossil-CO₂ emissions growth, the weakened land sink, and the near-exhaustion of the 1.5°C budget.
b16	Global Carbon Budget 2024	Earth System Science Data - Copernicus	2025-03	Quantifies the remaining carbon budget for 1.5°C at six years from January 2025, and documents that tropical forest sinks have turned to sources under combined climate stress and deforestation.
b17	Analysis: The climate papers most featured in the media in 2025	Carbon Brief	2026-01	Documents which scientific claims attracted independent commentary in 2025, including Hansen's aerosol paper and the carbon budget, and maps the line between genuine expert debate and politically driven amplification.
b18	NOAA Arctic Report Card 2025	NOAA Arctic Program	2025-12	Authoritative annual proxy record documenting that the ten warmest Arctic years are the last ten, multi-year ice has declined more than 95% since the 1980s, and permafrost warming is producing observable chemical changes in rivers.
b19	2025 Headlines and Overview - NOAA Arctic Report Card	NOAA Arctic Program	2025-12	Summary entry point for the 2025 Arctic Report Card, confirming June snow cover extent is now half what it was six decades ago, providing a key Northern Hemisphere snow-cover proxy.
b20	From record warming to rusting rivers: 2025 Arctic Report Card shows a region transforming faster than expected	The Conversation	2026-03	Accessible synthesis of the Arctic Report Card highlighting that Arctic glacier ice loss has tripled since the 1990s and that the October 2024 to September 2025 water year was the warmest Arctic period since records began 125 years ago.
b21	State of the Cryosphere Report 2024	International Cryosphere Climate Initiative (ICCI)	2024-11	Reviewed by over 50 cryosphere scientists, this report is the first to note growing consensus that melting ice sheets may be slowing ocean currents at both poles, and projects locked-in loss of at least one-third of European Alpine glacier mass by 2050.
b22	Physics-based early warning signal shows that AMOC is on tipping course	Science Advances	2024	Van Westen et al. provide a physics-based model showing AMOC is approaching a tipping threshold, cited widely in independent commentary as the key peer-reviewed counterpoint to more cautious IPCC AR6 language.
b23	Solar geoengineering moves into the spotlight as climate concerns grow	Science News	2025-04	Documents the rapidly shifting political landscape for SRM, including Harvard's SCoPEx cancellation, over 16 US state bills to ban solar geoengineering in early 2025, and the implication for future research governance.
b24	Climate science and uncertainty in an age of misinformation	Christian Science Monitor	2024-06	Draws the sharpest evidence-based demarcation between genuine scientific uncertainty (e.g. cloud feedbacks, ECS range) and industry- or politically-driven denial, showing that 70% of 2024 YouTube denial content attacked solutions or scientist integrity rather than the underlying physics.
b25	The Weather Has Entered The Body	Substack - Ricky Lanusse	2025-06	Synthesises recent attribution science for the 2025 Fennoscandia heatwave, Canada wildfires, and Amazon drought, grounding independent commentary in quantitative attribution studies and illustrating biodiversity and ecosystem feedback risks.