Key figures: Nicholas Stern (review author, chief economist HM Treasury; formerly World Bank chief economist 2000–2003); Gordon Brown (UK Chancellor of the Exchequer, commissioned the review); Tony Blair (UK Prime Minister); William Nordhaus (Yale economist, leading critic); Richard Tol (Hamburg Institute economist, critic); Joseph Stiglitz, Jeffrey Sachs (endorsers); Paul Wolfowitz (World Bank President, endorser)
Summary
The Stern Review on the Economics of Climate Change — a 700-page independent report released on 30 October 2006 — fundamentally reframed the climate crisis as an economic rather than purely environmental problem. Commissioned by UK Chancellor Gordon Brown in July 2005, economist Nicholas Stern led a team at HM Treasury to comprehensively assess the economic consequences of global warming and the costs of action versus inaction. The report’s central conclusion — that unabated climate change would permanently reduce global GDP by 5 to 20 percent, while strong early mitigation could stabilize the climate at an annual investment cost of approximately 1 percent of global GDP — became one of the most influential policy arguments of the decade. The Stern Review established climate economics as a field of urgent political relevance and shaped international climate negotiations through the remainder of the 2000s.
Background
Nicholas Stern and the Commission
Nicholas Stern, born 1946, was appointed Second Permanent Secretary and Head of the Government Economic Service at HM Treasury in 2003. Before that role, he served as Chief Economist of the World Bank from 2000 to 2003, where he worked on development economics and poverty reduction — experiences that informed his approach to intergenerational equity and discount rates in the climate review.
UK Chancellor Gordon Brown commissioned the review in July 2005, motivated by the growing scientific consensus on anthropogenic climate change, the approaching expiration of the Kyoto Protocol’s first commitment period (2012), and the political imperative to place climate policy on an economic rather than purely environmental footing. The decision to commission a review by a senior economist rather than a scientist or environmental minister signaled that the Blair government intended to reframe climate change as a Treasury concern, not merely an environmental portfolio issue.
Stern assembled a team of approximately 20 economists at HM Treasury over the following 14 months, drawing on extensive academic literature and consulting with independent scientists, economists, and officials from international organizations. The resulting report ran to approximately 700 pages of main text plus technical annexes.
Pre-Stern Economic Context
Before the Stern Review, the dominant economic analysis of climate change was provided by William Nordhaus of Yale University, whose DICE (Dynamic Integrated Climate-Economy) model suggested that the economically optimal response to climate change involved modest, gradually increasing carbon taxes and no aggressive near-term mitigation. Nordhaus’s analysis rested on standard discount rates of approximately 5–6 percent, which heavily devalued future damages relative to present mitigation costs, producing a result that favored delay.
The Intergovernmental Panel on Climate Change (IPCC) had produced economic assessments in its Third Assessment Report (2001) but largely confined economic analysis to one working group, without the political prominence of a dedicated government-commissioned synthesis. The Stern Review’s explicit government mandate — and its author’s position at the Treasury of a G8 nation — gave it an institutional authority the IPCC’s economic chapter lacked.
Key Findings and Recommendations
The Core Economic Case
The Stern Review’s analysis produced a stark comparison:
| Scenario | Estimated cost (% of global GDP per year, permanently) |
|---|---|
| Unabated warming (5–6°C by 2100) | 5–20% GDP loss, indefinitely |
| Strong early mitigation | ~1% GDP investment annually to stabilize at 500–550 ppm CO₂e |
Stern characterized climate change as “the greatest and widest-ranging market failure ever seen” — a phrase that became the review’s signature formulation, positioning the climate problem within the standard economic framework of externalities and market correction rather than as a moral or ecological issue.
The 5 percent lower-bound GDP loss figure applied to conservative projections, while the upper bound of 20 percent incorporated feedback effects, non-market impacts (ecosystem loss, human health), and risks of abrupt, irreversible tipping points in the climate system. The review was explicit that these were long-run, permanent losses — not temporary recessions.
Stabilization Target and Mitigation Costs
The review recommended stabilizing atmospheric greenhouse gas concentrations at 500–550 parts per million CO₂ equivalent — a target corresponding to approximately 2–3°C of eventual warming above pre-industrial levels. To achieve this:
- Annual global investment of approximately 1 percent of GDP was required, covering decarbonization of energy systems, low-carbon technology development, reforestation, and adaptation infrastructure.
- This figure was explicitly framed as a one-time structural investment, not an ongoing tax burden — analogous to the share of GDP devoted to defense or public infrastructure in developed economies.
The review’s carbon pricing recommendations included:
- A global carbon price of at least $25–30 per tonne of CO₂ in the near term, rising over time.
- Implementation via carbon taxes, cap-and-trade systems, or equivalent regulatory mechanisms, with the choice of instrument left to national governments.
- Significantly expanded climate finance flows to developing nations, recognizing that developing countries would bear disproportionate warming costs while having contributed least to cumulative emissions.
The Discount Rate: Innovation and Controversy
The most technically contested element of the Stern Review was its use of an extremely low social discount rate of approximately 1.4 percent (composed of a 0.1 percent pure time preference rate and a consumption growth component). Standard economic practice employed discount rates of 3–7 percent, which — applied to climate damages decades hence — produced present values low enough to justify modest near-term action at most.
Stern’s near-zero pure time preference rate reflected an ethical position: that future generations’ welfare deserved near-equal weight to present generations’, and that discounting solely on the basis of when someone is born was ethically indefensible. The review explicitly argued this point on philosophical grounds, drawing on utilitarian ethics and the work of philosopher Derek Parfit on intergenerational justice.
The implications were mathematically significant: at a 1.4 percent discount rate, damages of 20 percent of GDP in 2100 had a present value large enough to justify very substantial present spending — including the 1 percent of GDP annual mitigation cost. At Nordhaus’s 5.5 percent discount rate, the same future damages produced a far lower present value, justifying only modest near-term action.
Reactions and Debate
Endorsements
The review attracted prominent endorsements immediately upon publication:
- Tony Blair called it proof of the “overwhelming” economic case for climate action and pledged UK legislative follow-up.
- Joseph Stiglitz (Columbia University, Nobel laureate) praised the review’s economic framework.
- Jeffrey Sachs (Columbia Earth Institute) called it essential reading for policymakers.
- Paul Wolfowitz (World Bank President) endorsed the report’s emphasis on developing-nation vulnerability.
- Rajendra Pachauri (IPCC Chair) welcomed the review as complementary to the IPCC’s scientific work.
Criticisms
The review also drew significant expert criticism, primarily on technical economic grounds:
- William Nordhaus (Yale) argued that the near-zero discount rate was not justified by marketplace interest rates and produced policy conclusions that were “unambiguous” but unsupported by standard welfare economics. Nordhaus’s own DICE model, updated to use Stern’s discount assumptions, produced similar conclusions — which he took as evidence that the model was sensitive to ethical assumptions, not underlying economic facts.
- Richard Tol (Hamburg Institute) was one of the sharpest critics, calling the review “alarmist and incompetent” and contesting the upper-bound GDP loss estimates as implausible based on existing impact literature. He subsequently produced peer-reviewed work suggesting Stern had relied on unpublished and non-peer-reviewed damage estimates.
- Bjorn Lomborg (The Skeptical Environmentalist, Copenhagen Consensus) argued that climate change was real but that the economic case for prioritizing it over other global problems — disease, poverty — was not made by Stern’s analysis.
The resulting debate generated extensive academic literature examining the ethical foundations of long-run discount rates and their role in intergenerational climate policy — a field that remained active through the 2010s and 2020s.
Policy Influence
United Kingdom
The Stern Review had direct legislative consequences in the UK. It provided the foundational economic rationale for the UK Climate Change Act 2008 — the first national legislation to establish legally binding greenhouse gas emissions reduction targets. The Act required an 80 percent reduction in UK emissions by 2050 relative to 1990 levels, a target derived in part from the Stern Review’s stabilization pathway. Gordon Brown, who commissioned the review, became Prime Minister in June 2007, ensuring its influence on Treasury and legislative priorities.
Australia
Ross Garnaut, a leading Australian economist, was commissioned to conduct an equivalent review for the Australian government in 2007 at the explicit instigation of then-opposition leader Kevin Rudd. The resulting Garnaut Climate Change Review (2008) was explicitly modeled on the Stern Review’s framework and similarly recommended a carbon trading scheme. Australia’s subsequent Carbon Pollution Reduction Scheme (2009) and, later, Clean Energy Act (2011) drew heavily on Garnaut’s work and, through it, on Stern’s.
International Climate Negotiations
The Stern Review shaped the agenda of the December 2007 Bali Climate Conference (COP 13), which produced the Bali Action Plan establishing the negotiating track toward the Copenhagen Accord (2009) and, eventually, the Paris Agreement (2015). The review’s framing — that climate action was economically rational, not economically costly relative to inaction — provided developed-country governments with a framework for justifying domestic climate legislation to skeptical finance ministries.
The review also influenced the IPCC Fourth Assessment Report (AR4), released in four parts through 2007. The AR4’s Working Group III report on mitigation explicitly engaged Stern’s findings and the associated academic debate over discount rates, incorporating this literature into the IPCC’s own cost-benefit assessment.
Central Banks and Financial Regulation
In the long run, one of the Stern Review’s most durable legacies was establishing the framework for treating climate change as a macroeconomic and financial stability risk rather than merely an environmental externality. This framing — that climate-driven GDP losses posed systemic economic risks — later provided the conceptual basis for the Bank of England’s climate stress-testing exercises (beginning 2019), the Network for Greening the Financial System (NGFS, founded 2017), and the incorporation of climate risk into central bank frameworks in the 2020s.
The 2006 Climate Moment
The Stern Review was released in the same year as An Inconvenient Truth, Al Gore’s documentary that brought the scientific case for climate action to mainstream audiences, and the 2006 Climate & Energy Nexus, which saw crude oil prices hit a then-record high and California pass the world’s first comprehensive cap-and-trade legislation. Together, these three events — a documentary, an economic treatise, and a legislative milestone — made 2006 the year in which climate change definitively crossed from scientific and environmental discourse into the mainstream of economics and politics.
The Stern Review’s $30-per-tonne minimum carbon price recommendation was directly relevant to the crude oil price environment of the mid-2000s: with oil at $70–77 per barrel, the relative economics of low-carbon alternatives had shifted substantially, making the Review’s prescriptions appear less radical than they might have five years earlier. The Review also appeared in the same year that Muhammad Yunus won the Nobel Peace Prize for the Grameen Bank’s work on poverty alleviation — see Grameen Bank and Muhammad Yunus — a reminder that 2006 was a year of unusual concentration of economic ideas with transformative political ambitions.
Significance
The Stern Review marked a watershed in the mainstreaming of climate economics. By demonstrating — in the language of Treasury economics rather than environmental science — that the economic case for action far exceeded the case for inaction, it shifted the policy debate from whether the world should act on climate change to how and at what pace. Its characterization of climate change as a market failure gave policymakers an orthodox economic framework for intervention without requiring appeals to ecological ethics alone.
The review’s methodological choices remain contested, particularly the discount rate. But the policy direction it recommended — early, strong action to stabilize emissions, funded at the scale of a national defense budget — proved durable. The Paris Agreement’s 2°C target, agreed in 2015 and ratified in 2016, fell within the range Stern’s review identified as necessary to avoid the most severe economic damages.
In retrospect, the 1 percent of GDP mitigation cost estimate proved optimistic: subsequent analyses, particularly after the 2008 financial crisis and the scaling of renewable energy costs, revised both the cost and the timeline. But the fundamental claim — that delay was economically irrational — was subsequently reinforced by the falling costs of solar, wind, and battery technology, which made decarbonization cheaper than projected. The Stern Review, in this sense, overstated the cost of action and understated its eventual economic viability.
Sources
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[Stern Review on the Economics of Climate Change Wikipedia](https://en.wikipedia.org/wiki/Stern_Review) -
[HM Treasury: The Economics of Climate Change (The Stern Review) UK National Archives](https://webarchive.nationalarchives.gov.uk/ukgwa/20100812033308/http://www.hm-treasury.gov.uk/stern_review_report.htm) - Nordhaus, William. “A Review of the Stern Review on the Economics of Climate Change.” Journal of Economic Literature, 2007
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[UK Climate Change Act 2008 UK Parliament](https://www.legislation.gov.uk/ukpga/2008/27/contents) -
[Garnaut Climate Change Review Wikipedia](https://en.wikipedia.org/wiki/Garnaut_Climate_Change_Review) -
[IPCC Fourth Assessment Report IPCC](https://www.ipcc.ch/assessment-report/ar4/)