Incheon, Republic of Korea · 8 October 2018 — The Intergovernmental Panel on Climate Change (IPCC) released its most urgent assessment to date, warning that the world has roughly twelve years to enact emissions reductions of unprecedented scale if it is to limit global warming to 1.5°C above pre-industrial levels. The Special Report on Global Warming of 1.5°C (SR15), approved by the IPCC's 195 member governments after a week-long session in Incheon, represents the most comprehensive scientific assessment of the difference between 1.5°C and 2°C of warming ever conducted.
The report was requested by the United Nations Framework Convention on Climate Change (UNFCCC) in 2015, following the adoption of the Paris Agreement, to provide policymakers with a scientific road map for implementing the accord's temperature goals. It synthesises over 6,000 scientific references and draws on the work of 91 authors from 40 countries.
The Stakes: Why Half a Degree Matters
The report's central finding is stark: every fraction of a degree of warming matters. The difference between 1.5°C and 2°C is not marginal — it is the difference between manageable adaptation and cascading systemic failure across ecosystems, economies, and human societies.
The report details specific consequences at each temperature threshold:
| Impact Area | At 1.5°C | At 2°C |
|---|---|---|
| Coral reefs | 70–90% decline | >99% decline |
| Sea-level rise by 2100 | 0.26–0.77 m | 0.10 m additional rise |
| Arctic sea-ice-free summers | Once per century | At least once per decade |
| Species losing >50% range | 6% of insects, 8% of vertebrates, 18% of plants | 18% of insects, 16% of vertebrates, 44% of plants |
The Emissions Pathway
To stay within 1.5°C, the report outlines a narrow and rapidly narrowing pathway. Global net human-caused CO2 emissions must decline by approximately 45% from 2010 levels by 2030, reaching net zero around 2050. This requires what the report calls "rapid, far-reaching and unprecedented changes in all aspects of society."
The world had already warmed by approximately 1°C above pre-industrial levels at the time of the report's publication, with consequences visible in rising sea levels, more frequent extreme weather events, and shifting precipitation patterns. Current national climate pledges under the Paris Agreement — known as Nationally Determined Contributions (NDCs) — were assessed as insufficient to keep warming below 2°C, let alone 1.5°C.
The report identifies four key systems requiring transformation:
- Energy systems: Deep emissions reductions, with renewables projected to supply 70–85% of electricity by 2050. Coal use in electricity generation must decline to near zero.
- Land use: Shifts toward sustainable agriculture, reduced deforestation, and dietary changes. Afforestation and bioenergy with carbon capture required at scale.
- Urban infrastructure: Compact, connected cities with electrified transport and energy-efficient buildings.
- Industrial systems: Material efficiency, new production processes, and carbon capture technologies.
Carbon Dioxide Removal: A Necessary but Uncertain Tool
All 1.5°C pathways identified in the report rely on some form of Carbon Dioxide Removal (CDR) to compensate for residual emissions from sectors that are difficult to decarbonise, such as aviation and agriculture. The report acknowledges significant uncertainties around the feasibility and scalability of CDR methods, including afforestation, bioenergy with carbon capture and storage (BECCS), and direct air capture.
Implications for Africa and the Global South
The report's findings carry particular weight for African nations, where climate impacts are projected to be disproportionately severe despite the continent contributing less than 4% of global emissions. Key risks identified for Africa include:
- Water scarcity: An additional 350 million people exposed to severe drought at 2°C compared to 1.5°C
- Agricultural yields: Maize and sorghum yields in West and Southern Africa decline significantly more at 2°C
- Heat extremes: Dangerous heatwaves affecting millions more across the Sahel and Horn of Africa
- Coastal flooding: West African coastal cities face compounded risks from sea-level rise and storm surges
The report emphasises that climate action must be integrated with sustainable development and poverty eradication efforts, noting that poorly designed mitigation policies could exacerbate existing inequalities.
A Political Reckoning
The release of SR15 came just weeks before the COP24 climate summit in Katowice, Poland, where negotiators were tasked with finalising the 'rulebook' for implementing the Paris Agreement. The report's findings intensified pressure on governments to strengthen their emissions reduction commitments.
IPCC Chair Hoesung Lee stated at the report's launch: "Every extra bit of warming matters, especially since warming of 1.5°C or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems."
The report stopped short of prescribing specific policy measures, maintaining the IPCC's role as a scientific rather than political body. However, its conclusions left little ambiguity: the political and economic transformations required to meet the 1.5°C goal are without historical precedent in their speed and scale.
Sources
- IPCC, Global Warming of 1.5°C: An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, 8 October 2018
- World Meteorological Organization (WMO), Statement on the IPCC Special Report, October 2018
- UNFCCC, Decision 1/CP.21, Paris Agreement, December 2015
- IPCC Press Release, "Summary for Policymakers of IPCC Special Report on Global Warming of 1.5°C approved by governments", 8 October 2018
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Institutional Research Desk · Foresight Institute of Research and Translation
The collective editorial and research translation board of FIRAT, synthesising peer-reviewed evidence, policy briefs, and division milestones across our seven foundational research pillars.
