What It Is
The on Climate Change (IPCC) has 195 member governments and produces comprehensive Assessment Reports approximately every 6-7 years. The IPCC is the world's authoritative scientific body on climate change, providing the scientific foundation for global climate policy.
The IPCC was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme () to provide scientific assessments of climate change to policymakers.
Assessment Reports
The Sixth Assessment Report (AR6, 2021-2023) had three Working Group reports and a Synthesis Report. The IPCC's structure organizes climate science across three areas:
- Working Group I: covers physical science — the basis of climate change in atmospheric, oceanic, and earth-system science.
- Working Group II: covers impacts, adaptation, and vulnerability — the human and ecosystem consequences of climate change and how societies can adapt.
- Working Group III: covers mitigation — the options and policies for reducing greenhouse gas emissions.
Each Working Group's report is hundreds of pages with comprehensive coverage of the published literature. The Synthesis Report integrates the three Working Group findings into a policy-accessible summary.
Special Reports
The IPCC also produces Special Reports focused on specific topics:
- SR1.5 (October 2018): on 1.5°C warming pathways. This report was particularly influential, demonstrating the substantial differences between 1.5°C and 2°C warming and driving political momentum toward the lower target.
- SROCC: on oceans and cryosphere.
- SRCCL: on climate and land.
- SROCC and SRCCL were both highly influential in their respective domains.
Special Reports allow the IPCC to address emerging policy priorities between full Assessment Report cycles.
How the IPCC Works
The IPCC does not conduct original research — it assesses published literature. Author teams drawn from thousands of nominated scientists synthesize the published scientific evidence on each topic.
The process:
- Author nomination: governments and scientific bodies nominate scientists; the IPCC selects author teams with geographic and expertise balance.
- Multi-round drafting: authors produce successive drafts based on published evidence.
- Expert review: thousands of experts comment on drafts.
- Government review: government representatives review drafts and provide comments.
- Government approval: the Summary for Policymakers undergoes line-by-line approval by government representatives.
Reports are subject to government line-by-line approval of the Summary for Policymakers — a notable structural compromise allowing scientific while preserving government ownership of the policy-facing portions.
Nobel Peace Prize
The IPCC was awarded the 2007 Nobel Peace Prize jointly with Al Gore. The award recognized:
- The IPCC's role in building global scientific consensus on climate change.
- Its contribution to policy-makers' understanding.
- Its work as a model of international scientific cooperation.
The Nobel Prize elevated the IPCC's profile and provided political legitimacy at a moment when climate skepticism remained influential in some political contexts.
Why It Matters
The IPCC matters because it provides the authoritative scientific basis for global climate policy. Without the IPCC's structured assessment process, climate policy debate would lack the shared scientific foundation that has made global cooperation possible.
The IPCC's reports are referenced in essentially every major climate decision — the 's 1.5/2°C goals are directly grounded in IPCC analysis; NDC submissions reference IPCC scenarios; legal cases on climate liability cite IPCC findings.
Critiques
The IPCC has faced critiques:
- Conservatism: IPCC assessments have been criticized for being conservative relative to subsequent observed climate change.
- Government-approval distortion: the line-by-line approval process can dilute findings.
- Author selection: balance between geographic representation and disciplinary expertise can produce uneven results.
- Communication challenges: communicating uncertainty to policy-makers and public audiences remains difficult.
- Pace: 6-7 year cycles can lag the science.
Common Misconceptions
The IPCC is sometimes described as a research organization that produces original science. It does not — it assesses the published literature produced by the global climate research community.
Another misconception is that represent the IPCC's opinion. They represent the published scientific consensus as assessed by author teams.
Real-World Examples
The AR6 Synthesis Report (March 2023) integrated the Sixth Assessment Report findings and was the most influential climate-science document of recent years. SR1.5 (October 2018) dramatically shifted political conversation toward the 1.5°C target. The 2024 IPCC AR7 cycle launch has begun work on the Seventh Assessment Report, expected for completion in 2028-29.
Example
The IPCC's October 2018 SR1.5 report — that limiting warming to 1.5°C requires net zero CO2 emissions by 2050 — became the basis for the global 'net zero' policy movement.