Intergovernmental Panel on Climate Change (IPCC)

Intergovernmental Panel on Climate Change (IPCC)

Overview
The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body responsible for assessing the science related to climate change, its impacts and future risks, and options for adaptation and mitigation.

1. Establishment and Mandate

• Founded in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).

• Primary mandate: Provide policymakers with regular, objective assessments of the scientific basis of climate change, its impacts and future risks, and options for response.

• Fundamental principles:

  • Assessment based solely on peer-reviewed scientific and technical literature

  • Policy-relevant but not policy-prescriptive

2. Organizational Structure

• IPCC Plenary

  • Highest decision-making body

  • All member governments participate

  • Approves reports, adopts methodologies, elects leadership

• Bureau

  • Elected by the Plenary

  • Chair, Vice-Chairs, and Working Group Co-Chairs

  • Guides scientific work and oversees report preparation

• Secretariat

  • Based at the WMO headquarters in Geneva

  • Coordinates IPCC activities, logistics, communications

3. Working Groups and Task Force

• Working Group I (WG I): The Physical Science Basis

  • Assesses the physical science of climate change: observations, causes, projections

• Working Group II (WG II): Impacts, Adaptation and Vulnerability

  • Evaluates impacts on ecosystems, societies; assesses vulnerability and adaptation options

• Working Group III (WG III): Mitigation of Climate Change

  • Reviews options for reducing greenhouse gas emissions and removing CO₂

• Task Force on National Greenhouse Gas Inventories (TFI)

  • Develops methodologies for countries to estimate and report national greenhouse gas emissions

4. Assessment Reports

• Cycle and Purpose

  • Major Assessment Reports (AR): published roughly every 6–7 years

  • Special Reports: focus on specific topics (e.g., 1.5°C warming, oceans, land use)

  • Methodology Reports: provide guidelines for greenhouse gas inventories

• Key Phases of Report Production

  1. Scoping: Agree on outline and key questions

  2. Author Selection: Governments and organizations nominate experts; the Bureau appoints Coordinating Lead Authors, Lead Authors, Review Editors

  3. Drafting: Three draft stages—First Order Draft (scientific community), Second Order Draft (scientific and government review), Final Draft (line-by-line government approval of Summary for Policymakers)

  4. Approval: Summary for Policymakers is approved line-by-line at Plenary sessions

5. Major Assessment Reports to Date

• AR1 (1990): Confirmed human influence on climate; set groundwork for UNFCCC

• AR2 (1995): Strengthened evidence of human influence; introduced regional assessments

• AR3 (2001): Emphasized necessity of mitigation; linked to early policy debates

• AR4 (2007): Concluded warming is “unequivocal” and human-caused; shared Nobel Peace Prize

• AR5 (2013–2014): Detailed projected impacts; introduced Representative Concentration Pathways (RCPs)

• AR6 (2021–2022): Provided updated warming projections; stronger emphasis on risks, adaptation limits, and emission pathways

6. Special Reports

• Global Warming of 1.5°C (2018): Assessed impacts of 1.5°C vs 2°C warming; highlighted need for rapid, deep emission cuts

• Climate Change and Land (2019): Explored land use, desertification, food security, carbon sinks

• Ocean and Cryosphere (2019): Examined sea-level rise, polar ice loss, ocean acidification

• Cities, Cities and Climate Change Science (pending): Will assess urban vulnerability and adaptation

7. Methodologies and Guidelines

• 2006 IPCC Guidelines: Standardized methods for national greenhouse gas inventories

• 2019 Refinement to 2006 Guidelines: Updates to reflect advances in science and practice

8. Review and Quality Assurance

• Multi-stage peer review by experts and governments ensures comprehensiveness and credibility.

• Conflict of interest policies for authors and reviewers.

• Transparency: All drafts and reviewer comments are archived and publicly accessible.

9. Influence on Global Policy

• United Nations Framework Convention on Climate Change (UNFCCC): IPCC assessments inform COP negotiations.

• National Policies: Serve as scientific foundation for national climate action plans (NDCs).

• Finance and Investment: Guide climate finance decisions by multilateral development banks, investors, and governments.

• Public Awareness: Provide authoritative evidence that shapes media coverage and civil society discourse.

10. Recent Developments and Future Directions

• Enhancing regional focus: More granular assessments to support local decision-making.

• Improved integration of socioeconomic pathways with climate projections.

• Digitalization and Data: Incorporation of big data, machine learning, and observation networks.

• Equity and Justice: Greater attention to differential impacts and the needs of vulnerable communities.