IPCC Fifth Assessment Synthesis Report

The Intergovernmental Panel on Climate Change (IPCC) released the Synthesis Report of its Fifth Assessment Report (AR5) on Nov 2, 2014. The Synthesis Report provides an overview of the state of knowledge concerning the science of climate change, emphasizing new results since the publication of the IPCC Fourth Assessment Report in 2007. 

The report summarizes the main findings of the AR5 based on contributions from Working Group I - The Physical Science Basis, Working Group II - Impacts, Adaptation and Vulnerability, and Working Group III - Mitigation of Climate Change, plus two additional IPCC reports - ‘Special Report on Renewable Energy and Special Report on Managing the Risks of Extreme Events’ and ‘Disasters to Advance Climate Change Adaptation.’

The IPCC Fifth Assessment Report - produced by over 800 scientists worldwide and released over the past 13 months - is the most comprehensive assessment of climate change ever undertaken. In addition to the final versions of the 30-chapter report, cross-chapter materials, technical summary, and summary for policymakers, this latest release includes high-resolution graphics, frequently asked questions, and process information such as early drafts and searchable comments from reviewers.

Among the key findings of the report, human influence on the climate system is clear and growing, with impacts observed on all continents. Warming of the climate system is unequivocal in recorded history, and each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. Atmospheric concentrations of greenhouse gases are at levels that are unprecedented in at least 800,000 years. The report states that most of the world's electricity can - and must - be produced from low-carbon sources by 2050, otherwise the world faces "severe, pervasive and irreversible" damage.

However, the IPCC finds that options are available to adapt to climate change and implementing stringent mitigations activities can ensure that the impacts of climate change remain within a manageable range, creating a more sustainable future.

The Synthesis Report is divided into four topics:

1. Observed changes and their causes - focuses on observational evidence for a changing climate, the impacts caused by this change and the human contributions to it.

2. Future climate changes, risks, and impacts - assesses projections of future climate change and the resultant projected impacts and risks.

3. Future Pathways for Adaptation, Mitigation and Sustainable Development - considers adaptation and mitigation as complementary strategies for reducing and managing the risks of climate change.

4. Adaptation and mitigation - describes individual adaptation and mitigation options and policy approaches.

Topic 3 examines the factors that influence the assessment of mitigation and adaptation strategies, considering the benefits, risks, incremental changes, and potential transformations from different combinations of mitigation, adaptation, and residual climate-related impacts. It also considers outside factors that may influence choices about mitigation and adaptation, such as uncertainty, ethical considerations, and links to other societal goals.  

Topic 4 then assesses the prospects for mitigation and adaptation on the basis of current knowledge of tools, options and policies.


Rajendra K. Pachauri, who as IPCC Chair led the writing of the Synthesis Report, urged policymakers negotiating a climate agreement to base their decisions on science. “May I humbly suggest that policymakers avoid being overcome by the seeming hopelessness of addressing climate change,” he said. “It is not hopeless.”


Publication Date: November 2, 2014

Related Organizations:

  • The Intergovernmental Panel on Climate Change (IPCC)


Resource Category:

Resource Types:

  • Assessment
  • Climate science


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