IPCC: Climate Change 2014 – Synthesis Report
Intergovernmental Panel on Climate Change http://www.ipcc.ch/
November 2014

The Synthesis Report distils and integrates the findings of the three working group contributions to the IPCC Fifth Assessment Report — the most comprehensive assessment of climate change yet undertaken, produced by hundreds of scientists — as well as the two Special Reports produced during this cycle.

Headline statements from the Summary for Policymakers
:: Observed Changes and their Causes
Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems….

:: Future Climate Changes, Risks and Impacts
Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks….

:: Future Pathways for Adaptation, Mitigation and Sustainable Development
Adaptation and mitigation are complementary strategies for reducing and managing the risks of climate change. Substantial emissions reductions over the next few decades can reduce climate risks in the 21st century and beyond, increase prospects for effective adaptation, reduce the costs and challenges of mitigation in the longer term, and contribute to climate-resilient pathways for sustainable development…

:: Adaptation and Mitigation
Many adaptation and mitigation options can help address climate change, but no single option is sufficient by itself. Effective implementation depends on policies and cooperation at all scales, and can be enhanced through integrated responses that link adaptation and mitigation with other societal objectives….