A brief summary of conclusions from the IPCC Fifth Assessment Synthesis Report

Post date: Nov 7, 2014 3:17:31 AM

See http://www.ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR5_SPM.pdf

•  Greenhouse gas emissions from human activity are at the highest levels in history and the resultant rapid warming of the earth, its atmosphere and oceans has already had widespread impacts on human and natural systems.

•  The climate effects include melting snow and ice, rising sea levels, acidification of oceans, less cold extremes, more hot extremes and more heavy rainfall. These will get worse.

•  Many impacts will continue for centuries, even if emissions of greenhouse gases are stopped now.

•  Continued emission of greenhouse gases will cause irreversible damage. The risks of abrupt or irreversible changes increase the longer reductions in emissions and widespread adaptation is delayed. There are potential risks to multiple aspects of human life and to other species.

•  The risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries whatever their level of development.

• Mitigation by preventing change, and adaptation to change are complementary strategies for reducing and managing the risks.

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• Mitigation, including eliminating emissions of carbon dioxide, could limit warming to below 2°C above pre-industrial levels. But there would be substantial technological, economic, social, and institutional challenges in meeting the 2°C limit (considered the upper limit for human well-being).

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• Mitigation options are available in every major industry sector. The best approach would be to integrate action on measures to reduce energy use, decarbonize the energy supply and reduce greenhouse gas emissions by industry including carbon sinks in land-based sectors,

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• The prospects for effective adaptation and the possibility of climate-resilient pathways for sustainable development depend on immediate action on large scale emissions reduction.

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• The longer adaptation and mitigation are delayed the more expensive they get and the greater the risks.

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• Many adaptation and mitigation options can help but no single option is sufficient by itself. Effective implementation depends on cooperation in and across local, national and international communities, integrated responses that link adaptation and mitigation with social objectives, effective institutions and governance and innovation and investments in new technologies and infrastructure.