The world needs to take stringent action to move to a low-carbon economy before the end of the century to avoid severe impacts from warming of the climate, according to the final instalment of the fifth assessment report from the Intergovernmental Panel on Climate Change (IPCC).
The Synthesis Report released by the IPCC on 2 November draws together the findings of the fifth assessment report released in stages over the past 13 months. With over 800 lead authors and editors from over 80 countries drawing on more than 30,000 scientific papers, the IPCC describes it as the most comprehensive assessment of climate change ever undertaken.
The report notes that multiple mitigation pathways are available that could limit warming to below 2°C relative to pre-industrial levels, all of which would require substantial emissions reductions over the next few decades and near-zero emissions of CO2 and other long-lived greenhouse gases by the end of the century.
Most of the scenarios offered up to achieve this goal require the global share of low carbon options for electricity supply - nuclear, renewables and carbon capture and storage (CCS) - to increase from current levels of 30% to reach 80% by 2050, with fossil fuel generation without CCS almost entirely eliminated by 2100. There is no single solution: to be most cost-effective, mitigation needs to use a combined approach including measures to reduce energy use, reduce net emissions and enhance carbon sinks in land-based sectors as well as decarbonizing energy supply. However, the report does acknowledge that excluding certain mitigation technologies - such as nuclear - from the mix would lead to substantial increases in mitigation costs.
The IPCC documents note that virtually all energy options have related issues affecting their uptake or implementation, including those related to public perception. The primary issues highlighted for nuclear energy are anxieties focusing on health, safety and proliferation.
There is no time to waste: delaying additional mitigation until 2030 will substantially increase the challenges associated with limiting warming over the 21st century to below 2°C. "It is technically feasible to transition to a low-carbon economy. But what is lacking are appropriate policies and institutions," said co-chair of IPCC Working Group III Youba Sokona. "Compared to the imminent risk of irreversible climate change impacts, the risks of mitigation are manageable," Sokona added.
Options are available to keep climate change impacts within a manageable range while allowing for continued economic and human development, according to IPCC chair RK Pachauri. "All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change," he said.
Adaptation and mitigation are seen as complementary strategies for reducing and managing the risks of climate change. As well as reducing climate risks, limiting emissions over the next few decades will also increase the prospects for effective adaptation to climate change and reduce the costs and challenges of mitigation in the longer term, the report notes. Without additional mitigation efforts beyond those in place today, even allowing for adaptation, warming by the end of the 21st century will lead to high risk of severe, widespread, and irreversible global impacts.
The IPCC was set up in 1988 by the World Meteorological Organization (WMO) and United Nations Environment Programme (UNEP), endorsed by the United Nations General Assembly, and is the world body for assessing the science related to climate change. Its mission is to provide policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.
Researched and written
by World Nuclear News