Twenty-three hours behind schedule, member governments of the Intergovernmental Panel on Climate Change (IPCC) finally approved the Summary for Policymakers (SPM) of the Synthesis Report of its Fifth Assessment Report (AR5) and also adopted the Synthesis Report late afternoon on Saturday, 1 November in Copenhagen, Denmark.
Members formally approved the SPM at the 40th Session of the IPCC, which started on Monday, 27 October. The meeting was supposed to have ended Friday, 31 October, but it spilled over to the next day, after six grueling days (including some nights) of negotiations. Delegates, who had barely got any sleep since the third day of the negotiations, greeted the final approval of the SPM with applause. Scientists who authored the report and observers also attended the meeting, along side the member governments from nearly 190 countries.
The Synthesis Report (SR) distils and integrates the findings from the AR5, which is comprised of three working group (WG) reports on the ‘Physical Science Basis’ (WG1); ‘Impacts, Adaptation and Vulnerability’ (WG II); and ‘Mitigation of Climate Change’ (WG III). The SPM of the SR was negotiated line by line among governments and the authors, while the SR itself was adopted page by page.
In the line-by-line negotiations of the SPM, intense exchanges among governments and authors took place. Several difficult issues had to be resolved through contact groups, informal small groups or through huddles, which at times took many long hours to reach consensus. Given that the SPM is a synthesis of the longer SR, which in turn is a distillation of the main findings from AR5, the Copenhagen session revealed a north-south divide among member governments on the key messages to be conveyed.
In the initial draft which was presented to member states (dated 25 August), much of the SPM was on the science and aspects related to mitigation. Developing country members stressed the need for more balance, in relation to adaptation, sustainable development, and international cooperation in relation to finance and technology transfer. There was very little on finance in the SPM, which mainly focused on investments in mitigation, although there was acknowledgment about a gap in adaptation funding. An attempt by some developed country members to delete the notion of ‘technology transfer’ was also thwarted. Some improvements were made following the interventions by developing country delegates.
Among the most contentious issues included a box which was to contain “information relevant to Article 2 of the United Nations Framework on Climate Change (UNFCCC)”. This box had to be dropped from the SPM and the SR, owing to lack of consensus among member countries. (Article 2 refers to the objective of the Convention). Developing country members wanted more balance in the messages to be contained in the box relating to adaptation, sustainable development, finance and technology transfer. This was not agreed to by several developed country members, leading to the dropping of the box from the final documents.
Other issues that saw controversy were: a figure on the impacts attributable to climate change; the carbon budget; mitigation and adaptation in the context of sustainable development; characteristics of mitigation and adaptation pathways; technology transfer; and the placement of a figure on global anthropogenic carbon dioxide emissions (CO2). The placement of the figure on CO2 emissions was resolved in the early hours of Nov.1, after intense negotiations on this for five days, (Further details on these issues will be in forthcoming articles.)
Among the governments who often intervened included Saudi Arabia, Bolivia, Venezuela, China, St. Lucia, Brazil, El Salvador, Nicaragua, India, Maldives, the United States, Germany, Switzerland, Austria, Canada, Japan, Australia, the Netherlands, the United Kingdom, Norway and the European Union.
It is critical for policymakers to be informed by science, especially in view of the 2015 agreement negotiated under the UNFCC in Paris, said R K Pachauri, Chair of the IPCC, at the inaugural session of the meeting. Policymakers must avoid the hopelessness of overcoming climate change and while there remain challenges, the AR 5 shows that solutions exist, Pachauri added. He warned that while there is still time to adopt sustainable development pathways, “precious little of that time remains”. Pachauri chaired the IPCC session in Copenhagen.
The SPM highlights that human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases (GHGs) are the highest in history. Also, recent climate changes have had widespread impacts on human and natural systems.
The SPM also says that 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.
It also states that there are multiple mitigation pathways that are likely to limit warming to below 2°C relative to preindustrial levels. These pathways would require substantial emissions reductions over the next few decades and near zero emissions of CO2 and other long-lived GHGs by the end of the century. Implementing such reductions poses substantial technological, economic, social, and institutional challenges, which increase with delays in additional mitigation and if key technologies are not available.
The SPM identified adaptation and mitigation as 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.
Many adaptation and mitigation options can help address climate change, but no single option is sufficient by itself, the SPM warns. It states that effective adaptation and mitigation responses will depend on policies and measures across multiple scales: international, regional, national and sub-national. Policies across all scales supporting technology development, diffusion and transfer, as well as finance for responses to climate change, can complement and enhance the effectiveness of policies that directly promote adaptation and mitigation.
The SPM and the SR are divided into four sections: Observed Changes and their Causes; Future Climate Changes, Risks and Impacts; Future Pathways for Adaptation, Mitigation and Sustainable Development; and Adaptation and Mitigation. The AR5 assumes importance given that it is the most comprehensive assessment of climate change ever undertaken. Over 830 scientists from over 80 countries were selected to form author teams to produce the report. They drew on the work of over 1,000 contributing authors and about 2000 expert reviewers, and assessed over 30,000 scientific papers.
Among the other highlights, called headline statements, of the SPM include:
Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.
Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.
In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans. Impacts are due to observed climate change, irrespective of its cause, indicating the sensitivity of natural and human systems to changing climate
Changes in many extreme weather and climate events have been observed since about 1950. Some of these changes have been linked to human influences, including a decrease in cold temperature extremes, an increase in warm temperature extremes, an increase in extreme high sea levels and an increase in the number of heavy precipitation events in a number of regions.
Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Projections of GHG vary over a wide range, depending on both socioeconomic development and climate policy.
Surface temperature is projected to rise over the 21st century under all assessed emission scenarios. It is very likely that heat waves will occur more often and last longer, and that extreme precipitation events will become more intense and frequent in many regions. The ocean will continue to warm and acidify, and global mean sea level to rise.
Climate change will amplify existing risks and create new risks for natural and human systems. Risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries at all levels of development.
Many aspects of climate change and associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.
Effective decision making to limit climate change and its effects can be informed by a wide range of analytical approaches for evaluating expected risks and benefits, recognizing the importance of governance, ethical dimensions, equity, value judgments, economic assessments and diverse perceptions and responses to risk and uncertainty.
Without additional mitigation efforts beyond those in place today, and even with adaptation, warming by the end of the 21st century will lead to high to very high risk of severe, widespread, and irreversible impacts globally (high confidence). Mitigation involves some level of co-benefits and of risks due to adverse side-effects, but these risks do not involve the same possibility of severe, widespread, and irreversible impacts as risks from climate change, increasing the benefits from near-term mitigation efforts.
Adaptation can reduce the risks of climate change impacts, but there are limits to its effectiveness, especially with greater magnitudes and rates of climate change. Taking a longer-term perspective, in the context of sustainable development, increases the likelihood that more immediate adaptation actions will also enhance future options and preparedness.
Adaptation and mitigation responses are underpinned by common enabling factors. These include effective institutions and governance, innovation and investments in environmentally sound technologies and infrastructure, sustainable livelihoods, and behavioral and lifestyle choices.
Adaptation options exist in all sectors, but their context for implementation and potential to reduce climate-related risks differs across sectors and regions. Some adaptation responses involve significant co-benefits, synergies and trade-offs. Increasing climate change will increase challenges for many adaptation options.
Mitigation options are available in every major sector. Mitigation can be more cost-effective if using an integrated approach that combines measures to reduce energy use and the GHG intensity of endues sectors, decarbonize energy supply, reduce net emissions and enhance carbon sinks in land-based sectors.
Climate change is a threat to sustainable development. Nonetheless, there are many opportunities to link mitigation, adaptation and the pursuit of other societal objectives through integrated responses. Successful implementation relies on relevant tools, suitable governance structures and enhanced capacity to respond.