Editing IPCC:AR6/WGIII/Chapter-1 (section)

== Executive Summary ==

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'''Global greenhouse gas (GHG) emissions continued to rise to 2019: the aggregate reductions implied by current Nationally Determined Contributions (NDCs) to 2030 would still make it impossible to limit warming to 1.5°C with no or limited overshoot, and would only be compatible with''' '''''likely limiting warming''''' '''below 2°C if followed by much steeper decline, hence limiting warming to either level implies accelerated mitigation actions at all scales''' '''(''' '''''robust evidence''''' ''',''' '''''high agreement''''' ''').''' Since the IPCC’s Fifth Assessment Report (AR5), important changes that have emerged include the specific objectives established in the Paris Agreement of 2015 (for temperature, adaptation and finance), rising climate impacts, and higher levels of societal awareness and support for climate action. The growth of global GHG emissions has slowed over the past decade, and delivering the updated NDCs to 2030 would turn this into decline, but the implied global emissions by 2030 exceed pathways consistent with 1.5°C by a large margin, and are near the upper end of the range of modelled pathways which keep temperatures ''likely'' limit warming to 2°C (with &gt;65% probability). Continuing investments in carbon-intensive activities at scale will heighten the multitude of risks associated with climate change and impede societal and industrial transformation towards low-carbon development. Meeting the long-term temperature objective in the Paris Agreement therefore implies a rapid turn to an accelerating decline of GHG emissions towards ‘net zero’, which is implausible without urgent and ambitious action at all scales. The unprecedented COVID-19 pandemic has had far-reaching impacts on the global economic and social system, and recovery will present both challenges and opportunities for climate mitigation. {1.2, 1.3, 1.5, 1.6, Chapters 3 and 4}

'''While there are some trade-offs, effective and equitable climate policies are largely compatible with the broader goal of sustainable development and efforts to eradicate poverty as enshrined in the 17 Sustainable Development Goals (SDGs) (''' '''''robust evidence''''' ''',''' '''''high agreement''''' ''').''' Climate mitigation is one of many goals that societies pursue in the context of sustainable development, as evidenced by the wide range of the SDGs. Climate mitigation has synergies and/or trade-offs with many other SDGs. There has been a strong relationship between development and GHG emissions, as historically both per capita and absolute emissions have risen with industrialisation. However, recent evidence shows countries can grow their economies while reducing emissions. Countries have different priorities in achieving the SDGs and reducing emissions as informed by their respective national conditions and capabilities. Given the differences in GHG emissions contributions, degree of vulnerabilities and impacts, as well as capacities within and between nations, equity and justice are important considerations for effective climate policy and for securing national and international support for deep decarbonisation. Achieving sustainable global development and eradicating poverty as enshrined in the 17 SDGS would involve effective and equitable climate policies at all levels from local to global scale. Failure to address questions of equity and justice over time can undermine social cohesion and stability. International cooperation can enhance efforts to achieve ambitious global climate mitigation in the context of sustainable development. {1.4, 1.6, Chapters 2, 3, 4, 5, 13 and 17}

'''The transition to a low-carbon economy depends on a wide range of closely intertwined drivers and constraints, including policies and technologies where notable advances over the past decade have opened up new and large-scale opportunities for deep decarbonisation, and for alternative development pathways which could deliver multiple social and developmental goals (''' '''''robust evidence''''' ''',''' '''''medium agreement''''' ''')''' . Drivers for and constraints against low-carbon societal transition comprise ''economic and technological'' factors (the means by which services such as food, heating and shelter are provided and for whom, the emissions intensity of traded products, finance, and investment), ''socio-political issues'' (political economy, equity and fairness, social innovation and behaviour change), and ''institutional factors'' (legal framework and institutions, and the quality of international cooperation). In addition to being deeply intertwined all the factors matter to varying degrees, depending on the prevailing social, economic, cultural and political context. They often exert both push and pull forces at the same time, within and across different scales. The development and deployment of innovative technologies and systems at scale are important for achieving deep decarbonisation. In recent years, the cost of several low-carbon technologies has declined sharply, alongside rapid deployment. Over 20 countries have also sustained emission reductions, and many more have accelerated energy efficiency and/or land-use improvements. Overall, however, the global contribution is so far modest, at a few billion tonnes (tCO 2 -eq) of avoided emissions annually. {1.3, 1.4, Chapters 2, 4, 13 and 14}

'''Accelerating mitigation to prevent dangerous anthropogenic interference within the climate system will require the integration of broadened assessment frameworks and tools that combine multiple perspectives, applied in a context of multi-level governance (''' '''''robust evidence''''' ''',''' '''''medium agreement''''' ''')''' . Analysing a challenge on the scale of fully decarbonising our economies entails integration of multiple analytic frameworks. Approaches to risk assessment and resilience, established across IPCC Working Groups, are complemented by frameworks for probing the challenges in implementing mitigation. ''Aggregate frameworks'' include cost-effectiveness analysis towards given objectives, and cost-benefit analysis, both of which have been developing to take fuller account of advances in understanding risks and innovation, the dynamics of emitting systems and of climate impacts, and welfare economic theory including growing consensus on long-term discounting. ''Ethical frameworks'' consider the fairness of processes and outcomes which can help ameliorate distributional impacts across income groups, countries and generations. ''Transition and transformation frameworks'' explain and evaluate the dynamics of transitions to low-carbon systems arising from interactions amongst levels, with inevitable resistance from established socio-technical structures. ''Psychological, behavioural and political frameworks'' outline the constraints (and opportunities) arising from human psychology and the power of incumbent interests. A comprehensive understanding of climate mitigation must combine these multiple frameworks. Together with established risk frameworks, collectively these help to explain potential synergies and trade-offs in mitigation, imply a need for a wide portfolio of policies attuned to different actors and levels of decision-making, and underpin Just Transition strategies in diverse contexts. {1.2.2, 1.7, 1.8}

'''The speed, direction and depth of any transition will be determined by choices in the, environmental, technological, economic, socio-cultural and institutional realms (''' '''''robust evidence''''' ''',''' '''''high agreement''''' ''')''' ''.'' Transitions in specific systems can be gradual or rapid and disruptive. The pace of a transition can be impeded by ‘lock-in’ generated by existing physical capital, institutions, and social norms. The interaction between power, politics and economy is central in explaining why broad commitments do not always translate to urgent action. At the same time, attention to and support for climate policies and low-carbon societal transition has generally increased, as the impacts have become more salient. Both public and private financing and financial structures strongly affect the scale and balance of high- and low-carbon investments. COVID-19 has strained public finances, and integrating climate finance into ongoing recovery strategies, nationally and internationally, can accelerate the diffusion of low-carbon technologies and also help poorer countries to minimise future stranded assets. Societal and behavioural norms, regulations and institutions are essential conditions to accelerate low-carbon transitions in multiple sectors, whilst addressing distributional concerns endemic to any major transition. {1.3.3, 1.4, 1.8, Chapters 2, 4 and 15, and Cross-Chapter Box 1 in this chapter}

'''Achieving the global transition to a low-carbon, climate-resilient and sustainable world requires purposeful and increasingly coordinated planning and decisions at many scales of governance including local, sub-national, national and global levels''' '''(''' '''''robust evidence''''' ''',''' '''''high agreement''''' ''').''' Accelerating mitigation globally would imply strengthening policies adopted to date, expanding the effort across options, sectors, and countries, and broadening responses to include more diverse actors and societal processes at multiple – including international – levels. Effective governance of climate change entails strong action across multiple jurisdictions and decision-making levels, including regular evaluation and learning. Choices that cause climate change as well as the processes for making and implementing relevant decisions involve a range of non-nation state actors such as cities, businesses, and civil society organisations. At global, national and sub-national levels, climate change actions are interwoven with and embedded in the context of much broader social, economic and political goals. Therefore, the governance required to address climate change has to navigate power, political, economic, and social dynamics at all levels of decision-making. Effective climate-governing institutions, and openness to experimentation on a variety of institutional arrangements, policies and programmes can play a vital role in engaging stakeholders and building momentum for effective climate action. {1.4, 1.9, Chapters 8, 15 and 17}

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