Editing IPCC:AR6/WGIII/Chapter-4 (section)

==== 4.2.5.13 System Analysis Solutions Are Only Beginning to Be Recognised in Current Literature on Accelerated Mitigation Pathways, and Rarely Included in Existing National Policies or Strategies ====

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Most models and studies fail to address system impacts of widespread new technology deployment, for example: (i) material and resources needed for hydrogen production or additional emissions and energy required to transport hydrogen; or (ii) materials, resources, grid integration, and generation capacity expansion limits of a largely decarbonised power sector and electrified transport sector. These impacts could limit regional and national scale-ups.

Systemic solutions are also not being sufficiently discussed, such as low-carbon materials; light-weighting of buildings, transport, and industrial equipment; promoting circular economy, recyclability and reusability, and addressing the food-energy-water nexus. These solutions reduce demand in multiple sectors, improve overall supply chain efficiency, and require cross-sector policies. Using fewer building materials could reduce the need for cement, steel, and other materials and thus the need for production and freight transport. Concrete can also be produced from low-carbon cement, or designed to absorb CO 2 from the atmosphere. Few regions have developed comprehensive policies or strategies for a circular economy, with the exception of the EU and China, and policies in the EU have only emerged within the last decade. While China’s circular economy policies emphasises industrial production, water, pollution and scaling-up in response to rapid economic growth and industrialisation, EU’s strategy is focused more narrowly on waste and resources and overall resource efficiency to increase economic competitiveness ( [[#McDowall--2017|McDowall et al. 2017]] ).

Increased bioenergy consumption is considered in many 1.5°C and 2°C scenarios. System thinking is needed to evaluate bioenergy’s viability because increased demand could affect land and water availability, food prices, and trade ( [[#Sharmina--2016|Sharmina et al. 2016]] ). To adequately address the water-energy-food nexus, policies and models must consider interconnections, synergies, and trade-offs among and within sectors, which is currently not the norm ( [[IPCC:Wg3:Chapter:Chapter-12#12.4|Section 12.4]] ).

A systems approach is also needed to support technological innovation. This includes recognising unintended consequences of political support mechanisms for technology adoption and restructuring current incentives to realise multi-sector benefits. It also entails assimilating knowledge from multiple sources as a basis for policy and decision-making ( [[#Hoolohan--2019|Hoolohan et al. 2019]] ).

Current literature does not explicitly consider systematic, physical drivers of inertia, such as capital and infrastructure needed to support accelerated mitigation ( [[#Pfeiffer--2018|Pfeiffer et al. 2018]] ). This makes it difficult to understand what is needed to successfully shift from current limited mitigation actions to significant transformations needed to rapidly achieve deep mitigation.

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