Climate Change Mitigation
Expert-defined terms from the Postgraduate Certificate in Climate Risk Analysis course at London School of Planning and Management. Free to read, free to share, paired with a professional course.
Afforestation #
Afforestation
A deliberate process of establishing forest cover on lands that historically hav… #
It captures atmospheric CO₂ through tree growth, creating a biological carbon store. Practical application includes planting native species on degraded agricultural fields. Challenges involve long‑term land tenure security, water availability, and ensuring biodiversity benefits rather than monocultures.
Carbon Capture, Utilisation and Storage (CCUS) #
Carbon Capture, Utilisation and Storage (CCUS)
A suite of technologies that capture CO₂ from point sources or the atmosphere, c… #
Example projects include CO₂‑enhanced oil recovery and mineral carbonation. Major challenges are high capital costs, energy penalties, and public acceptance of underground storage sites.
Carbon Pricing #
Carbon Pricing
An economic tool that assigns a cost to each tonne of CO₂ emitted, incentivising… #
Implemented via a direct tax on fossil fuel combustion or a cap‑and‑trade scheme. Practical application includes revenue recycling for renewable energy subsidies. Challenges include setting an appropriate price level, avoiding carbon leakage, and political resistance.
Carbon Neutrality #
Carbon Neutrality
A state where the net amount of CO₂ emitted into the atmosphere is zero, achieve… #
Companies may purchase verified carbon offsets to compensate for residual emissions after internal reductions. The main challenge lies in ensuring the integrity and permanence of offset projects and avoiding “green‑washing”.
Carbon Offsetting #
Carbon Offsetting
The practice of compensating for emissions by funding external activities that r… #
Effective offsets must be additional, measurable, and permanent. Practical use includes travel‑related offsetting for conference attendees. Challenges involve verifying real climate benefit, avoiding double counting, and ensuring social equity in host communities.
Carbon Pricing #
Carbon Pricing
An economic instrument that imposes a cost on each tonne of CO₂ emitted, guiding… #
Implemented either as a direct tax on fossil fuel use or as a cap‑and‑trade system where allowances are auctioned. Practical outcomes include revenue for climate‑resilient infrastructure. Challenges encompass setting an optimal price, preventing carbon leakage, and achieving political consensus.
Carbon Sequestration #
Carbon Sequestration
The long‑term removal and storage of CO₂ from the atmosphere in physical reservo… #
Forests sequester carbon through photosynthesis, while soils retain organic carbon via microbial processes. Geological sequestration involves injecting compressed CO₂ into depleted oil and gas reservoirs. Challenges include permanence, monitoring, and potential leakage.
Carbon Tax #
Carbon Tax
A direct tax levied on the carbon content of fossil fuels, translating the socia… #
It provides a clear price signal that encourages energy efficiency and low‑carbon technology adoption. Countries like Sweden have demonstrated high tax rates with significant emission reductions. Implementation challenges involve setting tax rates that balance economic impact and climate ambition, and addressing regressive effects on low‑income households.
Decarbonisation #
Decarbonisation
The systematic reduction of carbon intensity in energy production, industrial pr… #
Strategies include shifting to renewable electricity, electrifying transport, and adopting energy‑efficient processes. Practical application is illustrated by the EU’s Power System Transformation. Challenges involve technology readiness, grid integration, and financing large‑scale infrastructure upgrades.
Direct Air Capture (DAC) #
Direct Air Capture (DAC)
A set of technologies that extract CO₂ directly from ambient air using chemical… #
Pilot plants in the United States and Iceland demonstrate scalability. The main challenges are high energy demand, cost per tonne of CO₂ removed, and the need for low‑carbon electricity to power the process.
Energy Efficiency #
Energy Efficiency
Measures that achieve the same service or output with less energy input, thereby… #
Examples include high‑efficiency LED lighting, building envelope retrofits, and industrial heat‑recovery systems. While cost‑effective, barriers include split incentives, upfront capital constraints, and insufficient information on performance gains.
Energy Transition #
Energy Transition
The overarching shift from fossil‑based energy systems to low‑carbon or carbon‑n… #
It involves expanding renewable generation, modernising grids, and deploying storage technologies. Practical illustration: Germany’s “Energiewende”. Challenges include maintaining system reliability, managing intermittency, and addressing workforce displacement in traditional energy sectors.
Emission Trading System (ETS) #
Emission Trading System (ETS)
A regulatory framework that caps total emissions and allocates tradable permits… #
Participants can buy or sell allowances, creating a market price for emissions. The EU ETS is the largest example, covering power, industry, and aviation. Challenges involve overall cap stringency, allowance allocation methods, and preventing market manipulation.
Feedstock Substitution #
Feedstock Substitution
Replacing carbon‑intensive raw materials (e #
g., fossil‑based plastics) with lower‑carbon alternatives such as bio‑based polymers or recycled content. This reduces embodied emissions in product lifecycles. Example: using bio‑derived polyethylene in packaging. Barriers include supply chain scalability, performance parity, and certification of sustainability credentials.
Green Hydrogen #
Green Hydrogen
Hydrogen produced by electrolysing water using electricity sourced from renewabl… #
Used as a clean fuel for hard‑to‑decarbonise sectors like heavy industry and shipping. Projects such as the “HyDeploy” trial in the UK illustrate early deployment. Main challenges are high electrolyser costs, water resource management, and establishing transport infrastructure.
Industrial Decarbonisation #
Industrial Decarbonisation
Targeted reduction of emissions from heavy industry (steel, cement, chemicals) t… #
For instance, using electric arc furnaces in steelmaking reduces reliance on coal. Challenges include retrofitting existing plants, high capital intensity, and ensuring product quality is maintained.
Land‑Use Change #
Land‑Use Change
Alterations in how land is managed, which can either release stored carbon (e #
g., forest clearing) or sequester it (e.g., afforestation). Accurate accounting is essential for national mitigation pledges. Practical tools include remote sensing and GIS mapping. Challenges involve balancing food security, biodiversity, and carbon goals.
Low‑Carbon Technology #
Low‑Carbon Technology
Any technology that emits substantially less CO₂ compared with conventional alte… #
Examples encompass wind turbines, solar photovoltaics, and advanced battery storage. Adoption is driven by cost reductions, policy incentives, and corporate sustainability targets. Barriers include technology maturity gaps, supply chain constraints, and financing for early‑stage innovations.
Negative Emissions #
Negative Emissions
Processes that actively remove CO₂ from the atmosphere, resulting in a net reduc… #
Approaches include afforestation, BECCS (bio‑energy with carbon capture and storage), and DAC. While essential for meeting 1.5 °C pathways, challenges involve scalability, land competition, and ensuring permanence.
Renewable Energy #
Renewable Energy
Electricity generated from naturally replenishing sources that emit little or no… #
Solar photovoltaics and onshore wind have become cost‑competitive with fossil generation. Integration challenges include intermittency, grid stability, and the need for storage or demand‑response solutions.
Renewable Energy Certificates (RECs) #
Renewable Energy Certificates (RECs)
Tradable instruments that verify that a certain amount of renewable electricity… #
Organizations purchase RECs to claim renewable sourcing for their electricity consumption. Challenges include ensuring additionality, avoiding double counting, and maintaining transparent tracking systems.
Resilience‑Focused Mitigation #
Resilience‑Focused Mitigation
Strategies that simultaneously reduce emissions and enhance system resilience to… #
For example, decentralised microgrids powered by solar reduce emissions while providing reliable power during extreme weather. Challenges lie in integrated planning, financing dual‑benefit projects, and aligning policy objectives across sectors.
Sector Coupling #
Sector Coupling
Linking traditionally separate energy sectors (power, heat, transport, industry)… #
An example is using excess renewable electricity for electric vehicle charging or for power‑to‑heat in district heating networks. Barriers include regulatory fragmentation, market design, and technical interoperability.
Smart Grids #
Smart Grids
Modernised electricity networks that incorporate information technology, sensors… #
Smart meters enable dynamic pricing, encouraging consumers to shift load to periods of high renewable generation. Key challenges are cybersecurity, data privacy, and ensuring equitable access to advanced grid services.
Solar Photovoltaics (PV) #
Solar Photovoltaics (PV)
Technology that converts sunlight directly into electricity using semiconductor… #
PV installations range from rooftop systems to utility‑scale farms. Declining module costs have accelerated adoption worldwide. Challenges include land use for large farms, recycling of end‑of‑life panels, and variability requiring storage or grid integration solutions.
Supply Chain Decarbonisation #
Supply Chain Decarbonisation
Reducing greenhouse‑gas emissions across the full lifecycle of products, from ra… #
Companies often engage suppliers in emissions reporting and set science‑based targets. Practical tools include Life‑Cycle Assessment (LCA) and carbon‑footprint calculators. Obstacles include data availability, supplier engagement, and the complexity of multi‑tiered supply chains.
Sustainable Aviation Fuel (SAF) #
Sustainable Aviation Fuel (SAF)
A drop‑in replacement for conventional jet fuel derived from renewable feedstock… #
SAF can reduce lifecycle CO₂ emissions by up to 80 % compared with fossil jet fuel. Barriers include limited production capacity, high cost, and certification processes for new feedstocks.
Technology Readiness Level (TRL) #
Technology Readiness Level (TRL)
A nine‑point scale used to assess the maturity of a technology, from basic princ… #
It helps investors and policymakers prioritise funding. For mitigation, many low‑carbon technologies are still at intermediate TRLs, requiring risk‑mitigation strategies and pilot demonstrations.
Thermal Energy Storage #
Thermal Energy Storage
Systems that store heat for later use, enabling better integration of renewable… #
Molten‑salt storage is common in concentrated solar power plants, while seasonal storage can be achieved with underground aquifers. Challenges include material degradation, thermal losses, and high upfront capital costs.
Transitional Finance #
Transitional Finance
Funding directed toward projects that reduce emissions in the short‑to‑medium te… #
Examples include financing natural‑gas plants with carbon capture or retrofitting coal‑fired plants with efficiency upgrades. Critics argue that such finance may delay full transition if not coupled with clear phase‑out pathways.
Vertical Farming #
Vertical Farming
A method of growing crops in stacked layers within controlled indoor environment… #
It reduces land use and can lower emissions associated with transportation. However, high energy demand for lighting and climate control can offset benefits unless powered by clean energy sources.
Water‑Energy‑Food Nexus #
Water‑Energy‑Food Nexus
The interdependent relationship among water, energy, and food systems, where act… #
For mitigation, shifting to renewable electricity can reduce water‑intensive thermal power generation, while efficient irrigation reduces energy demand. Managing trade‑offs requires cross‑sectoral governance and scenario analysis.
Zero‑Emission Vehicles (ZEVs) #
Zero‑Emission Vehicles (ZEVs)
Vehicles that emit no tailpipe CO₂, powered either by electricity stored in batt… #
Adoption is accelerated by subsidies, charging infrastructure roll‑out, and corporate fleet commitments. Challenges remain in battery material supply chains, recycling, and ensuring electricity used for charging is low‑carbon.
Carbon Budget #
Carbon Budget
The total amount of CO₂ that can be emitted globally while limiting temperature… #
g., 1.5 °C). The Intergovernmental Panel on Climate Change (IPCC) provides quantitative budgets. Nations use these to set national mitigation pathways. Main challenges include equitable allocation, accounting for non‑CO₂ gases, and translating global budgets into sector‑specific targets.
Climate‑Smart Agriculture #
Climate‑Smart Agriculture
Farming practices that simultaneously increase productivity, enhance resilience,… #
Techniques include conservation tillage, precision fertiliser application, and integrating trees on farms. Practical examples are the “4 per 1000” initiative aiming to increase soil carbon by 0.4 % per year. Barriers include farmer knowledge gaps, upfront costs, and market access for low‑carbon produce.
Distributed Generation #
Distributed Generation
Small‑scale electricity production located close to the point of consumption, of… #
It reduces transmission losses and can provide resilience during grid outages. Integration challenges involve voltage regulation, net‑metering policies, and ensuring fair compensation for producers.
Energy Storage #
Energy Storage
Technologies that store energy for later use, smoothing the mismatch between var… #
Lithium‑ion batteries dominate short‑term storage, while pumped hydro provides bulk, long‑duration capacity. Emerging options include flow batteries and hydrogen‑based storage. Key challenges are cost decline, material sustainability, and regulatory frameworks for storage participation in energy markets.
Emission Factor #
Emission Factor
A coefficient that quantifies the amount of CO₂ emitted per unit of activity, su… #
Emission factors are essential for calculating organisational carbon footprints. Accuracy depends on data granularity, fuel mix, and technology efficiency. Updating factors regularly is necessary to reflect grid decarbonisation progress.
Green Building #
Green Building
Construction and operation of buildings that minimise environmental impact throu… #
Certifications like LEED provide performance benchmarks. Practical measures include high‑performance insulation, smart HVAC controls, and daylighting design. Barriers include higher upfront costs, limited skilled labour, and regulatory approval processes.
Integrated Assessment Model (IAM) #
Integrated Assessment Model (IAM)
Computational frameworks that combine climate science, economics, and technology… #
Examples include the MESSAGE‑IAM and DICE models. They inform policymakers on cost‑effectiveness of different strategies. Limitations involve uncertainties in socioeconomic assumptions, parameter sensitivity, and the representation of non‑CO₂ gases.
Life‑Cycle Assessment (LCA) #
Life‑Cycle Assessment (LCA)
A systematic method for evaluating the environmental impacts of a product or ser… #
LCA quantifies embodied emissions, enabling identification of high‑impact stages for targeted mitigation. Challenges include data availability, methodological consistency, and incorporating indirect emissions such as supply‑chain logistics.
Low‑Carbon Economy #
Low‑Carbon Economy
An economic system where the majority of activities emit minimal CO₂, achieved t… #
Transition policies include carbon pricing, green public procurement, and innovation funding. Obstacles involve entrenched fossil‑fuel interests, workforce transition, and ensuring social equity during the shift.
Marginal Abatement Cost (MAC) #
Marginal Abatement Cost (MAC)
The incremental cost of reducing an additional tonne of CO₂ using a specific mit… #
MAC curves help rank measures from most to least cost‑effective. They are used by governments to design incentive schemes and by corporations to prioritise investments. Accuracy depends on reliable cost data, technology performance, and assumptions about future energy prices.
Net‑Zero Emissions #
Net‑Zero Emissions
A state where all anthropogenic CO₂ emissions are balanced by removals, resultin… #
Achieving net‑zero typically requires deep emissions cuts across all sectors combined with carbon removal technologies or nature‑based solutions. Corporate net‑zero pledges must align with science‑based targets and transparent accounting to avoid “green‑washing”.
Nature‑Based Solutions (NBS) #
Nature‑Based Solutions (NBS)
Interventions that protect, sustainably manage, or restore natural ecosystems to… #
Examples include restoring mangroves for coastal protection and carbon storage, and implementing agroforestry. Challenges involve ensuring permanence, measuring outcomes, and balancing land‑use competition with food production.
Power‑to‑X (P2X) #
Power‑to‑X (P2X)
A suite of technologies that convert surplus renewable electricity into other en… #
P2X enables sector coupling and storage of renewable energy in chemical form. Practical projects include the “Hywind” offshore wind‑hydrogen hub. Barriers are conversion efficiency losses, high capital costs, and the need for end‑use markets.
Renewable Portfolio Standard (RPS) #
Renewable Portfolio Standard (RPS)
A regulatory requirement that utilities obtain a specified percentage of electri… #
RPS policies have driven renewable deployment in several U.S. states. Implementation challenges include defining eligible technologies, ensuring cost‑effectiveness, and avoiding unintended spikes in electricity prices.
Scope 1, 2, 3 Emissions #
Scope 1, 2, 3 Emissions
Classification of greenhouse‑gas emissions #
Scope 1 (direct emissions from owned sources), Scope 2 (indirect emissions from purchased electricity, heat, or steam), and Scope 3 (all other indirect emissions across the value chain, such as product use and waste). Comprehensive mitigation strategies address all three scopes, though Scope 3 data collection is often most challenging.
Sectoral Decarbonisation #
Sectoral Decarbonisation
Tailored strategies to reduce emissions within a specific economic sector, such… #
Sectoral pathways consider unique technical constraints, policy levers, and market dynamics. For example, the aviation sector focuses on SAF and electric propulsion for short‑haul flights. Coordination across sectors is required to avoid carbon leakage and ensure system‑wide efficiency.
Smart Metering #
Smart Metering
Digital devices that record electricity consumption in near real‑time and commun… #
Enables time‑of‑use tariffs that encourage shifting demand to periods of high renewable generation. Implementation challenges include privacy concerns, installation costs, and ensuring that tariff structures actually influence consumer behaviour.
Sustainable Development Goals (SDGs) #
Sustainable Development Goals (SDGs)
A set of 17 global goals adopted by United Nations member states, with Goal 13 e… #
Mitigation efforts intersect with other goals such as clean water (SDG 6) and affordable clean energy (SDG 7). Aligning mitigation projects with multiple SDGs can attract broader financing but requires careful assessment of trade‑offs.
Technology Transfer #
Technology Transfer
The process of moving low‑carbon technologies from research institutions or deve… #
Mechanisms include joint ventures, public‑private partnerships, and international climate finance. Barriers include intellectual‑property rights, lack of local technical expertise, and differing regulatory environments.
Thermal Decarbonisation #
Thermal Decarbonisation
Reducing CO₂ emissions from space heating, industrial process heat, and water he… #
Strategies include electrifying heat via heat pumps, integrating renewable‑based district heating networks, and using biomass with carbon capture. Challenges involve retrofitting existing building stock, high upfront costs, and ensuring that electricity supply is decarbonised.
Urban Heat Island Mitigation #
Urban Heat Island Mitigation
Measures that reduce elevated temperatures in urban areas, which can lower energ… #
Approaches include reflective roofing materials, expanding urban tree canopy, and installing cool pavements. While primarily an adaptation measure, these actions also contribute to mitigation by decreasing electricity consumption.
Variable Renewable Energy (VRE) #
Variable Renewable Energy (VRE)
Renewable electricity sources whose output fluctuates with weather conditions an… #
Integration of VRE requires flexible generation, storage, and demand‑side management to maintain grid stability. Challenges include forecasting accuracy, transmission constraints, and market mechanisms that reward flexibility.
Zero‑Carbon Buildings #
Zero‑Carbon Buildings
Buildings that operate without emitting any net CO₂ over a defined period, typic… #
Certification schemes like the Zero Carbon Hub provide benchmarks. Barriers include higher design complexity, need for integrated planning, and ensuring occupant behaviour aligns with performance goals.