How to fight climate change?Some of the most authoritative climate analysts consider energy-efficiency measures, among the most cost-effective tools available.Some — such as including solar self-supply and home back-up batteries — are easy, widely available solutions individuals, corporates and organisations. There are more funding-intensive, but doable state-level responses, including Urban cooling projects, pumped-storage hydro electric power and nuclear power plants.Key target: Energy efficiencyWhy energy efficiency? Because they simultaneously reduce emissions, lower energy bills, and improve energy security..According to the International Energy Agency, the IPCC and the UN climate body, the world's most important climate-mitigation technologies include:Renewable energyEnergy efficiency measuresElectrificationEnergy storage, hydrogenCarbon captureSustainable transport, Nature-based carbon-removal solutions.Here is a broad list of technologies and strategies used to reduce greenhouse-gas emissions, improve energy efficiency, and help societies adapt to climate change.These are based on the most authoritative references, including International Energy Agency (IEA), the Intergovernmental Panel on Climate Change (IPCC), and the UN Framework Convention on Climate Change (UNFCCC), and International Renewable Energy Agency (Irena).Clean Energy GenerationSolar PowerWind EnergyHydroelectric PowerGeothermal EnergyTidal PowerWave EnergyGreen HydrogenAdvanced Nuclear PowerSmall Modular ReactorsEnergy StorageBattery energy storage systems (lithium-ion, sodium-ion, solid-state)Pumped-storage hydropowerThermal energy storageCompressed-air energy storageHydrogen storageGravity-based energy storageEnergy EfficiencyHeat exchangersHeat pumpsHigh-efficiency motorsLED lightingSmart thermostatsBuilding insulationEnergy-efficient windowsPassive house designDistrict heating and cooling systemsWaste heat recoveryTransportationElectric vehicles (EVs)Electric busesElectric rail systemsHigh-speed railHydrogen fuel-cell vehiclesSustainable aviation fuelElectric aircraftElectrified ports and shippingBicycle infrastructurePublic transit expansionIndustrial DecarbonizationGreen steel productionLow-carbon cementElectrified industrial heatingCarbon-neutral chemicalsIndustrial carbon captureCircular manufacturingMaterials recyclingCarbon Removal and Emissions ReductionCarbon Capture and Storage (CCS)Direct Air Capture (DAC)Bioenergy with carbon capture (BECCS)Enhanced rock weatheringBiocharSoil carbon sequestrationBlue carbon projects (mangroves, seagrass)Methane capture from landfillsAgriculture and FoodPrecision agricultureRegenerative farmingDrought-resistant cropsDrip irrigationAgroforestryVertical farmingAlternative proteinsReduced food wasteMethane-reducing livestock feed additivesNature-Based SolutionsReforestationAfforestationMangrove restorationWetland restorationPeatland protectionUrban tree plantingWatershed restorationCoral reef restorationClimate AdaptationFlood barriers and seawallsStormwater management systemsUrban cooling projectsClimate-resilient infrastructureEarly-warning systemsDrought management technologiesDesalination powered by renewablesWater recycling and reuseDigital and Smart SystemsSmart electrical gridsAI-based energy managementSmart metersDemand-response systemsBuilding automation systemsPrecision weather forecastingDigital twins for infrastructureEmerging TechnologiesPerovskite solar cellsFusion energySpace-based solar powerLong-duration battery storageSynthetic carbon-neutral fuelsOcean carbon removal technologiesAdvanced geothermal systemsTransparent solar windowsReferencesInternational Energy Agency (IEA). Net Zero by 2050: A Roadmap for the Global Energy Sector (2021).Identifies solar, wind, batteries, electric vehicles, heat pumps, hydrogen, carbon capture, and energy efficiency as core pillars of decarbonization.International Energy Agency (IEA). Energy Technology Perspectives 2020 (2020).Highlights electrification, advanced batteries, hydrogen, bioenergy, carbon capture, and renewable energy as essential technologies for achieving net-zero emissions.Intergovernmental Panel on Climate Change (IPCC), Working Group III.Concludes that technological innovation and improved efficiency are among the primary means of reducing future greenhouse-gas emissions and stabilizing atmospheric concentrations.United Nations Framework Convention on Climate Change (UNFCCC), Policies and Technologies for Mitigation.Lists renewable energy, efficient heating and cooling systems, carbon capture, sustainable transport, and building-efficiency measures as major climate-mitigation technologies: