Carbon dioxide (CO2) The predominant greenhouse gas trapping heat in the atmosphere. Persists for centuries in the atmosphere once emitted.

Carbon intensity How much CO2 is emitted in any given process or activity.

Embedded/embodied emissions The total amount of GHGs emitted in the course of producing a specific good, like a car, steel bridge or concrete building.

Fossil fuels The world runs on fossil fuel: 36 billion barrels of oil per year (100 million per day), eight billion tons of coal per year, four trillion cubic meters of gas. There are fifty years worth of proven oil and gas reserves, based on current consumption levels.

Greenhouse gases (GHGs) Gases emitted by burning fossil fuels, which trap heat in the atmosphere. Global annual GHG emissions are at an all-time high of 60 gigatons (37 of which are CO2).

Methane The second biggest greenhouse gas by volume. Shorter-lasting in the atmosphere than CO2 (a decade, vs. centuries) but much more potent at trapping heat (30-80x). ‘Natural’ gas is mostly methane.

Nitrous oxide The third biggest greenhouse gas, emitted when fertilizer goes into the soil. Long lasting like CO2 and potent like methane.

Parts per million Global atmospheric CO2 concentration, currently at about 420 parts per million, up from 340 ppm in 1980.

Scope 1 emissions Greenhouse gas emissions from a company’s operations that it directly controls.

Scope 2 emissions Emissions from the production of energy a company buys to use in its operations.

Scope 3 emissions Emissions produced by A) a company’s customers while using the company’s products; and B) a company’s suppliers.

Alternating current (AC) The type of current commonly used for most grid power distribution, and in homes.

Amps A measurement of flow in a circuit (e.g. 15 amps), or how much power can flow across that circuit in a given amount of time. Amps = Watts/Volts.

Circuit A closed-loop path for circulating electric current, including a source of charge and devices that can use or manipulate the current.

Direct current (DC) The type of current commonly used in industrial processes, electrical motors, power supplies, and to charge batteries.

Generator A machine that converts mechanical energy (e.g. from a turbine or diesel motor) into electrical energy.

Gigawatt A million kilowatts (or a thousand megawatts). Only the very largest power plants generate more than a gigawatt of power.

Inverter Hardware that converts AC to DC power (or vice-versa), among other functions.

Kilowatt (kW) A thousand watts; and a good measure of home electricity consumption. Your clothes dryer, for example, might ‘pull’ a kilowatt or more of power while running.

Kilowatt hour (kWh) A total amount of electricity stored or used (an appliance that requires one kilowatt, running for an hour, uses one kilowatt hour).

Megawatt A thousand kilowatts. Most utility scale power plants produce tens, or hundreds, of megawatts of power. And don’t forget your “megawatt smile!”

Terawatt A billion kilowatts (or a million megawatts or a thousand gigawatts). Large countries’ energy usage often runs into the terawatts.

Transformer Hardware that transfers electrical energy from one circuit to another and can increase or decrease voltages.

Turbine A machine spun by water, wind power or other energy source (e.g. burning fossil fuel), to generate electricity.

Volts Voltage is like water pressure in an electrical circuit: the higher the voltage, the more power can be delivered through a given sized circuit. Volts = Watts/Amps.

Watts A basic unit of electric power. Old light bulbs needed 100 watts to light up. Today’s LEDs only need ten or less. Watts = Volts * Amps.

Behind the meter The wiring, hardware and software on the customer side of the utility meter.

Blackouts and brownouts When a utility throttles electricity supply or cuts off whole blocks of customers so the grid doesn’t crash.

Distribution The local network that takes electricity from long-distance transmission and brings it to homes and businesses. Typically up to 33 kilovolts, stepping down to 240 volts.

Grid An interconnected set of electricity generators and consumers.

Load A unit of energy demand… whether a single light bulb or an entire factory.

Microgrid A local grid with its own generation and storage, that can be ‘islanded’ (isolated) from the public grid and run separately if needed.

Substation A facility with transformers that takes higher voltage electricity from the transmission network and steps it down to lower voltages for the distribution network.

Transmission The very high voltage network which carries electricity hundreds of miles from large power plants (typically at over 100 kilovolts) to local distribution networks.

Utilities Entities which generate, distribute and/or sell power on the grid.

Baseload power Power sources that generate steady, round the clock, output. Hydro, geothermal, nuclear and fossil plants can all do this today.

Curtailment When grid operators order wind or solar farms to turn off or reduce their output, because there’s no room on the grid for all their extra power.

Demand response Systems enabling electricity customers to temporarily lower their consumption in return for compensation when it will help balance the grid.

Dispatchable generation Power sources which can reliably be turned on anytime they’re needed by grid operators.

Distributed generation Power generation (e.g. rooftop solar) that’s distributed at the edges of the grid closest to users.

Duck curve The huge dip in load demand mid-day, followed by a dramatic rise as the sun goes down, on grids with lots of solar power generation.

Firming Using dispatchable generators to balance supply and demand on the grid, maintaining a constant frequency and avoiding instability.

Grid defection When businesses or homes can generate enough of their own energy to not need the public grid.

Interconnection queues Waitlists for newly-built renewable power plants to connect to the public grid’s transmission network.

Intermittent generation Generation sources which can’t always run on demand, like solar or wind farms when not coupled with batteries.

Peak load The time(s) of maximum load demand for a grid.

Peaker plant A power plant (usually gas) which typically only operates a few hours per day or week at times of peak demand.

Repowering Upgrading older power plants, for example with more powerful wind turbines, and/or converting them (e.g. coal to solar-plus-storage).

Utility scale Large power plants (wind, solar, gas etc.) that connect to the grid’s high-voltage transmission lines.

Virtual power plant The collective output of coordinated distributed resources (e.g. rooftop solar plus batteries) that can provide large amounts of power to the grid on demand when needed.

Agrivoltaics Combining solar arrays with farming or agriculture on the same piece of land.

Cell efficiency The most efficient silicon solar cells available today convert 23 or 24% of the sun’s energy into electricity; those in the lab can convert 30% or more.

Commercial solar Solar installed on buildings like warehouses, retail stores, or offices.

Floating solar Solar arrays designed to float on lakes, reservoirs, and even the ocean.

Grid tied solar: A simple solar system without a battery, which must push all the excess energy it generates to the grid.

Net energy metering (NEM) How utilities compensate homeowners and businesses for electricity they export to the grid from their rooftop solar panels.

Rooftop solar The ultimate distributed generation; rooftop solar cuts out the costs and losses of transmitting electricity from centralized power plants to end users.

Silicon perovskite cells Solar cells in development which pair traditional silicon with crystalline materials called perovskites, potentially resulting in higher energy yields and lower costs.

Siting and design software Software which can determine the optimal location and positioning of solar arrays, as well as facilitate design and permitting, is helping to lower overall deployment costs.

Solar carports Steel structures which enable solar panels to be installed on top of parking spaces.

Solar panels Are constructed out of layers of different materials – including glass, silicon, plastic, aluminum, copper, silver and lead – all sealed together.

Solar panel recycling Diverting the large volume of obsolete panels (20+ years old) from landfills is a challenging problem, just now being tackled by entrepreneurs.

Solar supply chain The world’s solar panel supply chain, dominated by China, starts with raw silicon, which is made into polysilicon, then ingots, then wafers, then cells, and finally into modules.

Solar trackers Solar mounts which enable panels to automatically pivot toward the sun as it moves, maximizing their efficiency.

Thin-film solar Uses thin layers of semiconductor material, like cadmium telluride, vs. thicker more rigid silicon, making them lighter, more flexible and potentially more versatile.

Utility scale solar Large solar farms that produce many megawatts of power, often located far from population centers.

Aerodynamic modeling Simulators and computational software tools are helping wind farm operators optimize overall wind farm output, e.g. by coordinating turbine controls to minimize wake effects.

Blade materials Modern, 200+ foot long turbine blades are made from lightweight, fiberglass-reinforced polyester and other composites like carbon fiber, optimizing performance but making recycling challenging.

Blade design Modern blades have evolved to incorporate high-lift airfoils, trailing edge noise-reduction add-ons, advanced blade tips, aeroelastic tailoring, and other performance enhancers.

Horizontal-axis turbines The most common type of wind turbine, like an airplane propeller, with three blades and the rotor shaft pointed in the direction of the wind.

Nacelle Housing with all the generating components of a wind turbine (gearbox, electronic systems, and either an induction or permanent magnet generator).

Floating wind Mounting turbines on giant floating platforms has enabled bigger wind farms in deeper ocean waters; less visible and drawing less opposition.

Fixed offshore wind The biggest offshore wind turbines, fixed to the ocean floor, can generate ten megawatts or more of power.

Onshore wind Easier to install than offshore, but with more local opposition. These turbines can be over 300 feet tall and generate three-plus megawatts of power.

Small wind Small distributed wind turbines ranging between one and 100 kilowatts which can be used to power homes, farms, schools, water pumps, and even feed energy into the grid.

Tower height Keeps growing, since power increases exponentially with wind speeds (which are faster higher off the ground), and longer blades extract more wind energy even at low speeds.

Wind supply chain The world’s wind supply chain includes manufacturing of very large blades, towers and generators, plus the challenging logistics of moving them around the world and installing them.

Closed loop hydro Dedicated pumped hydro systems where neither reservoir (upper or lower) is connected to an outside water source.

Conventional dams These mega-projects with human-engineered reservoirs are becoming less common. Among other factors (environmental destruction) the reservoirs let lots of water evaporate.

Dead pool If a dammed reservoir’s water level reaches this low point, water can no longer flow downstream from the dam. Before this, the dam would have stopped being able to generate power.

Hydropower Power generated by flowing water (e.g. from a river or reservoir) which spins a turbine as it rushes downstream.

Methane release Microbes and vegetation decomposing in hydropower reservoirs can cause methane release depending how they’re managed, but there’s a debate about how much.

Pumped hydro Pumping water uphill or upstream to a reservoir when electricity is cheap, then running the water down through generators to harness the energy when it’s most valuable.

Run-of-river hydro Generators not connected to a reservoir, which depend on seasonal flows and thus can’t produce energy on demand.

Small scale hydro Small hydro generators (10kW to 30MW), common in local communities, industrial and agricultural settings (rivers, canals, conduits, reservoirs etc).

Closed-loop geothermal Using water or another fluid flowing through pipes (rather than directly through subterranean rocks) to tap geothermal heat.

Drilling technologies Many of the oil and gas industry’s innovations, like hydraulic fracturing (‘fracking’) and horizontal drilling, can be applied to geothermal.

Enhanced geothermal New technologies (e.g. drilling and data) being developed to make geothermal practical in places that don’t already have natural geologies where water easily flows through rock.

Hydrothermal plants Traditional geothermal plants which take advantage of natural geologies (near hot springs and geysers etc) featuring heat and pathways for flowing water to tap the heat.

Geothermal energy Renewable energy generated by tapping heat coming up from the deep in the earth.

Superhot rock energy With the right drilling technology, gigawatts of energy could be generated from superhot (400 degrees Celsius) rocks miles deep in the earth.

Nuclear accidents Nuclear accidents and radiation releases (Three Mile Island 1979, Chernobyl 1986, Fukushima 2011) have made the public cautious about nuclear power in many countries.

Nuclear fission Fission reactors harness thermal energy from splitting uranium atoms, then use the heat generated to drive steam turbines and generators to create electricity.

Nuclear fusion A reaction in which two or more atomic nuclei combine to form a heavier one while releasing lots of energy. Still in development and far from ready to deploy for power generation.

Nuclear power Generates 10% of the world’s electricity (20% U.S.). There are currently over 400 fission reactors in the world (roughly 400 gigawatts), and more being built.

SMRs Small modular nuclear reactors are technologies that developers hope could someday safely provide portable, low-carbon power to balance renewables on the grid.

Anode The negative electrode in a battery.

AC coupled A battery that takes an AC current and converts it (with an inverter) to DC for storage, and then back to AC when the power is needed.

Battery cell The basic battery unit, with an anode, cathode and electrolyte. Can take various formats (e.g. cylindrical, prismatic, pouch), and be aggregated in large numbers into battery packs.

Battery recycling Processes and technologies in development to extract as much re-usable material as possible (e.g. lithium, cobalt, nickel etc.) from end-of-life EV and other batteries.

Cathode The positive electrode in a battery.

Continuous power How many kilowatts (aka kilo-volt-amps) a battery can output on a continual basis.

Cycle lifespan The number of times (cycles) you can charge and discharge a battery before it degrades and starts to lose performance.

DC coupled A battery that takes a DC current, and provides DC current back when its needed.

Energy density How much energy a given type of battery can store given its size and weight.

Flow batteries Long-duration grid batteries that store energy chemically as a bulk dissolved metal (e.g. iron) in large tanks of an aqueous electrolyte.

LFP lithium ion batteries Lithium iron phosphate (LFP) chemistry batteries are less storage dense than NMC chemistry batteries, but use fewer rare metals and are cheaper and safer (less prone to fire).

NMC lithium ion batteries Nickel manganese cobalt (NMC) chemistry batteries are energy dense, but have issues including cost, fire risk, and the use of rare and problematic metals.

Peak (or max) power How many kilowatts a battery can output in short bursts, e.g. to support momentary power surge needs like starting up an air conditioner unit.

Round trip efficiency The percentage of energy put into the battery that can ultimately be retrieved and used.

Sodium ion batteries Batteries in production now using cheaper sodium in place of lithium; will compete for both grid storage and EV applications.

Solid-state batteries Batteries in development using thin layers of solid electrolytes to carry lithium ions between electrodes, enabling faster charging and higher density.

Thermal batteries Heating or cooling a medium like water, sand, rock, bricks or molten salt to store energy for later (typically long duration or more than a day).

Battery swapping Successfully being deployed across Asia for two and three wheeled electric scooters.

Bidirectional charger A charger that can move electricity in two directions (e.g. in and out of a car’s battery).

eBikes Have exploded in popularity globally ($40+ billion market size in 2023), and outsell EVs in the U.S. Often an alternative to car ownership.

Electric airplanes Getting a big plane off the ground takes more energy than batteries can hold… for now. But that could change.

Electric buses Already ubiquitous in China, and spreading globally, electric buses make sense with their known routes/range and ease of charging at the depot.

E-scooters and motorcycles More popular than cars in Asia, two-wheeled vehicles (with their high emission two-stroke engines) are fast being replaced by electrified versions.

Fast DC charger A direct current charger that operates at 75kW or above and can charge a typical EV in less than an hour.

Level two charger An alternating current charger operating at 5-10kW that can charge a typical EV in four to eight hours.

Megawatt charging Ultra high speed charging infrastructure for trucks and other large-battery vehicles, currently in development.

Plug-in hybrids Vehicles with drivetrains which can run on both fossil fuel and electricity from a battery, alternating between the two as needed.

Structural battery pack Battery cells built into a structural (load bearing) component of an EV or other vehicle, in order to reduce overall weight and cost.

Trickle charging The slowest way to charge a car battery, by plugging it into a standard home wall (AC) outlet.

Vehicle to grid The transfer of power from a vehicle’s battery to the grid when that extra power is needed.

EV motors Most EV motors use three-phase AC current to set up a rotating magnetic field (RMF) to create torque, controlled by power electronics that respond to the accelerator.

Hub motor A motor integrated directly into the drive wheel(s) of a two wheeled e-bike or electric scooter, rather than attached by a chain or belt.

Induction motors EV motors which induce a current in the rotor’s copper (or aluminum) cladding, creating an electromagnetic field.

Permanent magnet motors EV motors where the rotor, with embedded permanent magnets, possesses its own magnetism. This is the most common type of EV motor.

Rare earths Hard-to-source elements like neodymium which are commonly used for the strong magnets in EV permanent magnet motors.

Regenerative braking Reversing an EV motor (using it as a generator) to slow the vehicle without brakes, thus generating AC power which is converted to DC and returned to the battery.

Rotor The moving part of an EV electric motor which feeds torque out through the transmission (usually single-speed in EVs) to a differential and then the wheels.

Stator The housing of an EV electric motor, which applies the AC current to create the rotating magnetic field. Mounted to the chassis and usually stuffed with copper windings.

Torque The force that causes rotation around an axis (like an axle). EV motors produce instant torque, directly proportional to the electric current applied.

Artificial intelligence AI, combined with lots of data, will undoubtedly help climate technologies become more competitive with fossil fuels. We just have no idea how yet.

Gallium nitride An emerging semiconductor material for power electronics which along with silicon carbide is enabling better, faster electrification.

Grid enhancing technologies Cheap software-based ways of getting 10-40% more out existing transmission lines, including dynamic line ratings, topology optimization, and advanced power flow control.

Grid forming inverters Smart inverters which can collectively ‘form’ a grid (e.g. a micro-grid) exactly matching the frequency of (and synchronizable with) the public grid.

Microinverters Small chip-based inverters used to convert the DC output of individual solar panels to AC power, among other applications.

Power electronics Semiconductor based hardware (e.g. inverters) for managing, converting and harnessing electrical currents, for example in EVs.

Silicon carbide This semiconductor material has helped drive the recent power electronics revolution, enabling greater range and faster charging in EVs for example.

Smart meters Chip enabled systems that can monitor and help manage electricity usage and characteristics (voltage dips, motor stalls) in real time.

Solid state breakers Chip-based replacements for traditional mechanical breakers, which will enable power to be more flexibly and efficiently distributed (e.g. eliminating dedicated circuits).

Solid state transformers Replacing analog transformers on telephone poles (big jugs of oil and wire) with microchips could turn the grid into a smart, flexible, peer-to-peer energy network.

Building envelope enhancements Upgrading building envelopes (floors, walls, roofs, windows, doors, etc.) to be better thermally insulated and air sealed.

Duct sealing Sealing leaky ducts can improve heating and cooling system efficiency up to twenty percent.

Insulation There are all different formats (and materials) of insulation, including loose-fill and blow-in, spray foam, rigid boards, and even radiant barrier insulation, which reflects heat.

Lighting upgrades Replacing traditional incandescent and fluorescent residential and commercial lighting with high efficiency LED lighting.

Moisture control An important efficiency factor in both summer and winter, as most people feel warmer indoors at higher relative humidity levels and cooler at lower ones.

Passive heating and cooling Building designs which take in and utilize the sun’s heat in winter, and keep it out in summer, resulting in comfort plus high efficiency.

Reflective roofs Roofs coated with materials containing specialized pigments that reflect sunlight and absorb less heat than standard roofs. 

Smart appliances Connected, software-configurable appliances which can pull energy from the grid (or a local battery) when it’s cleanest, cheapest, or both.

Smart sensors and thermostats Connected, software-configurable sensors which can help make sure energy isn’t wasted on unneeded heating and cooling.

Air source heat pump A heat pump that pulls heat from (or returns it to) the air.

Battery induction stove Induction stove with an integrated battery to handle cooking power peaks, enabling use of a standard outlet and avoiding wiring or panel upgrades.

Cold chain The end to end, energy-intensive supply chain for products which must be kept frozen or refrigerated such as food and medicines.

District heating and cooling A system which generates and distributes heat or cooling to an entire grouping of buildings or neighborhood.

Ground source heat pump A heat pump that pulls heat from (or returns it to) the ground.

Heat pump A highly efficient system for using electricity to shift heat from one place to another, enabling both heating and cooling.

Heat pump water heaters Two to three times more efficient than resistance heating models, for both residential and commercial applications.

Hydronic systems Heat pump systems that use water to bring heat or cold into a building through floor tubes (‘radiant floor’) and/or special radiators.

Induction stove An electric stove or cooktop which uses magnets to heat pots, energy efficiently and without the unhealthy and destructive emissions of gas stoves.

Inverter air conditioner An energy-efficient air conditioner, similar to a heat pump, that uses a microprocessor-controlled, variable speed compressor motor.

Mini-split A ductless heat pump system with an outside condenser to exchange the heat, connected to a wall unit which distributes the heat (or cool air) inside.

Refrigerant Fluid in a heat pump or air conditioner that transfers the heat or cold indoors. Newer ones are less climate damaging than the old ones were, but still not great.

Resistance heating The traditional (but not very efficient) method of using electricity to heat or cook, by flowing electrons through a resistive material like nichrome wire.

Alternative fertilizers Lower-emission, more efficient ways of getting nitrogen into soil, like biological solutions (natural bacteria, biological activators, genetically edited microbes).

Alternative proteins Cleaner alternatives to emissions-intensive meat and dairy products, like plant-based milks and meat substitutes (possibly even ‘cultured meat’ grown from animal cells).

Biofuels Fuels like bioethanol and biodiesel made from biomass (e.g. agricultural products like corn, soybeans or sugar cane) or bio waste. Much debate over their climate impact.

Decarbonizing fertilizer production Using green hydrogen or ammonia produced with renewable energy instead of the traditional Haber-Bosch process.

Haber-Bosch The traditional high-emission process for producing nitrogen fertilizer; fixes nitrogen into fertilizer (ammonia) using ‘steam-reformed’ (fossil fueled) hydrogen.

Fertilizer emissions Nitrogen fertilizer emits the potent greenhouse gas nitrous oxide when it enters the soil (twice the emissions of fertilizer production in fact).

Fertilizer reduction Reducing over-fertilization without sacrificing yields, through better data, farming practices (‘precision agriculture’), soil testing, etc.

Food waste A major emission reduction opportunity: 30-40% of the U.S. food supply is wasted, according to the USDA.

Increasing yields Various technologies are being developed (e.g. genetic editing of plants and animals) to increase yields per acre with less chemical fertilizer and pesticides.

Methane-reducing feed additives Products available today can reduce up to 30% of the methane emissions from cows (1.5 billion on the planet) digesting their feed.

Nitrogen runoff Fertilizer runoff into lakes, rivers, and oceans not only wastes the nitrogen (and its emissions), but pollutes drinking water and causes algal blooms and dead zones.

Pesticide reduction Production and distribution of chemical pesticides (mostly petroleum derived) may generate even more GHG emissions than fertilizer.

Regenerative farming Practices like planting cover crops or reducing tillage (plowing) to improve soil health and reduce erosion. May sequester some carbon, but may also reduce yields.

Vertical farming The idea of growing crops indoors in stacked high-tech high-yield factories, maximizing land use while minimizing weather and pesticide impacts.

Cement emissions Making cement is six percent of total global CO2 emissions; mostly from superheating limestone and clay in coal-fired kilns to make the binding agent for concrete.

Electric arc furnaces Much lower-emission than blast furnaces, they use electricity and scrap metal to make steel rather than coal, iron and coke.

Electricity driven processes Some chemical processes, like the production of chlorine to make PVC pipes or solvents, already use electricity, so can be decarbonized with renewable energy.

High temperature processes Harder-to-electrify industrial processes using heat over 500 degrees celsius, like iron and steelmaking and chemicals.

Hydrogen direct reduction Using green hydrogen instead of coal to reduce iron ore to pig iron (the most emissions-intensive part of steelmaking).

Metallurgical coal The coal used for steelmaking.

Methane leaks Stopping and cleaning up methane leaks (and venting and flaring) is a major emissions reduction opportunity for the oil and gas industry.

Low-temperature processes Easier-to-electrify industrial processes using heat under 200 degrees celsius, like food and beverage, pulp and paper, machinery.

New cement formulations in development will be key to decarbonizing cement; for example using less limestone to reduce kiln emissions.

Petrochemicals Chemicals made with fossil fuels, and then turned into products like clothes, toys and paints. They could account for 60% of oil demand in ten years by some estimates.

Plastics Plastics use fossil fuel as a primary feedstock (ingredient); this carbon gets emitted later when incinerated. Since alternative feedstocks aren’t yet scalable, reducing consumption is the best option.

Process heat Electrification, efficiency, heat pumps, and alternative heat sources (geothermal, hydrogen) are all needed to reduce massive fossil-fueled process heat emissions (gas steam boilers, coal-fired furnaces etc).

Refineries Oil refining (hydroskimming, hydrocracking and catalytic cracking) accounts for four percent of global CO2 emissions, plus significant methane emissions.

Thermal coal The coal used for electric power generation or heating.

Steel emissions Making steel, mostly with coal-fired blast furnaces, accounts for seven percent of total global CO2 emissions.

Ammonia (NH3) Can be made from hydrogen, and vice versa. And easier to transport than hydrogen, making it relevant for decarbonizing industry, shipping and agriculture (fertilizer is mostly ammonia).

Electrolyzer A machine that can create green hydrogen (by splitting H2O into H and O), and also green ammonia, using electricity from renewable energy as an input.

Fuel cell A machine that can convert gas into electricity. If run on 100% green hydrogen, could help decarbonize many things requiring electricity on demand.

Green hydrogen Hydrogen produced with 100% decarbonized electricity (e.g. solar or wind). But in practice, some fossil-fueled grid electricity still usually gets mixed in.

Hydrogen A pathway to decarbonize industrial and other processes using green hydrogen produced by electrolyzers. When burned, hydrogen emits only water.

Steam methane reforming How hydrogen is commonly produced today, using lots of methane gas and emitting lots of CO2.

Biologic carbon sequestration Storing carbon in grasslands, forests, soils, and aquatic environments.

Carbon capture Trying to catch carbon (e.g. when it’s generated by burning fossil fuels) before it goes into the atmosphere.

Carbon credits Financial products purporting to enable companies to offset their actual carbon emissions by sponsoring various unrelated carbon reduction projects.

Carbon sink Anything that absorbs more carbon from the atmosphere than it releases.

Direct air capture Using technology to pull carbon directly from the air, thus removing it from the atmosphere.

Geologic carbon sequestration Storing carbon in underground geologic formations, e.g. pressurized into a liquid and then injected into porous rock.

Liquid capture systems Pass air through chemical solutions to capture carbon.

Solid capture systems Pass air through filter materials that chemically bind with the CO2 to capture carbon.

Supercritical CO2 A superheated gas/liquid form of CO2 which could replace steam for driving turbines, dramatically increasing efficiency in almost any type of power plant.

Biologic carbon sequestration Storing carbon in grasslands, forests, soils, and aquatic environments.

Deforestation Ongoing profiteering-driven global deforestation is removing existing carbon sinks, raising the bar for climate solutions.

Nature-based solutions Protecting and restoring the natural world and enhancing its capacity to help counteract global GHG emissions.

Reforestation Restocking of forests that have been depleted/deforested, by replanting trees or supporting natural regeneration in areas affected by human clearing and/or natural disturbances.

Restoring biodiversity Reforesting also helps protect species diversity, as forests are home to the vast majority of species on the planet.

Restoring coastal wetlands Protecting and restoring peatlands and coastal wetlands (for example with mangroves), so they can not only absorb more carbon, but protect against flooding.

Reversing soil erosion Reforesting and planting trees is one of the best ways to hold back the wind and rain that drives soil erosion.

Urban nature solutions Can provide cooling, shade and flood mitigation as well as carbon absorption. Examples include prioritizing green roofs, urban forests, green spaces and canopy cover.

Bunker fuel The sulfur-laden, emissions-intensive fuel made from refinery dregs that powers most global shipping.

Dark/shadow oil tankers Over ten percent of the world’s tanker fleet is said to be ‘shadow’ or ‘dark’: old, uninsured, often unsafe and hard to trace, ideal for ferrying illegal (e.g. sanctioned) oil shipments.

Globalization The decades-long outsourcing of manufacturing and production to countries based primarily on cost (labor and materials), and assuming friction-free trade (now under question).

LNG Methane gas that’s been cooled down to liquid form so it can be transported internationally by tanker.

Reshoring Moving production and supply chains closer to consumption to reduce geopolitical risk (and also likely environmental impacts).

Supply chain weaponization Fossil fuel pipelines and shipping are at risk of sudden political weaponization, as happened recently with the Ukraine war and oil and gas from Russia.

Bikeability Efforts to make local communities as appealing and safe to people using bicycles (and eBikes) as possible, to get people out of cars and traffic.

Climate justice Making sure communities who’ve suffered from proximity to fossil fuels (extraction, processing, emissions, impacts etc) benefit equally or more so from decarbonization.

Community energy co-ops Local buying (often quasi-governmental) organizations which can purchase wholesale (and cleaner) electricity for their local communities.

Community solar Solar installed near a local community, whose output is is financed by and shared by that community.

Health Many health hazards and impacts of fossil fuels are local (carbon monoxide, diesel particulates, groundwater contamination etc), and local decarbonization efforts can alleviate them.

Public transportation Buses, light rail, subways, commuter trains, and other forms of public transit are all highly emissions-reducing compared to drivers sitting in traffic in cars.

Recycling A signature climate effort for many communities, recycling is getting more targeted as it becomes clear that not all things (e.g. plastics) can really be recycled effectively.

Resilience Local communities can become more self-reliant in the event of extreme weather or other disruptive events by developing local energy systems (e.g. solar, storage, microgrids).

Walkability Efforts to make local communities as appealing and safe to people getting around by walking as possible, to get people out of cars and traffic.

1.5/2.7 degrees A 2015 global agreement targeted limiting temperature rises over pre-industrial levels to about three degrees Fahrenheit (1.5 Celsius). Now looks unlikely.

Building codes and permitting Can either mandate decarbonization and help accelerate it, or make it far more difficult.

Cap and trade (emissions trading) Government programs requiring companies to reduce emissions below certain levels (caps), or buy emissions permits from others who’ve done so.

Carbon taxes Taxing carbon consumption or emissions to give incentives for reducing them.

Climate subsidies When governments support or help underwrite the cost of climate technologies and programs. Can be via tax, direct investment, loans etc.

Feed-in tariff A government policy compensating power plant developers for developing renewable energy for the grid.

IRA The U.S. Inflation Reduction Act, a massive multi-hundred-billion dollar investment in decarbonization and climate tech (both supply and demand side).

Resource adequacy Policies requiring utilities to have a certain amount of extra generating capacity on hand at all times. Becoming politicized as renewables undercut fossil plants on cost.

Tax credits Many countries use their tax codes to incentivize production and/or consumption of decarbonized energy.

Trade tariffs Import duties placed on key inputs (e.g. Chinese solar panels) which can split stakeholders politically (deploy faster vs. grow domestic capacity).

Banks Banks control the money flow to fossil fuel projects and infrastructure. In 2022, banks provided almost $700 billion to finance fossil fuel projects globally.

Cost curves Show how much cheaper technologies are getting (like climate tech), and how quickly.

Divestment When organizations with large investment portfolios (public pension funds, universities) sell off their investments in fossil fuel companies.

Energy as a service Financing arrangement where 3rd parties pay for building energy upgrades (e.g. efficiency or rooftop solar), and then sell services back to the building owners like a utility.

ESG Meant to be an investing shorthand for investing in companies that behave well across three broad areas (environmental, social, and governance).

Green bonds Money loaned (debt financing) to governments and companies, purportedly to be used on green projects.

Insurance companies Invest hundred of billions of dollars annually in fossil fuel projects, and also crucially underwrite them: without this insurance, the projects wouldn’t get built.

Power purchase agreement A long term commitment by a corporate buyer (‘offtaker’) to purchase power from a new (e.g. solar or wind) power plant.

Renewable energy certificate (REC) A certificate large energy buyers get that proves they’ve bought a certain amount of renewable energy.

Shareholder activism When shareholders use proxy fights or other forms of pressure to try to force companies to move faster on decarbonization.

Stranded assets Assets like coal power plants which are no longer profitable, but that a utility is stuck with contractually and must keep paying for.

Sunk cost The cost of something that’s paid for but no longer makes sense to use, like obsolete fossil fuel infrastructure.

Time of use rates Customers pay more or less per kWh at predetermined times of day, loosely based on when demand is higher and supply lower.

Total cost of ownership The complete cost of owning and operating an asset over time, including purchase, financing, operating (e.g. fuel) and maintenance costs.

Extreme heat, floods and drought The impacts of climate change create political instability, making it easier for world leaders to fall back on the familiar, perceived security of fossil fuels.

Fossil fuel subsidies Governments have been heavily subsidizing the fossil fuel ecosystem for decades, and continue to do so, often in the name of national security.

Generational habits Billions of people have become addicted to cheap fossil fueled goods and services, whether single use plastics, frequent air travel, eating lots of meat, or driving huge cars and trucks.

Geopolitical instability Is slowing the global deployment of renewables and electrification. For example, dependence on China’s supply chain and the tariffs and trade posturing affecting both solar and EVs.

Greenwashing When companies or other organizations claim to be investing in and serious about climate solutions, but actually aren’t at all (it’s just marketing).

Infrastructure limitations A shortage of high voltage transmission lines, for example, resulting in long wait times to connect new renewables (‘interconnection queues’), or the inability to connect them at all.

Interest rates Higher global interest rates and return expectations are making it harder to finance the up-front capital costs of climate solutions (e.g. wind projects) and infrastructure.

Jobs protection The fossil fuels industry employs 32 million people globally, not counting related jobs at risk from climate solutions (e.g. gas car manufacturing). That’s a powerful political lobby for fossil fuels.

Metals/minerals sourcing problems Many climate technologies are dependent on key commodities (e.g. cobalt, nickel, lithium, graphite, rare earths) that are currently produced or processed mostly by countries with endemic human rights violations.

Regulatory capture When government regulators get too cosy with the utilities or other fossil-fueled industries they presumably regulate.

Switching costs The up-front costs of switching from fossil-fueled infrastructure to long-term cheaper decarbonized alternatives.

Utility opposition Utilities are monopolies whose business model often depends on building fossil fuel plants and keeping them in service for decades, leading them to oppose anything (e.g. efficiency or rooftop solar) which undermines that model.

Workforce availability A shortage of skilled tradespeople (e.g. electricians or heat pump installers) can be a limiting factor and cost multiplier for many climate solutions, like electrification.

BTU British thermal unit.

CO2 Carbon dioxide.

CCS Carbon capture and storage.

CFC Chlorofluorocarbon.

CH4 Methane.

CNG Compressed methane gas.

COP Conference of parties (UNFCCC).

DAC Direct air capture.

ESG Environmental, social and governance.

GaN Gallium nitride.

GET Grid enhancing technologies.

GHG Greenhouse gas.

GWh Gigawatt-hour.

GWP Global warming potential.

ICE Internal combustion engine.

IRA Inflation reduction act.

ITC Investment tax credit.

kWh Kilowatt-hour.

kVA Kilovolt-amp.

LED Light emitting diode.

LFP Lithium iron phosphate.

LNG Liquified methane gas.

LPG Liquified petroleum gas.

MWh Megawatt-hour.

NEM Net energy metering.

NH3 Ammonia.

NMC Nickel managanese cobalt.

NOX Nitrous oxides.

N2O Nitrous oxide.

PPA Power purchase agreement.

PPM Parts per million.

PTC Production tax credit.

PUC Public utilities commission.

REC Renewable energy certificate.

ROI Return on investment.

SiC Silicon carbide.

SMR Small modular reactor.

TCO Total cost of ownership.

TOU Time-of-use (rates).

T&D Transmission and distribution.

VPP Virtual power plant.

V2B Vehicle to building.

V2G Vehicle to grid.

V2X Vehicle to anything.