Climate Technologies, Sorted by How Far They Have Scaled

Discussions of climate technology often mix proven, widely deployed tools with ideas that are still in the lab. Sorting them by how far they've actually spread gives a clearer picture of where emissions cuts are coming from today and where they might come from later. Global energy-related carbon dioxide emissions are around 37 billion tonnes a year, according to the International Energy Agency (IEA), so scale is the key question for any technology.

Already at large scale

Solar and wind power. In much of the world, new solar and onshore wind farms are now the cheapest source of new electricity. Together they have grown faster than any other power source over the past decade, and in 2024 they supplied a rapidly rising share of global electricity, according to the energy think tank Ember. Their main limitation is that output depends on the weather, which makes storage and stronger grids important.

Electric vehicles. The IEA reports that more than one in five new cars sold worldwide in 2024 was electric, including plug-in hybrids, with China accounting for the majority of sales. Transport is a major source of emissions, and EVs charged with increasingly clean electricity produce less carbon over their lifetime than comparable petrol cars, even counting battery manufacturing.

LED lighting. LEDs use a fraction of the electricity of incandescent bulbs and last far longer. They now dominate new lighting sales globally, quietly cutting a significant amount of electricity demand.

Growing quickly

Battery storage. Grid-scale batteries store solar power for the evening and help stabilize grids. Installations have been growing rapidly as battery prices have fallen, with large deployments in California, Texas, China and Australia.

Heat pumps. Heat pumps move heat rather than generating it, typically delivering three or more units of heat for each unit of electricity used. They're replacing gas and oil boilers in many countries, helped by subsidies, though high upfront costs and the need for well-insulated homes slow adoption in some places.

Methane leak detection. Methane, a powerful greenhouse gas, leaks from oil and gas operations, landfills and farms. Satellites, including the European Space Agency's Sentinel-5P and commercial satellites operated by companies such as GHGSat, along with aircraft surveys, can now spot large leaks, which are often cheap to fix once found.

Early stage

Direct air capture. Machines that pull carbon dioxide from the air exist, but they're expensive and tiny compared with emissions. Climeworks' Orca plant in Iceland, which opened in 2021, was designed to capture about 4,000 tonnes a year, roughly the annual emissions of several hundred US cars.

Green hydrogen. Hydrogen made with renewable electricity could help decarbonize steelmaking, fertilizer production and possibly shipping. Production is still small and costly, and many announced projects have been delayed or cancelled.

Low-carbon steel and cement. Steel and cement each account for a large share of industrial emissions. Pilot plants are testing hydrogen-based steelmaking in Sweden and new cement chemistries, but commercial scale is still years away for most.

Advanced nuclear. Small modular reactors are being developed in several countries, with tech companies signing agreements to buy their future power for data centers. Few, if any, are yet operating commercially in the West, and costs remain uncertain.

Grids: the less visible part

Cleaner electricity depends on the grid that carries it. Long-distance transmission lines move power from windy or sunny regions to cities, and interconnections between countries let surplus power flow where it's needed. Grid operators also use "demand response," paying large users to cut consumption at peak times, and smart charging that shifts electric vehicle charging to hours when power is cheaper and cleaner. These tools are less eye-catching than new technologies but are essential for using more renewable power.

Food and agriculture

Agriculture and land use account for roughly a fifth of global greenhouse gas emissions, much of it from cattle and fertilizer. Feed additives that reduce methane from cows' digestion, such as one approved in the EU and US known as Bovaer, are starting to be used on farms. More precise fertilizer application reduces nitrous oxide, another potent gas. Reducing food waste, which the UN Environment Programme estimates accounts for a substantial share of global emissions, needs little new technology at all.

What individuals can use today

• Choosing an electric vehicle, e-bike or public transport for regular trips.
• Replacing an old boiler with a heat pump when it needs replacing.
• Rooftop or community solar, where available.
• Insulation, draft-proofing and efficient appliances, which cut energy bills as well as emissions.
• Smart thermostats that reduce heating when nobody is home.

Technology isn't the only factor

Many climate technologies already work but spread slowly because of permitting delays, grid connection queues, upfront costs and policy uncertainty. Building transmission lines to connect new wind and solar farms, for example, often takes longer than building the farms themselves. Much of the near-term progress depends on deploying existing tools faster rather than waiting for breakthroughs.