Net zero emissions is technically possible, but the gap between what’s physically achievable and what’s actually happening is significant. Over 2,000 modeled pathways analyzed for the IPCC’s latest assessment show multiple routes to limiting warming to 1.5°C or 2°C, each relying on different combinations of renewable energy, reduced energy demand, and carbon removal. The technology exists or is rapidly emerging. The harder questions are speed, scale, and whether governments and industries will move fast enough.
What the Climate Models Actually Show
The IPCC’s Sixth Assessment Report evaluated more than 1,200 scenarios with enough data to assess their warming outcomes. From these, five illustrative pathways were selected, each taking a fundamentally different approach: heavy reliance on renewables, strong reductions in energy demand, extensive use of carbon dioxide removal, mitigation tied to broader sustainable development goals, and a slower, more gradual ramp-up of action. All five can keep warming below 2°C with greater than 67% probability, and several can hold the line at 1.5°C with at least 50% probability.
This matters because it means there’s no single “correct” path to net zero. A country with abundant wind and solar resources pursues a different strategy than one with heavy industry it can’t easily relocate. Some pathways avoid temperature overshoot entirely and don’t depend on pulling massive amounts of carbon back out of the atmosphere later. Others accept temporary overshoot and rely on net negative emissions in the second half of the century. The flexibility is real, but so is the urgency: every pathway that limits warming to 1.5°C requires reaching net zero CO2 emissions around mid-century.
Renewable Energy Is Scaling Fast
The electricity sector is the brightest spot in the net zero picture. Renewables supplied 30% of global electricity in 2023, and the International Energy Agency forecasts that share will reach 46% by 2030. Solar and wind alone are projected to account for 30% of global generation by that date, surpassing hydropower for the first time. Solar is on track to become the single largest source of renewable electricity in the world.
This growth is driven largely by economics. Solar panel costs have dropped roughly 90% over the past decade, and wind power has followed a similar trajectory. In most markets, building new solar or wind capacity is now cheaper than building new fossil fuel plants, and in many cases cheaper than continuing to run existing coal plants. The challenge isn’t whether renewables work. It’s whether the supporting infrastructure, especially electrical grids and energy storage, can keep pace with deployment.
The Hard-to-Solve Sectors
Electricity generation is only part of the picture. Some industries are far more difficult to decarbonize, and these “hard-to-abate” sectors represent the most serious technical obstacles to net zero. Steel and cement production require extremely high temperatures typically generated by burning fossil fuels. Long-haul aviation depends on energy-dense liquid fuels that batteries can’t yet replace at scale. And international shipping moves 80% of global trade on heavy fuel oil.
Shipping offers a useful case study in both the promise and the difficulty. The International Maritime Organization set a goal of net zero emissions from ships by or around 2050, with intermediate targets of at least a 20% reduction by 2030 and at least 70% by 2040 compared to 2008 levels. The technology pipeline includes biofuels, green hydrogen, ammonia, e-methanol, and wind-assisted propulsion like rotor sails. Bio-methane and renewable diesel are already commercially available. Maersk, the world’s largest container shipping company, has ordered 19 dual-fuel ships that can run on methanol. Major cruise lines are retrofitting vessels for methanol as well.
But commercially available doesn’t mean commercially dominant. Most of these alternative fuels cost significantly more than conventional fuel oil, and scaling production to supply the entire global fleet is a decades-long challenge. Operational changes like slow steaming (intentionally reducing ship speed to cut fuel use) and shore-side electrical power for docked vessels help at the margins, but they’re not transformative on their own.
Methane: The Fast-Impact Opportunity
Carbon dioxide gets the most attention, but methane is responsible for roughly a third of the warming that’s occurred since preindustrial times. It’s also a place where fast action can make a measurable difference, because methane breaks down in the atmosphere within about a decade compared to centuries for CO2.
The Global Methane Pledge, launched in 2021 and now signed by 159 countries, targets a 30% cut in methane emissions from 2020 levels by 2030. That target is considered essential to keeping 1.5°C within reach. Progress has been real but insufficient. National climate plans submitted through mid-2025 could deliver roughly an 8% cut by 2030, well short of the 30% goal. Closing that gap requires full implementation of technically proven control measures across oil and gas operations, agriculture, and waste management. The tools exist (leak detection, landfill gas capture, changes in livestock feed), but deployment lags far behind what’s needed.
The Critical Minerals Bottleneck
Every solar panel, wind turbine, battery, and electric vehicle requires minerals that must be mined, refined, and processed. This creates one of the most concrete physical constraints on the speed of the energy transition. Copper demand is expected to grow by 70% over the next 15 years. Lithium demand is forecast to be seven times greater than current production in that same period, with a projected supply shortfall of over one million tonnes, roughly five times today’s entire mine supply.
The IEA estimates that announced mining projects will meet only 70% of the copper and 50% of the lithium needed for current net zero pathways. Recycling helps, but forecasts suggest it will reduce total lithium mining requirements by only 10 to 20%. New mines take a decade or more to move from discovery to production. This isn’t an argument that net zero is impossible, but it highlights that the transition depends on physical supply chains that operate on long timelines and face permitting, environmental, and geopolitical obstacles. A 2025 analysis in Nature Communications described this as a “mining reality check” on net zero ambitions.
The Gap Between Possible and Probable
The honest answer to whether net zero is possible has two parts. Technically, yes. The IPCC’s modeling confirms multiple viable pathways using technologies that either exist today or are in advanced development. Renewables are scaling at a pace that would have seemed implausible 15 years ago. Solutions for hard-to-abate sectors are emerging, even if they’re not yet mature.
The harder part is execution. Net zero by 2050 requires simultaneously scaling renewable energy, building out electrical grids, opening new mines for critical minerals, deploying carbon removal technology, cutting methane by nearly a third in five years, and transforming industries like shipping, steel, and cement. Each of these is a massive undertaking on its own. Doing all of them in parallel, across every major economy, within 25 years, is unprecedented.
The constraints aren’t primarily about physics or engineering. They’re about capital allocation, political will, permitting timelines, supply chain logistics, and international coordination. Mineral supply shortfalls alone could slow the transition by years if new mining capacity doesn’t come online fast enough. Every year of delay in cutting emissions narrows the remaining pathways and increases reliance on carbon removal technologies that haven’t yet been proven at scale. The window is open, but it’s closing at a measurable rate.