UNEP's 18% by 2030 Is About 10.5 Billion Tonnes; Pledges Cover Under Half
Applied to UNEP's 2025 total, the 18% cut needed by 2030 is about 10.5 billion tonnes, and the yearly pace climbs from about 3.9% to 10.8% by 2040. Current national plans cover under half of the first step.
Switch off every chimney, tailpipe and furnace in the United States and India, and you would have removed about 10.3 billion tonnes of greenhouse gases a year. That is roughly the size of the first cut the United Nations now says the world must make by 2030: about 10.5 billion tonnes. (The country figures exclude land use, so this compares size, not substance.)
And it is the easy-looking step. UNEP's Emissions Gap Report 2026, "The Point of Return," published Wednesday, Oct. 21, says the lowest possible path (one where warming overshoots 1.5°C, then falls back) needs global emissions down 18% by 2030, 45% by 2035 and 69% by 2040, all measured against 2025. Applying those percentages to UNEP's 2025 total of 58.4 GtCO2e (gigatonnes of carbon dioxide equivalent: billions of tonnes, counting the other gases at their CO2-equivalent warming effect) gives roughly 47.9 Gt in 2030. UNEP's own figures may differ a little.
Eighteen percent is the shallow end of the path
Is it really "four years"? From today to Dec. 31, 2030 is 1,532 days, or four years and 71 days. The baseline is 2025, but 2025 was roughly flat on 2024, so nearly all of the 18% still lies ahead, on this reading. The ongoing "super" El Niño is likely to push land-use emissions up in 2026, Carbon Brief's breakdown says, which makes the starting line harder.
Now the part the headlines skip. On the same 58.4 Gt, 45% by 2035 means about 32.1 Gt, a cut of about 26.3 Gt. At 69% by 2040 the world is at about 18.1 Gt, a cut of about 40.3 Gt. The later steps are bigger, and they come faster.
Draw the path as a steady compound decline between UNEP's milestones and the pace shows itself: about 3.9% a year to 2030, about 7.7% a year from 2030 to 2035, and about 10.8% a year from 2035 to 2040. That is an interpolation, not a UNEP schedule.
UNEP's own summary is 5.7% a year over 2025-2035, against about 5% in the IPCC pathways, Climate Home News reported. Carbon Brief calls that "even more rapid" than the 5% a year that would have held 1.5°C without overshoot had cuts started in 2019.
In human terms, the world averages 6.6 tonnes of CO2e a year per head. A 45% cut on today's headcount is about 3.6 tonnes each, ignoring population growth. In economies, the 26.3 Gt cut is about the size of the three largest emitters combined (26.4 Gt).
The report attaches physical benchmarks, per RTE, CNN and UNEP's release. Coal-fired electricity falls at least 75% by 2035 and is phased out globally by about 2040. Methane drops at least 25% by 2035, and renewable capacity triples.
Pledges cover under half of the 2030 step
Countries' current national climate plans, called NDCs (nationally determined contributions, each country's pledge under the Paris Agreement), would deliver 5-8% by 2030 and 11-15% by 2035 if every one were met in full. Set against the need, that is 28% to 44% of the 2030 step, or about 2.9-4.7 Gt of about 10.5 Gt. For 2035 it is 24% to 33%, about 6.4-8.8 Gt of about 26.3 Gt.
Put plainly, pledges cover under half of the first step and a third or less of the second. The share covered falls as the steps grow.
The table sets the three paths side by side. The last column applies UNEP's percentages to its 2025 total of 58.4 GtCO2e, so treat it as approximate.
| Against 2025 levels | Lowest 1.5°C overshoot path | Below 2°C path | All current national plans (NDCs) | Lowest-path emissions, about |
|---|---|---|---|---|
| 2030 | -18% | -11% | -5% to -8% | 47.9 Gt |
| 2035 | -45% | -24% | -11% to -15% | 32.1 Gt |
| 2040 | -69% | -37% | not given | 18.1 Gt |
The below-2°C row, from Carbon Brief, is the reality check. Even that looser target asks for more by 2030 than current plans deliver; NPR puts it as emissions down "about 25%" over the next decade.
The warming ladder follows. Current policies point to about 2.8°C this century, unconditional NDCs to 2.7°C, and all NDCs delivered with similar efforts continuing to 2.6°C. Only pledges plus every net-zero promise except the US's reach 2.1°C, which UNEP calls "the most optimistic" case. Under current policies there is a 10% chance warming exceeds 3.4°C, per Carbon Brief and Nature.
The picture also worsened since last year. Central warming estimates for the NDC scenarios are about 0.2-0.3°C higher than in the 2025 report, which had 2.3-2.5°C. The reasons are the US withdrawal from the Paris Agreement and revised estimates of historical emissions. New pledges made a "negligible difference," Climate Home News and RTE reported, even with 124 parties filing third NDCs by Sept. 1, covering 75% of global emissions, per Carbon Brief.
One number moved the other way, and the report is blunt about why. The 2030 implementation gap narrowed mainly because of the US withdrawal: "policy changes, not policy progress," as Carbon Brief quotes it. A smaller gap on paper is not a smaller gap in the air.
The second Global Stocktake begins at COP31 in Antalya, Türkiye, which the UN climate secretariat lists for Nov. 9-20, 19 days from now.
Overshoot is a coin flip on getting back by 2100
Overshoot, as Carbon Brief defines it, means pathways where warming first exceeds 1.5°C and is then pulled back down by techniques that remove carbon from the atmosphere. In UNEP's best scenario the peak is about 1.7-1.8°C around mid-century, 0.2-0.3°C over the line. Warming then returns to 1.5°C by 2100 with a 50% chance. That is 74 years from 2026, and the best case is a coin flip.
Carbon Brief adds that the scenario keeps warming to 1.7-1.8°C through the century "with a 66% chance."
"The right unit isn't degrees, it's tons — of carbon dioxide, methane and other greenhouse gases."
Kate Marvel, Project Drawdown climate scientist, not involved in the report (CNN)
Degrees are the outcome; tonnes are the instrument. Every five years of CO2 emissions at current levels adds about 0.1°C to peak warming.
The coin flip also leans on removal nobody has proved. The lowest-overshoot path needs roughly 320 gigatonnes of CO2 removed and stored permanently this century, about eight years of global CO2 emissions at 2024 levels. UNEP says whether that scale can be reached is uncertain. Keywan Riahi, a report contributor, said of removal: "All of those technologies come with risks." That is why holding overshoot small is the point.
UNEP executive director Inger Andersen told reporters: "We are now saying this window has closed, but we can open it again by making the overshoot as brief as possible." António Guterres, the UN secretary-general, framed it the same way: "Overshoot is not surrender. We can still keep it as small and as short as possible – and bring temperatures back below 1.5 degrees by the end of the century."
Lingering has a physical cost. The report says each added fraction of a degree above 1.5°C "raises the risk of irreversible changes including in ice sheets, permafrost carbon, ocean circulation, and coral systems," as CNN quoted it. 2024 was the first calendar year above 1.5°C; Nature says 2026 is projected to be the second. Marvel adds: "Passing 1.5 degrees is a sign that we're not moving fast enough, but it doesn't mean we're doomed."
The US moved the wrong way while the rest held flat
The benchmarks are global, not national quotas, but the arithmetic tells you who carries the most weight. By UNEP's country estimates as tabulated by GreentechLead, 2025 emissions excluding land use were 16.1 Gt for China, 6.0 for the United States and 4.3 for India. Per person, the top two swap: 17.6 tonnes for the US, 11.4 for China and 3.1 for India.
Among the six biggest emitters, only the US had a notable increase in 2025: 133 million tonnes of CO2e, or about 2.3% on a base near 5.9 Gt. China, the EU, India, Russia and Indonesia were relatively flat. That is equal to most of the roughly 0.16 Gt global dip (the country figure excludes land use, the global one includes it), and the global figure carries high uncertainty.
The cause is framed two ways. Carbon Brief, reporting the report, points to rising electricity demand and a "rebound" of coal power, a likely mix of market factors including a colder winter and higher gas prices. NPR reported demand growth "as well as Trump administration policies that support the burning of fossil fuels," saying the administration has ordered coal plants to stay open longer than planned, rolled back vehicle fuel-efficiency standards and ended tax credits for solar and wind. The report includes a US statement that it "does not endorse or agree with its analysis or conclusions, and has not provided comments to this report."
The US has withdrawn from the Paris Agreement and will not take part in COP31, NPR says. Co-author Anne Olhoff told reporters, per Climate Home News, that the exit removes its former target from UNEP's projections and that the US has dropped its net-zero goal. NPR adds that the US tied Russia for the G20's highest per-person emissions in 2025, while China emits more in total "but has more than four times the population."
Who should move first is the sharpest dispute. Bill Hare of Climate Analytics, a science and policy institute, argues big polluters such as the US and Saudi Arabia need "to stop playing politics and face the scientific reality." The counter-fact: China and India account for about 95% of coal power capacity under construction globally, GreentechLead says. Lauri Myllyvirta of the Centre for Research on Energy and Clean Air, who sees room for China and India to overachieve their pledges, says: "The door to a much larger reduction than this over the next five years is open."
The good news is real, and it is the evidence for the first step. Since 2015, renewable capacity has grown three times faster than anticipated and solar PV seven times faster. Renewable electricity overtook coal-fired generation globally for the first time in 2025, RTE reported; GreentechLead gives renewables 10,730 TWh (33.8%) against coal's 10,476 TWh (33.0%). Andersen: "We have a wealth of success stories showing that emissions can be cut quickly."
Yet the world is "lagging particularly far behind" on moving away from fossil fuels and halting deforestation, Carbon Brief says.
The 18% is the cheap part. The same arithmetic shows the yearly pace nearly tripling by 2040, and today's pledges do not yet pay for even the first step.
