A temporary breach of the critical 1.5C global-warming limit is now completely inevitable following decades of insufficient climate action across the globe, according to a sobering new assessment released by the UN Environment Programme (UNEP).

In its annual emissions gap report, titled “The point of return,” the agency highlights that exceeding the Paris Agreement’s ambitious 1.5C threshold has become both imminent and unavoidable. Rather than preventing the breach entirely, the central task for the global community is now to minimize the size and scale of the temperature overshoot and establish a credible, scientifically sound return path to 1.5C by the end of the century.

Even under the absolute lowest possible overshoot scenario mapped out by scientists, global warming would first peak at around 1.7C to 1.8C toward the middle of the century before beginning a gradual decline. Achieving this scenario, which remains aligned with the long-term temperature goals of the Paris Agreement, would require profound and unprecedented global interventions. This includes cutting global greenhouse gas emissions by 18% by 2030 and 45% by 2035, alongside a massive, sustainable ramping up of carbon dioxide removal technologies to pull excess greenhouse gases directly out of the atmosphere.

In stark contrast, current climate pledges submitted by countries worldwide—even if they are fully and faithfully implemented—would only reduce emissions by 5% to 8% by 2030, and by 11% to 15% by 2035, when compared to 2025 levels. Despite this glaring ambition gap, the UNEP assessment identifies ample opportunity to accelerate climate action. It concludes that nations still possess the tools necessary to limit peak warming, shorten the duration of any temperature overshoot, and keep the core objectives of the Paris Agreement within realistic reach.

Emissions Comparable Between Recent Years

Looking closely at recent trajectories, the UNEP report notes that global greenhouse gas emissions in 2025 remained comparable to those recorded in 2024. Total human-driven emissions for 2025 reached approximately 58.4bn tonnes of CO2 equivalent, representing a minute dip of about 0.16bn tonnes compared to the previous year. However, because these figures are provisional and subject to high levels of uncertainty, analysts emphasize that it is not yet possible to definitively conclude the overall long-term direction of annual emissions.

Over recent decades, the underlying growth rate of global emissions has notably slowed down. Between 1990 and 2015, emissions increased by an average of 1.7% per year, whereas growth has averaged just 0.8% annually since 2016.

Breaking down the emissions data by gas category, fossil fuel CO2 emissions increased slightly in 2025 by between 0.4% and 1.1%. Nitrous oxide and fluorinated gases also saw increases at even higher rates, though their relatively small share of total greenhouse gas emissions means their overall contribution to the macro trend remains modest. Meanwhile, global methane emissions held steady over the period.

These increases were slightly counterbalanced by a reduction in carbon dioxide emissions originating from land use, land-use change, and forestry. This dip in land-use emissions was partially driven by a widespread decline in global wildfire activity, particularly across regions in Africa, South America, and parts of southeast Asia. Analysts note that these reduced wildfire levels were likely connected to the fading of El Niño conditions, though the subsequent arrival of a super El Niño cycle is expected to drive land-use emissions upward again.

When evaluating the performance of individual major economies, the world’s top emitters presented a largely flat emissions profile in 2025, with a notable exception. China, the European Union, India, Russia, and Indonesia all kept their emissions relatively stable, while the United States saw a significant increase. US emissions grew by roughly 133m tonnes of CO2 equivalent due to rising electricity demand, a colder winter that spiked heating needs, higher natural gas prices, and a temporary rebound in coal-fired power generation.

Across broader economic sectors, decarbonisation progress has been described as modest. The most tangible emissions decreases occurred within the power and transport sectors, fueled heavily by the rapid global expansion of solar energy and electric vehicles. However, overall transport emissions continued to climb due to growing demands for international aviation and maritime shipping. Furthermore, while electricity consumption from expanding data centres is projected to double by the end of the decade, data centres currently account for less than 1% of total global emissions.

New National Pledges Fall Far Short of Requirements

Under the framework of the Paris Agreement, all participating nations were scheduled to submit updated third nationally determined contributions outlining their climate targets for 2035 by February 2025. However, 95% of countries missed this initial deadline. A wave of countries subsequently submitted their pledges during a UN climate summit in New York and the COP30 climate talks in Brazil.

By the conclusion of COP30, roughly 63% of nations had produced their updated NDCs. By September 2026, that figure climbed to 124 countries, with pledges now covering approximately 75% of global greenhouse gas emissions. This broader participation provides a more robust foundation for assessing collective progress toward 2035 targets.

Despite this, the ambition of these updated pledges remains deeply inadequate. Fully implementing the third NDCs would lower global emissions in 2035 by 3.5bn tonnes of CO2 equivalent compared to 2030 targets—a reduction that falls far short of what is required to align with the Paris Agreement’s temperature goals. Furthermore, projected global emissions for 2035 are now about 3bn tonnes higher than estimated in previous reports, a shift largely attributed to the formal withdrawal of the United States from the Paris Agreement and improved harmonization with historical emissions datasets.

While the implementation gap between current policies and stated NDCs has technically narrowed, analysts warn that this is primarily the result of policy changes stemming from the US withdrawal rather than genuine policy progress by other nations. Most G20 member economies remain fundamentally misaligned with their stated net-zero trajectories, with the vast majority needing to dramatically accelerate their domestic emission reduction rates under current policies to stand a chance of meeting long-term climate targets.

The Emissions Gap Rains Persistent Challenges

The UNEP report models several core scenarios to evaluate the persistent emissions gap between current trajectories and sustainable pathways. Because previous scenarios developed around 2015 assumed immediate and aggressive emissions cuts that never materialized, researchers have constructed a new generation of pathways starting from 2025 to reflect ongoing policy delays.

The lowest 1.5C overshoot scenario requires immediate, deep, rapid, and sustained reductions, demanding that global greenhouse gas emissions fall by 18% by 2030, 45% by 2035, and 69% by 2040 relative to 2025 levels, before achieving net-zero CO2 emissions around mid-century. For a scenario limiting warming to below 2C, emissions would need to drop by 11% by 2030, 24% by 2035, and 37% by 2040.

Climate modeling using the FaIR emulator indicates that if countries simply continue with current national policies, the world is on track for roughly 2.8C of global warming over the course of the century. Even if all unconditional and conditional NDCs are fully implemented, warming is projected to reach between 2.6C and 2.7C by 2100. In the most optimistic scenario where countries meet both their NDCs and their long-term net-zero pledges, warming could theoretically be held to 2.1C.

These central warming estimates are notably higher than those published in previous assessments, driven by higher projected emissions and the retreat of major economies from international frameworks. Crucially, the report emphasizes that every five years of delay in implementing deep emission cuts locks in an additional 0.1C of permanent warming, making a 2C temperature rise increasingly difficult to avoid.

Uneven and Insufficient Progress on Global Stocktake Actions

The report also reviews international progress across nine distinct mitigation action areas outlined in the first global stocktake agreed at COP28. Overall, progress across these sectors is characterized as uneven and insufficient, though renewable energy deployment stands out as a major bright spot. Renewable capacity expansion has significantly exceeded expectations set a decade ago, causing energy-related CO2 emissions to grow 40% slower than previously projected. Renewable energy remains the single sector firmly on track for 2030.

Conversely, the world is lagging dangerously far behind in transitioning away from fossil fuels and halting global deforestation. While the growth rate of fossil fuel use has slowed, global coal usage may peak by 2030, but oil and natural gas consumption continue to rise under current policies. Similarly, international efforts to halt deforestation by the end of the decade remain severely off track, requiring a tenfold acceleration in the slowdown of forest loss.

To achieve the lowest overshoot scenario and successfully return global temperatures to 1.5C by 2100, the report outlines stark milestones for energy sectors. Minimizing overshoot will require reducing coal-derived energy by 15% by 2030, 55% by 2035, 75% by 2040, and 90% by 2050 compared to 2025 levels. Oil and gas will require more gradual short-term adjustments followed by steep long-term declines, culminating in reductions of 65% for oil and 75% for gas by mid-century.