A decade ago, the Paris Agreement was forged in France, an pivotal global pledge by nearly 300 countries to avert severe climate change. A key ambition was for worldwide greenhouse gas emissions to crest by 2025 and subsequently decrease, aiming to cap warming to above pre-industrial levels. With just two months remaining in the year and the U.N. climate summit, COP30, in Belém commencing in a week, it appears governments are poised to miss this crucial target.

U.N. Secretary General António Guterres acknowledged, “Let’s recognize our failure,” during an with the Guardian and Sumaúma, an Amazon-based news outlet. This admonition follows his review of national climate strategies, which he deems insufficient to prevent at least a temporary exceedance of the 2025 emissions peak. He stated, “The truth is that we have failed to avoid an overshooting above 1.5C in the next few years,” cautioning that such a failure could lead to “devastating consequences” globally.

Achieving the 1.5°C limit was a vital element of the Paris Agreement, requiring delicate negotiations for its inclusion. Staying on course would have necessitated a reduction in emissions by the close of this year, and a cut of almost half by 2030, relative to 2019 figures.

However, the reality differs significantly. The previous year marked the warmest on record, and with the global average temperature. Furthermore, the latest information indicates that global greenhouse gas emissions in 2024 increased from the preceding year. Although a single year of 1.5°C average global temperatures does not signify an irreversible breach of this limit, studies suggest it probably means the world will surpass 1.5°C within the coming two decades. The ramifications of persistent warming are already evident worldwide.

This global temperature standard was intended as a safeguard against the perilous effects of rising temperatures. Joeri Rogelj, a professor of climate science and policy at Imperial College London, states, “Between 1.5 and 2 degrees of warming, critical impacts are expected to accelerate rapidly.” He adds, “And these impacts are, for example, on ecosystems, on tropical coral reefs, on Alpine ecosystems, on Arctic ecosystems, which we know and we see already today, are suffering tremendously under the global warming that we are experiencing today.”

Nations submitted their individual climate action blueprints, known as nationally determined contributions (NDCs), under the Paris Agreement to achieve this objective. While these NDCs facilitated some progress in reducing emissions for certain countries, they proved insufficient to counteract substantial economic growth, according to Adrian Raftery, a University of Washington professor emeritus of statistics and sociology specializing in environmental science. He noted, “It turns out that in the past decade since the Paris accord was agreed, in spite of the great progress in carbon intensity and carbon efficiency, the total amount of carbon emissions in the world actually increased instead of down.” His research indicates that a rise in global GDP significantly fueled this increase in emissions.

Raftery conducted research investigating the probability of when worldwide emissions would ultimately peak. The study concluded a 22% chance of emissions peaking in 2025, with a 90% likelihood of this happening by 2045.

Leading up to COP30, nations are currently presenting revised NDCs valid through 2035. Should all countries, with the exception of the U.S. (which is pulling out of the Paris Agreement), fulfill their updated NDCs, Raftery suggests warming would be constrained to 2.1°C.

A report issued last week by the United Nations indicated that just over 60 nations had submitted updated national strategies for reducing greenhouse gas emissions—with over 100 countries having yet to submit theirs by the report’s release. Based on the NDCs received thus far—including one submitted by the U.S. during the final period of Joe Biden’s presidency before President Donald Trump’s withdrawal—greenhouse gas emissions would only be 6% below the anticipated 2030 level from prior NDCs, totaling approximately 13 gigatons. To restrict global warming to 1.5°C, emissions would need to decrease by around 45% from 2010 levels by 2030.

However, optimism persists. The International Court of Justice’s advisory opinion on climate change, released in July, determined that nations are obligated to safeguard and prevent environmental damage. Friederike Otto, a professor of climate science at Imperial College London, comments, “That actually makes it much easier for a lot of countries and governments to actually push through with more ambitious climate action.” Furthermore, renewable energy sources are increasingly cost-effective and prevalent compared to fossil fuels. The energy think tank reports that for the first time, renewable energy surpassed coal as the leading global electricity source, accounting for 34.3% of worldwide generation in the first half of 2025, while coal dropped to 33.1%.

Even if emissions are unlikely to peak this year, it does not imply an inability to halt global warming entirely. Otto asserts, “Even if we try and aim for 1.5 and end up with 1.6 that’s much, much better than not trying and saying. ‘Okay, we’ll just go with what we have now and give up on the rest,” she emphasizes that continued efforts towards emissions reductions remain crucial. “We can talk about temperature goals as much as we want, but without net-zero emissions, none of them are achievable,” she concludes.

Surpassing the 1.5°C threshold will indeed have repercussions. Rogelj states, “Exceeding 1.5 comes with consequences,” adding, “We don’t return to the same world after an overshoot.”