The global warming threshold of 1.5°C above pre-industrial temperatures (1850-1900) is now certain to be surpassed within a few years. In early September, the United Nations Environment Programme (UNEP) announced that the world has entered the "overshoot era," meaning it is now inevitable that the critical threshold of 1.5 degrees Celsius of global warming will be exceeded, likely within a few years. This development raises important questions about the consequences of crossing this threshold and how the world can respond. The goal of limiting global warming to 1.5°C compared to the pre-industrial era was first introduced in December 2015 with the signing of the Paris Climate Agreement. Before that, the scientific community had set the threshold for dangerous climate change at 2°C. However, a coalition of small island nations argued that even 1.5°C would bring severe risks, such as rising sea levels. Limiting warming to 1.5°C instead of 2°C would protect 10 million people from rising seas, reduce the number of people exposed to extreme heat by 420 million, and halve the number of people affected by water stress. Scientists say this would significantly reduce the number of people facing climate-related risks, as well as the number of species at risk of extinction. In recent years, the planet has experienced increasingly severe heat waves, with some periods temporarily exceeding 1.5°C of warming. According to the United Nations (UN), the first months above this threshold date back to 2015-2016, and the first twelve-month period above 1.5°C ran from February 2023 to January 2024. The years 2023, 2024, and 2025 are now considered to be outside the historical norm in terms of global temperatures. Last June, several authors of the Intergovernmental Panel on Climate Change (IPCC) estimated that at the current rate of emissions, the world will reach +1.5°C in three years, +1.7°C in twelve years, and +2°C in twenty-five years. In its report on the climate commitments of states in November 2025, the UN estimated that even with full implementation of current pledges, the world would warm by 2.3 to 2.5°C by 2100. If current policies are maintained, the warming would reach 2.8°C, a level that could threaten the habitability of the planet. Mirey Atallah, head of the Adaptation and Resilience Service of the UNEP, says, "There is no before/after, global warming is a continuous process. What needs to be remembered is that the hotter the world, the more dangerous it is." She highlights the worsening of heatwaves, droughts, fires, and heavy precipitation. The UNEP report emphasizes that beyond 1.5°C, the risk of triggering "tipping points" increases. These are critical points in the climate system, such as the melting of polar ice caps or the collapse of ocean currents, that could shift to a new state with irreversible and difficult-to-control consequences. "At that point, the entire world will become exponentially dangerous," warns Mirey Atallah. While some climate scientists suggest that reducing global temperatures could return the world to a more stable climate, they note that some changes, like rising sea levels and species loss, would be permanent. According to the UN, the only way to stabilize and reduce global temperatures is to eliminate and then reduce greenhouse gas emissions to negative levels. This would require removing 220 gigatonnes of carbon dioxide equivalent (CO2e) from the atmosphere to lower the temperature by just 0.1°C. However, achieving this would take more than 100 years of reforestation and forest management at the current scale, and the world continues to emit over 53 gigatonnes of CO2e annually. Additionally, natural systems like forests are becoming less effective at storing carbon. UNEP warns that beyond 1.8°C of warming, returning to 1.5°C will become nearly impossible. The UNEP highlights that the world now heavily relies on carbon removal techniques, but many are still immature, costly, or risky. Technologies such as injecting CO2 into the ocean or depleted gas fields are being explored, but they remain unproven at scale. Some scientists are also concerned about the growing interest in geoengineering, which involves reflecting sunlight to cool the planet. These approaches are still largely theoretical and carry significant uncertainties. The next IPCC report is expected to address these emerging technologies and their potential risks.