On June 19, 2025, a comprehensive study titled "Indicators of Global Climate Change 2024" was published in the journal Earth System Science Data, offering the latest invaluable insights into the accelerating changes across the global climate system. This annual update, produced by a collaboration of over 60 international scientists from 54 institutions, highlights alarming trends in greenhouse gas emissions, temperature rise, oceanic heat uptake, and sea-level increases. Notably, the remaining carbon budget to limit global warming to 1.5°C has shrunk drastically to 130 billion tonnes of CO2, a threshold that, if current emissions continue unabated, will be exceeded in just over three years. This stark projection underscores an urgent call for unprecedented cuts in emissions to mitigate the escalating climate crisis.
The study’s lead author, Professor Piers Forster of the University of Leeds, emphasizes that the unprecedented warming rates and levels documented reflect humanity’s insufficient climate response. Despite long-standing policy commitments such as the Paris Agreement, greenhouse gas emissions remain near historic highs, exacerbating the risks of dangerous climate impacts worldwide. The report details a continued upward trend in global average temperatures, with the 2024 annual surface temperature anomaly reaching an estimated 1.52°C above pre-industrial levels, of which approximately 1.36°C can be directly attributed to anthropogenic activities. This figure, while slightly lower than the World Meteorological Organization’s 1.55°C estimate, confirms a disturbing climate trajectory.
Integral to this study is the expansion of key climate indicators to include sea-level rise and terrestrial precipitation patterns, further broadening our understanding of the climate system’s multifaceted response to human-induced forcing. The research indicates a significant acceleration in oceanic heat content—approximately 91% of excess anthropogenic heat is absorbed by the world’s oceans, intensifying thermal stress on marine ecosystems and contributing to rising sea levels. Between 2019 and 2024, global mean sea levels rose by about 26 millimeters, effectively doubling the long-term 20th-century average rate of sea-level increase. These trends threaten coastal communities by amplifying storm surges and promoting coastal erosion, effects “locked in” due to the slow pace of sea-level rise responses to increased global temperatures.
The detailed thermal analysis reveals that the Earth’s energy balance has shifted considerably, with surplus heat accumulating at an accelerating rate compared to previous decades. The rate of global heating observed between 2012 and 2024 has roughly doubled relative to the 1970s and 1980s, underpinning rapid changes in vital climate components such as ice sheet mass loss and permafrost thawing. These processes, once thought to be gradual, are now manifesting with growing intensity and speed, creating feedback loops that may further exacerbate global warming. Furthermore, the decline in planet-cooling aerosols like sulphur dioxide, driven by pollution control measures, inadvertently diminishes a short-term global cooling counterbalance, leading to accelerated warming. This accentuates the need to target other short-lived climate pollutants such as methane, which could yield more immediate cooling benefits.
The human fingerprint on climate variability is unmistakable, as evidenced by temperature records that reveal a decade-average global warming of 1.24°C (2015–2024) compared to pre-industrial times, virtually all of which is linked to anthropogenic emissions. These emissions have averaged about 53 billion tonnes of CO2 equivalent annually over the past decade, predominantly from fossil fuel combustion and deforestation. Of particular note, international aviation emissions, which markedly declined during the COVID-19 pandemic, have rebounded to pre-pandemic levels by 2024, further complicating efforts to reduce global greenhouse gas outputs. Such trends illuminate the entrenched nature of fossil fuel reliance worldwide and the considerable challenges in transitioning to sustainable energy systems.
Land surface temperatures have witnessed more dramatic increases than global means, with maximum temperatures rising to around 1.9°C over the last decade. This localized extreme warming exacerbates risks of heatwaves, droughts, and wildfires, disproportionately impacting vulnerable ecosystems and human settlements. The decade 2015–2024 was found to be 0.31°C warmer than the preceding decade, a jump consistent with ongoing warming trends but intensified by the extraordinarily hot years of 2023 and 2024. These intensifying extremes bear direct consequences for food security, water availability, and human health, amplifying the urgency for immediate adaptive measures.
The report affirms that transient exceedance of temperature targets in any single year does not constitute a breach of international climate agreements, which require long-term averages to remain below thresholds such as 1.5°C. However, the fact that 2024’s annual temperature reached this critical mark signifies how rapidly we are approaching limits that may trigger irreversible and catastrophic climatic shifts. IPCC’s prior assessments, reiterated by this study, stress that only deep and rapid greenhouse gas emission reductions across all sectors can alter this trajectory and offer a path to climate resilience.
Ocean warming, a critical element detailed by Dr. Karina Von Schuckmann of Mercator Ocean International, is central to the climate crisis. The ocean’s capacity to absorb excess heat buffers atmospheric heating but comes at the cost of disrupting marine biodiversity and intensifying extreme weather events. The ocean’s temperature peak in 2024, reaching record high values globally, signals deteriorating conditions for coral reefs, fish stocks, and ecosystems pivotal for coastal livelihoods. This has rippling effects on economies and societies dependent on marine resources.
Sea-level rise, an ever-present threat explained by Dr. Aimée Slangen from the Royal Netherlands Institute for Sea Research, continues to imperil coastal populations and habitats worldwide. Since 1900, an accumulated rise of 228 mm might appear modest but already amplifies the destructiveness of storm surges and triggers soil salinization and habitat degradation. The inherently slow dynamic of sea-level response, driven by melting ice sheets and thermal expansion, means current emissions are locking in future unavoidable increases, a sobering concept for climate planners and policymakers.
The study further outlines critical radiative forcing changes and greenhouse gas concentrations that continue to shift the Earth’s climate equilibrium. The increase in greenhouse gases, combined with diminished sulphur dioxide emissions, tilts the balance toward warming despite the negative health implications of airborne particulates. This interplay between different atmospheric constituents complicates climate projections but concurrently points toward integrated mitigation approaches that target both long- and short-lived climate forcers.
Professor Joeri Rogelj of Imperial College London encapsulates the gravity of the findings, noting that the "window to stay within 1.5°C is rapidly closing." He highlights that the coming decade’s emission trajectories will decisively determine the rate and extent of climate warming. Every fraction of a degree matters, bringing more frequent and intense extreme weather phenomena with profound societal, environmental, and economic ramifications. The report calls for urgent, systemic climate action consistent with and accelerating beyond current policy frameworks.
In conclusion, the Indicators of Global Climate Change 2024 report presents a sobering and unequivocal call to action. It details the interlinked and rapidly evolving components of the Earth system under human influence, emphasizing that the climate crisis is not a future threat but a pressing contemporary reality. Through precise quantitative assessments and holistic system-level analysis, the study strengthens the scientific foundation necessary for informed policymaking and public understanding. As international negotiations and national strategies develop, the evidence underscores that the time to act decisively, with ambition and speed, is now.
Subject of Research: Not applicable
Article Title: Indicators of Global Climate Change 2024: annual update of key indicators of the state of the state of the climate system and human influence
News Publication Date: 19 June 2025
Web References:
- https://www.igcc.earth/
- https://unfccc.int/event/university-of-leeds-indicators-of-global-climate-change-annual-update-of-key-indicators-of-the-state
- https://drive.google.com/drive/folders/1QKq-WtyPSOYOSv4WIqNO91RzdvYH2EbV?usp=drive_link
References: Forster et al., 2025. DOI accessible from Earth System Science Data.
Keywords: Earth sciences, Climate change, Climate data, Climate sensitivity, Climate stability, Climate systems
