The climate crisis escalated significantly in 2024, which registered as the warmest year in the 175-year observational record and the first full calendar year to likely exceed 1.5°C above pre-industrial levels. According to the World Meteorological Organization (WMO), the annually averaged global mean near-surface temperature was 1.55°C (± 0.13°C) above the 1850–1900 average, clearly surpassing the previous record set in 2023. This surge in global heat, amplified by a strong El Niño event early in the year, accompanied record-breaking levels of greenhouse gas concentrations, ocean heat, and sea level rise, unleashing social and economic upheaval worldwide.
While the 1.5°C threshold was breached for a single year, it does not yet signify a permanent failure of the Paris Agreement’s primary goal, which is based on a long-term average. The data serves as a stark warning that the window to limit warming is closing rapidly. Human-induced warming continues to accelerate at an unprecedented rate, reaching 0.27°C per decade over the past 10 years. Despite the grim statistics, scientific consensus confirms that bold, immediate, and deep emissions reductions across all sectors can still slow the planet’s warming trajectory and secure a livable future. This requires a rapid transition away from fossil fuels, protection of natural carbon sinks, and a global commitment to decarbonization.
A Year of Unprecedented Heat
The record-breaking global temperature in 2024 was not an isolated anomaly but part of a clear and accelerating trend. Each of the last ten years, from 2015 to 2024, now represents the ten warmest years on record. While the strong El Niño that peaked at the start of the year contributed to the exceptional warmth, the primary driver remains the steadily increasing concentration of greenhouse gases from human activities. In fact, every single month between June 2023 and December 2024 set a new global temperature record for that respective month. The 2024 observed global temperature of 1.52°C is well above the best estimate of human-caused warming, which stands at 1.36°C, highlighting the combined impact of long-term anthropogenic warming and natural climate variability.
Key Climate Indicators at Record Levels
Beyond surface temperature, other critical indicators of climate change also reached alarming new highs in 2024, demonstrating the systemic nature of the crisis. These interconnected changes across the atmosphere, oceans, and cryosphere paint a comprehensive picture of a planet under severe stress.
Greenhouse Gas Concentrations
The fundamental driver of the climate crisis, greenhouse gas concentrations in the atmosphere, continued their relentless climb. Atmospheric carbon dioxide levels are now at their highest point in at least 800,000 years. This high rate of warming is a direct result of emissions reaching an all-time high of approximately 53.6 gigatonnes of CO2 equivalent per year over the last decade (2014–2023). This increase is primarily due to the burning of fossil fuels, industrial processes, and land-use changes.
Ocean Impacts
The world’s oceans, which absorb the vast majority of excess heat trapped by greenhouse gases, experienced unprecedented warming. Ocean heat content reached a new record in 2024, a trend with consequences that are irreversible for hundreds, if not thousands, of years. This absorbed heat drives thermal expansion of seawater, which is a major contributor to sea level rise. The rate of global mean sea-level rise has more than doubled, increasing from the 1993–2002 period to the 2014–2023 decade. Ocean warming also fuels more intense marine heatwaves and disrupts marine ecosystems.
Cryosphere in Retreat
The planet’s frozen regions, known as the cryosphere, are melting at an alarming rate. Glaciers around the world continued to retreat rapidly, and the Antarctic sea ice extent reached its second-lowest level ever recorded. This widespread melting contributes directly to sea level rise and threatens the stability of freshwater resources for millions of people. The loss of ice also reduces the Earth’s ability to reflect solar radiation, creating a feedback loop that amplifies warming.
Widespread Social and Economic Upheaval
The physical changes to the climate system in 2024 translated into devastating consequences for communities across the globe. Extreme weather and climate events caused massive economic losses, worsened food insecurity, and triggered widespread displacement. Heatwaves struck large parts of East Asia, Europe, and North America, shattering historical temperature norms. In Brazil, catastrophic flooding displaced over 630,000 people and resulted in billions of dollars in economic damages, while severe floods in East Africa displaced another half a million individuals. At the same time, severe drought gripped Mexico, leading to a 20–40% reduction in its corn production, and Zambia’s cereal harvest fell by 42%. These hazards led to the highest number of new displacements recorded in the last 16 years. In response to these escalating impacts, global organizations have intensified efforts to strengthen early warning systems, yet significant gaps remain; only about half of all countries worldwide have adequate systems in place to protect their populations.
The Narrowing Path to a Sustainable Future
To avoid the most catastrophic impacts of climate change, the Paris Agreement established a goal to hold the increase in the global average temperature to well below 2°C above pre-industrial levels and pursue efforts to limit it to 1.5°C. The fact that 2024 breached this 1.5°C threshold for a single year is a critical alert, but the goal itself refers to a consistent, long-term warming average. The world has a shrinking carbon budget—the total amount of CO2 that can still be emitted while keeping warming below 1.5°C. To stay within this budget, the Intergovernmental Panel on Climate Change (IPCC) states that global greenhouse gas emissions must peak before 2025 and be reduced by 43% by 2030 from 2019 levels. Achieving this requires immediate, rapid, and large-scale reductions across all sectors.
An Action Plan for a Livable Planet
While the challenge is immense, pathways to limit warming remain. This requires a coordinated global effort focused on systemic transformations in energy, industry, transport, and land use.
Energy Sector Transformation
The single largest source of emissions is the energy sector. A full decarbonization of electricity generation is needed by 2050. This involves an immediate halt to the construction of new coal-fired power plants and a rapid phaseout of existing ones, with developed countries aiming for a total phaseout by 2030. Simultaneously, the growth rate of renewable energy sources like solar and wind must be sustained and accelerated.
Sector-Specific Decarbonization
Other sectors require equally ambitious changes. In road transport, a critical step is to end the sale of new fossil fuel-powered cars before 2035, a transition already gaining momentum with the rising sales of electric vehicles. For buildings, all new construction should be fossil-free and near-zero energy, while renovation rates for existing buildings must increase dramatically to improve energy efficiency. Harder-to-abate sectors like heavy industry (steel, cement) and long-distance transport (aviation, shipping) require targeted policies and technological innovation to achieve deep emissions cuts.
Nature-Based Solutions
Protecting and restoring nature offers powerful solutions. Halting deforestation, promoting reforestation, and improving land management practices could reduce emissions by a substantial amount. Additionally, deep reductions in agricultural emissions, particularly methane from livestock and rice cultivation, are essential components of any viable pathway to limit warming to 1.5°C.
