global warming

According to data published by the European Centre for Medium-Range Weather Forecasts (ECMWF), which manages the Copernicus Climate Change Service, last year was the third warmest on record. Globally, the last 11 years have been the 11 warmest since records began, and global temperatures for the last three years (2023-2025) have exceeded, on average, 1.5°C above pre-industrial levels (1850-1900). This is the first time a three-year period has surpassed the 1.5°C threshold.

In 2025, climate change drove extreme weather events around the world, disproportionately affecting vulnerable and marginalised communities. In addition, global temperatures were exceptionally high, heatwaves were significantly more intense than 10 years ago, and millions of people were pushed to the limits of their ability to adapt. These are the main conclusions of the 2025 report published by the World Weather Attribution initiative, whose experts believe that ‘drastically reducing fossil fuel emissions remains the key policy for avoiding the worst impacts of climate change’.

One day after the deadline, COP30 in Belém (Brazil) has finally reached a minimal agreement. The text does not mention a roadmap for abandoning fossil fuels, as requested by more than 80 states, including the European Union. The agreement states that countries agreed to accelerate climate action and triple funding for developing countries facing extreme weather events.

At the current rate of carbon dioxide emissions, the 1.5°C temperature increase limit set in the Paris Agreement will be exceeded in four years. This is one of the predictions of the Global Carbon Budget 2025, the global report on the carbon balance, now in its 20th edition, which will be presented at COP30 in Belém (Brazil). Pep Canadell, one of its authors, analyzed its findings at a briefing organized by SMC Spain.

The Global Carbon Budget's projections for 2025 estimate that carbon dioxide (CO₂) emissions from fossil fuels will reach a new all-time high of 38.1 billion tons, an increase of 1.1% over 2024. This global report—now in its 20th edition and to be presented at COP30 in Belém, Brazil—estimates that emissions in the United States and the European Union will grow this year, in contrast to the decline in previous years, partly due to weather conditions and higher energy consumption. The study is published in the journal Earth System Science Data in preprint format.

Lakes are considered sentinels of climate change, although most research has focused on temperate regions. An international team analysed 10 tropical lakes in the central Amazon during the 2023 drought, which caused high mortality among fish and river dolphins. Using satellite data and hydrodynamic models, the authors show how intense drought and a heatwave combined to raise water temperatures: five of the 10 lakes experienced very high daytime temperatures, exceeding 37°C. Specifically, temperatures in the shallow waters of Lake Tefé soared to 41°C—hotter than a thermal bath. The study is published in Science.

COP30 will kick off on 10 November in Belém, a Brazilian city and gateway to the Amazon. Expectations are high because it coincides with the tenth anniversary of the Paris Agreement, whose goal of limiting the temperature increase to 1.5 °C was shattered in 2024. In addition, this year countries must present a new version of their measures to combat climate change in a turbulent geopolitical context, marked by the Trump administration's abandonment of the climate agenda.

Extensive warm-water coral reefs are facing widespread mortality and, unless global warming is reversed, will be lost, warns the report Global Tipping Points 2025. This is the first tipping point reached by the Earth system, the first in a series of tipping points that will cause ‘catastrophic’ damage—melting ice sheets, death of the Amazon rainforest, and collapse of vital ocean currents—unless humanity takes urgent action. The report also identifies positive tipping points that have been crossed on a global scale, for example in the area of solar energy and the adoption of electric vehicles.

Using data from the 180 companies with the highest carbon emissions—fossil fuel and cement producers—research has calculated that these companies contributed 50% to the increase in heatwave intensity since 1850-1900. The authors estimate that the individual emissions of each large polluting company may have contributed to the occurrence of between 16 and 53 heatwaves. The study, published in Nature, also shows that a quarter of the heatwaves recorded between 2000 and 2023 would have been virtually impossible without anthropogenic climate change.

So-called ‘supercell thunderstorms’ — incredibly intense phenomena that bring hurricane-force winds, hail, torrential rain and often tornadoes — will become more frequent in Europe as the Earth continues to warm. This is the conclusion of a study published in Science Advances, which indicates that the increase could reach 11% in a scenario where temperatures rise by 3°C.