climate change

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.

The adoption of plant-based diets could reshape agricultural employment worldwide. This is the main conclusion of an international study that estimates that by 2030, between 5% and 28% less agricultural labour would be needed, i.e. between 18 and 106 million fewer full-time jobs. The countries most affected would be those with agriculture based largely on livestock farming, while others, especially low-income countries, could need between 18 and 56 million more workers to grow fruit, vegetables, legumes and nuts. The study is published in The Lancet Planetary Health.

Around 5,800 deaths per year in Spain between 2012 and 2021 can be attributed to heat—twice as many as during the 1990s—according to a report published in The Lancet. In addition, of the deaths that occurred during 2022, around 22,000 can be attributed to air pollution, the publication adds. The Countdown report describes the impact of climate change on global health with more than 50 indicators reviewed by scientists. In the period 2020-2024, 61% of Spanish territory experienced at least one month of extreme drought per year; this figure is six times higher than the average for the period 1951-1960.

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.

Some ecosystems are able to adapt to moderate droughts, even if they last for several years. However, in scrublands and grasslands, when the phenomenon is extreme and prolonged, their capacity to store carbon plummets. This is the main conclusion of an international study that has assessed the effects of the duration and severity of droughts on the productivity of 74 grassland and pasture ecosystems on six continents. According to the authors, the most vulnerable areas are arid and semi-arid regions, such as those in the Mediterranean region and the southwestern United States. The study, published in Science, involves CREAF, CSIC and IICG-URJC, among other centres.

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.

The frequency of fire-related disasters increased significantly from 2015 onwards, according to a study analysing data from reinsurance companies between 1980 and 2023. Forty-three per cent of the 200 most damaging events, in terms of both human and economic damage, occurred in the last decade, the authors estimate in the journal Science. The risks were highest in the Mediterranean and in temperate coniferous biomes, and their frequency coincides with increasingly extreme weather conditions, they add. 

Premature deaths due to smoke pollution from wildfires will multiply to reach nearly 1.5 million deaths per year by the end of the century, according to a study published in Nature. The authors estimate that the increase will be much greater in Africa (11 times more deaths in 2095-2099 than in 2010-2014) than in Europe and the US (up to twice as many). Another study published in the same journal estimates that, under a high CO₂ emissions scenario, there will be more than 70,000 additional deaths per year from fires in the United States by 2050.

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.

The cyanobacterium Prochlorococcus, the smallest and most abundant photosynthetic organism on Earth, is an important producer of oxygen and is crucial to marine ecosystems. A team from the United States has collected data from ships sailing the Pacific Ocean over a ten-year period and concluded that these cyanobacteria could experience population declines of between 17% and 51% in tropical oceans by the year 2100, depending on the warming scenario. The results, which are the product of modeling work, are published in the journal Nature Microbiology and indicate that this microorganism is more vulnerable to climate change than previously thought.