Climate change: what the science shows today

The headlines are familiar: record temperatures, retreating glaciers, extreme weather. But what exactly does the science say today, beyond both alarmism and downplaying? This article sums up where climate research currently stands. No opinion, just data.

The sources come from the leading scientific institutions: the IPCC, the World Meteorological Organization (WMO), the European Earth observation programme Copernicus and peer-reviewed journals. The figures are as current as possible, as of autumn 2025.

2024 was the warmest year since systematic weather records began in 1850. The global average temperature stood at 15.10°C, which is 1.60°C above the pre-industrial level (reference period 1850-1900).

That marked the first time the symbolically important 1.5-degree threshold of the Paris Agreement was exceeded across an entire calendar year. 2025 continues the trend: over the first eight months, temperatures ran 1.42°C above the pre-industrial average.

Europe is warming twice as fast as the global average, making it the fastest-warming continent on Earth. Antarctica recorded its warmest annual temperature on record in 2025.

The concentration of carbon dioxide in the atmosphere reached a level in 2025 that has not occurred for more than two million years. In May 2025, 429.6 ppm (parts per million) was measured, the highest value in all of human history.

The rise is accelerating. Between 2023 and 2024, the CO2 concentration climbed by 3.58 ppm, the largest annual increase ever measured.

The oceans are the great heat store of the climate system, having absorbed over 90% of the additional heat. The heat content of the upper 2,000 metres reached an unprecedented high in 2024.

Sea surface temperatures in 2024 averaged 0.61°C above the 1981-2010 baseline. Marine heat waves are becoming more frequent and more intense, with direct consequences for fisheries, coral reefs and coastal ecosystems.

Global sea level is rising faster than at any point in the last 3,000 years. In 2024 a rise of 5.9 mm was recorded, well above the average annual rise of 3.4 mm since 1970.

Arctic sea ice reached its smallest winter extent since satellite observations began 47 years ago in March 2025. At 14.33 million km², the area was 1.31 million km² below the 1981-2010 average, and 800,000 km² below the previous record low from 2017.

One figure stands out. In the Northwest Passage through the Canadian Arctic Archipelago, sea ice cover fell to only about 3% of its total area at the end of September 2024, the lowest extent observed since 1960.

Scientists have identified roughly two dozen subsystems of the global climate that can exhibit tipping points, thresholds beyond which changes become irreversible and self-reinforcing.

The Global Tipping Points Report 2025 reaches a sobering conclusion: Earth has already crossed its first climate tipping point, the tropical coral reef system. Large-scale coral die-off can no longer be stopped.

2024 recorded the highest number of climate-driven displacements since 2008. More than 617 extreme weather events were reported, 148 of them classified as "unprecedented".

A scientific analysis of 29 weather events in 2024 found that climate change intensified 26 of them. Those events killed at least 3,700 people and displaced millions.

The consequences of climate change stopped being future scenarios a long time ago. They affect agriculture, water supply and health right now.

A recent study warns that warming beyond 1.5°C could put a third of global food production at risk. The hardest hit:

• Low latitudes: up to 50% of crop production at risk under unsuitable climate conditions
• Tropical root crops: yam and other crops that matter to low-income regions are particularly vulnerable
• Sub-Saharan Africa: warming above 3°C would threaten almost three quarters of current production

Rice, maize, wheat, potatoes and soybeans, the staples that supply over two thirds of the world's food energy, are all heavily affected.

The report "10 New Insights in Climate Science 2025" identifies several direct health consequences:

• Heat stress reduces labour productivity and puts outdoor workers at particular risk
• Dengue outbreaks are increasing, as rising temperatures help mosquitoes spread
• Falling groundwater levels threaten drinking water supplies worldwide

The IPCC Synthesis Report 2023 sums up the scientific findings and names clear thresholds:

The report "10 New Insights in Climate Science 2025", produced by more than 70 scientists from 21 countries, identifies the most important new findings:

The scientific data leaves little room for interpretation:

• Earth is warming faster than expected
• Emissions are still rising rather than falling
• The first tipping points have been crossed
• The effects are already measurable today

None of that means it is all lost. The science also shows this: every tenth of a degree of warming avoided makes a difference. The question is no longer whether climate change is real. It is how we deal with it.