#climate-change

What happened: The World Meteorological Organization's Greenhouse Gas Bulletin, released Oct. 27, put the global average CO2 concentration at 426.8 parts per million in 2025, 153% of the pre-industrial level. Methane and nitrous oxide also reached record highs. CO2 rose 2.8 ppm from 2024 to 2025, after an exceptional 3.5 ppm jump the year before.

Why it matters: CO2 stays in the air for centuries, so each increase locks in more warming. The WMO expects concentrations to rise again in 2026 because of fossil fuel burning and a strong El Niño that weakens land carbon sinks. It also flags record growth in SF6, a gas used in electrical equipment with a warming effect about 24,300 times that of CO2.

How much agreement is there? Broad agreement. These are measurements from the WMO's global monitoring network; the debate is about policy, not the readings.

Could someone help? Students can follow measurement records like the Keeling Curve, and utilities and regulators can push for alternatives to SF6 as grids expand.

What happened: The Lancet Countdown report, produced with the World Health Organization and led by University College London, estimated a record 710,000 heat-related deaths worldwide in 2023, UN News reported on Oct. 28. For the first time, more than seven in 10 of those deaths were attributed to human-caused climate change. The report tracks 54 indicators linking climate and health.

Why it matters: It finds extreme drought affected 51.8% of the world's land for at least a month in 2025, and conditions for dengue spread by one mosquito species rose 24% since the 1980s. It also says the 100 largest oil and gas companies plan to produce 150% more fossil fuels by 2040 than a 1.5°C path allows.

How much agreement is there? Some disagreement. The health trends are drawn from many research groups; the debate is over response. The authors want climate change formally declared a global health emergency before the COP31 talks, and they also note a record $2.1 trillion in clean-energy investment last year.

Could someone help? Communities and young volunteers can check on older or isolated neighbors during heat waves, and health groups can push for the national health adaptation plans the report tracks.

What happened: The UN Environment Programme published its Emissions Gap Report 2026, titled "The Point of Return," on Oct. 21. It says warming will pass the Paris Agreement's 1.5°C limit and that this can no longer be avoided. It now describes a "lowest possible" overshoot path: peak warming of about 1.7 to 1.8°C around mid-century, then a return to 1.5°C by 2100. That path would need emissions cut 18% by 2030, 45% by 2035 and 69% by 2040, compared with 2025.

Why it matters: On current policies the report projects about 2.8°C of warming this century, or 2.6°C if every national pledge is met. UN News reports that both figures are worse than last year's, partly because the United States withdrew from the Paris deal.

How much agreement is there? Some disagreement. The science is widely accepted; the fight is over what to do next. UN Secretary-General António Guterres says "overshoot is not surrender" and is calling for faster clean energy and a fossil-fuel phase-out. Getting back to 1.5°C would also require removing about 320 billion tonnes of CO2 from the air by 2100, according to UNRIC's summary of the report.

Could someone help? Climate groups and young people can push for clearer national targets ahead of the COP31 climate talks in Antalya, Türkiye, which begin next month.

What happened: The Glacier Garden in Lucerne has opened an exhibit whose German title translates as "Treasury of Ice." It shows things that have come out of Swiss glaciers as they melt: a bow from an ancient hunt, a Roman-era statuette, a cow skull, boots, ski gear, a cracked alpinist's helmet, a wine bottle and a crushed tube of mayonnaise. Director Andreas Burri says the glaciers are disappearing "very, very fast" and the museum wants to show this archive before it's gone.

Why it matters: Swiss glaciologists recently reported that the country lost 5.5% of its total glacier volume this year, the second-largest drop on record. The ice also holds pollen, soot from 16th-century wildfires and fallout from 20th-century nuclear tests. In August, the bodies of two Belgian hikers missing for decades emerged near the Trift glacier.

How much agreement is there? Broad agreement that Swiss glaciers are shrinking fast. The exhibit itself is documentation, not a solution.