Renewable-energy milestones were met in 2025, with China being the first country to surpass 1 terawatt in installed solar-power capacity. Credit: Chen Kun/VCG via Getty
The biggest science story this year was the political upheaval in the United States. Funding cuts, academic lay-offs and vaccine-sceptic policies have widely been seen as an attack on science, according to critics of President Donald Trump’s administration. The resulting damage to science could last way into the future.
But, there were also plenty of positive developments in 2025 that offer hope for the coming years. “From a non-US scientist, it’s somewhat business as usual. You just keep doing your job”, says Glen Peters, a climate-policy researcher at the Cicero Center for International Climate Research in Oslo.
Our recent Nature’s 10 package includes many good news stories — and there were many more. From gene-editing firsts to rapid disease containment and policy victories, Nature takes a look at some positive science stories of 2025.
Nature’s 10: Ten people who shaped science in 2025
Species recovery
This year saw populations of some endangered and near-extinct species bounce back owing to strong conservation efforts.
The green sea turtle (Chelonia mydas), which has been endangered since the 1980s, has now moved to ‘least concern’ on the International Union for Conservation of Nature (IUCN) red list. Efforts to protect the turtle’s eggs and measures to prevent their accidental capture in fishing nets have allowed populations to recover.
The ampurta (Dasycercus hillieri), a rat-sized Australian marsupial, moved from near-extinction to ‘least concern’ this year. Between 2015 and 2021, ampurta territory expanded by more than 48,000 square kilometres, despite dry conditions and food shortages.
Lastly, nations reached a historic milestone for marine conservation in September with the United Nations High Seas Treaty receiving approval from more than 60 countries. The treaty, which will come into effect in January, aims to legally protect biodiversity in international waters and conserve at least 30% of land and sea areas.
Ozone hole shrinks
The hole in the Antarctic ozone layer has shrunk to its smallest size since 2019, indicating the continued recovery of Earth’s protective upper atmosphere.
The ozone hole was first discovered in 1985 and is a result of human-emitted ozone-depleting chlorofluorocarbons (CFCs), such as coolants in refrigerators and aerosol sprays. The Montreal Protocol in 1987 phased out the production and use of CFCs, which has successfully curbed emissions1 . Since 1987, the average size of the ozone hole throughout the year has been gradually decreasing in size, with the smallest so far in 2019.
The ozone hole is on track to recover completely in the late 2060s, provided efforts to find climate-friendly alternatives to CFCs continues.
The hole in the Antarctic ozone layer has continued to shrink.Credit: CAMS
Gene-editing successes
This year “was a breakthrough year for gene editing,” says David Liu, a chemical biologist at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts. “In 2025, these technologies have achieved a number of medical milestones.”
“I view this year as an outstanding one, marked by the launch of many clinical trials”, adds Annarita Miccio, who studies gene therapy at the Imagine Institute at the Necker Hospital for Sick Children in Paris.
Huntington’s disease treated for the first time using gene therapy
The first gene therapy for Huntington’s disease proved striking, slowing the rate of cognitive decline in participants by 75%. Another gene-therapy trial for T-cell acute lymphoblastic leukaemia showed promise with the majority of 11 participating children and adults entering remission2. The new type of CAR-T-cell therapy uses base-editing technology to modify several genes in T cells, helping them to target the cancer cells.
Researchers also trialled the first use of a CRISPR technology tailored to an individual this year. Other successes include the first clinical trial for a gene therapy to treat a rare immune disorder called chronic granulomatous disease3, and another that corrected a pathogenic mutation, which can cause lung damage and liver disease4.
These clinical trials paved the way for developing mutation-specific strategies for rare diseases and demonstrated that collaboration between academia and industry can lead to cures for people with such diseases, says Miccio.
Renewable-energy boost
Renewable energy surpassed coal as the largest energy source for the first time globally this year. The achievement was helped by China becoming the first country in the world to install 1 terawatt of solar power capacity in May. In the first six months of 2025 alone, China installed new solar systems with a capacity of 256 gigawatts — twice as much as the rest of the world combined. The country plans to add a further 200–300 gigawatts of capacity for solar and wind energy in its five year plan, beginning in 2026.
What happened at COP30? 4 science take-homes from the climate summit
“China and many developing countries are deploying solar and wind [and] electric vehicles at pretty breakneck pace,” says Peters.
Around half of the European Union’s demand for electricity came from from renewables in the second and third quarters of this year. Renewable-energy capacity is projected to increase by almost 4,600 gigawatts between 2025 and 2030 — double the capacity deployed between 2019 and 2024.
However, greenhouse-gas emissions from fossil fuels reached a new high this year. It remains to be seen whether renewable energy can replace fossil fuels as the dominant global energy sources.
