BBC News

Life has changed a lot for the environmental activist in the space of a year.

The Norwegian-South African duo are tired and hungry after trekking hundreds of miles.

As Sydney gets a brand new zoo, animal experts question what we really learn from visiting captive animals.

As the annual COP25 climate change summit continues in Madrid, we asked delegates from all over the world how they were adapting their lives for the sake of the environment.

Scientists are getting closer to tracing the sources of meteorites that fall to Earth.

Tree conservation strategies based on genetic data are best suited for landscapes affected by a rapidly changing climate, a study suggests.

As plastic piles up on beaches, hermit crabs are getting trapped in plastic containers and killed.

British engineers test technologies that will be needed to bring samples of Martian rock to Earth.

A newly discovered planet offers insights into the Sun's demise in 5-6 billion years.

The Russian leader says the US "militarisation" of space means Moscow has to respond.

In the 'largest study of its kind' researchers studied 70,000 bird specimens over a 40-year period.

Nikki Henderson, who helped Greta Thunberg get to Madrid, reveals what happened on their 19-day journey.

Rangers on the Farne Islands in Northumberland use drones to keep track of the growing grey seal population.

The elm can be restored to its former glory despite Dutch elm disease, say experts.

Emissions of CO2 have risen in 2019, say researchers, as oil and gas use continues to grow.

Scientists make artificial nerve cells, paving the way for new ways to repair the human brain.

Climate activist Greta Thunberg said that adults should stop making young people "angry" over global warming.

Footage of a bear inscribed with "T-34" - the name of an iconic Soviet tank - is shared in Russia.

WWF and the Prado Museum join forces to raise the alarm during the COP25 summit in Madrid.

More than half of US national parks are threatened by invasive animals, like pythons and feral pigs.

Provisional data suggests the decade from 2010-2019 is the warmest yet recorded.

Nasa credited an Indian engineer, Shanmuga Subramanian, with helping locate the site of the debris.

Potent chemicals are unwittingly passed down from mother to calf, according to a UK study.

As the UN has its annual climate change conference, we look at what it's for and if it ever makes a difference.

The Malagasy tree boa is under threat from poaching and fires.

The president of the Marshall Islands tells a summit that rising tides threaten its existence.

The tiger has traversed 1,300km in five months, the furthest a big cat is known to have walked in India.

The notion that thinning ice shelves enable glacier speed-up and mass loss is cemented.

Almost 200 countries are meeting in Madrid to discuss what they're doing to tackle climate change.

The foam is said to be caused by pollutants in sewage mixing with sea water and frothed by waves.

Fishing nets and rope were among the debris found inside the whale which stranded on the Isle of Harris.

Delegates from almost 200 countries meet in the Spanish capital on Monday.

Henrik Stiesdal has been thinking about wind turbines since he was a teenager.

The new fruit took US scientists two decades to develop and the launch cost $10m (£7.9m).

Fifteen-year-old Cheikh Bamba Diaby got into robotics after he had to unblock his sister's mobile phone.

The mammal, believed to be a minke whale, was found below Battersea Bridge in London.

The Hollywood actor dismisses Jair Bolsonaro's claim he "gave money to set the Amazon on fire".

A fridge recycling plant believes it has found a more sustainable way to dispose of them.

A UK team arrives in Antarctica to test its theory for why so few iron meteorites are found there.

A huge wildlife haven is at risk as Russian coal ships exploit melting Arctic ice in Siberia.

A multi-billion-euro funding package for the European Space Agency is agreed by its member states.

Burning of the rainforest appears to speed up the melting of tropical glaciers, scientists find.

Scientists say the specimen could represent an evolutionary link between wolves and modern dogs.

It's the greenest election campaign ever - but how much are the parties promising on climate change?

Scientists team up with group Massive Attack to create blueprint that will 'transform the music industry'.

Households bought 54 "reusable" bags on average last year, research says, prompting calls for a ban.

Athena and Lisa, two major astronomy projects of the 2030s, should launch within a year of each other.

Scientists are shocked at what they find in the polluted waters, but say there is hope.

Irreversible climatic changes could be triggered in a few decades say some scientists but not everyone agrees.

A woman who records sightings of the unusual rodents found hotspots for them in East and West Sussex.