With days to go until Christmas, Santa might be somewhere out there worrying about how to deliver all the presents with his team of reindeer... meanwhile, just north of the Arctic circle, real reindeers herders are struggling with much bigger problems: climate change threatens their very livelihood.

The 10 most expensive weather disasters of 2021 caused more than $170 billion (€150 billion) in damages, UK charity Christian Aid has reported. That's up $20 billion on last year's figure.

West African nations will close their borders with Mali, sever diplomatic ties and impose tough economic sanctions in response to its delay in holding elections following a 2020 military coup, the 15-state regional bloc said on Sunday.

West African leaders have imposed punitive measures on Mali as the military stalls a return to civilian rule. The move comes as regional leaders met in Ghana to discuss the crisis.

The ECOWAS bloc has suspended Burkina Faso after the army overthrew the president. Burkina Faso is the third member to face punishments from the bloc as a result of a military takeover in roughly 18 months.

A coup in Burkina Faso follows military takeovers in Guinea and Mali as civilian administrations are blamed for a failure to tackle a rise in insurgent violence.

As climate change continues to take effect, we are all going to have to change the way we behave in order to survive. That's the conclusion of Eric Klinenberg, a professor of social science at New York University who's written a book focusing on the extreme 1995 heatwave in Chicago. Temperatures there hit over 41°C, killing hundreds of people. Klinenberg says it's not just infrastructure that will have to change, but the whole way we interact with our families and those living around us.

As climate change takes its toll, warm winter and unreliable snow are now the new reality. Will skiing become a relic of the past? Ski resorts can improvise and adapt, but can they survive? We take a closer look in this edition of Down to Earth.

The government must commit resources to fight the most pressing "danger" of climate change, former defense officials said in an open letter. "Australia has failed when it comes to climate threats," the letter read.

Narendra Modi set lofty climate goals at the COP26 climate conference. But his government has also watered down India's environmental rules, used protected lands for industrial purposes and stifled environmentalists, including 23-year-old Disha Ravi. In 2019 she launched the Indian wing of Fridays For Future, the movement inspired by Greta Thunberg. She was also arrested in 2021 for sedition and conspiracy over a document connected to India's farmer protests. She joins us on Perspective.

Australia is counting down to its next federal election on May 21. The environmental crisis is high on voters' minds and smaller parties and independents are gaining momentum by riding a wave of disillusionment over the conservative coalition's lack of climate action. With a hung parliament looking likely, these minor players could force the traditional parties to do more to tackle global warming. Climate change is an increasingly hot-button issue since the country's devastating bushfires of 2019-20. Our correspondents Richelle Harrison Plesse and Gregory Plesse report.

African Union leaders are meeting in Equatorial Guinea. Inflation and war in Ukraine are increasing food prices across Africa. Four AU member states are suspended because of coups.