The Sydney Opera House and the Harbour Bridge were plunged into darkness for an hour Saturday to raise awareness about climate change and its impact on the planet's vanishing biodiversity.

Teaching cows to use the toilet is not the easiest task, but a Dutch inventor is banking on a new bovine urinal to help cut emissions that cause environmental damage.

Tests have started on a farm in the Netherlands on the device which collects some of the 15 to 20 liters of urine that the average cow produces a day.

Mexico raised the warning level for the Popocatepetl volcano to one step shy of a red alert Thursday, after it repeatedly spewed ash, smoke and lava into the air.

Ocean heat hit a record high in 2018, the United Nations said Thursday, raising urgent new concerns about the threat global warming is posing to marine life.

Germany recorded its warmest year in 2018, a period also marked by a drought lasting months, the country's DWD weather service said Tuesday.

"It was very scary, we were running in all direction, the water was full of snakes," recalls 39-year-old Otelea Jose after arriving from one of the areas worst hit by southern Africa's deadly cyclone.

Disease is threatening to aggravate the already dire conditions facing millions of survivors following the powerful tropical cyclone which ravaged southern Africa 10 days ago, officials warned on Sunday.

A "very destructive" category 4 cyclone slammed into Australia's remote northern coast on Saturday, while a second, equally powerful storm bore down on the country's west.

Cyclone Trevor, pushing a big storm tide and packing winds of up to 250 kilometres per hour (150 mph), made landfall on the sparsely populated Northern Territory coast near the Gulf of Carpentaria town of Port McArthur, the Bureau of Meteorology reported.

The Missouri River floodwater surging on to the air base housing the U.S. military's Strategic Command overwhelmed round-the-clock sandbagging by airmen and others. They had to scramble to save sensitive equipment, munitions and dozens of aircraft.

Days into the flooding, muddy water was still lapping at almost 80 flooded buildings at Nebraska's Offutt Air Force Base, some inundated by up to 7 feet (2.1 meters) of water. Piles of waterlogged corn cobs, husks and stalks lay heaped everywhere that the water had receded, swept onto the base from surrounding fields.

A cyclone that ravaged three southern African countries last week has killed at least 350 people, affected more than 1.7 million others and left 15,000 people still stranded by floods, according to estimates Thursday.