Shipping, pollution and overfishing have reduced areas of "wilderness" to just 13 percent of the world's oceans, a study showed Friday, warning untouched marine habitats could completely vanish within half a century.

Vanuatu renewed a state of emergency on the volcano-hit island of Ambae Friday and ordered the compulsory evacuation of all residents.

Raging wildfires killed 74 people including small children in Greece, devouring homes and forests as terrified residents fled to the sea to escape the flames, authorities said Tuesday.

Dozens of wildfires have hit countries across northern Europe and Greece as a heatwave continues to hold across much of the continent. 

Japanese officials issued new warnings Monday as a deadly heatwave blankets the country, producing record high temperatures in Tokyo just two years before the city hosts the 2020 Summer Olympics.

Japan's severe heatwave killed at least 15 people and sent more than 12,000 to hospital in the first two weeks of July, official figures show as the temperature neared 40 degrees C (104 F) in many cities on Sunday.   

Twelve people died of heatstroke in the week ending July 15 after three perished in the preceding week, according to latest data.

At least 10 people have died after floods spurred by Typhoon rains struck central and northern Vietnam, authorities said Saturday.

A vast fire in northern California has destroyed 50 km2 (more than 12,000 acres), left one person dead and is threatening Yosemite National Park, authorities said Tuesday.

In the waters of the Arabian Sea, a vast "dead zone" the size of Scotland is expanding and scientists say climate change may be to blame.

Finland sides with democracy and fighting climate change, its deputy prime minister said on Monday, as presidents Donald Trump and Vladimir Putin held a historic summit in Helsinki.