China on drought alert - and other environment stories you need to read this week

Torrential rain hit parts of New Zealand for a fourth day on 19 August, forcing hundreds of people from their homes as rivers overflowed their banks and waterlogged ground becomes unstable.

California's grid operator urged the state's 40 million people to ratchet down the use of electricity in homes and businesses on 17 August as a wave of extreme heat settled over much of the state, stretching power supplies to breaking point.

It comes as a new study finds the risk of rare 'megafloods' in California will become more likely, more frequent and more disastrous, the Guardian reports.

While another study predicts climate change will cause an 'extreme heat belt' across parts of the US that will affect over 100 million people in the next 30 years, according to CNN.

Smoke from a huge wildfire in central Portugal enveloped skyscrapers known as the "Four Towers" in Madrid 400 km (250 miles) away on 16 August, and residents of the Spanish capital complained of a strong burning smell. The fire, which has ravaged Portugal's Serra da Estrela national park, started on 6 August and has reignited after it was put out.

Caribbean countries should pressure developed nations to provide more financing to mitigate the effects of climate change at the upcoming COP27 climate talks, the prime minister of The Bahamas Philip Davis said at a summit of regional officials on 16 August.

Grenada's former Climate Resilience Minister Simon Stiell will become the new United Nations climate chief, UN Secretary General António Guterres announced on 15 August. Stiell will take over as Executive Secretary of the United Nations Framework Convention on Climate Change with under three months before the latest round of climate negotiations at COP27 in Egypt. He will replace Mexican diplomat Patricia Espinosa.

China has issued its first national drought alert of the year as authorities battle forest fires and mobilize specialist teams to protect crops from scorching temperatures across the Yangtze river basin.

The national 'yellow alert', issued late on 18 August, comes after regions from Sichuan in the southwest to Shanghai in the Yangtze delta have experienced weeks of extreme heat, with government officials repeatedly citing global climate change as the cause. The alert is two notches short of the most serious warning on Beijing's scale.

In one of the Yangtze's important flood basins in central China's Jiangxi province, the Poyang Lake has now shrunk to a quarter of its normal size for this time of year, state news agency Xinhua said.

As many as 66 rivers across 34 counties in the southwestern region of Chongqing have dried up, state broadcaster CCTV said on 19 August.

Across the southwest of the country, curbs were extended on 22 August on power consumption as a result of declining hydropower output and rising electricity demand.

On 17 August, the central province of Hubei became the latest to unveil an effort to induce rainfall, by sending airplanes to fire the chemical silver iodide into the clouds.

Other regions on the Yangtze have also launched "cloud seeding" programmes, but with cloud cover too thin, operations in some parched areas have stayed on standby.

Australia's government is planning to introduce new regulations targeting vehicle carbon emissions to boost the uptake of electric cars, as it looks to catch up with other developed economies.

Just 2% of cars sold in Australia are electric compared with 15% in Britain and 17% in Europe, and the country risked becoming a dumping ground for vehicles that can't be sold elsewhere, Climate Change and Energy Minister Chris Bowen said on 19 August.

Apart from Russia, Australia is the only OECD country to either not have or be developing fuel efficiency standards, which encourage manufacturers to supply more electric and no-emission vehicles, he said.

"To me, this is ultimately about choice. And policy settings are denying Australians real choice of good, affordable, no emissions cars," Bowen told an electric vehicle summit in Canberra.