Australian authorities have warned people to stay indoors as a severe heatwave along the northwestern coast pushed temperatures to a blistering 50.7C.

The temperature is a high last seen 62 years ago.

Climate scientists and activists have raised alarm bells that global warming due to human-driven greenhouse gas emissions, especially from fossil fuels, is close to spiraling out of control.

The planet's hottest years on record have all been within the last decade, with 2021 being the sixth-hottest, the US National Oceanic and Atmospheric Administration showed this week.

An iron ore mining region in the northwest, Australia's Pilbara, where temperatures hit the record high yesterday, is known for its hot and dry conditions. Temperatures there usually hover in the upper 30s this time of year.

Australia is one of the world's biggest carbon emitters per capita, but the government has refused to back down from its reliance on coal and other fossil fuel industries, saying to do so would cost jobs.

Scientists have found that rising temperatures can hit public health and outdoor labour productivity, resulting in billions of dollars in economic losses.

Australia lost an average of A$10.3 billion (more than €6bn) and 218 productive hours every year in the last two decades because of heat, according to a global study published this week by researchers at Duke University.

These losses will only deepen in the coming decades as the world heads towards global warming of 1.5C degrees above pre-industrial times, they warned.

"These results imply that we don't have to wait for 1.5C of global warming to experience impacts of climate change on labour and the economy ... Additional future warming magnifies these impacts," said lead author Luke Parsons.