The egg sac was an unwanted surprise for the resident who found it, but good news for the Australian Reptile Park.

Australians exceeded 1 gigawatts of rooftop solar panels for the first time last year with the market set to expand further in 2018 amid ongoing worries about electricity prices, according to Green Energy Markets.

Only 30 per cent of Australians can correctly identify a rip, and about two out of three of those who say they can, cannot do so correctly.

South-eastern Australia is in for another burst of summer later this week, with most of coastal NSW including Sydney facing severe heatwave conditions.

Scientists are learning the potential for drones extends beyond missile launches or pizza deliveries to more edifying endeavours - such as collecting whale mucus.

Damaging "gale force winds" of up to 100 kilometres an hour are battering the state's coastline, and fanning bush fires near Newcastle.

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Worried the electricity system won't keep up over summer? Worry about coal, seriously.

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A Yellow Alert to take action and get ready to go to shelter was issued on Wednesday afternoon covering areas from Cape Leveque to Bidyadanga.

The court said that law did not prevent killing one species to advance the scientific understanding of another.

The fossilised remains of a giant burrowing bat that lived in New Zealand millions of years ago has been found in Central Otago.

One of the nation's largest coal-fired power stations has had six failures of one of its units in the past three weeks, placing added strain on the power grid, and prompting a call for fossil-fuel plants to be set the same reliability standards being considered for renewable energy suppliers.

The volcano, named Havre, 1000 kilometres north-west of the country's North Island, was discovered in 2002.

The Swamp Park's general manager thought he was looking at trees sticking out of the water. Then he saw teeth.

Despoiling the environment risks triggering the collapse of civilisations, a threat that goes back at least as far as Greeks, new research by Australian-based scientists has revealed.

At least 13 people have died and thousands have fled from their homes as a powerful rainstorm triggered flash floods and mudslides on slopes where a series of intense wildfires burnt last month.

The NSW government has issued warnings about debris and faecal contamination for many parts of Sydney's coast.

Freezing nights and sweltering days: 2017 was a year of extremes for Canberra.

The mop-up resumed at first light after severe thunderstorms battered the state overnight.

The cold air that enabled this snow to fall came from the same cold-air outbreak seen in the eastern US last month.

Australia's posted its third-warmest year on record in 2017, with the eastern half including NSW and Queensland notching their hottest annual readings.

Hundreds of dead bats were left scattered on the ground and dangling from trees after extreme heat decimated a Sydney colony on Sunday.

Sydney recorded almost 22,000 lightning strikes as a spate of thunderstorms swept across the city early on Tuesday with more storms threatening in coming days.

Thunderstorms tore through Sydney on Tuesday morning, with lightning strikes causing power outages across the city.

Another year of near-record global temperatures and the recent heat spike in major Australian cities should serve as warning of the vulnerability of populations to global warming, a leading climate researcher said.

A new study has found that warming temperatures are turning one of the world's largest populations of green sea turtles all-female.

Sydneysiders responded to the near-record heat with the highest water use in 15 years, with another belter likely to build by the end of the week.

Penrith's top of 47.3 degrees was more than just a local record, and the hot weather is set to stick around.

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A tanker carrying Iranian oil was ablaze in the East China Sea on Sunday after colliding with a cargo ship.

In the end, it didn't quite break the record for Sydney's hottest day, but that was hardly cool comfort for Penrith residents who sweltered through 47.3-degree temperatures on Sunday.