Australia this week experienced its hottest day on record and the heatwave is expected to worsen, exacerbating an already unprecedented bushfire season, authorities said Wednesday.

The average nationwide temperatures of 40.9 degrees Celsius (105.6 degrees Fahrenheit) on Tuesday beat the previous record of 40.3 degrees Celsius in January 2013, the Bureau of Meteorology said.

Air pollution forced schools to close on Sunday in parts of Iran including Tehran, state media reported, as the capital lay under a thick cloud of smog.

A marathon U.N. climate summit wrapped up Sunday with little to show, squeezing hard-earned compromises from countries over the global warming battle plan but falling well short of what science says is needed to tackle the emergency.

The COP25 deal "expresses the urgent need" for new carbon cutting commitments to close the gap between current emissions and the Paris treaty goals of capping global warming at below two degrees, host country Spain said in a statement.

Given the stakes -- the survival of civilization, no less -- it didn't seem unreasonable to expect 196 nations gathered in Madrid to forge a global warming action plan to declare, in clear and simple language, that they would do a bit more, do a little better.

South African farmer Steve Bothma heaved a sigh of relief when the weatherman finally predicted rain.

United Nations climate negotiations in Madrid were set to wrap up Friday with even the best-case outcome likely to fall well short of what science says is needed to avert a future ravaged by global warming.

The COP25 summit comes on the heels of climate-related disasters across the planet, including unprecedented cyclones, deadly droughts and record-setting heatwaves. 

U.S. President Donald Trump on Thursday slammed Time magazine's naming of Greta Thunberg as 2019 Person of the Year, saying the climate activist should "chill" and go see a movie.

Swedish activist Greta Thunberg accused rich countries of "misleading" people over climate action at U.N. talks in Madrid on Wednesday as scuffles broke out between security guards and environmental protesters.  

Greta Thunberg, the Swedish teenager who became the voice of conscience for a generation facing the climate change emergency, was named Wednesday as Time magazine's 2019 Person of the Year.

The United States and Saudi Arabia are among major polluters showing "hardly any signs" of reducing their greenhouse gas production, a global assessment of countries' emissions trajectories said Tuesday at United Nations climate talks.