April 2016 was the hottest April in recorded history, and broke temperature records by the highest margin ever, according to NASA.

This year is set to be the hottest on record, with the last three months in a row having broken temperature records, and the last seven months having been at least one degree warmer than previous years, .

Spiralling global temperatures from 1850-2016 (full animation) https://t.co/YETC5HkmTr pic.twitter.com/Ypci717AHq

— Ed Hawkins (@ed_hawkins) May 9, 2016

The Cape Grim monitoring station in Tasmania recorded atmospheric carbon dioxide levels exceeding 400 parts per million (ppm).

Monitoring stations in the northern hemisphere have exceeded 400ppm before, but are known to have far more seasonal variance than those in the southern hemisphere.

“This milestone is a wake up call that our actions in response to climate change need to match the persistent rise in CO2,” NASA carbon and water cycle research scientist Dr Erika Modest said.

“Climate change is a threat to life on Earth and we can no longer afford to be spectators.”

Senior lecturer of the Science and Technology Studies Program at University of Wollongong, Dr Adam Lucas said the temperature increases are “alarming”.

“Given these various pieces of data that have come out, it’s extremely concerning,” he said.

“Clearly we need to be taking this issue far more seriously then we are, and it seems to me that one of the biggest issues that we need to grapple with is our dependence on fossil fuels – this is by far the biggest contributor to anthropogenic climate change.”

Australia is the fifth largest producer of coal, and ranks 45th out of the 50 largest economies in per capita emissions, according to the Green Innovation Index: International Edition.