A CSIRO report has declared the chances of global warming being the result of human industry as 99.999 percent likely.

The paper published yesterday in the Climate Risk Management journal noted December 2013 was the 346th consecutive month where global land and ocean temperatures exceeded the monthly average of the 20th century.

In other words, not since February 1985 have global conditions been below the average mark.

The likelihood of such an occurrence without human contribution is less than one in 100,000, the report said.

A graph of temperature anomalies over the 20th century. (CSIRO)

Researchers looked at rates of greenhouse gas emissions modelled alongside increases in temperature and compared results without the emissions.

They also looked at other possible contributions, including volcanic eruptions and El Nino weather patterns in making its finding of human culpability.

The report makes particular note that certain trends quoted by sceptics – such periods of falling temperatures – are in fact signs of climate change.

“One would expect a far greater number of short periods of falling temperatures…if climate change was not occurring,” it said.