Family First Senator Steve Fielding has made up his mind on global warming - there's not enough evidence that it's real.

After talks with the Government and top scientists, Senator Fielding, who holds a crucial Senate vote, has released a document setting out his position.

"Global temperature isn't rising," it says.

On emissions trading, Senator Fielding said he wouldn't risk job losses on "unconvincing green science".

The document was prepared with the help of some of the country's most prominent climate-sceptic scientists.

It says it is a "fact" that the evidence does not support the notion that greenhouse gas emissions are causing dangerous global warming.

The Senate is due to debate emissions trading legislation this week.

The Government is struggling to muster enough votes to pass the legislation.

Senator Fielding's stance appears to torpedo the chance of the scheme passing as the Government would need his support, as well as that of the Greens and independent Nick Xenophon.

Otherwise, the Government would need the support of the Opposition to pass the scheme.

Source: Australian Associated Press