The findings are contained in Hunter Business Chamber-commissioned research into the likely effects of emissions trading on carbon-producing large industries and small to medium enterprises.

The 26 industry groups the Hunter Valley Research Foundation data indicated would be most affected included aluminium, electricity supply, cattle, iron and steel, black coal and transport.

The industry groups directly employ between 30,000 and 36,000 workers in the region and indirectly 50,000 employees.

"None of the companies surveyed believe they are adequately prepared for the introduction of the carbon pollution reduction scheme," chamber chief executive Peter Shinnick said.

The research shows the aluminium sector, the most emission-intensive group in the region, would suffer the most.

Depending on the carbon trajectory and renewable energy targets used, it was possible local plants would stop investing in new capital.

"If it were to eventuate, the loss of the aluminium sector would see the gradual loss of $1.7 billion of revenue and about 2000 employees directly and a further loss of $1.1 billion of revenue and 4650 employees through indirect flow-on impacts," Mr Shinnick said.

He said he was aware of several Hunter companies that had deferred about $1 billion worth of capital investment until the uncertainty about emissions trading had been resolved. More than half of the small to medium businesses surveyed either agreed or strongly agreed that climate change would have a direct impact on their businesses over the next 20 years.