Australia's multibillion-dollar mining, farming and tourism industries face significant threats as worsening global warming causes more dangerous and extreme weather, the world's leading climate science body will warn.

A final draft of a five-year assessment by the UN's Intergovernmental Panel on Climate Change (IPCC) - seen by Fairfax Media - details a litany of global impacts from intensifying climate change including the displacement of hundreds of millions of people, reduced crop yields and the loss of trillions of dollars from the global economy.

The report is the second part of the IPCC's fifth major assessment and focuses on climate change's impacts and how the world might adapt. It will be finalised at a meeting in Japan next weekend before its release on March 31.
The final draft Australasia chapter also outlines significant local threats if human-caused climate change gets worse, in particular high confidence that fire seasons, particularly in southern Australia, will extend in high-risk areas.


There is also significant risk of increased damage and death from heatwaves resulting from more frequent extreme high temperatures. Flood risk too would be worse.
The draft says these new extremes imply Australia's mammoth mining industry is increasingly vulnerable without adaptation measures. The report points to significant loss of coal exports revenue of $5 billion to $9 billion when mines were flooded in 2011.
Tourism also faces some significant threats, the draft says. The Great Barrier Reef is expected to degrade under all climate change scenarios, reducing its attractiveness to visitors.
Australia's $1.8 billion ski industry is identified as most negatively affected, with little option for it to counteract threats.
For Australian farming a 4 per cent reduction in the gross value of beef, sheep and wool is expected with 3 degrees of warming above a 1980-99 baseline.

Dairy output is projected to decline in all regions, except in Tasmania.
Out of the major risks identified for Australia in the draft, the loss of montane ecosystems and changes in coral reefs, appear to be very difficult to avoid. The draft also finds modelling consistently indicated the range of many wildlife species will contract.

And there is high confidence climate change is already affecting Australia's oceans, with climate zones and species shifting hundreds of kilometres southwards.

Professor Jean Palutikof - a review editor of the assessment and director of Australia's National Climate Change Adaptation Research Facility - said while adaptation measures were important, there were limits to what the world could do and it was important to cut global emissions to ensure these thresholds are not reached.
''I think it is quite black and white, there is a risk we will go beyond the limits of the natural environment and human society to adapt to the climate'' she said.

A spokesman for Environment Minister Greg Hunt said the government recognised the importance of adapting to the impacts of climate change, pointing to the refunding of the National Climate Change Adaptation Research Facility, which it has asked to ''focus on putting practical adaptation information in the hands of decision-makers so we can build a stronger, more resilient Australia''.