Scientific authors and government representatives from around the world have spent the weekend negotiating the final text of the report by the Intergovernmental Panel on Climate Change at a meeting in Yokohama, Japan.

Several leaked drafts of the report indicate the panel will warn that observed impacts of climate change are substantial. The drafts say changes in climate have already affected all continents and the oceans.

The drafts also identify significant risks - and limited benefits - in coming decades as the planet warms and weather becomes more extreme. The risks include death and injury in low-lying coastal communities, extreme heat and food insecurity.

The final report, the first of its kind since 2007, will be released on Monday morning with the wording of the key 29-page summary almost certain to change from the leaked draft versions. The report is the second part of the IPCC's fifth big assessment of climate change.

Key projections in the leaked drafts, including a March 25 version, include impacts on hundreds of millions of people of coastal flooding; crop reduction; and trillions of dollars in global economic losses.

The draft stresses that climate change risks become much greater with continued high emissions of greenhouse gases than if ambitious action is taken to cut them, saying ''unchecked emissions increase the likelihood of severe and pervasive impacts that may be irreversible or unanticipated''.

The draft also says the impact of recent climate-related extremes, such as heatwaves, droughts and floods, reveal significant vulnerability of some ecosystems and many human systems.

''For countries at all income levels these impacts are consistent with a significant lack of preparedness for current climate variability in some sectors,'' the draft says.

The draft stresses that ''adaptation'' work, to adjust to the climate change, can help build a richer and more resilient world.

Professor Jean Palutikof, director of the National Climate Change Adaptation Research Facility, said Australia had the money and experience to adapt to many aspects of climate change, but there was a risk it would not be realised. Key areas were coastal flooding threats, increased biosecurity and bushfire risks from climate change.

Some senior scientists fear a contraction of national climate adaptation research, pointing to a recent decision by CSIRO to close a dedicated flagship (high-priority research project) on the issue. CSIRO spokesman Huw Morgan said adaptation research would continue to have a significant profile at the organisation.

NCCARF was saved from the scrapheap by the Abbott government, albeit with reduced funding of $9 million for three years. It was asked by the government to focus on coastal flooding, with a spokesman for Environment Minister Greg Hunt saying it was ''because there is a lack of a consistent national approach''.

Professor Palutikof said Australia had been a leader in climate change adaptation research but with the closure of the CSIRO flagship and other losses it risked falling behind.

Associate Professor Richard Eckard, director of the Primary Industries Climate Challenges Centre, said industry had neither the capacity nor interest in always doing adaptation research, and without a national approach Australia risked missing out on the gains and protections climate change adaptation measures would provide.