According to a draft report by a special United Nations panel hundreds of millions of people, mainly in Asia, could be displaced by the end of this century as global warming causes sea levels to rise.
The final draft report of the Intergovernmental Panel on Climate Change (IPCC) enumerates other aspects of the potentially huge socioeconomic impact of global warming on the human race as well.
Media reports say this includes severe food shortages arising from falling agricultural production.
It also stresses a need for adaptive measures to mitigate those impacts along with reducing greenhouse gas emissions.
The IPCC is in the process of releasing its Fifth Assessment Report, the first since 2007, in stages.
It is expected to serve as a basis for use in international talks on a climate change framework that will succeed the Kyoto Protocol.
Subtitled The Physical Science Basis and released in September, the first part predicted that continued growth in carbon dioxide emissions would raise global mean temperatures by a maximum of 4.8 degrees Celsius by the end of the 21st century.
That’s above the rise of about one degree Celsius that has occurred since the Industrial Revolution of the mid-18th century.
Global sea levels are likely to rise by a maximum of 80 centimetres, the September report said.
The second part of the Fifth Assessment Report, scheduled for approval at a meeting in Yokohama, Japan, in March, will summarise the latest research 
results on the impact of global warming.
It predicts that erosion from the rising sea levels and other factors will result in a loss of coastal lands, which will likely force hundreds of millions of people, many of them in Asia, to migrate within the next 80 years.
High temperatures and other effects of global warming will cause farm production to fluctuate wildly from year to year, on top of a falling trend of up to two per cent per decade, the draft report says.
That, combined with a population growth and an increase in demand of 14 per cent per decade, is likely to cause crop supplies to fall short and prices to soar.
Tropical nations, with high poverty rates, are particularly vulnerable to serious food shortages, according to the report.
The habitats of marine life will shift, with diversity of species to increase in intermediate and high latitudes but decrease in tropical areas by the mid-21st century, the report says.
It predicts the maximum catch potential will drop in coastal waters in the Sea of Japan and in Pacific waters south of Japan but will grow off north eastern Japan.
Catches will decrease globally by the end of this century if warming proceeds at a faster rate, the draft report added.
As for the economic impact, the draft document says a 2.5-degree Celsius rise in global mean temperatures relative to the levels before the Industrial Revolution could cause a loss of 0.2-2 per cent in income.
It also says spreading poverty and other factors could heighten the risk of violent conflicts.
At the same time, the draft report stresses the importance of adaptive measures and says the development of heat-resistant crop strains and new cultivation technologies could raise farm output by 15-18 per cent of current production.
A third part of the IPCC Fifth Assessment Report to address the issue of greenhouse gas reductions will be released in Germany in April.
