Climate change harms 325 million people and kills 300,000 every year, says a report released by the Global Humanitarian Forum (GHF).
The Anatomy of a Silent Crisis report said 99% of the deaths linked to climate change, including those credited to hunger, poverty and lack of water occur in the global South.
The report predicts by the year 2030 the number of deaths linked to climate change will be 500,000 a year, and a further 600 million people will be adversely affected.
GHF says although developing countries are the lowest greenhouse gas emitters they bear 90% of the burden of climate change.
Kofi Annan, former UN Secretary General and GHF president, launched the report in London on May 29. He called the report an incentive for governments attending the Copenhagen conference on climate change in December "to come to the most ambitious international agreement ever negotiated, or continue to accept mass starvation, mass sickness and mass migration on an ever growing scale".