The costs of inaction on climate change will be "catastrophic", according to US Secretary of State John Kerry. Mr Kerry was responding to a major report by the UN which described the impacts of global warming as "severe, pervasive and irreversible". He said dramatic and swift action was required to tackle the threats posed by a rapidly changing climate.
Our health, homes, food and safety are all likely to be threatened by rising temperatures, the report says. Scientists and officials meeting in Japan say the document is the most comprehensive assessment to date of the impacts of climate change on the world.
In a statement, Mr Kerry said: "Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice. "There are those who say we can’t afford to act. But waiting is truly unaffordable. The costs of inaction are catastrophic."
Rajendra Pachauri, chair of the Intergovernmental Panel on Climate Change (IPCC), which produced the report, told BBC News: "Even in rich countries, the impacts of climate change could lead to greater incidents of pockets of poverty, even in rich countries could lead to impoverishment of some particular communities.
"However there is an equity issue, because some of the poorest communities in the poorest countries in the world are going to be the worst hit."