Climate change has made history an inaccurate guide for farmers as well as energy investors who must rely on probabilities and scenarios to make decisions, the head of a United Nations agency said on Wednesday.

Africa's farmers need help to access loans, fertilizer and export markets to avoid future food supply crises caused by climate change and commodities speculation, a top agricultural expert said on Tuesday.

A new global free trade accord could help fight climate change by making clean-energy products more widely available, the World Trade Organization and United Nations Environment Program said on Friday.

Bucking conventional thinking about the climate hazards of shipping products by air, land and sea, the two agencies argued that a new Doha Round pact would do more good than harm.

Zimbabwe is on the brink of having 100,000 infections of cholera, a preventable disease that has already killed 4,283 people there and remains a serious threat, the Zimbabwean Red Cross and its partners said on Tuesday.

Natural disasters threaten to trigger widespread damage and distress in emerging economies, many of which are already on the brink because of the global recession, a United Nations body said on Sunday.

Airlines will reduce their carbon emissions by nearly 8 percent this year as they slash the number of flights they operate in line with a drop in both cargo and passenger demand, executives said on Tuesday.

The world's airlines have agreed to new fuel efficiency and carbon emission targets which go much further than the levels required through regulation, an industry group said on Saturday.