A new audio message purporting to come from al-Qaeda leader Osama Bin Laden is on Islamist websites, say reports.
In it "Bin Laden" expresses concern over natural disasters and calls for greater aid efforts for the victims, said US-based intelligence group Site.
The 11-minute undated tape shows a still image of Bin Laden and scenes of people in disaster zones receiving aid.
The tape would be Bin Laden's first public comments since March, but its authenticity has not been confirmed.
In the recording, the voice says more people are affected by climate change than wars, and appears to refer to recent flooding in Pakistan.
"The catastrophe (in Pakistan) is very big and it is difficult to describe it," says the voice.
"What we are facing... calls for generous souls and brave men to take serious and prompt action to provide relief for their Muslim brothers in Pakistan."
The tape said a "capable relief task force" should be established to deal with disasters in Muslim countries and to study regions at risk from flooding and climate change, the AFP news agency reports.
It also called for greater investment in agriculture, saying the issue was "not about gains or losses, but about life or death."
In March this year, another message said to be from Bin Laden threatened Americans would be killed if the US executed the alleged mastermind of the 9/11 attacks, Khalid Sheikh Mohammed.
Mr Mohammed is currently facing trial in the US along with four other people suspected of being involved in the attacks.
In a previous recording said to be of Bin Laden, broadcast in January, he blamed the US for global warming.
Bin Laden is the world's most-wanted man, with the US offering a reward of up to $25m (£17m) for information leading to his capture.
One theory is that he is hiding in the border area between Pakistan and Afghanistan, but has evaded capture despite a massive US operation to find him.
In January, US Secretary of Defense Robert Gates said he had received no reliable information on his whereabouts for "years".