The warning comes from Leigh Daynes, head of media at the British Red Cross, who admits that the response to its public appeal has been very slow.
"Five weeks in, the appeal has raised £450,000," he said. "We took more in one day of the Beslan school appeal than we did in four weeks of the Middle East conflict."
Daynes believes that the public has so far given less generously than to other appeals because it is a man-made disaster.
"The coverage has concentrated on the politics," he said. "We must change how we communicate to get people to think about the human suffering."
Ceasefire Today is celebrating the ceasefire agreed on Monday in Lebanon. The coalition of 16 voluntary groups has been lobbying the Government and MPs to support a ceasefire since 12 July.