Familiar faces and voices took to the stage at the World Climate Conference as weather presenters grappled with a core issue, how best to inform their audience about climate change.

Wedged between the pondered complexity of climate scientists and the demands of the average viewer or listener for certainty come rain or shine, the weather men and women act as a go-between - and the scapegoat if the forecast errs.

"The truth is we're the ones out there and the face they trust," remarked US TV weather anchor and meteorologist John Toohey-Morales during the Climate Broadcasts Forum in Geneva.

After two decades in the geopolitical and research arena, the science behind climate change is more conclusive and reliable than ever, meteorologists and officials said.

"Imagine farmers being able to determine what to plant and where based on drought forecasts three to five years out," said Jane Lubchenco, administrator of the US National Oceanic and Atmospheric Administration.

Weather forecasts have gained a degree of reliability that allows presenters to give their audience an idea how to dress or tend livestock for the next day or five.

But climate predictions seasons, years or decades down the road are another matter.

"We are challenged to communicate uncertainties and present them as certainties," Ugandan weather journalist Patrick Luganda pointed out.

The impacts of climate change are still painted with a broad brush, both in terms of their effect on weather and their geographical spread, and are often steeped in scientific jargon and raw data.

While weather forecasting can give precise temperatures and predict drizzle, sun, snow or frost locally the next day - "deterministic" in the jargon - climate predictions involve probability and wide patterns or areas.

That often defies the 30-second to three-minute weather bulletin.

"You must on TV always talk to four year-olds and to 80 year-olds, the whole range," said Spanish broadcast meteorologist Tomas Molina.

"But it needs to be said only once, the message has to pass quickly."

Meanwhile, years of contradictory and often politicised debate added to public uncertainty.

"We've muddied the waters," said Claire Martin of Canadian Broadcasting Corporation, the chairwoman of the International Association of Broadcast Meteorology.

"How do we make people realise that the science does stand upright?"

A survey highlighted by Toohey-Morales suggested that even many US weather anchors were still sceptical about climate change.

"We face a tremendous challenge in the United States regarding educating our audience," he told his foreign colleagues.