The Prime Minister said more frequent ‘extreme weather events’ driven by climate change were the main driver as Cumbria and the north braces for more hell.
However experts branded his comments “ludicrous excuses” blaming lack of investment on flood defences for the disaster and pointed to historic flooding which pre-dated global warming.
They accused the Prime Minister of deflecting attention away from accusations Britain is woefully unprepared for severe weather.
Climatologists say although devastating, the floods have nothing to do with global warming but are part of a natural weather cycle.
They say heavy and persistent rain not only in the UK but across the world has been bolstered by an especially strong El Nino this year.
The phenomenon – on course to be the strongest on record – is triggered by wind changes in the Pacific Ocean leading to a build up of warm water around the coast of Peru.
It has catastrophic impacts on the world’s weather including heavy rain and floods in America and South America and warmer than average temperature across Asia.
Although its effects are still under discussion, it is thought increased atmospheric moisture may be responsible for heavy rain over Europe.
Mr Cameron spoke as he paid a visit to the northern city of York, currently devastated by weeks of heavy rain.
He said: “What has happened – the level of the rivers, plus the level of rainfall – has created an unprecedented effect and so some very serious flooding.
“We do seem to face more of these extreme weather events and problems of floods.
“People are told that things that are one in 50, or one in 100, or one in 200 years, they seem to be happening more often.
“So what we should be doing is continuing with the very high level of investment in flood defences.
“The flood barriers have made a difference, both the permanent ones and the temporary ones, but it’s clear in some cases they’ve been over-topped, they’ve been over-run and so of course we should look again about whether there is more we can do.”
Dr Benny Peiser, director of the Global Warming Forum, slammed the Prime Minister for shrouding the real problem of poor flood defences with excuses.
He said: “Flooding has happened through the centuries, though uncommon, what we are seeing is nothing new.
“The most likely explanation is that the current El Nino has thrown more moisture into the air as sea waters have evaporated over the Pacific.
“This has nothing to do with climate change but is a natural phenomenon which was happening a long time before climate change took over the agenda.
“This is just an excuse for the failure of a number of governments to address the reality that Cumbria and flood prone regions face.”
Although Britain has been hit by extreme rainfall over the past few weeks, floods have ravaged UK shores for centuries – before climate change was named.
The North Sea flood of 1953 is long held as one of the most catastrophic natural disasters in British history.
Around 30,000 people were forced from their homes and more than 300 people lost their lives as water swept down the east coast.
In 1864 the Great Sheffield Flood claimed 270 lives and in 1928 heavy rain and melting snow doubled the amount of water in the Thames overflowing into London.