By Chris Ledgard
BBC Radio 4, PM
If you spend any time west of Swindon this summer, you are likely to bump into Mr Brunel.
Storm surges are already causing problems on the track
On the bicentenary of the great engineer's birth, exhibitions and re-enactments abound and one or two Isambard Kingdom look-alikes are doing good business.
The diminutive genius didn't mind a row, and it would be intriguing to know what he would make of the controversy surrounding one of his most picturesque creations - the stretch of the Great Western Railway between Exeter and Plymouth.
Running towards Dawlish and Teignmouth, the line passes estuarine mud and sand flats dotted with sea birds and pleasure boats, while on the inland side the track is edged with red sandstone cliffs.
But the line flirts dangerously with the sea.
"The track at Dawlish is increasingly vulnerable, and the government has got to explore alternative tracks," says Anthony Steen, the Conservative MP for the nearby Totnes constituency.
"Global warming is going to be increasingly an issue, but Network Rail has decided it's not imminent enough. There needs to be a new track - full stop."
But Network Rail is taking action. It is supporting a new study, funded by the government, which will examine the effects of climate change on the railway using Dawlish as a case study. The company has decided safety and performance on coastal railways will be affected by rising sea levels.
At the Oxford headquarters of the UK Climate Impact Programme (UKCIP), this kind of approach is applauded. There, they talk about "mitigation" and "adaptation" responses to climate change.
Brunel's coastal stretch may not last another 50 years
And, according to UKCIP's Gerry Metcalf, there should be more emphasis on adaptation - accepting the inevitable and coping with it.
"I think it's demonstrably under-considered. The climate conditions we're experiencing in the first half of this century are the result of the emissions that were made at the back end of the last century - they are unavoidable. So we need to adapt."
Back in Dawlish, seaside aromas of chips and seaweed mingle with a faint whiff of climate change fatigue. I meet a local amateur historian, Angela Marks.
"I have been told an apocryphal story that the odd train has actually caught a fish. There has also been seaweed on trains pulling into Exeter, with the locals commenting 'rough down at Dawlish again'. And this was years ago."
So will one of Britain's most spectacular stretches of railway fall victim to climate change?
It would be dramatic - and hugely expensive - to re-route the line, a move opposed by the Liberal Democrat MP for the area, Richard Younger-Ross.
"There's no evidence that the railway has to be re-routed at the moment. Network Rail has just spent £9m on securing the rock-face and the track," he said.
"To me that's a good investment compared with the hundreds of millions of pounds it would cost to build a new line"
But his Conservative neighbour, Anthony Steen, doesn't buy the investment argument.
"They don't spend £9m for fun. They're building fortifications against the sea. King Canute didn't succeed - he got washed away.
"Exactly the same is going to happen to Network Rail's fortifications. That line won't be there in 50 years' time."
Responding to a parliamentary question from Mr Steen this week, the Transport Minister, Derek Twigg, said: "The government has no plans to re-open any lines as an alternative route bypassing Dawlish Warren. Network Rail will work with Devon County Council to manage the sea defences in the long term as changes occur to sea levels."
We'll know the results of the railway study at the end of year, and doubtless they'll make interesting reading. But we'll never know the answer to the crucial question.
What would Mr Brunel's solution be?