I remember reading about this last year. There was actually scientific study on it golly gee. A guy who should know actually had this to say about this quite not so mainstream idea:
Mahfuzur Rahman, head of Bangladesh Water Development Board's Coastal Study and Survey Department, has also been analysing the buildup of land on the coast.
He told AFP findings by the IPCC and other climate change scientists were too general and did not explore the benefits of land accretion.
"For almost a decade we have heard experts saying Bangladesh will be under water, but so far our data has shown nothing like this," he said.
I guess he and the scientist who actually studied the issue should not believe their lying eyes.
In Silt, Bangladesh Sees Potential Shield Against Sea Level Rise
.....The efforts have been limited to small experimental patches, not uniformly promising, and there is still ample concern that a swelling sea could one day soon swallow parts of Bangladesh. But the emerging evidence suggests that a nation that many see as indefensible to the ravages of human-induced climate change could literally raise itself up and save its people — and do so cheaply and simply, using what the mountains and tides bring.
“You can do a lot with the silt that these rivers bring,” said Bea M. ten Tusscher, the Dutch ambassador to Bangladesh. The Netherlands, itself accustomed to engineering its vulnerable low-lands, helps Bangladesh with water management projects. “Those are like little diamonds,” Ms. ten Tusscher said. “You have to use it.”
Satellite images show that in the natural process of erosion and accretion — in some places speeded up by a series of man-made dams and channels — Bangladesh has actually gained land over the last 35 years.....
Notice the man made attempts have been "limited and experimental patches" the rest has been natural. So despite the hype of rising oceans to the contrary, the country most at danger is actually growing in size. Makes you wonder huh?