Which city in Norway faces the biggest rise in sea levels?

Norway's "steep and rocky" coast, together with post-glacial rebound had led to stable or falling sea levels historically in Norway, according to the authors of a new joint report from the Norwegian Mapping Authority and the Norwegian Meteorological Institute.

"Unlike other coastal countries, Norway is therefore yet to feel the impacts of sea-level rise," the report reads. "The danger is that this can foster a false sense of security, where the long-term risks are not understood or ignored."

The researchers found that sea level rise due to global warming had already started to reverse the relative decline in sea levels in much of Western and Southern Norway, meaning relative sea levels are now starting to creep up. 

"The results from this report show that sea-level rise is starting to push up water levels in some parts of the country, most notably in Western and Southern Norway," they wrote. "Owing to global warming, Norway is transitioning from a country with on average falling or stable sea levels, to one with rising sea levels." 

So which cities are most affected? 

Stavanger is the city likely to be worst affected by rising sea levels between now and the year 2100, the report found. 

In the highest emissions scenario, in an extreme scenario of "rapid ice sheet loss" from Antarctica, the city could experience a maximum sea level rise of close to two metres (1.92m).  

This is nearly half a metre more than the relative sea level rise faced by Oslo in this extreme circumstance and significantly more than Tromsø can expect. 

Bergen, was however not far behind with a maximum sea level rise in this "rapid ice sheet loss scenario" of up to 1.85m. 

In the much more likely scenario of 3C temperature rise, the researchers predicted that sea levels in Stavanger were most likely to rise by some 45cm, compared to 13cm in Oslo and 27cm in Tromsø. 

Lise Peterson, emergency manager in Stavanger, said that the city's built-up harbour area was most exposed. 

"The biggest challenges are down here where we already have buildings," she told Norwegian state broadcaster NRK, when their reporters visited, conceding that Stavanger was "in a bad position" even if the world met its most ambitious emissions reduction targets. 

Even so, the rise in the sea level Norway is facing remains between 40 percent and 70 percent of the global average, meaning most other countries face even bigger problems.   

But the researchers pointed out that even a rise in sea levels of 0.1m would lead to a tripling of the flood risk in many locations. 

"This means that, unless timely adaptation measures are taken, flooding will develop into a chronic problem," they warned. 

Looking further ahead until 2300, the researchers predicted a much more severe rise in sea level rise, with a likely rise between 1.4 metres and 4 metres in a high emission scenario and a maximum rise of 16m possible but very unlikely.