Climate change is causing sea levels to rise faster than the worst-case scenario predicted by scientists, a new study has found.
The study found ‘considerably greater sea-level rises could be realised’ than those predicted by recent assessments made by the United Nation’s Intergovernmental Panel on Climate Change (IPCC).
According to the IPCC, the average global sea levels are unlikely to rise by more than 1.1 metres within this century even with the most intensive greenhouse gas emission scenarios.
However, new research published in Ocean Science yesterday, February 2, found that upper sea-level projections by the IPCC are too low and that levels could rise by as much as 1.35 metres by 2100.
The projected global sea-level rise by the end of this century in various IPCC reports is at best conservative and consequently underestimates the upper bound of what is referred to as the likely sea-level rise by the end of this century,’ researchers of the study, The transient sensitivity of sea-level rise, wrote.
The main cause of this rise in sea-level is greenhouse gas emissions, which causes oceans to expand and ice on land to melt. This is particularly worrisome for populations who live near coastlines as it increases the dangers of flooding, superstorm and tidal surges.
Aslak Grinsted, a geophysicist at the University of Copenhagen who co-authored the research said that ‘it means our carbon budget is even more depleted’.
‘The most unpredictable thing is human behaviour, I think, and then secondly what will happen to Antarctica,’ he added.
He said 200 billion metric tons of carbon will need to be cut, the equivalent of approximately five years of global emissions if we want to remain within the thresholds that were previously predicted.
‘The models we are basing our predictions of sea-level rise on presently are not sensitive enough. To put it plainly, they don’t hit the mark when we compare them to the rate of sea-level rise we see when comparing future scenarios with observations going back in time,’ Grinsted said.
The researchers hope that their method, which used computer models to predict a future scenario, will give a more accurate picture of rising sea-levels as previous forecasts were made using historical data from the past 150 years.
By looking at data going back several centuries, scientists said they found a discrepancy of about 25cm.
‘Observations are telling us that the rate has been accelerating over the past 150 years. This means we can create a picture of how the connection between temperature and sea-level rise has been, historically,’ they said in a statement.
‘But 150 years is not very long, actually, because of the great inertia in the warming of the oceans and inland ice sheets, so several hundreds of years can pass before we see the full consequences of warming in the atmosphere,’ they added.
If you have a story you want to tell, send it to UNILAD via [email protected]