Tag Archives: Storm surges

Extreme sea levels could soon become annual events

Extreme sea levels are inevitable. Researchers now know more about their scale. Prepare for high tides almost every year.

LONDON, 8 September, 2021 − Those who live by the sea could soon enough be at risk from it. Extreme sea levels − those episodes of high tide, storm surge and coastal flood − that now happen only once in every century could within a lifetime be happening every year.

And this is increasingly likely even if nations act on promises made six years ago and make drastic reductions in fossil fuel use. The global warming already inevitable because of the last decades of greenhouse gas emissions makes frequent flooding ever more likely.

US, European and Australian researchers report in the journal Nature Climate Change that they used computer projections to model what would be likely to happen to sea levels at 7,283 coastal locations worldwide over the next 70 years, under a range of scenarios that saw global temperatures rise to between 1.5°C and 5°C.

The bad news is that at least half of them face a massive increase in the frequency of extreme episodes by 2070.

“How much warming will it take to make a 100-year event an annual event? Not much more than what has already been documented”

The most vulnerable regions will be in the tropics and subtropics, including the Mediterranean Sea, the Arabian Peninsula, the southern part of North America’s Pacific Coast, Hawaii and the Caribbean, the Philippines, Indonesia and much of the southern hemisphere.

“One of our central questions driving this study was this: how much warming will it take to make what has been known as a 100-year event an annual event? Our answer is, not much more than what has already been documented,” said Claudia Tebaldi, of the Pacific Northwest National Laboratory in the US.

In the last century, the world has warmed by at least one degree Celsius above the average for most of human history: in 2015, in Paris, 195 nations vowed to contain global temperature rise to “well below” 2°C by 2100, and ideally to no more than 1.5°C. That promise has yet to be backed up by concerted, dramatic international action.

In fact, the planet could surpass the 1.5°C limit, at least temporarily, some time this decade. Within 70 years, at present rates of emissions, the world will be committed to a potentially catastrophic global average rise of 3°C.

Warmth in store

And, researchers have warned, and warned again, coastal flooding could reach devastating levels. So the latest study simply confirms an alarming future, and adds a little more certainty to the zones more at risk.

The research is also a reminder that although drastic cuts and a concerted effort to restore the natural world could limit the rise in global air temperatures, the world’s oceans are subject to a slower timetable: the warming that has already happened will increasingly be reflected in tide levels for decades to come.

Like all such projections, the potential outcome ranges from optimistic to very pessimistic. With a temperature rise of just 1.5°C, seven-tenths of the studied locations might experience little increase in flood frequency. At the gloomier end of the spectrum, 99% could see flooding multiply 100-fold.

“It’s not huge news that sea level rise will be dramatic even at 1.5°C and will have substantial effects on extreme sea level frequencies and magnitude,” Dr Tebaldi said. “This study gives a more complete picture around the globe. We were able to look at a wider range of warming levels in fine spatial detail.” − Climate News Network

Extreme sea levels are inevitable. Researchers now know more about their scale. Prepare for high tides almost every year.

LONDON, 8 September, 2021 − Those who live by the sea could soon enough be at risk from it. Extreme sea levels − those episodes of high tide, storm surge and coastal flood − that now happen only once in every century could within a lifetime be happening every year.

And this is increasingly likely even if nations act on promises made six years ago and make drastic reductions in fossil fuel use. The global warming already inevitable because of the last decades of greenhouse gas emissions makes frequent flooding ever more likely.

US, European and Australian researchers report in the journal Nature Climate Change that they used computer projections to model what would be likely to happen to sea levels at 7,283 coastal locations worldwide over the next 70 years, under a range of scenarios that saw global temperatures rise to between 1.5°C and 5°C.

The bad news is that at least half of them face a massive increase in the frequency of extreme episodes by 2070.

“How much warming will it take to make a 100-year event an annual event? Not much more than what has already been documented”

The most vulnerable regions will be in the tropics and subtropics, including the Mediterranean Sea, the Arabian Peninsula, the southern part of North America’s Pacific Coast, Hawaii and the Caribbean, the Philippines, Indonesia and much of the southern hemisphere.

“One of our central questions driving this study was this: how much warming will it take to make what has been known as a 100-year event an annual event? Our answer is, not much more than what has already been documented,” said Claudia Tebaldi, of the Pacific Northwest National Laboratory in the US.

In the last century, the world has warmed by at least one degree Celsius above the average for most of human history: in 2015, in Paris, 195 nations vowed to contain global temperature rise to “well below” 2°C by 2100, and ideally to no more than 1.5°C. That promise has yet to be backed up by concerted, dramatic international action.

In fact, the planet could surpass the 1.5°C limit, at least temporarily, some time this decade. Within 70 years, at present rates of emissions, the world will be committed to a potentially catastrophic global average rise of 3°C.

Warmth in store

And, researchers have warned, and warned again, coastal flooding could reach devastating levels. So the latest study simply confirms an alarming future, and adds a little more certainty to the zones more at risk.

The research is also a reminder that although drastic cuts and a concerted effort to restore the natural world could limit the rise in global air temperatures, the world’s oceans are subject to a slower timetable: the warming that has already happened will increasingly be reflected in tide levels for decades to come.

Like all such projections, the potential outcome ranges from optimistic to very pessimistic. With a temperature rise of just 1.5°C, seven-tenths of the studied locations might experience little increase in flood frequency. At the gloomier end of the spectrum, 99% could see flooding multiply 100-fold.

“It’s not huge news that sea level rise will be dramatic even at 1.5°C and will have substantial effects on extreme sea level frequencies and magnitude,” Dr Tebaldi said. “This study gives a more complete picture around the globe. We were able to look at a wider range of warming levels in fine spatial detail.” − Climate News Network

Katrina 'could soon happen every other year'

FOR IMMEDIATE RELEASE
Storms as intense as Hurricane Katrina could in a few decades be occurring in the Atlantic every other year under the influence of the changing climate, researchers say.

LONDON, 19 March – Extreme storm events on the scale of Hurricane Katrina which caused widespread damage in the Gulf of Mexico in 2005 will occur far more often because of climate change, a new study says.

The research says the threat from extremely damaging hurricane-induced storm surges in the Atlantic will increase significantly as global temperatures rise.

Hurricanes are very sensitive to temperature changes, and the number of Katrina-magnitude storms may double because of the increase in global temperatures, the researchers report in the Proceedings of the National Academy of Sciences.

Storm surges are localised increases in sea level, brought about by extreme low pressure, which causes the sea to rise in a dome underneath. These surges sometimes run ashore at high tide and devastate local populations. With Hurricane Katrina, it was the surge that caused the widespread coastal flooding of New Orleans.

Dr Aslak Grinsted, lead author of the report, said: “It is always difficult to say what caused individual extreme weather events. Our analysis indicates however that we have passed a global warming threshold where we are having twice as frequent Katrina-magnitude surges.”

This study differs from earlier research into possible links between hurricanes and warmer sea surface temperatures by looking as well at the effect of warmer air.

Sharp rise predicted

 

One of the report’s co-authors, Dr Svetlana Jevrejeva, of the National Oceanography Centre in Liverpool, UK, said their approach was novel because previous studies had used climate models to forecast future hurricane frequency.

She said: “These findings have been controversial, and there is much disagreement among scientists regarding the relationship between hurricanes and temperature.

“In our study we used sea level data measured by various tide gauges throughout the twentieth century to see how extreme sea level during hurricanes has changed with temperature.”

The researchers then combined these historic data with projections of climate change, to predict how many Katrina-like storm surges would occur in the future:

“The results show that the extreme sea levels observed during Hurricane Katrina will become ten times more likely if average global temperatures increase by 2°C”, said Dr Jevrejeva. That would mean a storm surge of Katrina proportions every other year.

The UN’s Intergovernmental Panel on Climate Change predicts that global average temperatures could rise by somewhere between 2°C and 6°C by the end of this century. They have already risen by about 0.7°C since the start of the industrialised era two centuries ago.

Data queried

 

The researchers say the number of hurricanes as severe as Katrina could double, and possibly rise much more, with every 1°C rise in global temperatures.

The US National Oceanic and Atmospheric Administration says Hurricane Katrina caused an estimated $108 billion of damage, with last year’s superstorm Sandy thought to have cost $75 billion.

But the study has already attracted some criticism. USA Today quotes the climatologist Judith Curry of Georgia Institute Technology as saying the researchers used “a very incomplete data set”, using tide gauge measurements from only six US sites.

“I find this paper to be very misleading,” Professor Curry said. “Their statistical projection is totally unconvincing, since it is based on a data set that incompletely represents US landfalling hurricane activity since 1923.”

The study involved scientists from Liverpool, Beijing Normal University, the University of Copenhagen, the University of Lapland and Uppsala University, Sweden. – Climate News Network

FOR IMMEDIATE RELEASE
Storms as intense as Hurricane Katrina could in a few decades be occurring in the Atlantic every other year under the influence of the changing climate, researchers say.

LONDON, 19 March – Extreme storm events on the scale of Hurricane Katrina which caused widespread damage in the Gulf of Mexico in 2005 will occur far more often because of climate change, a new study says.

The research says the threat from extremely damaging hurricane-induced storm surges in the Atlantic will increase significantly as global temperatures rise.

Hurricanes are very sensitive to temperature changes, and the number of Katrina-magnitude storms may double because of the increase in global temperatures, the researchers report in the Proceedings of the National Academy of Sciences.

Storm surges are localised increases in sea level, brought about by extreme low pressure, which causes the sea to rise in a dome underneath. These surges sometimes run ashore at high tide and devastate local populations. With Hurricane Katrina, it was the surge that caused the widespread coastal flooding of New Orleans.

Dr Aslak Grinsted, lead author of the report, said: “It is always difficult to say what caused individual extreme weather events. Our analysis indicates however that we have passed a global warming threshold where we are having twice as frequent Katrina-magnitude surges.”

This study differs from earlier research into possible links between hurricanes and warmer sea surface temperatures by looking as well at the effect of warmer air.

Sharp rise predicted

 

One of the report’s co-authors, Dr Svetlana Jevrejeva, of the National Oceanography Centre in Liverpool, UK, said their approach was novel because previous studies had used climate models to forecast future hurricane frequency.

She said: “These findings have been controversial, and there is much disagreement among scientists regarding the relationship between hurricanes and temperature.

“In our study we used sea level data measured by various tide gauges throughout the twentieth century to see how extreme sea level during hurricanes has changed with temperature.”

The researchers then combined these historic data with projections of climate change, to predict how many Katrina-like storm surges would occur in the future:

“The results show that the extreme sea levels observed during Hurricane Katrina will become ten times more likely if average global temperatures increase by 2°C”, said Dr Jevrejeva. That would mean a storm surge of Katrina proportions every other year.

The UN’s Intergovernmental Panel on Climate Change predicts that global average temperatures could rise by somewhere between 2°C and 6°C by the end of this century. They have already risen by about 0.7°C since the start of the industrialised era two centuries ago.

Data queried

 

The researchers say the number of hurricanes as severe as Katrina could double, and possibly rise much more, with every 1°C rise in global temperatures.

The US National Oceanic and Atmospheric Administration says Hurricane Katrina caused an estimated $108 billion of damage, with last year’s superstorm Sandy thought to have cost $75 billion.

But the study has already attracted some criticism. USA Today quotes the climatologist Judith Curry of Georgia Institute Technology as saying the researchers used “a very incomplete data set”, using tide gauge measurements from only six US sites.

“I find this paper to be very misleading,” Professor Curry said. “Their statistical projection is totally unconvincing, since it is based on a data set that incompletely represents US landfalling hurricane activity since 1923.”

The study involved scientists from Liverpool, Beijing Normal University, the University of Copenhagen, the University of Lapland and Uppsala University, Sweden. – Climate News Network

Katrina ‘could soon happen every other year’

FOR IMMEDIATE RELEASE Storms as intense as Hurricane Katrina could in a few decades be occurring in the Atlantic every other year under the influence of the changing climate, researchers say. LONDON, 19 March – Extreme storm events on the scale of Hurricane Katrina which caused widespread damage in the Gulf of Mexico in 2005 will occur far more often because of climate change, a new study says. The research says the threat from extremely damaging hurricane-induced storm surges in the Atlantic will increase significantly as global temperatures rise. Hurricanes are very sensitive to temperature changes, and the number of Katrina-magnitude storms may double because of the increase in global temperatures, the researchers report in the Proceedings of the National Academy of Sciences. Storm surges are localised increases in sea level, brought about by extreme low pressure, which causes the sea to rise in a dome underneath. These surges sometimes run ashore at high tide and devastate local populations. With Hurricane Katrina, it was the surge that caused the widespread coastal flooding of New Orleans. Dr Aslak Grinsted, lead author of the report, said: “It is always difficult to say what caused individual extreme weather events. Our analysis indicates however that we have passed a global warming threshold where we are having twice as frequent Katrina-magnitude surges.” This study differs from earlier research into possible links between hurricanes and warmer sea surface temperatures by looking as well at the effect of warmer air.

Sharp rise predicted

  One of the report’s co-authors, Dr Svetlana Jevrejeva, of the National Oceanography Centre in Liverpool, UK, said their approach was novel because previous studies had used climate models to forecast future hurricane frequency. She said: “These findings have been controversial, and there is much disagreement among scientists regarding the relationship between hurricanes and temperature. “In our study we used sea level data measured by various tide gauges throughout the twentieth century to see how extreme sea level during hurricanes has changed with temperature.” The researchers then combined these historic data with projections of climate change, to predict how many Katrina-like storm surges would occur in the future: “The results show that the extreme sea levels observed during Hurricane Katrina will become ten times more likely if average global temperatures increase by 2°C”, said Dr Jevrejeva. That would mean a storm surge of Katrina proportions every other year. The UN’s Intergovernmental Panel on Climate Change predicts that global average temperatures could rise by somewhere between 2°C and 6°C by the end of this century. They have already risen by about 0.7°C since the start of the industrialised era two centuries ago.

Data queried

  The researchers say the number of hurricanes as severe as Katrina could double, and possibly rise much more, with every 1°C rise in global temperatures. The US National Oceanic and Atmospheric Administration says Hurricane Katrina caused an estimated $108 billion of damage, with last year’s superstorm Sandy thought to have cost $75 billion. But the study has already attracted some criticism. USA Today quotes the climatologist Judith Curry of Georgia Institute Technology as saying the researchers used “a very incomplete data set”, using tide gauge measurements from only six US sites. “I find this paper to be very misleading,” Professor Curry said. “Their statistical projection is totally unconvincing, since it is based on a data set that incompletely represents US landfalling hurricane activity since 1923.” The study involved scientists from Liverpool, Beijing Normal University, the University of Copenhagen, the University of Lapland and Uppsala University, Sweden. – Climate News Network

FOR IMMEDIATE RELEASE Storms as intense as Hurricane Katrina could in a few decades be occurring in the Atlantic every other year under the influence of the changing climate, researchers say. LONDON, 19 March – Extreme storm events on the scale of Hurricane Katrina which caused widespread damage in the Gulf of Mexico in 2005 will occur far more often because of climate change, a new study says. The research says the threat from extremely damaging hurricane-induced storm surges in the Atlantic will increase significantly as global temperatures rise. Hurricanes are very sensitive to temperature changes, and the number of Katrina-magnitude storms may double because of the increase in global temperatures, the researchers report in the Proceedings of the National Academy of Sciences. Storm surges are localised increases in sea level, brought about by extreme low pressure, which causes the sea to rise in a dome underneath. These surges sometimes run ashore at high tide and devastate local populations. With Hurricane Katrina, it was the surge that caused the widespread coastal flooding of New Orleans. Dr Aslak Grinsted, lead author of the report, said: “It is always difficult to say what caused individual extreme weather events. Our analysis indicates however that we have passed a global warming threshold where we are having twice as frequent Katrina-magnitude surges.” This study differs from earlier research into possible links between hurricanes and warmer sea surface temperatures by looking as well at the effect of warmer air.

Sharp rise predicted

  One of the report’s co-authors, Dr Svetlana Jevrejeva, of the National Oceanography Centre in Liverpool, UK, said their approach was novel because previous studies had used climate models to forecast future hurricane frequency. She said: “These findings have been controversial, and there is much disagreement among scientists regarding the relationship between hurricanes and temperature. “In our study we used sea level data measured by various tide gauges throughout the twentieth century to see how extreme sea level during hurricanes has changed with temperature.” The researchers then combined these historic data with projections of climate change, to predict how many Katrina-like storm surges would occur in the future: “The results show that the extreme sea levels observed during Hurricane Katrina will become ten times more likely if average global temperatures increase by 2°C”, said Dr Jevrejeva. That would mean a storm surge of Katrina proportions every other year. The UN’s Intergovernmental Panel on Climate Change predicts that global average temperatures could rise by somewhere between 2°C and 6°C by the end of this century. They have already risen by about 0.7°C since the start of the industrialised era two centuries ago.

Data queried

  The researchers say the number of hurricanes as severe as Katrina could double, and possibly rise much more, with every 1°C rise in global temperatures. The US National Oceanic and Atmospheric Administration says Hurricane Katrina caused an estimated $108 billion of damage, with last year’s superstorm Sandy thought to have cost $75 billion. But the study has already attracted some criticism. USA Today quotes the climatologist Judith Curry of Georgia Institute Technology as saying the researchers used “a very incomplete data set”, using tide gauge measurements from only six US sites. “I find this paper to be very misleading,” Professor Curry said. “Their statistical projection is totally unconvincing, since it is based on a data set that incompletely represents US landfalling hurricane activity since 1923.” The study involved scientists from Liverpool, Beijing Normal University, the University of Copenhagen, the University of Lapland and Uppsala University, Sweden. – Climate News Network