Giant storms that wreak havoc across China, Japan, Korea and the Philippines have grown 50% stronger in the past 40 years due to warming seas





The destructive power of the typhoons that wreak havoc across China, Japan, Korea and the Philippines has intensified by 50% in the past 40 years due to warming seas, a new study has found.

The researchers warn that global warming will lead the giant storms to become even stronger in the future, threatening the large and growing coastal populations of those nations.

“It is a very, very substantial increase,” said Prof Wei Mei, at the University of North Carolina at Chapel Hill, who led the new work. “We believe the results are very important for east Asian countries because of the huge populations in these areas. People should be aware of the increase in typhoon intensity because when they make landfall these can cause much more damage.”

Typhoons can have devastating impacts in east Asia. In 2013, typhoon Haiyan hit the Philippines, killing at least 6,300 people and affecting 11 million. Typhoon Nina struck China in 1975, dumping 100cm of rain in a day and leading to 229,000 deaths and 6m destroyed buildings. Last week typhoon Lionrock left 11 people dead in northern Japan and caused power blackouts and property damage, while in July typhoon Nepartak hit Taiwan and China, killing at least nine people and leaving a trail of destruction.

In the new research, published in Nature Geoscience, the scientists took data collected independently by centres in Japan and Hawaii and, after accounting for differences in the way it had been collected, showed that typhoons in the north-west Pacific had intensified by 12–15% on average since 1977. The proportion of the most violent storms - categories 4 and 5 - doubled and even tripled in some regions over that time and the intensification was most marked for those storms which hit land.

The intensity of a typhoon is measured by the maximum sustained wind speed, but the damage caused by its high winds, storm surges, intense rains and floods increases disproportionately, meaning a 15% rise in intensity leads to a 50% rise in destructive power.

Facebook Twitter Pinterest People take cover under a tree after strong winds brought by typhoon Rammasun, locally called Glenda, battered Manila in the Philippines, July 2014. Photograph: Romeo Ranoco/REUTERS

The researchers showed that the intensification of typhoons making landfall occurred because warmer coastal seas provided more energy to growing storms, enabling their wind speeds to increase more rapidly.

Scientists are not yet able to determine whether manmade climate change or natural cycles are to blame for the warming seas in the region because 40 years is a relatively short time span for such phenomena. But Wei is clear that the future global warming, as projected by the UN’s Intergovernmental Panel on Climate Change, would heat the oceans in the region and lead to even more intense typhoons.

Mei said: “We want to give the message that typhoon intensity has increased and will increase in the future because of the warming climate.” He said action was needed to both prepare for future typhoons and to reduce carbon dioxide emissions to curb warming: “Understanding intensity change is very important for disaster preparation.”

Prof Kerry Emanuel, an expert on tropical cyclones at MIT and not involved in the new research said: “The results leave little doubt that there are more high intensity events affecting south-east Asia and China, and these are also intensifying more rapidly.”

“This is significant for these nations because what matters, in the end, is landfall size and intensity,” he said. “Stronger storms cause higher storm surges, which often cause the most destruction and loss of life.” Previous work by Emanuel showed tropical cyclones are likely to become more frequent and stronger if climate change is not curbed.</s>Intensity changes in landfalling typhoons are of great concern to East and Southeast Asian countries1. Regional changes in typhoon intensity, however, are poorly known owing to inconsistencies among different data sets2,3,4,5,6,7,8. Here, we apply cluster analysis to bias-corrected data and show that, over the past 37 years, typhoons that strike East and Southeast Asia have intensified by 12–15%, with the proportion of storms of categories 4 and 5 having doubled or even tripled. In contrast, typhoons that stay over the open ocean have experienced only modest changes. These regional changes are consistent between operational data sets. To identify the physical mechanisms, we decompose intensity changes into contributions from intensification rate and intensification duration. We find that the increased intensity of landfalling typhoons is due to strengthened intensification rates, which in turn are tied to locally enhanced ocean surface warming on the rim of East and Southeast Asia. The projected ocean surface warming pattern under increasing greenhouse gas forcing suggests that typhoons striking eastern mainland China, Taiwan, Korea and Japan will intensify further. Given disproportionate damages by intense typhoons1, this represents a heightened threat to people and properties in the region.</s>Study: Typhoons that slam Asia getting much stronger

WASHINGTON (AP) — Typhoons that slam into land in the northwestern Pacific — especially the biggest tropical cyclones of the bunch — have gotten considerably stronger since the 1970s, a new study concludes.

Overall, landfalling Asian typhoon intensity has increased by about 12 percent in nearly four decades. But the change is most noticeable for storms with winds of 209 kilometers per hour or more (130 mph), those in categories 4 and 5. Since 1977, they've gone from a once-a-year occurrence to four times a year, according to a study Monday in the journal Nature Geoscience.

These are storms like Lionrock that in August killed at least 17 people, about half of them elderly residents of a Japanese nursing home, and Haiyan — one of the strongest storms on record, killing more than 6,000 people in the Philippines in 2013.

Study lead author Wei Mei, a climate scientist at the University of North Carolina, connects the strengthening of these storms to warmer seawater near the coasts. That provides more fuel for the typhoons. Along much of the Asian coast, water has warmed by nearly 0.8 degrees (1.4 degrees Fahrenheit) since the late 1970s. Mei didn't study why the water is warming, but says it is probably due to a combination of natural local weather phenomena and warming from the burning of fossil fuels.

Mei and two other outside scientists say it is too early to say precisely that the increased intensity is from man-made climate change.

But as the world warms more in the future, stronger storms are likely to get even more intense, especially north of 10 degrees North latitude, where China, Taiwan, Korea and Japan are located, Mei says.

Colorado State University hurricane researcher Phil Klotzbach says the study makes sense and raises interesting questions, but adds that some of the storms before 1987 might have had their wind speeds under-estimated. Mei said he thinks that time period actually had better measurements because planes were then flying into storms to gauge their strength.

Mei didn't study tropical cyclone intensification in other parts of the world.

Follow Seth Borenstein at http://twitter.com/borenbears and his work can be found at http://bigstory.ap.org/content/seth-borenstein</s>Typhoons that slam into Japan, China, Taiwan and the Korean Peninsula have gotten considerably stronger since the 1970s, a new study concludes.

Overall, Asian typhoon intensity has increased by about 12 percent in the last four decades, according to a study released Monday in the journal Nature Geoscience.

But the change is most noticeable for category 4 and 5 storms with winds of 209 kph or more. Since 1977, they’ve gone from a once-a-year occurrence to four times a year.

These are storms like Typhoon Lionrock, which in August killed at least 17 people, about half of them elderly residents of a Japanese nursing home, and Haiyan — one of the strongest storms on record, killing more than 6,000 people in the Philippines in 2013.

Study lead author Wei Mei, a climate scientist at the University of North Carolina, connects the strengthening of these storms to warmer seawater near coasts. This provides more fuel for the typhoons. Along much of the Asian coast, water has warmed by nearly 0.8 degree (1.4 degrees Fahrenheit) since the late 1970s.

Mei didn’t study why the water is warming but says it is probably due to a combination of natural local weather phenomena and warming from the burning of fossil fuels.

He and two other outside scientists say it is too early to say precisely that the increased intensity is from man-made climate change.

But as the world warms more in the future, stronger storms are likely to get even more intense, especially north of 20 degrees north latitude, where eastern China, Taiwan the Korean Peninsula and Japan are located, Mei says.

Colorado State University hurricane researcher Phil Klotzbach says the study makes sense and raises interesting questions but adds that some of the storms before 1987 might have had their wind speeds underestimated.

Mei said he thinks that time period actually had better measurements because planes would fly into storms to gauge their strength.

Mei didn’t study tropical cyclone intensification in other parts of the world.

A week after Typhoon Lionrock hit the Tohoku region, hundreds of residents remained isolated in Iwate Prefecture as of Tuesday with roads still cut off.

In the town of Iwaizumi, an estimated 321 residents were believed to be still isolated, with another 167 people facing the same situation in the city of Kuji.

Authorities on Monday lifted an evacuation order in Iwaizumi that was issued in preparation for approaching Typhoon Namtheun, the 12th typhoon this year. The storm weakened Monday and was redesignated as a tropical depression.

Some elementary schools in the town reopened for classes Tuesday. Volunteer activities, which had been suspended, were also resumed.

“All of our 141 children are safe. But some have seen their houses damaged as well as their relatives affected (by the storm),” Kazue Takahashi, principal of one of the reopened elementary schools in Iwaizumi, told a schoolwide assembly. “I know it’s hard, but please remember that you can return to normal life when in school.”

Iwaizumi was one of the hardest-hit areas in Iwate. Nine residents of a group home for the elderly were killed when the facility was flooded.

On Tuesday morning, some 30 Iwaizumi officials, including Mayor Katsumi Date, observed a moment of silence where prayers were offered for the victims of the typhoon at the start of a meeting of the town’s disaster response committee.

“It doesn’t feel real to me that one week has passed,” Date said after the meeting. “I feel truly sorry and filled with regret.”

At the prefectural government office in Morioka, Iwate Gov. Takuya Tasso and other officials also prayed for the disaster victims.

Typhoon Lionrock left 16 people dead and seven missing in Iwate, and two dead and two missing in Hokkaido.</s>The most destructive categories of tropical storms to strike the heavily populated regions of east Asia are becoming more intense and increasing as much as four-fold in frequency because of climate change, according to new research by US-based scientists.

Since the late 1970s, typhoons making land in a region stretching from Vietnam and the Philippines to Korea and Japan have become 12 per cent to 15 per cent more intense.

Those hitting south-east Asia with a category 4 or 5 strength have more than doubled in number, with the increase even more for China and Taiwan and regions north, the paper published in Nature Geoscience on Tuesday found.

The increase in sea-surface temperature is key to providing extra energy to tropical storms, with the outcome for the megacities of the region looking grimmer.

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For eastern Asia, the strongest storms are now as many as four or more a year compared with about one a year three decades ago, the researchers found.

"The intensification is strongest for typhoons that tend to make landfall because of the stronger warming of the coastal waters near east and south-east Asia," said Wei Mei, a researcher in the department of marine sciences at the University of South Carolina and co-author of the paper.

Additional warming is expected to intensify the storms, particularly in some of east Asia's main economic centres, Mei said: "The typhoons striking mainland China, Taiwan, Japan, and Korea will intensify further because of the faster warming of waters of 20 degrees north."

The paper's release comes just days after China and the United States used the backdrop of the G20 leaders summit in east China's Hangzhou city to announce the world's two biggest carbon emitters would formally ratify the Paris climate agreement.

"Our response to climate change bears on the future of our people and the wellbeing of mankind," Xi Jinping, China's president, said.

This year is well on course to becoming the hottest year on record with preliminary data for August revealing yet another month with record-breaking warmth in a row.

The north-west Pacific basin has both the largest data set of super typhoon-strength storms and the clearest trend towards intensification as the planet warms, Steve Turton, an adjunct professor at the Central Queensland University, said.

This year has also been an active one for the region.

By contrast, the trends are not being replicated so far in the south-west Pacific, northeast of New Zealand and Australia.

"In the Australian region, it's pretty flat," Turton said. "We are not seeing any trends at all."

That outcome, though, is expected to change.

"With global warming of the oceans and atmosphere, we can expect tropical cyclones to increase in frequency and intensity in all the basins," Turton said.

Apart from the social and economic consequences of more intense storms, ecosystems such as forests are likely to suffer more destruction and take longer to recover or favour species more able to cope with disruption, he said.

For hilly regions, such as Hong Kong or elsewhere in the storm tracks, populated areas may become more exposed to landslides from the intensifying storms, he said.</s>China, Taiwan, Japan and the Koreas will experience more violent typhoons under climate change, said researchers Monday, presenting evidence for a recent rise in storm intensity caused by ocean warming.

Scientists have struggled to identify changes in the intensity and frequency of typhoons over the northwest Pacific ocean -- never mind trying to pinpoint a role for global warming.

Contradictory trends emerge from records such as the Joint Typhoon Warming Center and the Japan Meteorological Agency -- the two most widely-used data sets in typhoon research, according to the US-based study authors Wei Mei and Shang-Ping Xie.

They have now corrected the available data for differences in methodology and discovered a single, clear trend.

"Over the past 37 years, typhoons that strike east and southeast Asia have intensified by 12-15 percent," they wrote in the journal Nature Geoscience.

And the data showed this intensification, in turn, was linked to ocean surface warming -- possibly caused by climate change, though this is yet to be proven.

Projections for ocean warming if humans continue to emit planet-harming greenhouse gases, said the team, "suggest that typhoons striking eastern mainland China, Taiwan, Korea and Japan will intensify further.

"Given disproportionate damages by intense typhoons, this represents a heightened threat to people and properties in the region."

The human population in these coastal areas was growing fast, they pointed out, and sea levels were rising.

The world's nations concluded a pact in Paris last December to halt the march of climate change, which threatens stronger storms, longer droughts and land-gobbling sea-level rise.

This would be achieved by curbing the emission of heat-trapping gases from the use of fossil fuels.
A study concludes that typhoons in Asia are becoming stronger.