Breathing Highways and Sponge Cities

The Great Change: Breathing Highways and Sponge Cities

During the 20th Century, the rate of global warming was twice as fast in Taiwan (1.7°C) as for the world as a whole (0.74°C). Partly as a result, the number of days with rainfall decreased dramatically and typhoons gained strength. In 2009, Typhoon Morakot dropped over 1,000 mm (39.4 inches) in a single day and caused the loss of 699 lives. A massive mudslide wiped out Xiaolin Village and 474 people were buried alive. In 2015, Typhoon Soudelor left similar damage. It took months to repair the roads.

Then Taiwan and East China were struck by Dujuan, known in the Philippines as Typhoon Jenny, a killer storm and the thirteenth typhoon of the 2015 Pacific typhoon season. Eight months later, Nepartak became the third most intense tropical cyclone on record with 114 deaths and more than $1.5 billion damage in Taiwan and East China. September brought Meranti, a super typhoon and the strongest ever to make landfall in China in more than 1000 years of records. Meranti’s peak sustained winds tied the record set by Haiyan in 2013, 195 mph (315 km/h), comparable to a tornado, or a Category 5 hurricane on the Saffir-Simpson scale. In Taiwan, nearly 1 million households lost power and 720,000 lost water supplies. Flooding in Zhejiang took 902 homes and affected 1.5 million people.

Between those punctuations, the erratic weather brought long droughts. New Taipei City had to enforce water restrictions when the Shihmen reservoir went dry in April. All cities along coasts or rivers have engineered means to remove excess water and to prevent flooding. Few have the means to sustain themselves in severe droughts. Read More

Act now to protect millions from floods — study

When we think of climate catastrophes, flooding is pretty high on the list of nightmare scenarios. But it's not just rising sea levels that are threatening communities with inundation: New research shows that ever more of us are at risk from rivers bursting their banks.
As the global temperature rises, water evaporates into the air, humidity increases, clouds form — and what goes up must come down. It's among the laws of physics: Warmer air holds more moisture, meaning bigger clouds that can travel further, resulting in even more extreme storms.
Since the mid-1980s, climate scientists have recorded a 20 percent increase in record-breaking rainfall around the world — with devastating consequences.
In 2017, flooding across India, Bangladesh and Nepal affected 40 million people, and more than 1,200 died. In flooding in Sierra Leone, more than 1,100 people perished. As Peru recorded 10 times the normal level of rainfall, hundreds of thousands of people were displaced and at least 70 killed.
To round out the inventory of flooding's impact for last year, lives were also lost to flooding in China, the Philippines, Italy, and Vietnam, among other locations.
And 2018 has carried the trend forward. This week, at least 17 people were killed as dramatic storms swept California. Roads looked like rivers and homes were destroyed.

(http://www.dw.com/en/act-now-to-protect-millions-from-floods-study/a-42110153

Global warming made Hurricane Harvey deadly rains three times more likely, research reveals

Global warming made Hurricane Harvey deadly rains three times more likely, research reveals | US news | The Guardian

Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding in Houston in August, was made three times more likely by climate change, new research has found.

Such a downpour was a very rare event, scientists said, but global warming meant it was 15% more intense. The storm left 80 people dead and 800,000 in need of assistance.

The scientists from the World Weather Attribution (WWA) initiative usually publish their assessments of the role of climate change in extreme weather events around the world as soon as possible. However, in this case they waited for the work to be confirmed by peer review because of the current US government’s opposition to strong action on climate change.

The researchers said their new work shows global warming is making extreme weather events worse right now and in the US. The cost of the damage caused by Hurricane Harvey has been estimated at $190bn (£140bn), which would make it the most costly weather disaster in US history, more than Hurricanes Katrina and Sandy combined.

A series of new reports have found that extreme heatwaves, droughts, floods, storms and wildfires across the planet have been made more likely or more intense by rising global temperatures. The UK’s Energy and Climate Intelligence Unit (ECIU) analysed 59 studies of the influence of climate change on extreme weather published in the last two years and found warming has made matters worse in 70% of cases and better in just 7%. https://goo.gl/otTj6y

The House of the Future Is Elevated

Three months after Hurricane Harvey churned through Texas, dumping 51 inches of rain and damaging an estimated 150,000 homes, the state’s most populous county took a bureaucratic step that has huge implications for how it will deal with the risk of future flooding.

On December 5, Harris County, which surrounds the City of Houston, approved an overhaul of its flood rules, expanding them from 100-year floodplains—which have a 1 percent change of flooding in a given year—to 500-year floodplains. The new rules (which don’t apply inside Houston city limits) will compel people building houses in some areas to elevate them up to eight feet higher than before.

“We had 30,000 houses that flooded” from Harvey, said John Blount, the county engineer, who put forward the rule changes. Before the floodwaters even subsided, hundreds of county employees fanned out to survey the damage. “We went to every one of those houses and figured out how much water got in them, and then we did a statistical analysis,” Blount said.

The data was geocoded, factoring in location and neighborhood conditions, and one result was the increased elevation rule. (The county is also buying out 200 of the most vulnerable homes and hopes to buy out thousands more, but those represent a small fraction of the homes inside the floodplain.)

Harris County’s new rules are the most stringent flood-related development restrictions anywhere in the United States, according to Blount. If a future Harvey-sized deluge comes, almost all the homes in the area will be safe, he said: “Had that same event happened, at the same location but [with houses] built to the new standard, 95 percent or more would not have flooded.”

For a structure, standing water is a fearsome enemy. Even a small amount of flooding in a home can exile its inhabitants for weeks and require costly repairs. After Harvey, tens of thousands of evacuees lived in hotels or with friends as workers in their homes tore out drywall to prevent the spread of mold, which can sicken residents. And more Harveys are coming: As my colleague Robinson Meyer reported, a new MIT study concludes that Harvey-scale flooding in Texas is six times as likely now as it was in the late 20th century, and will only get more likely as this century wears on. More

How to Build a City That Doesn’t Flood? Turn it Into a Sponge

The number of ​cities around ​the world is ​growing quickly.​ In her book,​ ​ Replenish: ​The Virtuous ​Cycle of Water ​and Prosperity ​ , Sandra ​Postel, the ​director of the ​Global Water ​Policy Project, ​reports that ​over the past ​35 years, the ​number of ​cities in China ​alone has ​climbed from ​193 to 653.​ ​As urban and ​suburban areas ​expand , the ​stormwater ​runoff problems ​will grow as ​well. ​

But now ​there’s a ​movement around ​the world to ​build smarter ​and “​spongier” ​cities that can ​absorb ​rainwater ​instead of ​letting it flow ​through miles ​of pavement and ​cause damaging ​floods. ​From Iowa to ​Vermont and ​from San ​Francisco to ​Chicago , urban ​infrastructure ​is getting a ​reboot. ​

Creating ​better ​stormwater ​management ​systems ​requires using ​green ​infrastructure ​elements in ​urban planning ​and restoring ​some of the ​rain-retention ​capacity that ​cities have ​lost to ​urbanization. ​These elements ​can be roughly ​broken into two ​categories: the ​man-made ​engineered ​replacements of ​the natural ​water pathways ​and the ​restorations of ​the original ​water routes ​that existed ​before a city ​was developed. ​

Man-Made ​Solutions: Rain ​Gardens, ​Bioswales, and ​Porous ​Pavements ​

Traditional ​road construction,​ made with ​asphalt, gravel ​and sand, is a ​very compacted ​structure that ​leaves little ​space between ​the particulates,​ and thus no ​room for the ​rainwater to ​seep through. ​In the ​construction ​industry that ​gap measure is ​described by ​the term “​air void,”​ which is ​typically set ​at four percent ​for the ​traditional ​pavement mix, ​says Richard ​Willis, ​Director of ​Pavement ​Engineering and ​Innovation at ​National ​Asphalt ​Pavement ​Association. ​More

Super Typhoon Haiyan

On November 8, the devastating Super Typhoon Haiyan came ashore in the Philippines, killing more than 2,000 people, displacing 660,000 more, and impacting nearly 10 million throughout the islands. Those who have been affected are now struggling to survive without access to power, food, shelter or clean drinking water. The storm is being described by disaster management experts as one of the most intense and strongest of its kind to make landfall. On November 11, Yeb Sano, the Philippines' delegate at the United Nations Framework Convention on Climate Change now underway in Poland spoke out powerfully and poignantly, saying: "To anyone who continues to deny the reality that is climate change, I dare you to get off your ivory tower and away from the comfort of your armchair. I dare you to go to the islands of the Pacific, the islands of the Caribbean and the islands of the Indian Ocean and see the impacts of rising sea levels ... to the hills of Central America that confront similar monstrous hurricanes, to the vast savannas of Africa where climate change has likewise become a matter of life and death as food and water becomes scarce ... And if that is not enough, you may want to pay a visit to the Philippines right now." To underscore the urgency of the situation, Sano has chosen to fast until the UN makes real progress on a plan for action to solve the climate crisis. Our hearts and thoughts go out to everyone who has been impacted by this terrible event. Some of our own Climate Reality Leaders are among those affected by the devastation, and I hope you'll join me in keeping them in your thoughts as we wait for more news. Although the full extent to which climate change influenced Super Typhoon Haiyan has not yet been determined, the storm is another reminder of how climate change has already made extreme weather more extreme. This horrific example of dirty weather shows just how critical your work to put a market price on carbon and a political price on denial is. There are other and equally important ways for us all to help right away. By joining the relief effort, you can help provide immediate assistance to those impacted by the typhoon and now living with its aftermath. Please contact the Philippine Red Cross, Team Rubicon, or UNICEF to donate and find out about other ways to help. The Climate Reality Project family

©2012 THE CLIMATE REALITY PROJECT. ALL RIGHTS RESERVED.

 

Top 10 cities most at risk of natural disaster

Earthquakes, Floods, Storms, Tsunamis, Etc...

All the natural disasters in the news lately made us wonder what parts of the world were most threatened by things like floods & earthquakes. Massive reinsurer Swiss Re (a reinsurance company sells insurance to insurance companies, allowing them to offload some risks...) has a new report titled "Mind the risk: A global ranking of cities under threat from natural disasters" (pdf) that sheds some light on exactly that. Using their sophisticated modelling software and huge database of past events, they came up with a probabilistic ranking.

There are all kinds of ways to look at the data, but here are some of the most interesting variations.

Swiss Re/Screen capture

There are all kinds of ways to look at the data, but here are some of the most interesting variations.

 

Swiss Re/Screen capture

The list changes a bit if we look at it by "working days lost". More European and US cities appear on the top 10.

If we look at just earthquake risk, this is what the top 10 looks like for both people affected and working days lost: More

 

Northeast Pakistan hit by 'surprise' floods, as monsoon rains intensify

SIALKOT, Pakistan (Thomson Reuters Foundation) - “We kept quivering with fear the whole night and could not sleep even a wink,” recalled Salma Zehra, a mother of five teenage children. The family trembled to think that the roof of their mud house could cave in at any time, as the rain lashed down in a huge thunderstorm.

Mehtabpur, District Sialkot, Pakistan

By early morning on July 22, the house in Mehtabpur village in northeast Pakistan’s Sialkot district was waist-deep in water. The torrential downpour had left Zehra’s two buffaloes dead, the 45-year-old said in a shaky voice.

Another bout of heavy rain followed later that night. The Dek tributary of the Chenab River in Sialkot, 192 km (122 miles) from Islamabad, burst its banks, submerging more than 72 villages in the district.

Besides Sialkot, other districts in Punjab province have also suffered massive damage to crops across 1,000 hectares of land, as well as to properties. According to the district disaster management authorities of Sialkot, Gujranwala and Narowal, an estimated 400 villages have been flooded.

Officials have declined to give final figures for the losses, but say dozens have died and thousands of people remain stranded in the affected parts of the three districts. Some are starting to return home, but many houses have collapsed and must be rebuilt, they report.

Sialkot District Coordination Officer Iftikhar Ali Sahu told Thomson Reuters Foundation thousands of people had been trapped on the roofs of their houses during the worst of the flooding. “Mortality among cattle is high - the number of dead animals continued to rise as the floodwaters began to recede on July 26,” he added.

The situation in adjoining districts is just as bad. In Narowal alone, around 2,000 people were marooned on their rooftops in some seven villages a week ago.

Less than 30 percent of the floodwater has yet to recede, according to Mujahid Sherdil, director-general of the Punjab Provincial Disaster Management Authority.

Machines have been brought in to help drain water out of the flood-affected areas, and he hopes the task will be accomplished in the next two to three days, he told Thomson Reuters Foundation from Lahore.

Sherdil said the torrential rainfall had caused breaches of irrigation canals, streams and natural dams, and the floods had washed away crops, livestock, roads, bridges, buildings and even entire villages.

Farmers say surviving cattle in flood-hit areas are now at risk.

“Besides paddy, maize and vegetable crops, fodder fields are also underwater. This has created an acute shortage of fodder, and it is barely possible to save our cattle from the looming threat of hunger and disease,” said Zehra’s husband, Ghulam Abbas.

METEOROLOGISTS ‘STARTLED’

The above-normal monsoon rains in Punjab’s northeastern districts have taken weather experts by surprise.

“Last month, we predicted that this year monsoon rains across the country would remain normal with no possibility of flooding. But unexpected heavy rains in the northeastern districts are startling for us,” said Ghulam Rasul, a senior weather scientist at the Pakistan Meteorological Department (PMD) in Islamabad. “This shows how monsoon rains have become erratic and unpredictable in timing, volume and intensity.”

Sherdil, head of the Punjab disaster management agency, said the heavy rains and flooding had caught them unprepared.

“We were closely following the weekly and monthly forecasts of PMD that never predicted heavy rains of unprecedented significance for July in northeastern parts, which have been nearly 40 percent above normal for the month,” he said.

It has been difficult to get aid into the affected areas due to damaged and flooded roads and bridges, he said. “Nevertheless, we left no stone unturned to get the emergency relief items including food, medicines, to the flood victims on boats – although (they arrived) a bit late,” he added.

MONSOON SHIFTS

In June 2012, scientists argued in the Nature Climate Change journal that global warming would make understanding changes in the South Asian monsoon more difficult.

They said the impacts of short- and long-term monsoon shifts would affect the lives of over a billion people in the region, who rely on rainfall for agriculture, hydropower generation, economic growth and basic human needs.

Understanding how the South Asian monsoon will alter due to climate change is necessary to cope with the effects, reduce the risk of disasters and safeguard people’s livelihoods, they underlined.

“Addressing the uncertainties in projected changes of the monsoon variability in coming years will remain a daunting challenge for climate scientists,” said Arshad Abbasi, a water and energy expert at the Sustainable Development Policy Institute in Islamabad.

Arshad Khan, the executive director of the Global Change Impact Study Centre (GCISC), the research arm of Pakistan’s Federal Climate Change Division, said the country is in the grip of unpredictable weather patterns.

Intense monsoon rains will be a common phenomenon, particularly on the country’s southern plains which lack water reservoirs and are highly vulnerable to floods, he warned.

And a spurt in the speed of glacial melt, due to rising global temperatures and above-normal monsoon rains, is likely to cause rivers to overflow and burst their banks across the country, he added.

GOVERNMENT EFFORTS

Officials at the Climate Change Division, which operates under the oversight of the prime minister, said efforts are underway to tackle the vagaries of climate change across different sectors of the economy, particularly agriculture and water.

“Consultations are being made with national and provincial disaster management authorities, and officials of federal and provincial environment, agriculture, irrigation departments to implement national climate change policy to mitigate the impacts of changing weather patterns and erratic monsoon rains,” said a senior official, who coordinates policy at federal and provincial levels.

The Climate Change Division is developing climate adaptation plans for the agriculture, water and irrigation sectors, which will be implemented in Pakistan’s four provinces in collaboration with international NGOs and provincial government offices.

It is also working on programmes to ensure that climate change is considered in other sectors such as health and education, to make them more climate-resilient.

Abbasi of the Sustainable Development Policy Institute said the best ways to avert the growing threat of floods in Pakistan include efficient watershed management, reforestation in northern mountain areas and the revival of riverine forests.

Saleem Shaikh and Sughra Tunio are Islamabad-based journalists specialising in climate change and development issues. More

Global Warming May Shift Summer Weather Patterns

By altering the heat balance between land and sea, manmade global warming may be altering summer weather patterns in the Northern Hemisphere, a new study found.

The study, published on Sept. 30 in Nature Geoscience, shows that the sprawling high pressure areas that set up shop over the Western North Atlantic and North Pacific Oceans during the summer months have become larger and stronger during the past 40 years, and these trends are likely to continue during the next several decades as temperatures increase.

These changing weather patterns could have far-reaching impacts, from redirecting powerful hurricanes toward the East Coast, to making the Southeast and Central states see-saw more frequently between extremely hot and dry summers and cooler, wetter summers. In addition, a shift in the strength and shape of the North Pacific subtropical high could affect the South Asian Monsoon, which is already being altered by warming and increased regional pollution.

The study does not formally attribute the cause of the recent trends, but says that the future changes will most likely be driven by global warming.

Although highs (the big "H" symbols on your local TV weathercast) are typically associated with pleasant weather, the position and shape of these systems shape large-scale weather patterns, helping to determine the locations of subtropical deserts. More importantly for the U.S., they help steer the most powerful storms on Earth, and modulate rainfall amounts in the Central, Southeast, and Mid-Atlantic states.

The Atlantic subtropical high, more commonly known as the “Bermuda High” because of its semi-permanent location near that Western Atlantic island during the summer months, helps determine whether Atlantic hurricanes recurve harmlessly out to sea before reaching the East Coast, or make landfall with potentially devastating impacts.

Hurricanes tend to skirt around the edges of the high by catching a ride on the clockwise flow of air around the periphery.

The Bermuda High also helps draw warm and humid air up the Eastern seaboard, contributing to some of the most intense heatwaves on record.

The study, which relies on climate model simulations as well as weather data for the past 40 years, shows that the Bermuda High has already expanded westward, which could be making summertime rainfall in the Central and Southeast U.S. much more variable. More