Tag Archives: flooding

Climate change is slowing down Europe’s storms, raising flooding risks

Europe should brace for more intense storms, new research reports, as climate change stands to power them up in the future.

Flooding in Sigonella, Sicily, Italy, in 2005. Image via Pixabay.

Intense, slow-moving rainstorms on the old continent will become more common in the future, according to experts at Newcastle University and the Met Office, UK. In absolute terms, we may see a 14-fold increase in their current frequency across dry land by the end of the century, they report. Such storms generally carry large amounts of precipitation which can cause extensive damage through flooding.

Slower storms tend to pose more of a risk because they dump precipitation on overall smaller areas, which means these are affected more strongly.

More of a bad thing

“With recent advances in supercomputer power, we now have pan-European climate simulations resolving the atmosphere in high detail as short-range weather forecasting models do,” explains lead author Dr. Abdullah Kahraman, of Newcastle University’s School of Engineering. “These models have grid spacing of approximately 2 km, which allows them to simulate storm systems much better, resulting in better representation of extremes”.

Although we’re already seeing flash floods across areas of Europe that traditionally never had to face them, such events will become even more common by the end of the century. Heating climate stands poised to make storms move slower over land, making them more likely to produce flooding through rainfall accumulation.

This, the team explains, is the first study to look at how the speed storms move at will be influenced by climate change. Most research regarding climate change and weather are focused on estimating the frequency and violence of freak or severe weather events to come.

“Using these state-of-the-art climate simulations, we have developed metrics to extract potential cases for heavy rainfall, and a smaller, almost-stationary subset of these cases with the potential for high rainfall accumulations. These metrics provide a holistic view of the problem, and help us understand which factors of the atmosphere contribute to heavy rainfall changes.

Since governments the world over have lagged behind on efforts to lower greenhouse gas emissions, there isn’t much we can do to avoid this increase in slow storms, according to the team. Under a RCP8.5 (business as usual) scenario, we can expect serious impacts throughout Europe, they add, from a combination of freak weather and more common storms, as well as the increase in slow-moving storms. The recent flooding seen in Germany and Belgium sadly underscores why such storms are dangerous to life and property, they add.

Europe itself is poorly suited to deal with slow-moving storms, as they are naturally very uncommon occurrences here, and generally confined to parts of the Mediterranean Sea. This means that predicting how they will evolve in the future, and which areas are likely to see the most of them, is vital to help people adapt and put systems in place to prevent loss of life due to flooding, as well as to limit the damage they can incur.

The paper “Quasi‐Stationary Intense Rainstorms Spread Across Europe Under Climate Change” has been published in the journal Geophysical Research Letters.

Changes in moon’s ‘wobble’ could cause record floods in 2030

High-tide flooding in Honolulu. Credit:  Hawaii Sea Grant King Tides Project.

The U.S. coastline can expect to see three to four times as many high-tide flood days each year during the 2030s. Normally, in such a situation, climate change is to blame (and truthfully, it will definitely contribute to some extent to floods in North America in the future), but this time we also have to look to the moon. According to a new study, in the mid-2030s, the moon will enter a tide-amplifying cycle that, when combined with global sea-level rise due to climate change, could cause troublesome higher-than-usual high tides.

The moon is held in place by Earth’s gravity. But just because it’s smaller — the moon only has about 1/100th the mass of Earth — that doesn’t mean that the moon doesn’t exert its own influence on Earth. The moon’s gravitational pull on the planet generates what’s called the tidal force, causing water in the oceans to bulge out on the side closest to the moon and the side farthest from the moon. These bulges are what we know as high tides.

Since the planet rotates, every region of Earth will pass through both of these bulges each day. When you’re in one of these bulges where the water wants to travel towards the moon, you experience a high tide. But when you’re outside the reach of these bulges, you experience a low tide.

It takes half a lunar day, on average 12 hours and 25 minutes, from one high tide to the next, so we have high and low tides nearly twice a day. The change from low to high tide is known as flood tide, while the change from high to low tide is called ebb tide

The tidal force causes water to bulge toward the moon and on the side opposite the moon. These bulges represent high tides. Credit: NOAA.

Since continents prevent the water in the ocean from perfectly following the moon’s pull, there will be some variation between high and low tide from place to place. It can range from almost no difference to over 16 meters (50 feet). As a result, water in the world’s oceans sloshes around like it would in an oddly shaped bathtub rather than in a smooth and even basin.

High tide (left) and low tide (right) in the Bay of Fundy in Canada. Image credit: Wikimedia Commons, Tttrung. Photo by Samuel Wantman.

Besides topography, tidal range can also be affected by the moon’s phase (when the sun and the moon are aligned, their gravitational pull combines to exert more influence on the ocean) and the wobble of the moon’s orbit.

Earth’s natural satellite has an elliptical orbit, leading to variation in the velocity at which it circles the planet and causing the “light side” to appear at slightly different angles throughout any given month. In other words, the moon “wobbles” similarly to a rocking ship at sea.

It does so in a rhythmic 18.6-year cycle. During the first half of the cycle, tidal forces are slightly suppressed, leading to lower high tides and higher low tides. During the other half of the cycle, the pattern is reversed, with higher high tides and lower low tides.

At the moment, we’re in the tide-amplifying part of the cycle. This phase will repeat itself in the mid-2030s. There’s nothing new about this wobble, first reported in 1728. But by this timeframe, scientists expect global sea levels to reach levels where higher tides can cause problems, according to a new study published in Nature Climate Change by researchers at NASA.

The researchers claim that during the next higher-than-usual high tide phase of the lunar cycle, American coastal cities could flood up to four times as often as they do now. These floods will sometimes occur in clusters lasting a month or longer, depending on the positions of the moon, Earth, and the sun.

“It’s the accumulated effect over time that will have an impact,” said Phil Thompson, an assistant professor at the University of Hawaii and the lead author of the new study.  “But if it floods 10 or 15 times a month, a business can’t keep operating with its parking lot under water. People lose their jobs because they can’t get to work. Seeping cesspools become a public health issue.”

According to the researchers, the higher sea levels amplified by the lunar cycle will cause frequent flooding in almost all U.S. coastlines, apart from far northern coastlines like Alaska.

The good news is that urban planners have ample time to prepare for the upcoming high tide floods.

“From a planning perspective, it’s important to know when we’ll see an increase,” said study co-author Ben Hamlington of NASA’s Jet Propulsion Laboratory in Southern California. “Understanding that all your events are clustered in a particular month, or you might have more severe flooding in the second half of a year than the first – that’s useful information.” A high-tide flood tool developed by Thompson already exists on the NASA team’s sea level portal, a resource for decision-makers and the general public. The flood tool will be updated in the near future with the findings from this study.

Flooding caused by climate change is costing the US billions every year

The climate crisis is costing the United States economy billions every year due to flooding alone, a new study by Standford University researchers showed. Rainfall contributed a third of the costs of flooding over the past three decades, totaling almost $75 billion of the estimated $199 billion.

Image credit: Flickr / Vilma

Flooding is considered by insurance companies the number-one natural threat in the US, even before wildfire and storm, with 14.6 million properties at substantial risk. The frequency and severity of the phenomenon are increasing as the climate crisis kicks in, with the floodplains expected to grow by 45% by the end of the century.

A growing amount of flooding is already happening in the US, especially in the Mississippi River Valley, Midwest, and Northeast, while coastal flooding has also doubled in a matter of decades, according to the Fourth National Climate Assessment, a 2017 report that looked at climate change in the US.

The Intergovernmental Panel on Climate Change (IPCC), a leading group of climate experts, said in a report in 2012 that climate change “has detectably influenced” several of the water-related variables that contribute to floods, such as rainfall and snowmelt. Still, connecting climate change with flooding and its costs hasn’t been an easy task.

Many factors can lead to a flood. There are weather events such as prolonged or heavy rains but also human-driven elements such as the way waterways are managed and the alterations done to the land. Growing urbanization, for example, adds impermeable surfaces such as pavement and alters natural drainage systems.

“The fact that extreme precipitation has been increasing and will likely increase in the future is well known, but what effect that has had on financial damages has been uncertain,” lead author Frances Davenport said in a statement. “Our analysis allows us to isolate how much of those changes in precipitation translate to changes in the cost of flooding, both now and in the future.”

Davenport and Standford University researchers combined high-resolution climate and economic data with advanced methods from economics to quantify the link between historical precipitation variation and historic flooding costs. They showed that climate change is largely to blame for the growing cost of flooding in the US.

The researchers developed a model based on observed precipitation and monthly reports of flood damage, controlling factors that might affect flooding costs like increases in home values. Then they calculated the change in extreme rain in each state and finally used the model to calculate the economic damages if the changes in extreme precipitation hadn’t happened.

When considering all the individual states, changes in rain patterns represented 36% of the flooding costs in the US from 1988 to 2017, according to the study. The effect of changing rain was primarily driven by increases in extreme precipitation, which have been responsible for the largest share of flooding costs historically.

“Previous studies have analyzed pieces of this puzzle, but this is the first study to combine rigorous economic analysis of the historical relationships between climate and flooding costs with really careful extreme event analyses in both historical observations and global climate models, across the whole United States,” said senior author Noah Diffenbaugh.

The researchers believe their findings have implications beyond flooding in the US. They believe it could be applied to other natural threats, to climate effects in different sectors of the economy, and to other regions of the planet, helping to understand the costs and benefits of climate change mitigation and adaptation.

The study was published in the journal PNAS.

The US Midwest readies for flooding as it copes with coronavirus outbreak

As it braces for the coronavirus outbreak, the US will soon have to add another concern to its list: flooding, likely exacerbated by climate heating.

Credit Wikipedia Commons

Up to 23 states are set to experience moderate to severe flooding in the spring, according to the National Oceanic and Atmospheric Administration (NOAA), with the central and southeastern regions of the country under the higher risk.

“Nearly every day, dangerous flooding occurs somewhere in the United States and widespread flooding is in the forecast for many states in the months ahead,” Ed Clark, director of NOAA’s National Water Center, said on a statement.

NOAA expects an ongoing rainfall, a highly-saturated soil and above-normal precipitations in the coming months, especially in the Mississippi River basin, the Missouri River basin and the Red River of the North.

Any substantial local rainfall could cause flooding in these areas, already experiencing a high level of soil moisture, according to NOAA’s projections, based on the assessment of a number of factors such as drought, soil moisture, and snowpack.

Aware of the upcoming challenge, a group of regional mayors has been working together to get ready for the flooding, also coordinating the federal agencies and Congress. But the coronavirus outbreak is making those plans more difficult, having to deal with several crisis situations at the same time.

“The current situation with COVID-19 presents us a fight on two fronts: one front, we have the ongoing coronavirus pandemic, and on the other, what promises to be a very active spring 2020 flood season,” Sharon Broome, mayor of Baton Rouge, Louisiana, told Buzzfeed News.

Flooding forecast issued by the NOAA.

Having to work on the two fronts simultaneously will be a gargantuan challenge for many states. But it will also be an opportunity to understand better the type of overlapping impacts that will get more common as the world gets warmer.

Human-induced global warming has increased the number, the frequency and the intensity of extreme weather events across the globe. In the US, it’s now more commons to see more intense rains and longer periods of warmer weather, according to the National Climate Assessment.

To anticipate the floods, states have been accumulating reserves of personal protective equipment for the first responders to floods, including masks, gloves and head coverings. Some districts have also started to distribute premade sandbags to vulnerable communities to avoid a last-minute crisis.

At the same time, the Red Cross will be working soon with local officials on plans to shelter people that will be eventually displaced by the flooding, hoping to relocate them to hotels and dorms. But doing so in the middle of a coronavirus outbreak will be tricky, as officials will have to ensure a proper distance between people.

Setting up a shelter will require to screen people for symptoms of COVID-19 before allowing them access, getting their temperatures checked, for example. Those that exhibit symptoms would have to be isolated from the rest, Trevor Riggen, senior vice president of disaster cycle services at the American Red Cross, told BuzzFeed.

The COVID-19 pandemic is shaping up to be one of the most pressing challenges the country has faced in peacetime. Any additional pressure could prove absolutely devastating unless serious prevention and preparation measures are taken.

Careful preparation is more important than ever, as is staying calm and focused, authorities warn.

“I feel like more than anything, we’re just trying to keep our people in some state of calm as we daily put out these bleak circumstances, these bleak numbers,” said Belinda Constant, mayor of Gretna, Louisiana. “We’re just praying every day that we don’t end up in a state of anarchy.”

Losing mangroves would increase flood damages by $65 million, study claims

Climate change is bringing a long list of consequences around the world, with sea-level rise as one of the most significant ones. A higher level of the oceans can cause coastal flooding, which means billions to deal with flood damages.

The inconspicuous mangrove might be a priceless ally in this issue, more than paying for themselves in environmental services.

Credit Wikipedia Commons

Mangrove forests can reduce flooding to a tremendous extent. Without them, flood damages would increase by 65 billion dollars per year, according to a new study.

“Mangroves provide incredibly effective natural defenses, reducing flood risk and damages,” said in a statement Pelayo Menéndez, a postdoctoral fellow in the Institute of Marine Sciences at UC Santa Cruz and first author of the paper.

Menéndez and his colleagues were able to appraise the economic value of mangrove forests for flood risk reduction across more than 700,000 kilometers of coastline worldwide. They used economic models and engineering, identifying when, where and how mangroves reduced flooding.

Losing mangroves would mean that 15 million more people would be flooded annually across the globe, according to the study. Mangroves can reduce waves and storm surges, also serving as the first line of defense against flooding and erosion, the researchers argued.

“Now that we can value these flood protection benefits, it opens all kinds of new opportunities to fund mangrove conservation and restoration with savings for insurance premiums, storm rebuilding, climate adaptation, and community development,” said coauthor Michael Beck.

The US, China, India and Mexico receive the greatest economic benefits from mangroves, according to the study, while Vietnam, India and Bangladesh get the largest benefits in terms of people protected. Many coastal stretches near cities get more than 250 million per year in flood protection benefits from mangroves.

There are mangrove forests in more than 100 countries but they are increasingly challenged and destroyed by aquaculture and coastal development. The mangrove-covered surface has declined globally from 139,777 square km in 2000 to 131,931 square km in 2014. Losing them can increase coastal risk, especially in developed areas with exposure to the coastal populations.

The good news is that mangroves can easily be restored to avoid damages from coastal flooding, the study showed. The forests are resilient and there are many projects in place across the globe to restore them.

“They can grow like weeds, even around cities, if we give them a chance,” Beck said. Except these ‘weeds’ can save billions of dollars and help millions of people

The next step for the researchers will be to use the data to reduce risks and increase mangrove conservation. That’s why they are already working with the World Bank, insurance companies and conservation groups. “This study helps demonstrate the importance of conserving mangroves where they exist today,” they argued.

Previous studies have also looked at the benefits of mangroves and reached similar conclusions. The World Bank estimated in 2018 that if mangroves were lost 18 million more people would be flooded every year, increasing damages to property by 16%.

The study was published in Scientific Reports.

More problems in Texas — Chemical plants start leaking after Harvey

Things are not getting much better in Texas.

Harvey struck Texas with biblical force. Image credits: Brant Kelly.

Everything is bigger in Texas — the cars, the floods, the chemical plants. Unfortunately, the last two make an unfortunate couple. Following the dramatic effects of Hurricane Harvey, at least 25 plants have been completely shut down or at least experienced some kind of technical problem. These problems are not only costing a lot of people a lot of money, but they’re now putting communities at risk.

Air pollution

Since Harvey started taking its toll, refineries and chemical plants have reported more than 2,700 tons (5.4m pounds) of extra air pollution; a figure that’s growing by the hour. This happened due to the direct damage caused by the hurricane, as well as the shutting down process, which causes a spike in the emissions. This led to air pollution rising way above the usual levels (which were already too high), and Texas is experiencing one of its worst smogs in history.

Take the Chevron Phillips Chemical plant in Sweeny, Texas, for instance. Through its shut down alone, it accounted for more than 100,000 pounds of carbon monoxide, 22,000 pounds of nitrogen oxide, 32,000 pounds of ethylene, and 11,000 pounds of propane, according to the to the Texas Commission on Environmental Quality (TCEQ). Another Chevron facility in Cedar Bayou reported comparable figures. But it gets even worse.

According to a report by the Center for Biological Diversity, a cocktail of nearly 1m pounds of particularly harmful substances such as benzene, hexane, sulfur dioxide, butadiene, and xylene have been emitted by over 60 petroleum facilities, most of them operated by ExxonMobil, Shell, and Chevron.

Worse than ever

Chester awaits evacuation from his ravaged neighborhood near Rockport, Texas. Harvey has hurt humans and animals alike. Image credits: Glenn Fawcett.

Houston is no stranger to bad air quality. Ever since the Clean Air Act was introduced in 1970, Houston never met the national air quality standards. However, this is different — and much worse.

“It’s a really serious public health crisis from the pollution and other impacts people are facing,” said Bakeyah Nelson, executive director of Air Alliance Houston.

“Communities in close proximity to these facilities will get the worst of it, as they get the worst of it on a daily basis. There’s also the acute danger of one of these facilities exploding in neighbourhoods where storage tanks are adjacent to people’s back yards. It’s a very real threat and it’s a very precarious situation.”

Many people have already reported “unbearable petrochemical smells” for almost a week now, though the TCEQ has not indicated that these leaks can cause significant health hazards. In all truth though, the TCEQ website doesn’t even offer guidance for storm-related emissions.

The real figures might even be higher than this — though they might also be lower. TCEQ Media Relations Manager Andrea Miller told New Republic that companies are likely over-reporting emissions since underestimating them would lead to massive fines. But not everyone is convinced. Daniel Cohan, an air pollution expert at Rice University, said emissions are possibly much higher than what’s being floated around, and this places communities at great risks. In the short run, exposure can cause problems such as muscle weakness, nausea, and gastrointestinal issues. Prolonged exposure to the chemicals heightens the risk of cancer, so this should not be treated lightly.

“The emissions could be many times higher,” he said. “A lot of the risks for carcinogens and neurotoxins come following exposure for a long time but the immediate concern is that people in the neighborhoods around the plants, a lot of low-income Hispanic communities, will suffer itchy eyes and throat complaints. The air will be unpleasant to breathe.”

“It’s concerning how state policies allow enormous amounts of pollution during shut down and start up periods. I hope the next few days are the worst of it.”

The main issue here is the sheer number of plants in Texas. Petrochemical plants are not cars — it’s not as easy as turning a key and restarting them, it’s a complex process. However, the fact that plants were allowed to operate so close to residential areas in the first place also doesn’t help, and Houston’s lack of zoning regulations certainly didn’t help. Perhaps, after the waters calm down in Texas, it would be a good time to revise some of those regulations.