Thursday, August 26, 2021

 

Forget massive seawalls, coastal wetlands offer the best storm protection money can buy

shutterstock.
Robert Costanza, Crawford School of Public Policy, Australian National University

Coastal communities around the world are facing increasing threats from tropical cyclones. Climate change is causing rising sea levels and bigger, more frequent storms.

Many coastal communities are pondering what to do. Should they build massive seawalls in a bid to protect existing infrastructure? Do they give up on their current coastal locations and retreat inland? Or is there another way?

In the US, the US Army Corps of Engineers has proposed building a 20-foot high giant seawall to protect Miami, the third most populous metropolis on the US east coast. The US$6 billion proposal is tentative and at least five years off, but sure to be among many proposals in the coming years to protect coastal communities from storms.


Read more: A 20-foot sea wall won’t save Miami – how living structures can help protect the coast and keep the paradise vibe


But seawalls are expensive to build, require constant maintenance and provide limited protection.

Consider China, which already has a huge number of seawalls built for storm protection. A 2019 study analysed the impact of 127 storms on China between 1989 and 2016.

Coastal wetlands were far more cost effective in preventing storm damages. They also provided many other ecosystem services that seawalls do not.

How wetlands reduce storm effects

Coastal wetlands reduce the damaging effects of tropical cyclones on coastal communities by absorbing storm energy in ways that neither solid land nor open water can.

The mechanisms involved include decreasing the area of open water (fetch) for wind to form waves, increasing drag on water motion and hence the amplitude of a storm surge, reducing direct wind effects on the water surface, and directly absorbing wave energy.

Wetland vegetation contributes by decreasing surges and waves and maintaining shallow water depths that have the same effect. Wetlands also reduce flood damages by absorbing flood waters caused by rain and moderating their effects on built-up areas.

Coastal wetlands can absorb storm energy in ways neither solid land nor open water can.
Coastal wetlands can absorb storm energy in ways neither solid land nor open water can. Shutterstock

In 2008 I and colleagues estimated coastal wetlands in the US provided storm protection services worth US$23 billion a year.

Our new study estimates the global value of coastal wetlands to storm protection services is US$450 billion a year (calculated at 2015 value) with 4,600 lives saved annually.

To make this calculation, we used the records of more than 1,000 tropical cyclones since 1902 that caused property damage and/or human casualties in 71 countries. Our study took advantage of improved storm tracking, better global land-use mapping and damage-assessment databases, along with improved computational capabilities to model the relationships between coastal wetlands and avoided damages and deaths from tropical cyclones.

The 40 million hectares of coastal wetlands in storm-prone areas provided an average of US$11,000 per hectare a year in avoided storm damages.


Read more: Rising seas allow coastal wetlands to store more carbon


Pacific nations benefit most

The degree to which coastal wetlands provide storm protection varies between countries (and within countries). Key factors are storm probability, amount of built infrastructure in storm-prone areas, if wetlands are in storm-prone areas, and coastal conditions.

The top five countries in terms of annual avoided damages (all in 2015 US dollar values) are the United States (US$200 billion), China (US$157 billion), the Philippines (US$47 billion), Japan (US$24 billion) and Mexico (US$15 billion).

In terms of lives saved annually, the top five are: China (1,309); the Philippines (976); the United States (469)l India (414); and Bangladesh (360).

Floodwaters inundate Manila suburbs in November 2020 following Typhoon Vamco.
Floodwaters inundate Manila suburbs in November 2020 following Typhoon Vamco. Ace Morandante/Malacanang Presidential Photographers Division/AP

Other ecosystem services

Coastal wetlands also provide other valuable ecosystem services. They provide nursery habitat for many commercially important marine species, recreational opportunities, carbon sequestration, management of sediment and nutrient run-off, and many other valuable services.

In 2014 I and colleagues estimated the value of other ecosystem services provided by wetlands (over and above storm protection) at about $US 135,000 a hectare a year.

But land-use changes, including the loss of coastal wetlands, has been eroding both services. Since 1900 the world has lost up to 70% of its wetlands (Davidson, 2014).

Preserving and restoring coastal wetlands is a very cost-effective strategy for society, and can significantly increase well-being for humans and the rest of nature.

With the frequency and intensity of tropical cyclones and other extreme weather events projected to further increase, the value of coastal wetlands will increase in the future. This justifies investing much more in their conservation and restoration.The Conversation

Robert Costanza, Professor and VC's Chair, Crawford School of Public Policy, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 

Next Up: Toilets? 

And a bit of good news.

Thursday, August 19, 2021

 

You may have heard the ‘moon wobble’ will intensify coastal floods. Well, here’s what that means for Australia

Shutterstock
Mark Gibbs, Australian Institute of Marine Science

Extreme floods this month have been crippling cities worldwide. This week in China’s Henan province, a year’s worth of rain fell in just three days. Last week, catastrophic floods swept across western Germany and parts of Belgium. And at home, rain fell in Perth for 17 days straight, making it the city’s wettest July in 20 years.

But torrential rain isn’t the only cause of floods. Many coastal towns and cities in Australia would already be familiar with what are known as “nuisance” floods, which occur during some high tides.

A recent study from NASA and the University of Hawaii suggests even nuisance floods are set to get worse in the mid-2030s as the moon’s orbit begins another phase, combined with rising sea levels from climate change.

The study was conducted in the US. But what do its findings mean for the vast lengths of coastlines in Australia and the people who live there?

A triple whammy

We know average sea levels are rising from climate change, and we know small rises in average sea levels amplify flooding during storms. From the perspective of coastal communities, it’s not if a major flood will occur, it’s when the next one will arrive, and the next one after that.

But we know from historical and paleontological records of flooding events that in many, if not most, cases the coastal flooding we’ve directly experienced in our lifetimes are simply the entrĂ©e in terms of what will occur in future.

Flooding is especially severe when a storm coincides with a high tide. And this is where NASA and the University of Hawaii’s new research identified a further threat.

Researchers looked at the amplification phase of the natural 18.6-year cycle of the “wobble” in the moon’s orbit, first identified in 1728.

The orbit of the moon around the sun is not quite on a flat plane (planar); the actual orbit oscillates up and down a bit. Think of a spinning plate on a stick — the plate spins, but also wobbles up and down.


Read more: Predators, prey and moonlight singing: how phases of the Moon affect native wildlife


When the moon is at particular parts of its wobbling orbit, it pulls on the water in the oceans a bit more. This means for some years during the 18.6-year cycle, some high tides are higher than they would have otherwise been.

This results in increases to daily tidal rises, and this, in turn, will exacerbate coastal flooding, whether it be nuisance flooding in vulnerable areas, or magnified flooding during a storm.

View of Earth from the Moon
The moon’s orbit isn’t on a flat plane. It oscillates up and down, like a plate would when it spins on a stick. Shutterstock

A major wobble amplification phase will occur in the mid-2030s, when climate change will make the problem become severe in some cases.

The triple whammy of the wobble in the moon’s orbit, ongoing upwards creep in sea levels from ocean warming, and more intense storms associated with climate change, will bring the impacts of sea-level rise earlier than previously expected — in many locations around the world. This includes in Australia.

So what will happen in Australia?

The locations in Australia where tides have the largest range, and will be most impacted by the wobble, aren’t close to the major population centres. Australia’s largest tides are close to Broad Sound, near Hay Point in central Queensland, and Derby in the Kimberley region of Western Australia.

However, many Australian cities host suburbs that routinely flood during larger high tides. Near my home in Meanjin (Brisbane), the ocean regularly backs up through the storm water drainage system during large high tides. At times, even getting from the front door to the street can be challenging.

Derby, WA, has one of the biggest tidal ranges in Australia. Shutterstock

Some bayside suburbs in Melbourne are also already exposed to nuisance flooding. But a number of others that are not presently exposed may also become more vulnerable from the combined influence of the moon wobble and climate change — even when the weather is calm. High tide during this lunar phase, occurring during a major rainfall event, will result in even greater risk.


Read more: High-tide flood risk is accelerating, putting coastal economies at risk


In high-income nations like Australia, sea-level rise means increasing unaffordability of insurance for coastal homes, followed by an inability to seek insurance cover at all and, ultimately, reductions in asset values for those unable or unwilling to adapt.

The prognosis for lower-income coastal communities that aren’t able to adapt to sea-level rise is clear: increasingly frequent and intense flooding will make many aspects of daily life difficult to sustain. In particular, movement around the community will be challenging, homes will often be inundated, unhealthy and untenable, and the provision of basic services problematic.

What do we do about it?

While our hearts and minds continue to be occupied by the pandemic, threats from climate change to our ongoing standard of living, or even future viability on this planet, haven’t slowed. We can pretend to ignore what is happening and what is increasingly unstoppable, or we can proactively manage the increasing threat.

Some coastal communities, such as in Melbourne’s bayside suburbs, may experience flooding, even if they never have before. Shutterstock

Thankfully, approaches to adapting the built and natural environment to sea-level rise are increasingly being applied around the world. Many major cities have already embarked on major coastal adaptation programs – think London, New York, Rotterdam, and our own Gold Coast.

However, the uptake continues to lag behind the threat. And one of the big challenges is to incentivise coastal adaptation without overly impacting private property rights.


Read more: For flood-prone cities, seawalls raise as many questions as they answer


Perhaps the best approach to learning to live with water is led by the Netherlands. Rather than relocating entire communities or constructing large barriers like sea walls, this nation is finding ways to reduce the overall impact of flooding. This includes more resilient building design or reducing urban development in specific flood retention basins. This means flooding can occur without damaging infrastructure.

There are lessons here. Australia’s adaptation discussions have often focused on finding the least worst choice between constructing large seawalls or moving entire communities — neither of which are often palatable. This leads to inaction, as both options aren’t often politically acceptable.

The seas are inexorably creeping higher and higher. Once thought to be a problem for our grandchildren, it is becoming increasingly evident this is a challenge for the here and now. The recently released research confirms this conclusion.


Read more: King tides and rising seas are predictable, and we're not doing enough about it The Conversation


Mark Gibbs, Principal Engineer: Reef Restoration, Australian Institute of Marine Science

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Saturday, August 14, 2021

Let’s talk about Elephants

 

An African Elephant from the Ndutu region which adjoins the Serengeti Plain
-Thanks to the unknown photographer



Thought we needed a break from climate and weather related phenomena, so yesterday being World Elephant Day, perhaps we should talk a bit about these (mostly) gentle giants. Sadly, as with most other species we've been talking about elephants have also been experiencing rapid decline. A huge survey in 2016 found that there were less than 400,000 African Elephants left and they had declined by 30% in just seven years. The Asian Elephant has fared even worse with only 30,000 remaining and the smaller, more elusive Forest Elephant which lives in South East Asia now has such low numbers that it's considered critically endangered. According to the World Wildlife Fund, 96 elephants a day are being killed by poachers and usually only for their tusks.

Besides being the biggest mammals in the world – with the African Bush Elephant standing around 3.96 m (13 ft) high and weighing in at over ten tonnes, elephants have a number of other remarkable attributes such as their ability  to communicate through seismic communication and infrasound and the fact that they display a number of traits which we associate with humans such as a sense of self -awareness and the capacity to feel empathy.  You can read more about them here or here. Afterwards you could take the IFAW Quiz to see how well you know your elephants. My main focus today though is on some of the good things happening around Elephant Conservation.

 

Indian Elephants - Can you spot the difference? Do the IFAW Quiz and find out.


-Thanks to the unknown photographer

  A novel way to beat poachers

Since poaching remains the biggest threat to elephants, US based Working Dogs for Conservation has come up with  novel idea. Using the same techniques used to train dogs to detect firearms and narcotics, they have created teams to detect and track hundreds of poachers and illegal traps. Initially used for this purpose on the Serengeti Plain in Tanzania and the Luangwa Valley in Zambia, their work now includes border patrols in Malawi and Kyrgyzstan to detect and prevent  illegal wildlife products reaching Asia or other destinations.

Nor does their work stop there. With the USA also a popular end destination, sniffer dogs are trained to  to detect wildlife products in closed shipping containers and mail items in order to disrupt the trade at that point.

Interestingly, the dogs used for this purpose are usually strays which would otherwise have been euthanised. Afterwards they go on to enjoy a long and happy retirement, so it’s a double bonus in terms of animal welfare.

 

Mother and calf at Chitwan Elephant Sanctuary, Nepal

 

What do you feed an orphan Elephant?

Orphans are often left behind after adult elephants have been killed for their tusks. According to the IFAW it takes 50 gallons (189.27 litres) of milk a day to feed them. In pre -pandemic times this used to be provided by using baby formula paid for with tourist dollars, but with tourism grinding to a halt, the keepers of the Reteti Elephant Sanctuary in Northern Kenya have had to look elsewhere. They found that local goat herders had surplus milk which they couldn’t sell because livestock markets had also been closed due to the pandemic. Luckily testing showed that it made a reasonable substitute, so this has resulted in a new and positive partnership. 

  

How bees are helping Chinese villagers protect their crops against Elephants

I learned this snippet from doing the IFAW Quiz. Apparently elephants are terrified of bees, so one of its programs focuses on teaching modern beekeeping techniques to Chinese villagers who had been subject to elephant incursions thus keeping the Elephants from destroying crops. It also provides alternative sources of income for villagers. IFAW also provides micro credit to farmers in South Yunnan and teaches people ways to coexist with elephants. With only 3,000 elephants left in the wild,  China is encouraging the establishment of wildlife corridors and planting of suitable vegetation so that a small migratory herd in Yunnan Province can move freely.

 In December 2017 China, the main market for ivory, took the remarkable step of banning sales of ivory with Hong Kong set to follow suit in 2021. Unfortunately, demand persists and ivory continues to be sourced from countries where it remains legal such as Japan or more likely from Thailand, Myanmar and Vietnam and where enforcement is lax. However, times are changing. Research by the World Wildlife Fund has shown that the main buyers these days are older generations, particularly older women from provincial towns, who still see it as a status symbol and a store of wealth. The WWF  hopes that by educating travellers via travel agents and tour guides, its popularity will continue to wane.

Elephants have a long history in Asian culture and usually symbolise Good Luck. It's high time for  elephants to have a bit of luck too. 

 

Now about that "Moon Wobble" and protecting our coastal cities.....

Sea Level Rise 1 - The Moon Wobble and what other countries are doing

Sea level Rise 2 - Is there a cheaper way than seawalls?

 

 


 

 

 

 

 


Friday, August 06, 2021

Europe’s catastrophic flooding was forecast well in advance – what went so wrong?

 

Rescue workers in Paris during recent floods 

This Photo by Unknown Author is licensed under CC BY-NC

 

Almost 200 people dead and many others still missing. Billions of euros’ worth of damage. Communities devastated. Thousands of homes destroyed and their occupants traumatised.

I am a flood forecaster who helped to set up the forecasting system that was used to predict the recent floods in Germany and surrounding countries. I saw days in advance that they were coming. I read reports of rainfall and river levels rising. And then I watched with growing horror as the death toll surged.

The European Flood Awareness System (EFAS), which I helped to set up, is part of the EU’s Copernicus Emergency Management Service. It provides early information on flooding to national and local authorities across Europe. I work closely with people there in my role as an independent flood scientist at the University of Reading to improve and analyse EFAS data. I don’t work in the team that issues early flood information to authorities, but looking at the data with colleagues, I could see early on just how serious the floods looked.

Forecasts on Friday July 9 and Saturday 10 for the Rhine catchment, covering Germany and Switzerland, had shown a high probability of flooding that would begin on Tuesday July 13. Subsequent forecasts also showed the Meuse in Belgium would be affected. The forecasts in the following days showed that there was little doubt that a major flood was coming.

EFAS sends out bulletins of early information which are designed to be read, understood and acted on by experts. They are not directly available to the public. Public flood warnings come from the national and regional weather, environment and civil protection agencies, and EFAS information needs to be used by these authorities alongside their own forecasts.

The first EFAS bulletin was sent to the relevant national authorities on Saturday July 10. More updates continued over the following days as more precise predictions became available. Formal flood notifications were issued to authorities in Germany, Belgium, Netherlands, Switzerland and Luxembourg, as well as the Emergency Response Coordination Centre (ERCC) of the European Commission throughout Monday and Tuesday. As the event neared and uncertainty in the forecast shrank, the predicted start of the flooding was pushed to Wednesday for smaller rivers and Thursday for the larger downstream rivers. Around 25 individual warnings were sent out to parts of the Rhine and Meuse.

The German weather service, DWD, had independently forecast extremely high rainfall too and issued warnings for more than 200 mm of rain in the same areas several days ahead of time, saying that flooding was possible. Regional warnings were also issued, for example by the Environment Agency in the German state of Rhineland-Palatinate, one of the areas hit particularly hard by flooding.

The floods that did happen matched the scale and distribution of those that were forecast several days before. I was very surprised, therefore, that so many people died, given that authorities knew about the event and had sufficient warnings to get people to safety before the floods began.

Where flood warnings fail

Clearly, tragically, the whole system designed to save lives by ensuring people act on warnings before floods arrive, did not work as it should have done. It may be that individual parts of the system worked exactly as they were designed, and it is certainly true that forecasts were accurate, and there were some warnings issued through official channels. In some areas, many authorities did act in time, to evacuate people, erect temporary flood defences, and move vehicles to higher ground. But this clearly did not happen everywhere.

In the middle of an election campaign, some German leaders in national and regional government still seemed to defend the locally-devolved nature of disaster management in Germany, insisting that the warnings were adequate and agencies did their work well. It is like claiming that the maiden voyage of the Titanic was a success because 99% of its engineering worked perfectly throughout. While their arguments may be true on an individual scale, unless those in power admit that the system ultimately failed, they risk failing to learn lessons and put others at risk in the future.

Science, in large part, is about helping people see the invisible. What is the use of a perfect forecast if the people it is supposed to warn cannot see the danger they are in? Effective flood warnings require people to be able to see into the future and imagine their house full of water, to assess the likelihood of that happening, and to see the multiple paths they could take to keep them, their family, and their property safe.


Read more: Report from Europe's flood zone: researcher calls out early warning system gridlock amid shocking loss of life


I recently took part in an exercise encouraging scientists, from senior professors to school pupils, to trace the path of water in a river through time using just their imagination. Weeks later, we are seeing what happens when people cannot visualise the threat of a river ripping down their street, or a lake appearing in their house. These are the elements of flood warnings that must improve.

As climate change increases risks from heatwaves, fires and floods, we need to not only slash emissions but prepare ourselves for the problems we already have in store. Even with sufficient decarbonisation measures – which we are still yet to see from any major government – there is no avoiding the consequences of a hotter, more turbulent environment.The Conversation

Hannah Cloke, Professor of Hydrology, University of Reading

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sunday, August 01, 2021

Say Thanks to a Ranger today

 


 

Say a big Hi and a Thank You to all our Rangers today

Text Box: This Photo by Unknown Author is licensed under CC BY-SA-NC

 

I was going  to cover write  more about the animals  – e.g. Marine creatures such as Whales and Sharks, The Elephants, Primates and Reptiles, who’ve all had special days recently, but iwhereever you look the story is much the same, extinction is happening before your eyes, not that there aren’t heroic efforts underway around the world to prevent it. We shall take these up again from time to time, but let’s celebrate World Ranger Day today, if you are east of the international dateline, yesterday if  to the west, and give a big shout out to those at the front lines.

Being a ranger is even deadlier than being a journalist these days. One thousand one hundred and twelve have died in the line of duty since 2009. While those who challenge poachers in Africa and Asia have been most at risk, others have died through encounters with wild animals, through drowning, motor vehicle accidents and fire. Over the past year Covid 19 has also contributed to the death toll.

Many of these deaths were unavoidable but there are also those which could have been prevented with more support. See the Thin Green Line Organisation for ways to help internationally with things like training and equipment and for families left behind. Many rangers are now also without income because of the loss of tourism due to the pandemic so they would appreciate help here too, if you can. In the end we’ll lose all our animals if we don’t look after our rangers and their habitat. Instead of erecting memorials, perhaps adequate water supplies would be a start. Many of our walking tracks, huts and even some seats in our national parks are dedicated to the rangers who have helped to preserve them, so that’s might be another positive way to commemorate their work.

Meet Kenya’s fantastic female rangers

 


Don't forget your local rangers either. For Aussies click here and don’t forget to thank our indigenous rangers as well who not only have vast areas of natural landscape to protect, but indigenous cultural sites too.