Category: Features

The pain of the past a warning-call for the future

The pain of the past a warning-call for the future

By Erin Owain

On the 54th anniversary of the Aberfan disaster, a rainfall-induced coal tip landslide which claimed the lives of 116 children and 28 adults in the coal mining town in South Wales, the Welsh Government and others are calling for urgent action by the UK Government in light of future increases in winter rainfall due to climate change.

While the predominant focus of action on the impacts of climatic changes across the UK has been geared towards flood risks and flood mitigation, the projected increase in winter rainfall of up to ~25% by 2100 under “worse-case” scenario (RCP8.5) could increase the intensity and frequency of precipitation-induced landslide, especially in old mining towns, where old coal tips are prone to such incidents even in today’s climate. Last year in Wales, a 60,000-tonne landslide in Tylorstown was triggered by heavy rainfall caused by Storm Dennis, and this incident called for urgent action.

Last week, a review led by the Welsh Government, with the co-operation of the Coal Authority, councils and Natural Resources Wales, issued a letter to the UK Chancellor stating that more than half a billion pounds would be needed to ensure the safety of 2,000 old coal tips in Wales over the next 10 years.

In October, the UK government provided £2.5m to help clean up and secure the Tylorstown site. The half a billion pound requested by the Welsh Government to help secure coal tips in South Wales and prevent future rainfall-induced landslide may be but a drop in the ocean compared to the costs of reacting to future landslide events.


Cover image from the PA Archive/Press Association Images
One of Earth’s most biodiverse habitats lies off the Scottish west coast – but climate change could wipe it out

One of Earth’s most biodiverse habitats lies off the Scottish west coast – but climate change could wipe it out

By Heidi Burdett and Cornelia Simon-Nutbrown

Maerl beds stud the ocean floor like underwater brambles. They’re pastel pink and, despite their knobbly appearance, made up of a red seaweed. This algae has a limestone skeleton which gives it a complex three-dimensional structure that is quite unlike the slimy seaweeds you may be more familiar with.

In fact, the closest thing to a maerl bed you’ve probably heard of is a coral reef. Like tropical reefs, the seaweeds in maerl beds interlock as they grow, creating nooks and crannies that serve as the perfect home for a huge range of sealife. Maerl beds are one of the world’s most biodiverse habitats, but unlike coral reefs, few people have heard of them and even fewer study them.

Also known as “rhodolith beds”, maerl beds are found in coastal waters all over the world, from the poles to the equator, but pockets of this habitat form European strongholds off Scotland’s west coast and islands. Sadly, our new research has revealed how climate change threatens to destroy much of this natural heritage before its wonders have been brought to light.

A clump of knobbly, pink, coralline seaweed.
A piece of Scottish maerl that is well over 100 years old. Nick Kamenos, Author provided

Climate change and maerl beds

Maerl grows at a glacial pace – just 0.2 mm per year in Scotland. This makes it difficult for these habitats to respond to rapid changes in water temperature or ocean currents. But these are just the kind of environmental changes that are expected around Scotland over the coming century.

Until recently, scientists had only conducted small-scale experiments on maerl, so we knew very little about how Scotland’s beds would respond to climate change. To overcome this, we developed a computer model that can predict how the multiple changes to Scotland’s climate will affect the distribution of this habitat by 2100.

Astonishingly, even in the best-case scenario, where emissions are rapidly reduced from current levels, we predict that maerl bed distribution will shrink by 38% by the end of the century. If global emissions stick to their current trajectory, we predict a massive 84% decline in maerl bed distribution around Scotland. Without major changes we will likely follow this path, or worse.

Our research tells us that this would be devastating for the flora and fauna that call this habitat home, including commercially important species such as juvenile pollack, hake and scallops.

Scotland’s maerl beds under ‘worst-case’ warming scenario

Two maps comparing maerl bed distribution off the Scottish coast today and in 2100.
Simon-Nutbrown et al. (2020), Author provided

Refuge areas

Only international efforts to rapidly reduce greenhouse gas emissions could improve the situation for Scotland’s maerl beds. But managing the coastal ocean better – with regulation of trawling and pollution – could soften the blow. Since our model found that the rate of habitat decline will be fastest between now and 2050, the need for rapid action is even more urgent.

It’s unrealistic to expect the entire coastal ocean of a country to be placed under strict marine protection. After all, these regions are very valuable to a range of industries and interests, like tourism, shipping and fishing. Where then, should we focus our efforts? Our computer model helps with this too.

We have identified some key areas in which maerl populations are likely to persist in local micro-climates. Here, temperatures are not predicted to rise as much as the surrounding water and changes in waves and currents at the seafloor are expected to be less pronounced. This will allow maerl beds to remain in areas such as Loch Laxford, mainland Orkney and mainland Shetland. Protecting and monitoring these refuge areas could maximise the chances of these habitats surviving for future generations to enjoy.

Seafloor habitat with pink clumps of maerl, rocks and seaweed.
A Scottish maerl bed brimming with life. Nick Kamenos, Author provided

Knowing where a habitat might continue to thrive in the future is crucial for planning how to manage coastal seas better, and being able to map these areas can help reconcile their protection with other activities. The refuge areas we found will now be considered as priority conservation areas by the Scottish Government.

Climate change is expected to affect maerl beds all around the world, so the computer model we’ve created can now find other areas where they may be able to cling on globally. Conservation can be long, gruelling work, so being able to focus marine protection efforts in areas with the highest chance of survival could help safeguard at least some of this habitat for future generations.


This article was originally posted on The Conversation.
Cover photo by Lukaassek/ Shutterstock
Meet the Acclimatise Team ft. Olivia Palin

Meet the Acclimatise Team ft. Olivia Palin

What is your role at Acclimatise? What does a typical workday look like for you?

I’m a Senior Consultant at Acclimatise. I work with a range of organisations on assessing, managing, and financing climate resilient activities. For the past year I’ve been on secondment to global resources company, BHP. My role there has been to support the update and implementation of their climate adaptation strategy.  A typical workday starts at around 6am, when I’m available for calls and collaboration with the team based across Australia. When that window closes, I’m focussed on writing technical content and briefings, and perhaps liaising with teams in Chile, Canada, and the US.

Prior to BHP (and Covid 19!) I led Acclimatise’s Caribbean and Latin American regional operation based in Barbados. My workdays at that time involved much more regional travel and face to face collaboration across the islands.

What inspired you to work on climate issues?

An enduring feeling awakened during my childhood in SE Asia; a life lived in harmony with nature makes most sense for all the beings on this beautiful blue planet.

What’s your favourite book/series to reread and why?

The Summer Book by Tove Jansson. It’s about a young girl and her grandmother spending a summer together on a tiny island in the Gulf of Finland. I like to revisit the celebration of simplicity, family, and nature.

I also have to say The Lord of the Rings. I love J. R. R. Tolkien’s characters, creativity and songs, as well as the magic and quest at the heart of it all. As I walk around Oxford, where I live, I can’t help thinking about the places he might have wandered and been inspired by while he conjured the story.

What climate action would you like to see happen on a global scale in the coming decade?

Lots of decentralised action to support shifts in perception, reduction in meat and dairy consumption, safe cycling, and protection of green spaces.

What were your favourite subjects in school?

Geography, History, English, and Drama.

Where is your happy place?

In the sea (preferably on a surfboard) or in the mountains. Freights Bay in Barbados is hard to beat!


Rainfall Explorer: Achieve next-level insight into global rainfall and flood patterns

Rainfall Explorer: Achieve next-level insight into global rainfall and flood patterns

Today, the EO4SD Climate Resilience Cluster releases the Rainfall Explorer, a cutting-edge tool that enables users to readily obtain near real-time extreme rainfall statistics for past major flood events recorded anywhere in the world.

Global annual dollar damages from floods have increased from an average of US $4bn in 1971 to around US $40bn by 2015. Despite increasing flood-related losses, there remains low capacity to understand historic flood – rainfall patterns, trends, and impacts, across most of the world. These gaps in understanding compound uncertainties about how extreme rainfall and flood hazard could change under a future climate.

All of this increases the imperative to leverage new and existing data to derive deeper insights that may improve early-warning of near-term flood risks and inform development of robust, climate resilient strategies to deal with future flood risk. Our tool, which is already used by the World Bank and Multilateral Investment Guarantee Agency, seeks to be part of the solution.

Rainfall return level and return period data during late July 2016 over Maryland (USA) visualised using the Rainfall Explorer.

It is well understood that prolonged heavy rainfall is a key trigger of major flood events globally. However, catchment characteristics, land cover, topography, drainage, flood control, and other factors (including how these change in these over time) result that flood propensity for similar amounts of rainfall varies significantly from place-to-place. Further, a range of factors lead an area to be flood-prone at a given point in time, including the height the water table, ground saturation, and river discharge. And whilst the Rainfall Explorer presents rainfall statistics over a 5-day period, destructive flash floods may be triggered by intensive rainfall falling in a few hours.

Nevertheless, analysing accumulated rainfall in the lead-up major floods in an area can help to illuminate the relationship between rainfall and flood propensity. Using this tool, users may select past floods or areas of interest to obtain rainfall statistics, including the amount of rainfall (mm) recorded 5-days prior to a flood, the return period (years) of this rainfall, and the range of the rainfall return period for the selected area or flood.

  • In turn, these statistics can assist users to:
  • Identify patterns and trends in flood occurrence, flood severity and rainfall totals, and rainfall return levels
  • Identify rainfall thresholds likely to trigger a large flood in an area of interest
  • Identify the amount of rainfall associated with a past material flood event of interest
  • Understand the likelihood of rainfall associated with past flood events
  • Find the return period (years) for a given 5-day rainfall amount (mm)
  • Find the 5-day rainfall return level (mm) for a given return period (years)
  • Map the region affected by a past flood event, together with the 5-day rainfall amount and return period associated with the event

The Rainfall Explorer currently leverages the Dartmouth Flood Observatory archive of large flood events (1984 to 2020) and a 40-year timeseries of processed Copernicus ERA5 Reanalysis daily precipitation data, at 30km x 30km spatial resolution, available near-real time (with 5 days delay from present time). ERA5-Land Reanalysis daily precipitation data, at enhanced 9km x 9km spatial resolution, will be available in early 2021. All data are stored and computed in the cloud, meaning that users may access the Rainfall Explorer using only a web browser, wherever they are.

Access the Rainfall Explorer here.


The Rainfall Explorer is an EO4SD tool led by Telespazio Vega UK and Sistema GmbH, with the support of Acclimatise and GMV. We thank the World Bank and MIGA for valuable feedback provided during the development of this tool.


This article was originally posted on the EO4SD CR website.
Drought and heat together menace American West

Drought and heat together menace American West

By Tim Radford

Climate change really is a burning issue. Simultaneous drought and heat are increasingly likely for more of the American West.

LONDON, 13 October, 2020 − The American West is about to get hotter. It is also about to get drier. To make things worse, extremes of heat and of drought will happen more often at the same time.

And to compound the damage, such simultaneous assaults are likely to extend over larger areas and become more intense and more frequent, thanks to climate change driven by profligate use of fossil fuels and other human decisions.

This is not a prediction based on computer simulations of the future. It is already happening, and the story can be traced − according to the journal Science Advances − in the narrative of hot spells and dry weather over the entire contiguous United States for the last 122 years.

Not only have combined hot and dry episodes increased in frequency, they have also grown in size in geographic terms. Where once they happened in confined localities, they now extend over whole regions, such as the entire West Coast, and parts too of the Northeast and the Southeast.

Another Dust Bowl?

“Dry-hot events can cause large fires. Add wind and a source of ignition, and this results in ‘megafires’ like the 2020 fires across the west coast of the United States. Drought and record-breaking heatwaves, coupled with a storm that brought strong winds and 12,000 lightning events in a span of 72 hours, caused more than 500 wildfires,” said Mohammad Reza Alizadeh, of McGill University in Canada, who led the research.

Heat extremes can be damaging or even devastating. So can drought. When the two coincide, their compound impact can be tragic. The study also suggested that in some way such double jeopardy events could be self-propagating: they could spread downwind, seriously bad news for the American West and other areas at risk.

Long before any fears of the climate emergency, the US Midwest was scarred by drought, and in the 1930s Oklahoma and Kansas in particular became a “Dust Bowl” and inspired the classic novel The Grapes of Wrath by the American writer John Steinbeck.

“We observed that concurrent dry and hot events of similar intensity are becoming more frequent,” said Mojtaba Sadegh, an engineer at Boise State University in Idaho, and the senior author.

“Our results point to an urgent need to take action to enhance resilience to compound hot and dry events”

“The difference is that, in the 1930s, lack of precipitation led to the local atmosphere becoming hotter, whereas in recent decades increased temperatures are driving aridity. The triggering mechanism for compound dry-hot events is changing from lack of precipitation to excess heat.”

The warning of worse to come coincides with news that California’s fires have become so bad that they warrant a new classification: the “gigafire”, with so much smoke emitted from the combined fires of California and Oregon that fumes have been detected in New York, in northern Europe, and far into the Pacific.

Researchers have repeatedly warned of the double hazard of heat and drought and the combined impact on the US, as a consequence of climate change driven by greenhouse gas emissions from power station chimneys and automobile exhausts, as well as destruction of the natural wilderness.

“This research raises an alarm about increasing frequency and intensity of compound hot and dry events,” said Dr Sadegh. “Three such events between 2011-2013 in the US caused $60bn (£46bn) in damages. Our results point to an urgent need to take action to enhance resilience to compound hot and dry events.” − Climate News Network


Cover photo by Madu Shesharam on Unsplash.
What is holding back the promise of nature-based solutions for climate change adaptation?

What is holding back the promise of nature-based solutions for climate change adaptation?

By Heidi Tuhkanen

The case is increasingly clear that nature-based solutions offer cost-effective ways to address climate change adaptation. This perspective piece examines the issues that deserve greater attention to expand the use and financing of such measures.

The benefits of using green infrastructure and nature-based solutions to address the adaptation needs arising from climate change are increasingly clear. Such projects have been shown to be cost effective, to provide social benefits, and also to mitigate emissions that contribute to climate change.

Meanwhile, the need is great. According to the Climate Policy Institute, an estimated $180 billion annually will be needed over the next decade to cover the cost of adaptation – a figure that the public sector cannot meet on its own. In recognition of the shortfall, finance mechanisms have surfaced to fund nature-based solutions by enabling investment from a range of private and public-sector actors.

So, why are so few projects in the pipeline?

The problem is certainly not a lack of interest. More than 150 people attended a recent seminar on the subject that I helped to organize with the UN Environment Programme and The Nature Conservancy at Climate Week NYC. Our seminar on private-sector adaptation finance and nature-based solutions in coastal areas (recording here) is one of many events, such as Financing Nature Based Solutions for Water Security and Financing Blue Carbon, that have recently explored the issue.

These events raise matters that must be addressed to generate greater investment in nature-based solutions, particularly in coastal and marine areas, and to capitalize on the potential of these strategies. Discussions at the Climate Week NYC seminar raised key insights about issues that should be high on the agenda.

Key insights from The Private-sector Adaptation Finance and Nature-based Solutions seminar

1. Expand understanding about the value of nature-based solutions.

All levels of government and the private sector need a greater appreciation for and awareness of the potential for nature-based solutions. More awareness is needed about the value of natural assets – and the far-reaching, cascading effects that their loss could have on societies and economies.

2. Increase the awareness of innovative financing tools.

Many of the finance mechanisms are new and being piloted in specific cases. People don’t know about them. At the seminar, a number of new financial mechanisms were presented. Blended finance mechanisms – like debt-for-nature swaps, risk- sharing instruments, and first-loss instruments – combine public- and private-sector finance to help offset the risks, and to distribute the benefits that nature-based-solution projects involve. Nature-based insurance is being used in Mexico to fund coral reforestation and maintenance, recovery from hurricane damage, and worker training for reef reparation. Fee-based funding – first in the form of a departure tax and currently in the guise of a Pristine Paradise Environmental Fee – is being used in Palau to transfer funds from tourists to the communities and governments that manage the Marine Sanctuary. Carbon credits in Kenya are funding community-based mangrove reforestation, which not only buffers disaster risks, but also captures carbon. Similar efforts are being replicated in other places. Furthermore, green and blue bonds exist, though they have yet to be used at high levels.

3. Understand the challenges of financing nature-based solutions.

Similar to many adaptation projects, nature-based solutions are often too small and too high risk to attract investors; thus, mechanisms are needed to pool, mainstream and de-risk projects. Projects also tend to be tailored to local conditions; pilots take time to get off the ground; and many of the effects are long term – all of which limit replicability. Further work, however, is being done to see how such arrangements could be replicated in other geographies and with other ecosystems. New ways are needed to manage natural resources and new partnerships between multiple stakeholders (public and private) to leverage private financing for projects that provide public goods and benefits. To push the demand for adaptation, higher standards and/or regulation, along with risk awareness are needed.

4. Address the issues posed by the neediest countries.

Many current examples of private-sector financed, nature-based models are from middle- and high-income countries. By contrast, low-income and least-developed countries are among the most vulnerable to climate impacts, and therefore in greatest need of investment. Private or blended finance opportunities are limited because of perceived high risk and low return on investment. My own research concludes that green bonds are limited in terms of their use in such countries as a mechanism to scale up private financing for adaptation and resilience.

5. Give greater attention to the trade-off between social and environmental benefits.

Livelihood benefits to communities are often mentioned as a component of nature-based solutions. What will the distribution of benefits be among stakeholders with private financers in the picture? How can projects ensure equitable access to benefits throughout society?

6. Examine the potential for hybrid measures to extend the benefits of nature-based solutions.

Hybrid nature-based solutions combine grey and green infrastructure. They may offer a way to increase the availability of alternatives to grey infrastructure. In fact, hybrid models may be the only solution available for some situations. For example, pure nature-based solutions may not be an option in dense urban areas, and may not be sufficient for adapting to severe climate impacts. Some hybrid models are actually traditional methods that are making a comeback. One example is the use of fences to start the formation of sand dunes to help protect coastal regions. However, innovation and experimentation with these solutions are needed to come up with new possibilities as well as to assess their effectiveness and replicability.

Although we are still far away from reaching the funding needed for adaptation, these new and diverse opportunities for private finance of nature-based solutions move us closer to the goal. The Global Commission on Adaptation recently called for the demonstration of innovative finance models to scale-up investments in nature-based solutions. This call specifically seeks to mobilize private finance. This call and other initiatives recognize the potential of such approaches. Nature provides benefits that are the backbone of societies and economies. It can also be the backbone of resilient adaptation.


This article was originally posted on the Stockholm Environment Institute website and was republished on PreventionWeb.
UNDRR’s International Day for Disaster Risk Reduction – 2020 Edition

UNDRR’s International Day for Disaster Risk Reduction – 2020 Edition

Tomorrow marks the UNDRR’s International Day for Disaster Risk Reduction. Held every 13 October, the day celebrates how people and communities around the world are reducing their exposure to disasters and raising awareness about the importance of reining in the risks that they face.

This year’s edition continues as part of the “Sendai Seven” campaign, focusing on Target E: “Substantially increase the number of countries with national and local disaster risk reduction strategies by 2020.”  This year’s theme is about conveying that many disasters can be avoided if there are disaster risk reduction strategies in place to manage and reduce existing levels of risk.

You can find dedicated resources, stories, articles and events taking place around this day, here.

https://iddrr.undrr.org/
Meet the Acclimatise Team ft. Laura Canevari

Meet the Acclimatise Team ft. Laura Canevari

What is your role at Acclimatise? What does a typical workday look life for you?

I work as climate risk analyst and business development associate at Acclimatise. My work as risk analyst is focused on adaptation within the private sector, whilst my work as BD associate focuses on developing climate services for financial institutions. What this means in practice is designing mechanisms (i.e. tools, training programs, guidelines) to help financial institutions mainstream climate change considerations into their governance and risk management practices, and in alignment with the TCFD recommendations.

A lot of my work revolves around opening up conversations with new potential partners and clients, speaking at international events, and getting the word out about the great work that we do. I also work a lot “behind the scenes”, thinking strategically about business development for the company (especially in Latin America, where I am currently based), and helping the Acclimatise passionate and collaborative culture permeate with new recruits.

What inspired you to work on climate issues?

The reality of climate change first hit me when I was undertaking my bachelor in Marine Science in Australia. At the time (over a decade ago) I attended the testimonies of Pacific islanders and got struck by the changing realities that they were experiencing; and by the fact that relocation of entire communities was not just some projected change on a chart, or something that would happen sometime in the distance future: it was in fact a reality many people were already experiencing.  I then decided to join a Friends of the Earth action program on climate awareness called “Sisters of the planet” and an activist climate change group at my university. This later led to me pursuing a career both as a practitioner and an academic on climate change adaptation. 

What do you like to do in your free time?

I am an avid reader of world literature and in particular a fanatic of Russian classics.

More recently, I have started to search for modern “philosophers” with framings that may help me understand and better lead under the current changing reality: T. Picketty, M., Sandel, A. Sen, to name a couple. When I am not behind a book, doing yoga or meditating, I give the floor to the interests stemming from my dual culture. On the Italian side, I love to cook (especially for a small group of close friends); whilst on the Colombian side, I love to dance!

If you could have dinner with anyone (past or present), who would it be and why?

I have always wanted to dine with the Dalai Lama. I think being in his presence would be enough to gain some of his inner peace and his compassionate outlook on life.

What do you think the Coronavirus pandemic can teach us about climate change?

There is nothing fair about COVID-19. Just as there is nothing fair about climate change. It needs to be our institutions, our governments, civil society and us individually that bring justice to the uneven playground in which humans thrive whilst they explore their humanity.

Both issues share a story on the need for solidarity, for being compassionate and for standing for, and giving voice to, those that can´t.

Tell us a little bit about your new business!

In my role as business associate at Acclimatise, I have had the chance to attend so many great events and meetings. I started paying attention and realised that we are just about to reach a massive break through: a total change in paradigm. What I mean by this is that it is now very evident that climate change is not just an environmental issue, but also a threat to our socio-economic and financial systems . Whilst listening to financial institutions talking about “Greening the financial system and financing green”, I realised that there is still an important gap between these institutions and where finance is needed. So, I decided that it was time to move out of the comfort of my Oxford office and head back to Latin America, to help local project developers access international finance for adaptation and resilience building projects. My new company ITACA is doing just that: raising awareness on the risks and opportunities stemming from a changing climate, and helping project developers (especially MSMEs) access international finance. In this way I aim to help accelerate adaptation and resilience in the region, whilst also supporting financial institutions greening their portfolios.

Three things on your bucket list:

Is this where you store dreams you would like to achieve later?

I don’t have one. Anything that I want to achieve, I pursue it in the present moment.


Rivers flood, seas rise – and land faces erosion

Rivers flood, seas rise – and land faces erosion

By Tim Radford

Polar melting cannot be separated from farmland soil erosion and estuarine flooding. All are part of climate change.

Climate heating often ensures that calamities don’t come singly: so don’t forget what erosion can do.

In a warmer world the glaciers will melt ever faster to raise global sea levels ever higher. In a wetter world, more and more topsoil will be swept off the farmlands and downriver into the ever-rising seas.

And the pay-off of silt-laden rivers and rising sea levels could be catastrophic floods, as swollen rivers suddenly change course. Since many of the world’s greatest cities are built on river estuaries, lives and economies will be at risk.

Three new studies in two journals deliver a sharp reminder that the consequences of global heating are not straightforward: the world responds to change in unpredictable ways.

First: the melting of the ice sheets and the mountain glaciers. Researchers warn in the journal Nature Climate Change that if the loss of ice from Antarctica, Greenland and the frozen rivers continues, then climate forecasters and government agencies will have to think again: sea levels could rise to at least 17cms higher than the worst predictions so far.

“Avulsions are the earthquakes of rivers. They are sudden and sometimes catastrophic. We are trying to understand where and when the next avulsions will occur”

That means an additional 16 million people at hazard from estuarine floods and storm surges.

In the last 30 years, the flow from the Antarctic ice cap has raised sea levels by 7.2mm, and from Greenland by 10.6mm. Every year, the world’s oceans are 4mm higher than they were the year before.

“Although we anticipated the ice sheets would lose increasing amounts of ice in response to the warming of the oceans and the atmosphere, the rate at which they are melting has accelerated faster than we could have imagined,” said Tom Slater of the University of Leeds, in the UK, who led the research.

“The melting is overtaking the climate models we use to guide us, and we are in danger of being unprepared for the risks posed by sea level rise.”

Dr Slater and his colleagues are the third team to warn in the last month that observations of climate already match the worst-case scenarios dreamed up by forecasters preparing for a range of possible climate outcomes.

Erosion risk rises

The latest reading of glacial melt rates suggests that the risk of storm surges for many of the world’s greatest cities will double by the close of the century. But coastal cities – and the farmers who already work 38% of the terrestrial surface to feed almost 8bn people – have another more immediate problem.

In a warmer world, more water evaporates. In a warmer atmosphere, the capacity of the air to hold moisture also increases, so along with more intense droughts, heavier rainfall is on the way for much of the world. And the heavier the rain, or the more prolonged the drought, the higher the risk of soil erosion.

In 2015 the world’s farmers and foresters watched 43 billion tonnes of topsoil wash away from hillsides or blow away from tilled land and into the sea. By 2070, this burden of silt swept away by water or blown by wind will have risen by between 30% and 66%: probably more than 28 bn tons of additional loss.

This could only impoverish the farmland, according to a study by Swiss scientists in the Proceedings of the National Academy of Sciences. It could also impoverish people, communities and countries. The worst hit could be in the less developed nations of the tropics and subtropics.

But the flow of ever-higher silt levels into ever-rising seas also raises a new hazard: hydrologists call it river avulsion. It’s a simple and natural process. As conditions change, so rivers will naturally change their flow to spill over new floodplains and extend coastal lands.

Survival in question

But river avulsions can also be helped along by rising sea levels. Since 10% of humanity is crowded into rich, fertile delta lands, and since some of the deadliest floods in human history – two in China in 1887 and 1931 claimed six million lives – have been caused by river avulsions, the question becomes a matter of life and death.

US scientists report, also in the Proceedings of the National Academy of Sciences, that rising sea levels alone could make abrupt river avulsion more probable, especially as delta lands could be subsiding, because of groundwater and other extraction.

The dangers of avulsion are affected by the rate of sediment deposit in the river channels, and this is likely to rise with sea levels. This in turn raises the level of the river and eventually a breach of a levee or other flood defence will force the river to find a swifter, steeper path to the sea.

Cities such as New Orleans and the coastal communities of the Mississippi delta are already vulnerable. “Avulsions are the earthquakes of rivers,” said Michael Lamb, of California Institute of Technology, one of the authors.

“They are sudden and sometimes catastrophic natural events that occur with statistical regularity, shifting the direction of major rivers. We are trying to understand where and when the next avulsions will occur.” – Climate News Network


This article was originally posted on The Climate News Network.
Five innovations for a resilient built environment in Africa

Five innovations for a resilient built environment in Africa

By Olivia Nielsen and Sabine Kast

Most of the building stock that will be needed over the next century in Africa is yet to be built. As the last continent to urbanize, Sub-Saharan Africa has a unique opportunity to learn from others and adopt resilient and sustainable practices from the onset.

Africa’s cities are already booming as thousands of rural households move to find better opportunities in the cities. Though the COVID-19 pandemic may have temporarily slowed this rural-to-urban migration, the trend appears to be inevitable.

The continent is not immune to natural hazards as the South gets hit by stronger and stronger cyclones, causing devastation and loss of life, homes and livelihoods. An estimated 240,000 houses were destroyed or damaged last year alone in Mozambique. North, South and east Africa also experience regular earthquakes.

A new motto has emerged claiming that there are no natural disasters, shifting the blame to poorly designed built environment and inadequate prevention systems which contribute death, destruction and economic losses.

Yet, Africa’s building sector seems to be repeating some of the mistakes of the past. Quality control remains a major issue across the continent where buildings are known to collapse even in the absence of natural hazards.

The COVID-19 pandemic has highlighted the need to urgently invest in disaster preparedness and mitigation. A disaster can quickly destroy decades of economic progress. While earthquakes are a quick disaster, a pandemic is a slow moving one. Our built environment must be designed to withstand these disasters and protect us.

Fortunately, resilience doesn’t need to be expensive and new technologies and innovations are constantly bringing down costs. As we are required to work remotely, we are developing new technologies to improve risk reduction during the pandemic and beyond. A few examples:

  • Machine learning to develop risk maps.  Formal maps are rarely updated in Africa and often only cover major urban areas. Yet, local risk maps are fundamental to supporting proper urban development and reducing risks in the long term. Without risk maps, it is difficult to anticipate which properties may be vulnerable to flooding, landslides or even earthquakes and typhoons. Developing these maps should be a major priority to support planned urban development and make investments that will last. When on-the-ground data collection is time-consuming or made difficult with social distancing requirements, machine learning algorithms can be used to process satellite data and build local risk maps. This technology can help Africa overcome its major map gap and support municipalities across the continent develop urban plans that mitigate the risks of flooding, landslides and sea rise. Without access to detailed risk maps, buildings may be built in precarious ways which may lead to devastating life and property losses. Fortunately, machine learning is making this mapping process cheaper and faster.
  • Artificial Intelligence to assess the built environment. The World Bank’s Global Resilient Housing Group has developed technology to capture images from satellites and drones, which are processed through an algorithm to assess structural deficiencies. Without even setting foot on the ground, thousands of buildings can be assessed in a matter of minutes and enable policymakers to prioritize interventions. For example, buildings that present a high risk of collapsing during an earthquake or typhoon can be efficiently identified and thus retrofitted before the next disaster strikes.
  • Apps to undertake remote quality control. New apps, such as iBuild+ Miyamoto, have been developed to enable homeowners to quickly undertake a damage assessment of their home. Just like telehealth, they now have expert engineers at the tip of their fingertips- for a fraction of the cost! By uploading geotagged photos of their homes, households can access expert advice at a fraction of the costs. This app can also be used to monitor the quality of construction works and identify issues in real time before it is too late.
  • Programs to address and rate the resilience of new buildings: IFC, the private sector arm of the World Bank Group, is piloting a new program, the Building Resilience Index. The Index standardizes and quantifies disaster risk, gives guidance on risk management, and creates a reporting system on adaptation and resilience for the construction sector. The new tool will enable construction developers to identify ways of improving building resilience while minimizing costs. For investors and households, the Index will provide reassurance that the building can withstand significant hazards and protect both lives and properties.
  • Low-cost retrofit solutions. Retrofits are so rarely undertaken because they are deemed too expensive by both households and policymakers. Building new homes is easier to implement instead. But now, new construction technologies, such as Polypropylene (PP) bands or fiber-reinforced paint, are emerging that will not only make these retrofits cheaper but also much easier to implement. With little training, households can easily apply these retrofits themselves and bypass engineering and labor costs- which can often be crippling. Though easy to apply, these technologies are effective and enable households to greatly reduce the likelihood of structural collapse.

Construction will be a major driver of economic recovery worldwide, accounting for around 13% of the global GDP. These innovations can be part of a global effort to build (back) better. As cities in Africa continue to grow, climate change continues to accelerate and jobs are desperately needed, there has never been a better time to invest in resilience!


This article was posted on PreventionWeb.