Category: Climate Change Impacts

Protecting wetlands helps communities reduce damage from hurricanes and storms

Protecting wetlands helps communities reduce damage from hurricanes and storms

By Siddharth Narayan, University of California, Santa Cruz and Michael Beck, University of California, Santa Cruz

2017 was the worst year on record for hurricane damage in Texas, Florida and the Caribbean from Harvey, Irma and Maria. We had hoped for a reprieve this year, but less than a month after Hurricane Florence devastated communities across the Carolinas, Hurricane Michael has struck Florida.

Coastlines are being developed rapidly and intensely in the United States and worldwide. The population of central and south Florida, for example, has grown by 6 million since 1990. Many of these cities and towns face the brunt of damage from hurricanes. In addition, rapid coastal development is destroying natural ecosystems like marshes, mangroves, oyster reefs and coral reefs – resources that help protect us from catastrophes.

In a unique partnership funded by Lloyd’s of London, we worked with colleagues in academia, environmental organizations and the insurance industry to calculate the financial benefits that coastal wetlands provide by reducing storm surge damages from hurricanes. Our study, published in 2017, found that this function is enormously valuable to local communities. It offers new evidence that protecting natural ecosystems is an effective way to reduce risks from coastal storms and flooding.

Coastal wetlands and flood damage reduction: A collaboration between academia, conservation and the risk industry.

The economic value of flood protection from wetlands

Although there is broad understanding that wetlands can protect coastlines, researchers have not explicitly measured how and where these benefits translate into dollar values in terms of reduced risks to people and property. To answer this question, our group worked with experts who understand risk best: insurers and risk modelers.

Using the industry’s storm surge models, we compared the flooding and property damages that occurred with wetlands present during Hurricane Sandy to the damages that would have occurred if these wetlands were lost. First we compared the extent and severity of flooding during Sandy to the flooding that would have happened in a scenario where all coastal wetlands were lost. Then, using high-resolution data on assets in the flooded locations, we measured the property damages for both simulations. The difference in damages – with wetlands and without – gave us an estimate of damages avoided due to the presence of these ecosystems.

Our paper shows that during Hurricane Sandy in 2012, coastal wetlands prevented more than US$625 million in direct property damages by buffering coasts against its storm surge. Across 12 coastal states from Maine to North Carolina, wetlands and marshes reduced damages by an average of 11 percent.

These benefits varied widely by location at the local and state level. In Maryland, wetlands reduced damages by 30 percent. In highly urban areas like New York and New Jersey, they provided hundreds of millions of dollars in flood protection.

Wetland benefits for flood damage reduction during Sandy (redder areas benefited more from having wetlands). Narayan et al., Nature Scientific Reports 7, 9463 (2017)., CC BY

Wetlands reduced damages in most locations, but not everywhere. In some parts of North Carolina and the Chesapeake Bay, wetlands redirected the surge in ways that protected properties directly behind them, but caused greater flooding to other properties, mainly in front of the marshes. Just as we would not build in front of a seawall or a levee, it is important to be aware of the impacts of building near wetlands.

Wetlands reduce flood losses from storms every year, not just during single catastrophic events. We examined the effects of marshes across 2,000 storms in Barnegat Bay, New Jersey. These marshes reduced flood losses annually by an average of 16 percent, and up to 70 percent in some locations.

Reductions in annual flood losses to properties that have a marsh in front (blue) versus properties that have lost the marshes in front (orange). Narayan et al., Nature Scientific Reports 7, 9463 (2017)., CC BY

In related research, our team has also shown that coastal ecosystems can be highly cost-effective for risk reduction and adaptation along the U.S. Gulf Coast, particularly as part of a portfolio of green (natural) and gray (engineered) solutions.

Reducing risk through conservation

Our research shows that we can measure the reduction in flood risks that coastal ecosystems provide. This is a central concern for the risk and insurance industry and for coastal managers. We have shown that these risk reduction benefits are significant, and that there is a strong case for conserving and protecting our coastal ecosystems.

The next step is to use these benefits to create incentives for wetland conservation and restoration. Homeowners and municipalities could receive reductions on insurance premiums for managing wetlands. Post-storm spending should include more support for this natural infrastructure. And new financial tools such as resilience bonds, which provide incentives for investing in measures that reduce risk, could support wetland restoration efforts too.

Improving long-term resilience

The dense vegetation and shallow waters within wetlands can slow the advance of storm surge and dissipate wave energy. USACE

Increasingly, communities are also beginning to consider ways to improve long-term resilience as they assess their recovery options.

There is often a strong desire to return to the status quo after a disaster. More often than not, this means rebuilding seawalls and concrete barriers. But these structures are expensive, will need constant upgrades as as sea levels rise, and can damage coastal ecosystems.

Even after suffering years of damage, Florida’s mangrove wetlands and coral reefs play crucial roles in protecting the state from hurricane surges and waves. And yet, over the last six decades urban development has eliminated half of Florida’s historic mangrove habitat. Losses are still occurring across the state from the Keys to Tampa Bay and Miami.

Protecting and nurturing these natural first lines of defense could help Florida homeowners reduce property damage during future storms. In the past two years our team has worked with the private sector and government agencies to help translate these risk reduction benefits into action for rebuilding natural defenses.

Across the United States, the Caribbean and Southeast Asia, coastal communities face a crucial question: Can they rebuild in ways that make them better prepared for the next storm, while also conserving the natural resources that make these locations so valuable? Our work shows that the answer is yes.


This is an updated version of an article originally published on Sept. 25, 2017.The Conversation Siddharth Narayan, Postdoctoral Fellow, Coastal Flood Risk, University of California, Santa Cruz and Michael Beck, Research professor, University of California, Santa Cruz. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo by NPS Everglades/Flickr (public domain)
New report by IPCC finds world faces huge risks if warming is not kept below 1.5C

New report by IPCC finds world faces huge risks if warming is not kept below 1.5C

By Elisa Jiménez Alonso

The UN Intergovernmental Panel on Climate Change (IPCC) has released a special landmark report on the impacts of 1.5 °C warming above pre-industrial levels. The report finds unprecedented changes would be necessary worldwide to keep warming below 1.5 °C but that it would massively decrease global climate risks.

The half-degree difference between 1.5 °C and 2 °C, the target range set out in the Paris Agreement during COP21, is a significant one. “Every extra bit of warming matters, especially since warming of 1.5°C or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems,” Hans-Otto Pörtner said, who leads the working group on impacts and adaptation.

At the current rate of warming, we could reach the 1.5 °C target as early as 2030 and 2052. Keeping to that ambitious warming target would significantly lower the risks of droughts, floods, extreme heat and poverty for millions of people across the globe. For example, the proportion of the global population exposed to water stress would be 50% lower at 1.5 °C than at 2.0 °C.

Climate adaptation needs will be much lower at 1.5 °C, above it there are limits to adaptation and adaptive capacity for some human and natural systems, meaning losses would become inevitable.

However, keeping to that target and not exceeding it would require “rapid and far-reaching” transitions across all sectors and human carbon dioxide emissions would have to be reduced by 45% from 2010 levels by 2030, reaching net zero by 2050.

“We have presented governments with pretty hard choices. We have pointed out the enormous benefits of keeping to 1.5 °C, and also the unprecedented shift in energy systems and transport that would be needed to achieve that,” said Jim Skea, co-chair of the working group on mitigation. “We show it can be done within laws of physics and chemistry. Then the final tick box is political will. We cannot answer that. Only our audience can – and that is the governments that receive it.”

At the moment the world is on track for disastrous 3 °C warming. Amjad Abdulla, IPCC board member and chief negotiator for AOSIS (Alliance of Small Island States) said “the report shows that we only have the slimmest of opportunities remaining to avoid unthinkable damage to the climate system that supports life as we know it.”

Download the IPCC special report on global warming of 1.5 °C by clicking here.


Cover photo by Zooey/Flickr (CC BY-SA 2.0)
‘Eternal’ Swiss snow is melting faster

‘Eternal’ Swiss snow is melting faster

By Paul Brown

Scientists say stretches of “eternal” Swiss snow are melting faster than 20 years ago, with serious impacts for water supply and tourism.

Parts of Europe’s alpine mountain chain are undergoing accelerating melting, as the “eternal” Swiss snow thaws ever faster, threatening both the skiing industry and the nation’s water supply.

Over a period of only 22 years, thousands of satellite images have provided irrefutable evidence that an extra 5,200 square kilometres of the country are now snow-free, compared with the decade 1995-2005.

Researchers from the University of Geneva and the United Nations Environment Programme have used data from four satellites which have been constantly photographing the Earth from space, compiling a record published by the Swiss Data Cube, which uses Earth observations to give a comprehensive  picture of the country’s snow cover and much else besides, including crops grown and forest cover.

It is the loss of snow cover that most disturbs the scientists. What they call “the eternal snow zone” still covered 27% of Swiss territory in the years from 1995 to 2005. Ten years later it had fallen to 23% – a loss of 2,100 sq km.

The eternal snow line marks the part of Switzerland above which the snow never used to melt in summer or winter. It is also defined as the area where any precipitation year-round has an 80-100% chance of being snow.

“We have stored the equivalent of 6,500 images covering 34 years, a feat that only an open data policy has made possible”

Other parts of the country, including the Swiss Plateau (about 30% of Switzerland’s area), the Rhone Valley, the Alps and the Jura mountains are also losing snow cover, adding up to the 5,200 sq km total. These areas, below the eternal snow line, have until now usually had lying snow in the winter.

The study was launched in 2016 on behalf of Switzerland’s Federal Office for the Environment. Knowing the extent of snow cover and its retreat is essential for developing public policies, the researchers say.

Beyond the economic issues linked to the threat to ski resorts – a familiar area of concern, heightened by this latest research, as many of them now face shortened seasons or outright abandonment – other problems such as flood risk and water supply are coming to the fore. Snow stores water in the winter for release in spring and summer, for both agriculture and drinking water.

Currently the increasing loss of ice from glaciers in the summer is making up for the missing snow, but previous work by scientists has shown that in the future, when glaciers disappear altogether, Switzerland could face a crisis.

The researchers have relied on the information available from the Data Cube to establish what is happening on the peaks. By superimposing repeated pictures of the same place over one another they have been able to observe small changes over time.

Wealth of data

The data was made freely available to researchers. One of them, Grégory Giuliani, said: “We have stored the equivalent of 6,500 images covering 34 years, a feat that only an open data policy has made possible. If we had had to acquire these images at market value, more than 6 million Swiss francs would have been invested.

“Knowing that each pixel of each image corresponds to the observation of a square of 10 by 10 meters, we have 110 billion observations today. It is inestimable wealth for the scientific community.”

Apart from snow cover scientists are worried about many other changes taking place in Switzerland because of climate change. They already know that glaciers are melting at record speeds and plants, birds and insects are heading further up the mountains, but there is much else to be gleaned from the new data base.

The Data Cube offers the possibility of studying vegetation, the evolution and rotation of agricultural areas, urbanisation and even water quality, as satellite images can be used to monitor three essential indicators in lakes and rivers: suspended particles, whether organic or mineral; chlorophyll content; and surface temperature.

The data are freely accessible, not only to scientists worldwide but also to the public, making it easy to compare data for specific areas of the territory at different times. “Our ambition is that everyone should be able to navigate freely in Swiss territory to understand its evolution”, said Grégory Giuliani.


Paul Brown, a founding editor of Climate News Network, is a former environment correspondent of The Guardian newspaper, and still writes columns for the paper.

This article was originally published on Climate News Network.

Cover photo by Steve Evans/Flickr (CC BY-NC 2.0)
Wildfires in Mediterranean Europe will increase by 40% at 1.5°C warming, say scientists

Wildfires in Mediterranean Europe will increase by 40% at 1.5°C warming, say scientists

By Cristina Santin,Swansea University and Stefan H Doerr, Swansea University

Europe’s Mediterranean regions have strong sunshine, bright blue seas, beautiful beaches, and pretty holiday houses immersed in pine forests that provide welcome shade. It sounds very inviting, but such a scenario is also perfect for severe wildfires such as the ones that killed 99 people this July in the popular holiday resort of Mati, in Greece.

Now, new research in Nature Communications suggests that the summer fire season in Mediterranean Europe is going to get worse. Under the hottest climatic predictions of 3°C warming, the area that is currently burned every year would double. Even more worryingly, 40% more area would be burnt even if the Paris Climate Agreement is fulfilled and warming stays below “only” 1.5°C.

So, time for Europeans to start looking for other holiday destinations? Hang on. Let´s look at the new study in more depth first.

In this modelling exercise, a team of scientists led by Marco Turco, a fire researcher at the University of Barcelona, predict the area that would burn in future summers in Mediterranean Europe following different degrees of warming. They base their approach on the findings of a recent study from some of the same authors, which looked at Portugal, Spain, southern France, Italy and Greece, and established a direct association between the area burnt in the summer months and summer drought in recent decades (1985-2011). They use that “fire-drought” relationship to estimate the area burnt under the drought conditions forecasted in three different warming scenarios (1.5°C, 2°C and 3°C).

The climate obviously has a direct effect on fires, as hotter conditions lead to drier vegetation more susceptible to burning. But the authors also account for indirect effects such as drier conditions reducing plant growth, meaning there is less vegetation to “fuel” the fires. This “non-stationary” climate-fire modelling is important because if the indirect effects were not considered the predictions of area burnt would be even higher.

So, are Turco and co-authors right? Will the future look blacker for the Mediterranean? Will tragic events, like those in Mati, become more frequent? Turco’s predictions, even if in many ways the most advanced to date, still carry a huge uncertainty, but they add to the growing list of studies that forecast more Mediterranean fire activity in future.

Climate change is not the only factor

What their study is unable to predict is the influence of perhaps the most important factor behind the future occurrence of fires, also the very same factor that is responsible for accelerated climate warming: humans.

Humans are the main source of ignition in most of the Mediterranean, and the main modifiers of vegetation cover. Including them (or us) in scientific models of fire is very challenging, and can radically change the results. For example, at the global scale, models that rely on climate change tend to predict a very substantial increase in area burnt – a hotter world means more fires, as you’d expect. But when human effects are incorporated, the estimated total area burnt can actually decrease to levels even below current ones. This is essentially because more and more land worldwide is being urbanised or converted to agriculture, resulting in smaller and more fragmented “wildland” areas that can burn.

We still have plenty to worry about, however, as global averages form only a small part of the story. In some parts of the world, such as Canada and the US, the area burned is already on the increase. Meanwhile, some houses are being built further into forests and other flammable vegetation, while other houses are finding themselves now surrounded by vegetation as nearby fields are abandoned and left to nature. Both situations leave more people exposed to fires.

In Mediterranean Europe the situation is particularly complex as the ongoing abandonment of traditional land uses is changing the vegetation more dramatically than climate change. Intensely grazed or cultivated land is becoming overgrown with shrubs or replaced with fire-prone forest stands, a trend that makes the landscape more flammable. This, combined with climate warming, can provide the perfect recipe for fire disasters. For example, Greece has seen less than half the area burned so far this summer than the 2008-17 average), but lots of dry vegetation for fuel, strong winds and a high population density combined to cause Greece’s deadliest fire on record.

The future of fire in Mediterranean Europe ultimately depends on the decisions we make. That means complying with the Paris Climate Agreement to reduce global warming but also adapting effectively to the increased risk of fire. And this does not necessarily mean suppressing all fires, which is often not possible, but managing the fuel and how we live among it. Policies aimed at removing fire completely from the landscape have long proven to fail, even if many countries still follow them.

Instead we need to create fire-resilient landscapes and fire-resilient societies. A holiday house in the middle of a pine forest may sound idyllic, but it can be a death trap when a fire occurs, and the study by Turco and his co-authors suggests that this will be even more likely in the future.The Conversation


Cristina Santin, Sêr Cymru II Fellow & Senior Lecturer, Geography & Biosciences Departments, Swansea University and Stefan H Doerr, Professor of Geography and Editor in Chief of the International Journal of Wildland Fire, Swansea University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo by Michael Held on Unsplash

The Conversation

After the storm passes: the reality of hurricane aftermaths

After the storm passes: the reality of hurricane aftermaths

By Georgina Wade

On 20 September 2017, an onslaught of catastrophic weather changed the lives of 3 million people forever. One year later, residents of Puerto Rico are still reeling from the effects of Hurricane Maria, a Category 4 storm that resulted in economic losses of nearly $140 billion and killed nearly 3,000 people directly and in its aftermath.

The tenth most intense Atlantic hurricane on record and the most intense tropical cyclone worldwide of 2017, it was a mix of highly favourable environmental conditions that allowed Maria to undergo explosive intensification as it approached the Caribbean islands.

It was the strongest storm to make landfall in Puerto Rico in 85 years with sustained winds of 155 mph (ca 250 km/h) resulting in a blackout across the entire island and dumping six months’ worth of rain in less than four days. Trees were uprooted, homes were destroyed, and widespread flooding caused more than 1.1 million Puerto Ricans to register for Federal Emergency Management Agency (FEMA) aid. With no power, running water was cut off for much of the population. Communications to and from Puerto Rico became nearly impossible for days. And when the cloud cover finally broke, the chaos during the storm was only matched by the disarray following it.

The aftermath

With the island’s power grid knocked out, it was only last month that electricity was finally restored to all customers. Emergency health services were left paralysed trapping people in need of care in their homes without access to medication or telephone service.

While previous government estimates had the death toll at 64, an independent study from George Washington University, released 11 months after the storm, found that an estimated 2,975 had died after Maria. The analysis suggested that Hurricane Maria was the second-deadliest storm to ever hit U.S. shores, following the Galveston, Texas hurricane of 1900 that killed an estimated 6,000 people.

Maria demolished 87,094 homes, with another 385,703 sustaining major damage. Up to a quarter of a million people were displaced. A year later, blue tarps covering damaged houses can still be seen by overpassing aircraft. What were supposed to be temporary fixes, are now tattered and fading in the sun as the island struggles to rebuild.

More than 200,000 Puerto Ricans left the island temporarily, with about 11,000 currently living in New York. However, housing funds set aside for Puerto Rican families forced to flee have now ceased. Just last month, a judge ruled that families had to move out from temporary FEMA housing by 14 September.

A long road ahead

Long after a storm dissipates, people still face a harsh reality. A single hurricane can undo years of development and plunge prosperous households into poverty from one day to the next. And while people are quick to focus on the immediate physical costs from hurricane strikes, the resounding social costs can be felt for decades to come.

Grenada, for example, is still dealing with the consequences of being hit successively in 2004 and 2005 by Hurricanes Ivan and Emily. Estimated losses amounted to 200 percent of gross domestic product and Grenada remains in “debt distress” according to the International Monetary Fund.

The Caribbean happens to be the most tourism-dependent region in the world. More than 47 million international visitors travelled to the Caribbean in 2016, spending $31 billion, according to an Oxford Economics study. When hurricanes Irma and Maria battered the Caribbean last fall, the region lost nearly 1 million visitors and an estimated $900 million USD in tourism-related spending. As tourism infrastructure is restored, further losses totalling more than $3 billion USD are expected over the next four years.

Such disasters also have an effect on mental health. Psychologists estimate that 30 to 50 percent of the Puerto Rican population is experiencing post-traumatic stress disorder, depression, or anxiety following Hurricane Maria.

“The storm takes away the foundations of society. Everything you thought gave you certainty is gone,” says psychologist Domingo Marques, an associate professor at Albizu University in San Juan. “You see people anxious, depressed, scared.”

Everyday routines that once included work and school commutes can come grinding to a halt, only contributing to the semblance of disarray many feel following such catastrophic events. Survivors may bounce back after a few months, or they may experience ongoing stressors, such as financial issues or problems finding permanent and safe housing.

While early disaster recovery efforts often focus on physical reconstruction, psychological recovery efforts typically end up on the back burner.

Building back better

Work towards a more resilient Caribbean starts with building back better. With a changing climate promising more intense storms in the future, it’s increasingly important that action is taken to not only recover from a storm, but to increase resilience to future ones.

In January 2018, following the Caribbean’s devastating hurricane season, The Overseas Development Institute (ODI) held its eventBuilding Back Better: A resilient Caribbean after the 2017 hurricanes”. The conference addressed four pillars for resilience building: Ecosystems and planning; Codes and practices; Economies; and Governance. Tying in with The Sendai Framework for Disaster Risk Reduction, the central idea is that stakeholders should share responsibility in reducing disaster risk and that growing disaster risk is putting a stronger emphasis on better preparedness and overall resilience.

Roundtable discussions included a debate on best approaches to financing and implementing post-disaster resilience building. As noted by several of the presenters, the damage caused by an extreme event can be two to three times higher than the annual GDP of the countries affected. This can mean that funds get diverted from other annual budgets such as education, transport or general development. And with a short timeframe between immediate disaster recovery and preparation for the next event, efforts to build long-term resilience are especially challenging.

Despite this, disasters caused by storms like Irma and Maria open windows of opportunity to rethink the measures needed to ensure a sustainable future. In some cases, disasters can be used to generate political momentum to increase climate resilience. For example, following the almost total devastation to the island of Dominica due to Hurricane Maria, the country responded with its intention to be the “first climate resilient country in the world”.

But many things are needed to build back better. To begin with, it requires a deep understanding of the causes of disaster, recovery processes and future climate risks. Additionally, it requires high levels of commitment from policymakers, the international aid agencies and donors supporting recovery, and from communities already engaged in recovery.

In their briefing paper, ODI introduced four principles that can help guide stakeholders as they transition from immediate responses to longer-term recovery.

  • Learn from history and avoid repeating it: understanding the historical and cultural factors that led to disaster is critical to identifying solutions.
  • Develop a holistic recovery framework: recovery frameworks should be based on priorities and activities in existing development strategies and land-use plans, to avoid creating a parallel planning system.
  • Create transparent, accountable and participatory processes: building consensus on key issues requires involving the widest possible array of relevant stakeholders
  • Leave no one behind: Certain types of intervention can deepen marginalisation. Recovery efforts should be built on the principle of ‘leave no one behind’.

Ultimately, disasters can be both a crisis from which to learn and an opportunity to do things better. While hurricanes are a common feature of the Caribbean, there has been limited investment in resilience building to address the many social repercussions of such storms. To avoid further human suffering, ‘building back better’ must become central to development efforts. Climate-related disasters should be used to challenge current decision making and promote investment on long-term climate resilience in the Caribbean and globally.


Cover photo by US Government (public domain): While conducting search and rescue in the mountains of Puerto Rico a Customs and Border Protection Air and Marine Operations Black Hawk located this home with HELP painted it is roof.
Climate science faces ‘pivotal moment’ and government questions

Climate science faces ‘pivotal moment’ and government questions

By Natalie Sauer in Incheon, Climate Home News

The UN’s climate science body began one of its “most important meetings” on Monday, as it presents to governments a report on warming the world just half a degree more than today.

The authors of the Intergovernmental Panel on Climate Change’s (IPCC) latest report will meet government delegates from Monday to Friday in Incheon, South Korea.

They will attempt to broker agreement on the policy recommendations from the IPCC’s latest major report, which looks at the impacts of 1.5C warming above pre-industrial levels, together with suggestions on how to stay below that mark.

The most recent draft of the ‘summary for policy makers’, published by Climate Home News, highlighted stark differences between the impacts of warming 1.5C and the upper limit imposed by the Paris deal of 2C. The world has already warmed roughly 1C.

The key question at this meeting will be how the draft changes after this week’s intense scrutiny from diplomats who represent national interests.

Hoesung Lee, the chair of the IPCC, described the conference as “one of the most important meetings in the IPCC’s history”.

“Science alerts us to the gravity of the situation, but science also, and this special report in particular, helps us understand the solutions available to us,” he said.

“This is a critical point in history,” said Youssef Nassef, director of Adaptation at the United Nations Framework Convention on Climate Change (UNFCCC) told the opening plenary on Monday. “The window of opportunity is rapidly shrinking and we must all work together to turn things around.”

Elena Manaenkova, deputy secretary of the World Meteorological Organization, also opened the session in earnest, stressing that the world stood “at a pivotal moment”.

“We need greater ambition and a greater sense of urgency,” she said.

Some governments, including the European Union, hope the report, ordered by the 2015 Paris Agreement, will bolster calls for more rapid emissions cuts.

Others fear the report for the same reason. On Monday, India’s Business Standard reported that the US has questioned the basis for the report in the lead up to this week’s conference. Last week, authors rejected reports that they were susceptible to political pressure.

South Korean environment minister Kim Eunkyung told the conference: “I understand that are still some climate sceptics out there. But let me tell you this: truth is truth. Climate change cannot be denied, or avoided.”

Drawing from the latest research on climate change, the report is the result of a mammoth collaboration between 91 authors and 114 co-authors. In total, the IPCC received 42,000 comments on the drafts of the report. Authors are bound to address each comment as part of the review process. Manaenkova said that the work as nothing short of “heroic”.

The final report is due out on Monday 8 October.


This article was originally published on Climate Home News and can be accessed by clicking here. It is shared under a Creative Commons license.

Further reading by Climate Home News:

Cover photo by Alfonsojung/Pixabay (public domain): Incheon skyline.
Americans who live far from coasts should also be worried about flooding

Americans who live far from coasts should also be worried about flooding

Editor’s note: This is an article that was written last year, however, the lessons from Hurricane Harvey still hold true and are also relevant to the aftermath of Hurricane Florence earlier this month.

By Nina Lam, Louisiana State University

Catastrophic flooding in Houston from Hurricane Harvey is the latest reminder that floods kill more people in the United States than any other type of natural disaster and are the most common natural disaster worldwide. Many communities along U.S. coastlines have begun to take heed and have slowed development in coastal flood zones. The bad news, as Harvey shows, is that inland communities are also at risk – and in some, development in flood zones is increasing.

With post-doctoral research associate Yi Qiang and graduate students, I recently studied development patterns in the United States from 2001 to 2011. We found that while new urban development in flood zones near coasts has generally declined, it has grown in inland counties. This is a worrisome trend. It implies that people who have experienced flooding on the coast migrate inland, but may not realize that they are still vulnerable if they relocate to an inland flood zone.

That’s what we have seen firsthand here in Louisiana. Thousands of people fled New Orleans after Hurricane Katrina in August 2005 and settled 80 miles inland in Baton Rouge. A decade later, many of these same people lost everything again when a 500-year flood event struck Baton Rouge in August 2016.

Climate change effects, such as sea level rise and potentially more extreme weather, are increasing the risk of flooding, hurricanes and storm surges in coastal areas. Some communities are considering moving coastal populations inland to protect them. However, our research shows that people should be very careful about moving inland. They can still face flood hazards if their property is located in a high-risk flood zone.

Not just a coastal issue

Flooding can happen wherever large rainstorms stall over an area, as we have seen in Boulder, Colorado in 2013; in Texas and Louisiana in 2016; and over Houston now. However, if communities take steps to reduce flood risk, they can mitigate the danger to people and property.

When we assess flood risk in a given location, we consider three questions.

  • Hazard: How likely is a flood event?
  • Exposure: How many people and physical assets are located there?
  • Vulnerability: Do people have the capacity to deal with the event?

Flood risk is the product of these three elements.

We can decrease flood risk by reducing any of the three elements. For example, communities can reduce hazard by building flood control structures, such as dams and levees. They can use laws and policies, such as land use controls, to reduce exposure by steering housing development away from flood zones. And they can make people and property less vulnerable through other measures, such as elevating houses and developing better flood warning systems and emergency preparedness plans.

How can people learn about flood risks where they live? The Federal Emergency Management Agency has created flood zone maps for most parts of the United States. The maps are based on models that consider factors such as elevation, average rainfall and whether a location is near a river or lake that could overflow.

FEMA maps classify flood zones into three categories: high-risk, moderate-low risk and undetermined. High-risk zones have at least a 1 percent chance of being inundated by flood in any given year. These areas are also called base flood or 100-year flood zones.

To obtain a federally insured mortgage on property in a 100-year flood zone, buyers are required to have flood insurance. This policy is designed to make people less vulnerable in the event of a flood, but it increases the cost of home ownership. As a result, flood zone designations can be very contentious.

100-year flood zones are based on a combination of statistics, hydrogeology and society’s tolerance for risk.

Moving into harm’s way

We undertook this study because we wanted to develop a clear baseline showing how Americans’ exposure to flood hazards has changed over the past decade. To assess levels of exposure to flood hazards nationwide, we compiled urban development, flood zone and census data and overlaid them on a county map of the nation.

Overall, we estimated that as of 2011, more than 25 million Americans lived in flood zones. We also found that inland communities were less responsive to flood hazards than coastal communities and were doing a poorer job of steering development out of flood-prone areas.

The three U.S. counties with the largest concentrations of people living in flood zones are located on the Gulf of Mexico. They are Cameron Parish, Louisiana (population 6,401, with 93.6 percent in flood zones); Monroe County, Florida (population 66,804, with 91.4 percent in flood zones); and Galveston County, Texas (population 241,204, with 82.8 percent in flood zones).

These are all coastal communities, where flood risks should be well-known to all residents. But we also found inland counties where the share of the total population living in flood zones increased over the decade we examined. A number of those with the largest increases are bordered by rivers, such as Marshall County in western Kentucky, which sits between Kentucky Lake and the Ohio River. We also identified several hot spots where urban development has increased in coastal flood zones, including New York City and Miami.

Heavy rainfall from Tropical Storm Harvey is forecast to reach hundreds of miles inland. National Weather Service

Reducing exposure now

This alarming trend points to a need for more awareness, education and communication about flood risk, especially in inland counties. More affordable housing in nonflood zones and strategies to mitigate floods are also needed, especially inland.

Why would people move to inland flood zone areas? Some may be unaware of the risk. Others may plan to adapt through steps such as elevating their houses or buying flood insurance. Still other may accept the risk because they want to be closer to relatives or workplaces, or for other cultural, political or institutional reasons.

Our analysis has pinpointed a number of regions of concern. The next step is to produce in-depth analyses of these regions, in order to understand why people are locating in flood zones there, and to devise local strategies to reduce overall U.S. flood risks. Climate change, land subsidence or sinking, and construction of new levees and dams will change long-term flood exposure in these areas over time. Therefore, local governments, mortgage lenders and homeowners should review current FEMA flood hazard maps for accuracy.

This research provides national context for a detailed study that we are carrying out examining resilience and sustainability in the Mississippi River Delta. Our goal is to understand how human actions combined with natural environmental conditions may have caused land to sink in the Mississippi Delta. Our research on development in flood zones reminds us that flooding problems in low-lying coastal regions are not unique and also affect areas well away from the shore.The Conversation


Nina Lam, Distinguished Professor of Louisiana Environmental Studies, Louisiana State University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo by Steve Zumwalt/FEMA (public domain): Jamestown, Colo., Sep. 15, 2013 — The small mountain town of 300 has been cut off because of Boulder County flood.
A journey across Alaska to discover climate change: Part 2

A journey across Alaska to discover climate change: Part 2

By Brooke Larsen and Alastair Baglee

Brooke Larsen and Kailey Kornhauser are bicycle riding across Alaska. Unsupported and self-propelled, they recently won a ‘Lael Rides Alaska’ women’s scholarship to ride 1001 miles from the coastal town of Seward in the south, all the way to Deadhorse and the Arctic Ocean in search of stories about climate change.

In Part 1 we saw Brooke and Kailey reach their journey’s half way point at Fairbanks. Now the real challenge awaits as they head north to the town of Deadhorse on Alaska’s North Slope high in the Arctic along the remote, steep and unpaved Dalton Highway.

Before setting off on the Dalton Highway, we listened to more stories from folks in Fairbanks and reflected on the impacts of a warming world we had witnessed thus far. We couldn’t stop thinking about our conversation with permafrost researchers at Eight Mile Lake off of Stampede Road, not far from Denali National Park and the place where Chris McCandless of Into the Wild died. Once we reached the research site, after biking up a series of short but painfully steep hills, we had to walk along narrow wood planks over thawing, muddy ground. We learned from the Northern Arizona University research team that Alaska has always had to deal with seasonal uneven ground, but now areas that once remained frozen are starting to thaw.

A rapidly changing landscape

Researchers from Northern Arizona University.

Historically permafrost has acted as a carbon sink, but as temperatures warm, permafrost thaws and becomes a carbon source. This is a big deal. Arctic permafrost currently stores more carbon than all the carbon humans have emitted into the atmosphere since the Industrial Revolution. While thawing permafrost escalates global climate change, it also has serious implications for the land and ecology of the Arctic. Drainages will change course and composition, the ground will sink, tree lines will move further up in elevation, and animals will change migration patterns. The people that rely on these lands for subsistence and spirituality will lose their way of life.

The researchers all reflected on the emotions of studying such dire science. I remembered a term I had heard from a climate scientist back home: Pre-Traumatic Stress Disorder. The term resonated with the team, and some questioned whether instead of measuring data they should be in the street demanding action. However, Megan, one of the lead researchers, concluded, “We contribute in the ways we can.”

Scott Rupp, the Deputy Director of the International Arctic Research Center.

In Fairbanks, we continued to learn more about the changes rapidly occurring across Alaska from Scott Rupp, the Deputy Director of the International Arctic Research Center. Scott tries to quantify uncertainty by building climate change models that can help Alaskans adapt to a warming world. He noted, “Here, there is such an immediate need for information that there isn’t a lot of time to think about impending doom.” He emphasized that climate change is already impacting almost everybody across the state, even if they don’t realize it yet. Personally, he’s observed big changes in wildfire in the area. While his models show that climate change will increase wildfires in the Boreal forests of central Alaska, Scott has witnessed the increase first hand while living in Fairbanks the past 20 years.

Beyond the science, though, we also heard stories from those on the frontlines. Esau Sinnok, an intern with Native Movement and a student at the University of Alaska-Fairbanks, comes from the Inupiaq community of Shishmaref. Melting sea ice and rising seas have pushed the 600-person Inupiaq community to repeatedly vote to relocate since 1973. Esau expressed skepticism about the community receiving the 250 million dollars needed to relocate. He said, “FEMA won’t do anything until after it falls apart.” The lack of federal assistance stings even deeper when considering that the Inupiaq people didn’t live permanently in Shishmaref prior to colonization. It was an important place for hunting sea life, but not a place for year-round inhabitance. Esau is the lead plaintiff in the case Sinnok v. State of Alaska—a climate lawsuit brought by 16 Alaskan youth. He is focusing on quickly finishing his studies at the University of Alaska-Fairbanks so he can continue to fight for his people. “It’s my responsibility to go back to my community. All 600 people raised me,” he said.

1,000 miles on the Dalton Highway

After meeting with people for a few days in Fairbanks, we finally set off for the most challenging part of our 1,000-mile ride: the Dalton Highway. We were pleasantly surprised by the road condition. Most blogs make the Dalton seem horrible. There was some loose gravel and potholes, but a decent amount of the supposedly unpaved road was paved, and for the most part, the gravel was in better condition than the deep, sandy unpaved roads we bike in the American Southwest. What challenged us more was the road’s grade. In the section known as the “rollercoaster,” hills were so steep we often had to get off and walk our bikes. When we slowed down, mosquitos and gnats swarmed, forcing us to quickly pull out our bug head nets.

The vast wildness of the surrounding landscape kept our spirits high. We often biked until 10 p.m. or later, our path lit by the midnight sun. Over each hill, the Brooks Range revealed more of itself in layers of blue, green, and gray. However, alongside feelings of awe, we also felt grief. While we admired the region’s beauty, we also felt anxiety about the Trans-Alaska Pipeline snaking along a few yards from our pedal strokes. The further north we went, the closer we came to the Arctic National Wildlife Refuge, a sacred region for the Gwich’n People under imminent threat from oil drilling.

Halfway through our journey, we reached Wiseman, where we stayed with Jack Reakoff, a famous local trapper, hunter, and tour guide whose family moved to Wiseman before the pipeline was built. He let us stay in one of his cabins, ceiling covered in sheep and caribou antlers, a grizzly bear head roaring down on us. We bathed in the Middle Fork Koyukuk River that flowed a couple hundred meters from his yard. Luckily the weather was beautiful, hovering around 80 degrees Fahrenheit (26.6C), making the bitter cold water seem more inviting. When we returned to the cabin, we were greeted by a familiar face. My partner, Galen, was in the middle of editing a film on the Arctic National Wildlife Refuge, and he couldn’t resist the chance to return to a part of the country he loved.

Brooke and Kailey crossing the Arctic Circle.

The next day we completed the final climb of the journey over Atigun Pass—the highest highway pass in Alaska. We felt such relief when we reached the top and couldn’t wait for a couple days of cruising through the Arctic. However, shortly after we reached the summit, ominous clouds surrounded us. As we descended, rain and mud soaked us. About fifteen miles down from the summit, Kailey’s brakes went out, pushing her into a panic attack as the fog became denser, the rain poured harder, and temperatures neared freezing.

Brooke and Kailey on the Dalton Highway. Photos by Galen Knowles.

The next few days only got colder and wetter. Visibility was so bad that truck drivers pulled over and threw us their vests. We thought the infamous mosquitos would pose the biggest challenge in the Arctic. Instead, temperatures dropped so low that the swarms nearly disappeared. When we finally reached Deadhorse, it was hard to feel celebratory in a town built solely for the oil and gas industry, especially after a miserable couple days of biking. However, spirits rose soon enough as we filled our bellies with warm food, took long hot showers, and slept.

Meeting scientists and campaigners

Bryan Thomas at NOAA’s Barrow Observatory.

Kailey and I reached the final destination of our tour not by bike, but plane. Our flight back to Fairbanks (where we’d fly out from to return home) had a layover in Barrow. We decided to extend our layover in this northern-most U.S. city to interview a few more people. Last year, temperatures reached such abnormally high levels in Barrow that algorithms removed data because it seemed unreal. We spent time with Bryan Thomas at NOAA’s Barrow Observatory, one of four NOAA observatories that contribute data to NOAA’s climate models and the famous Keeling Curve. Bryan works tirelessly to ensure that data collection instruments are functioning and working accurately. Regarding the importance of this long term observation, he said, “If we weren’t watching, we wouldn’t know.” He doesn’t believe he will see the Keeling Curve start to go down in his lifetime, concluding, “just like justice, the curve bends eventually, but it takes a long time.”

A taster of muktuk.

Alexander, a local young Inupiaq and the manager of the Airport Inn where we stayed, highlighted coastal erosion as his main climate change concern. He talked about the trifecta of rising seas, melting sea ice, and thawing permafrost that puts Inupiaq communities at particular risk. He discussed how melting sea ice not only has impacts on sea life, but also destabilizes subsistence livelihoods. Whaling is central to Inupiaq culture, and less sea ice makes this traditional subsistence practice increasingly dangerous and difficult. He reflected, “It affects us economically and spiritually.” Before we left, he let us try some muktuk from this year’s whale hunt.

Despite the dire situation, youth organizers in Barrow, Ana, Muck, and Naomi, left us with hope. They recently graduated from high school and are headed off to colleges across the country in the fall of 2018. Ana and Muck have been part of Alaska Youth for Environmental Action (AYEA). They learned how to lobby their representatives and found that communities across Alaska face similar challenges when it comes to climate change and environmental justice. They expressed concern about rising sea levels and the resulting coastal erosion. The ocean is central to their lives. Muck was born in the Philippines and moved with his family to Barrow when he was five. He said, “The ocean has always been a big part of my life.” Much of the North Slope’s economy is closely tied to the oil and gas industry. People rarely speak against the industry out of fear of losing jobs or heat to their homes. When asked about the conflict between climate action and the dominance of the oil industry, Ana responded, “We are an environmental paradox.” These young people find hope in groups like AYEA and young people standing up across the world. When asked how they feel about the pressure put on their generation, they all replied, “Empowered.” Social media has allowed them to stay connected to young organizers nationwide. Even though temperatures were well below freezing, they still stood outside their school for 17 minutes in coordination with the national March for Our Lives movement earlier this year.

Ana, Much, and Naomi from Alaska Youth for Environmental Action.

Overall, Kailey and I left Alaska full of gratitude for the opportunity to bike across such a wild, threatened place and meet inspiring people. The journey empowered us not only as women cyclists, but also young people concerned about a warming world. The climate challenges facing Alaska are daunting. Few places provide such a powerful glimpse into how human-caused climate change is already here. However, alongside the doom and gloom, Alaskans are rising. Their resistance, resilience, and adaptability show that a commitment to place, love of community, and a locally-driven just transition away from fossil fuels are our best bets at securing a thriving, regenerative future.

You can read about each segment of our ride in-depth on our website blog. We will be posting reflections from Alaska each week, with the goal of continuing to share stories from future rides.

Thanks to Brooke Larsen for sharing her stories, head to her Instagram to see more pictures from the trip Instagram.


Cover photo by Galen Knowles, used with permission.

Read more about how climate change is impacting Alaskan communities on our network:

Video: Climate change swallows an Alaskan school

Alaskan village hit by erosion and melting permafrost is denied request for disaster declaration

Alaskan town threatened by climate change gets federal funding for relocation

First ever assessment of climate change influence on India’s hydropower plants points to increased generation potential

First ever assessment of climate change influence on India’s hydropower plants points to increased generation potential

Will Bugler

Climate change will have a significant impact on India’s hydropower plants, according to a new study. Changes in rainfall patterns, snowmelt and streamflow in India’s major rivers however, will affect the design and operation of India’s planned and current hydro plants. Amazingly however, the role of climate change on hydroelectric facilities in the country remains largely unexplored.

India is the world’s 7th largest producer of hydropower, and the predictable, low-carbon energy source is vitally important for the country’s ambitions to improve energy supplies and cut greenhouse gas emissions. With India’s population continuing to grow, the demand for clean energy will rise in the coming years. Hydropower offers considerable potential to meet some of this demand. Estimates suggest that the country uses less than 20 % of its total hydropower potential.

Dams must be built to last

As with other large infrastructure developments, proper consideration of climate change on hydroelectric facilities is essential. The lifespan of a large, concrete dam can extend to well over 100 years. A hydropower dam built today will be operational in a considerably different climate in its later life.

The study, undertaken by researchers from the Indian Institute of Technology, provides the first-ever assessment of climate change impacts on the hydropower potential of 7 large hydropower projects in India. Each facility has an installed capacity of over 300 MW, and most are among the top 10 largest hydropower projects in the country.

The study found that all 7 reservoirs studied are projected to experience greater levels of overall rainfall by the end of the century, with some being up to 18% wetter than today. However, the increase in rainfall will not be evenly spread throughout the year. The authors expect that much of the increase will fall as heavy, monsoon rains. This means that the hydro-electric dams may have to withstand more severe flood events than have been previously experienced. It also means that streamflow will not increase throughout the year, meaning that the increased rainfall is unlikely to be matched by a similar increase in electricity generation potential.

The study also found that snow cover is likely to decline affecting several catchments of hydroelectric facilities. This decline in snow cover will mean reduce its contribution to streamflow in the winter season.

Other factors affect streamflow

Overall, the study found that that there would be an increase in streamflow for the 7 hydropower facilities, and that with good planning, India could increase its overall generation from hydropower. Planners should take account of climate-driven changes in streamflow to best capitalise on these changes.

To do this, it will be important to consider other factors, notably the changing demand for irrigation. Increased irrigation demand can have a significant effect on streamflow and reduce hydropower production capacity. If rain falls over shorter periods of time and in more intense bursts, the demand for irrigation in the longer dry periods is likely to rise. This could offset some of the potential increase in generation.

Other factors such as changing land-use patterns will also have significant impacts on India’s hydropower production capacity. However, it is clear from this study that climate change will have significant influence on the streamflow that reaches each facility. As streamflow is highly localised, and dependent of many contributing factors relating to local geography, assessments should be carried out on all current and proposed hydropower plants to assess how they will operate under various climate scenarios.

The study Projected Increase in Hydropower Production in India under Climate Change can be found here.


Kumar, A., Kumar, K., Kaushik, N., Sharma, S. & Mishra, S. Renewable energy in India: Current status and future potentials. Renew. Sustain. Energy Rev. 14, 2434–2442 (2010).

Cover photo by Thangaraj Kumaravel/Flickr (CC BY 2.0): Sharavathi hydroelectric power plant view.
Australian ecosystems crippling under weight of climate change

Australian ecosystems crippling under weight of climate change

By Georgina Wade

­­Ecosystems across Australia are on the brink of collapse under climate change. Research published in Nature Climate Change analysing the interaction of gradual climate trends and extreme weather events since the turn of the century describes a series of sudden and catastrophic ecosystem shifts that have occurred recently across Australia.

Amongst the most notable tragedies, a mass mortality of corals on the Great Barrier Reef occurred in 2016 after 30% of the reef’s corals died in a relentless nine-month marine heatwave with an additional 20% bleached to death in 2017. And with Australia’s average sea temperature having increased by about 1°C since the start of the 19th century and continuing to climb, the remaining corals face the same fate.

Australia is one of the most climatically variable places in the world. In a study from Environmental Research Letters, Australia showed the highest inter-annual variability of any continent and also showed the highest biome-level variability of any continent for tropical forest, temperature broadleaf forest, and tropical savannas and grasslands.

And despite being a highly populous region involving numerous activities that transform the natural landscape, Australia retains large tracts of near-pristine natural systems.

Many of these regions are iconic, providing benefits to the tourism industry and sustaining outdoor activities while providing precious ecological services. In spite of this, the stress of climate change and extreme weather events is causing environmental alterations in these valuable ecosystems.

The research examined several ecosystems across Australia that have experienced catastrophic changes in the last decade and found that undisturbed systems are not necessarily more resilient to climate change.

Describing a combination of “presses” and “pulses” in which gradual climate change can be thought of as an ongoing “press” on which the “pulse” of extreme events is now superimposed, the case studies provide a range of examples in which both can interact to push an ecosystem to a “tipping point”.

The difficulty in foreseeing the timing and severity of extreme weather events makes predicting ecosystem collapses essentially impossible. Additionally, the cost of targeted interventions can be exorbitant.

Between the uncertainty and associated costs, interventions are difficult to implement and might even require controversial methods like assisted colonisation. Ecosystem management will not only require high policy and philosophy fluidity, but decisions will increasingly need to be made faster and potentially without fully understanding ecological and evolutionary consequences.


Harris, R.M.B et al. (2018). Biological responses to the press and pulse of climate trends and extreme events. Nature Climate Change, Vol. 8, pages 579–587 (2018).

Cover photo Wikimedia Commons (CC BY-SA 3.0): Bleached branching coral (foreground) and normal branching coral (background). Keppel Islands, Great Barrier Reef.