As the demand for climate services grows, questions are beginning to be asked about the assumptions behind some of the tools and methods used to translate climate science into information that can be used by decision-makers. Many of these assumptions are considered to be proprietary, and therefore exist within a ‘black box’, with end users unable to scrutinise the methodologies. This means that users are not able to fully understand the assumptions that underpin the findings of the climate risk analysis, and the recommended course of action. Are we making resilience decisions in the dark?
There are an estimated 350 commercial climate and weather services providers in the U.S., a rapidly growing figure as the market continues to mature, and the impacts of climate change to commerce become more frequent and intense. In the U.S., commercial service providers rely on publicly available data, from agencies like NOAA and NASA, to develop value-added products and services for decision-support. This may be targeted at a particular sector, or in relation to a particular climate or weather hazard. An example of a value-added service could include a flood risk assessment tool that alerts property developers to flood risk potential. The property developer leverages this information to avoid investment in a particular area or build to withstand future flood risk potential.
The U.S. model of free and open access to data has created the foundation for a commercial value-added weather service industry that has enabled a sub-sector worth around $7 billion. For meteorologists or technological savvy entrepreneurs, this presents a large market opportunity to develop value-added tools based on information that is freely available. While anybody could theoretically access NOAA or NASA data to inform climate and weather-related decision-making the data is usually not available in formats that are accessible to a non-expert user. Therefore, the value-added process is an important step to make the information useable, and inform decision-making.
The users of the products likely do not understand the climate and weather data behind the applications, nor the value-added processes that render this information usable. The end results – a level of risk, or a dollar sign – may be the only information they are interested in. However, for those users that want to dig a bit deeper into the data and processes that inform the service, they may run into a black box. In crude terms, the general approach to developing a client-facing service appears to be: meteorological data (i.e. NOAA / NASA) + other data + client specific information + proprietary algorithm = value-added service.
While service providers may disclose the meteorological information that they are accessing (such as station data from NOAA) the process of adding value to this information is often considered proprietary. Commercial service providers generally do not disclose their methodology in fear of compromising their cutting edge against a competitor. They provide demos of the service but do not open up the contents. This raises the question of how can the products be open to scrutiny and comparison if they are proprietary? How can a user make an informed decision between one service and the next, if they don’t have substantial information about either?
Importantly, there is no consensus on governance standards for developing, or applying climate services (Adams et al, 2015). The WMO’s Global Framework on Climate Services is guiding the development of climate services for decision-support in climate sensitive sectors, particularly in developing countries, however there is no entity – to our knowledge – vetting commercial applications.
Climate services are a big and growing industry, with new firms continuing to enter the market. As individuals and businesses are increasingly making risk-management decisions based on the output of these services, worth large sums of money, what mechanisms are in place to ensure the integrity of these services? Will the black boxes become more transparent? Will a third-party be allowed to peer inside the black boxes? Or will the market grow in a similar to that of the catastrophe modeling industry where black boxes are the norm
York City Panel on Climate Change (NYCPCC), released last month, its 2019
report on the science of climate change and its implications for New York
City. The report finds that climate change is affecting everyday life in New
York today, and that climate impacts will continue to increase over the coming
decades, hitting the poorest neighbourhoods hardest.
The NYCPCC, which has been helping NYC prepare for climate
change since 2008, found that extreme weather events are becoming more
pronounced, high temperatures in summer are rising, and heavy downpours are
increasing. The report finds that areas with lower incomes and the highest
percentages of African American and Hispanic residents are consistently more
likely to suffer the impacts of climate change. The panel advises that
community engagement is critical for more effective and flexible adaptation
efforts in the most at-risk communities.
The report serves as a “further wakeup call on the need to
move urgently and take action on climate change” according to New York’s mayor
Bill de Blasio. “This [report] shows what New Yorkers learned acutely during
Sandy – climate change is real and an existential threat,” he said.
Records show that maximum daily summer temperatures have
been rising at rates of 0.5°F per decade at JFK Airport and 0.7°F per decade at
LaGuardia Airport since 1970. Sea level recorded at The Battery in lower
Manhattan continues to rise at a rate of 0.11 inches per year since 1850. These
changes are broadly in line with the climate change projections made by the
NPCC in 2015.
The report also emphasises that climate change is already
affecting the daily life of NYC residents, especially for those who
live in coastal communities where nuisance flooding is becoming more frequent
and for those who operate and use the city’s critical infrastructure during
heatwaves and heavy downpours. Economic losses from hurricanes and floods have
significantly increased in past decades and are likely to increase further in
the future from more intense hurricanes and higher sea level rise.
“Recent scientific advances have allowed the NPCC to better
detail climate vulnerabilities in the city, such as where nuisance floods might
occur more frequently,” says William Solecki, co-chair of the NPCC. “This
improved knowledge has, in turn, helped the panel craft new sets of tools and
methods, such as a prototype system for tracking these risks and the
effectiveness of corresponding climate strategies.”
One of those tools is the Antarctic Rapid Ice Melt Scenario,
which the NPCC created to model the effects of melting ice sheets on sea level
rise around NYC. The model predicts that under a high-end scenario, monthly
tidal flooding will begin to affect many neighbourhoods around Jamaica Bay by
the 2050s and other coastal areas throughout the city by the 2080s.
“The NPCC 2019 report tracks increasing risks for the city
and region due to climate change,” says Cynthia Rosenzweig, co-chair of the
NPCC and senior research scientist at Columbia University’s Earth Institute.
“This report, the third by the NPCC in ten years, continues to lay the science
foundation for development of flexible adaptation pathways for changing climate
To help manage the dynamic climate and public policy
contexts, the NPCC 2019 report recommends that the city put in place a
coordinated indicator and monitoring system to enable the city and its
communities to better monitor climate change trends, impacts, vulnerability,
and adaptation measures. The report also notes that property insurance can be a
catalyst for infrastructure resilience by encouraging investment in adaptation measures
prior to a disaster through a reduction in premiums.
Other NPCC recommendations include:
continuing broad assessments of climate change
across the metropolitan region with federal, state, and regional partners (for
example, NOAA’s Consortium for Climate Risk in the Urban Northeast);
using updated methods for the next set of NPCC
climate change projections; and
hosting a NYC Climate Summit once during every
Melting glaciers, rising sea levels, global warming and violent storms: the effects of climate change are well documented. But a growing weather trend that has caused much concern is storm clustering – when three (sometimes more) hurricanes or typhoons group together in a short space of time, gathering strength and unleashing even greater devastation.
The development of a tropical depression – a low pressure area with thunderstorms and winds below 39mph – to a tropical storm that attains hurricane strength in less than six hours, shows how quickly these things can intensify.
But increased frequency is also a trend, as storms follow each other in quick succession. Those who question the existence of climate change should look at the global hurricane history, or even the hurricane pattern in their own country. If we look at these storms, patterns of increasing intensity and frequency clearly demonstrate how climate change is having a direct impact on the way hurricanes behave.
In developed countries coastal residents in affected areas are keenly aware of these hazards and respond well during emergencies by liaising with local agencies and heading to designated shelters during evacuations. But this is not the case in developing and underdeveloped countries, although basic response awareness exists through devastating experience and a degree of public information.
Predicting the big ones
Thanks to advances in hurricane forecasting and hindcastingtechniques, situations like the Galveston hurricane in 1900, which struck the Texas coast without any official warnings, are happily a thing of the past.
But the real issue is how prepared we are around the world for the increasing frequency of hurricanes and their terrifying “gang” version, hurricane trios. This violent onslaught of hurricane-strength storms batters communities and destroys buildings and infrastructure from the US to the Caribbean to South-East Asia. But should communities on the coast stay and defend, or retreat altogether?
Hurricanes hammered the Atlantic from 2016 and 2018, including the Category 5 Matthew (2016), the Harvey-Irma-Maria trio (2017), which registered Category 4, 5 and 4 respectively, and Category 4 Florence and Michael (2018). This not only revealed the rising trend in intensity and frequency, but also alerted the world to the phenomena of clustering.
Critically, predicting the path of a hurricane depends on forecasting the dynamics of its intensity. Understanding the factors that contribute to the sudden changes in the strength (or weakening) of a hurricane is crucial. Changes in wind direction, interaction with the land at the coast, and ocean temperature and depth all play their part in altering the intensity of a hurricane that is highly sensitive to even slight changes.
In general, the accuracy of predicting the way a hurricane intensifies and then re-intensifies in less than 24 hours is more challenging than predicting its path. But these dynamics are the underlying factors which compound the threat of hurricane frequency. These dynamics are also capable of further altering storm surge characteristics by triggering coastal and inland flooding – such as abnormal rises in water levels – which often result in shocking devastation.
Hurricane Michael in 2018 was the perfect example of the importance of predicting how rapidly a hurricane has intensified before it hits the coast, in this case Florida. The predicted track of the storm was almost accurate but its intensity was more difficult to assess.
The National Hurricane Center forecasted Michael’s path by issuing a five-day cone of uncertainty advising of sustained winds of 65mph. However, the sudden change in the storm’s dynamics changed a Category 1 hurricane to a Category 4 with winds of 155mph. This underscores the uncertain and variable nature of hurricane prediction.
Building on sand
Despite these emerging and changing weather-related risks, residential and public buildings are still going up on affected coastal areas. Recent research in China identified a tsunami that swept away the present-day coastal province of Guangdong in 1076AD. It means storm-related surges have been documented in the region for more than 1,000 years – yet still building and expansion goes on heedless of the risk.
This is almost the same situation for all vulnerable coastal cities. For instance, Florida has hundreds of thousands of coastal residents living in Low Elevation Coastal Zones – land that is less than ten metres above sea level and within 200km of the coast – but yet again construction there continues despite the threat of hurricanes every season.
Developers are already conceiving storm-resilient buildings that can withstand winds of at least 200mph – a Category 5 hurricane. But it’s unlikely many have considered the compounded stress effect on structures having to continuously withstand hurricane force winds more frequently and in quick succession.
Building massive sea defences along vulnerable coastlines is practically impossible and isn’t a permanent solution to increasing coastal storm hazards. There is no point in risking lives by remaining, as storm clusters can be unpredictable. It is simply too dangerous, so evacuation is the only option. However, when it comes to coastal assets and investments, defending in a more appropriate and sensible way is required.
Some coastal cities are planning ahead. A recent development of extensive parks in Boston, US, aims to protect the urban shoreline infrastructure from flooding. And a 2009 studyrevealed the effectiveness of mangrove planting in coastal areas of India to protect the shoreline and reduce cyclone damage. But more practical solutions are needed, especially in more vulnerable developing regions, because cluster storms are not going away any time soon.
This article was originally published on The Conversation and was republished under Creative Commons Licensing.
Extreme temperatures can have a significant impact on the
risk of developing cardiovascular complications, a new study suggests. Researchers
from Ludwig Maximilian University in Munich, Augsburg University Hospital and
Nördlingen Hospital, found that high temperatures are a contributing factor to
heart attack rates, and suggests climate change may have increased the risk.
It has long been assumed that severe spikes in temperature
increase the risk of heart attack. “In the case of very high and very low
temperatures in particular, this has been clearly demonstrated. In this latest
study, we wanted to see to what extent the heat and cold-related heart attack
risk has changed over the years,” explains Dr. Kai Chen, researcher at the
Institute of Epidemiology at Helmholtz Zentrum München.
The research team looked at over 27,000 heart attack
patients between 1987 and 2014. The individual heart attacks were compared
against meteorological data on the day of the attack and adjusted for a range
of additional factors, such as the day of the week and socioeconomic status. “Our
analysis showed that, over the last few years, the risk of heat-induced heart
attack with increasing average daily temperature has risen compared to the
previous investigation period,” explains Chen.
Individuals with diabetes or hyperlipidaemia were
particularly at risk over the latter period. The researchers suspect that this
is partly a result of global warming, but that it is also a consequence of an
increase in risk factors such as diabetes and hyperlipidaemia, which have made
the population more susceptible to heat.
“Our study suggests that greater consideration should
be given to high temperatures as a potential trigger for heart attacks; especially
in view of climate change,” explains lead researcher Dr. Alexandra
Schneider. “Extreme weather events, like the 2018 heat waves in Europe,
could in future result in an increase in cardiovascular disease. At the same
time, there is likely to be a decrease in cold-related heart attacks here in
Germany. Our analysis suggests a lower risk in the future, but this lower risk
was not significant and very cold days will continue to represent a potential
trigger for heart attacks.”
Kai Chen, Susanne Breitner, Kathrin Wolf, Regina Hampel, Christa Meisinger, Margit Heier, Wolfgang von Scheidt, Bernhard Kuch, Annette Peters, Alexandra Schneider, A Peters, H Schulz, L Schwettmann, R Leidl, M Heier, K Strauch. Temporal variations in the triggering of myocardial infarction by air temperature in Augsburg, Germany, 1987–2014. European Heart Journal, 2019; DOI: 10.1093/eurheartj/ehz116
The City of Cape Town – and southwest Africa more generally – experienced its worst drought on record between 2015 and 2018. With fresh rains as well as careful water management, the city has now emerged from this environmental and economic emergency.
The final consequences of the drought might never be known for certain. This is because the effects on groundwater depletion or biodiversity loss may not appear until years after the event. But the economic impact of the drought is more easily identified. Over 30,000 jobs have been lost in the agricultural sector in the Western Cape region, caused by a 20% decrease in agricultural production.
There are other consequences too, such as the impact on the city’s international reputation, as well as residents’ and policymakers’ experiences of water restrictions and the threat of “Day Zero”.
So what are the lessons learnt?
The City of Cape Town has recently released a draft strategy for water supply and management which aims to ensure safe access to water and sanitation for all the city’s residents, efficient water use, diversified water sources and shared costs and benefits by 2040. This strategy has been strongly informed by events of the past three years and is a bold statement of intent. As such, it sets a benchmark for sustainable development in the city and the wider region. The strategy is aimed at increasing usable water availability and managing that water better. But some elements are missing.
An uncertain future
Missing parts of the strategy include the uncertainty of future trends in climate, economic activities, population growth, water demand and infrastructure investment needs. Increasing water availability is easy in theory because it is based on balancing supply to need. But this water needs to come from somewhere.
Rainfall is becoming ever more precarious, groundwater aquifers are depleted, and river and dam water is already allocated. Desalinisation is an option. But this is expensive and has unknown environmental impacts.
Another option is water redistribution. In the recent drought, water was diverted from the agriculture sector to supply the city. But this had ripple effects on farming communities and economies. This approach is probably no longer sustainable.
There is also the option of reducing water demand. The new draft strategy doesn’t specifically mention managing demand – it makes vague reference to the need to use water wisely. It may be that the memory of water restrictions is too recent to discuss in this document. But water management is not just about supplying water, it’s about changing hearts and minds. These take much longer to change. For some Capetonians, the drought is over and normal business is resumed. For others, the spectre of Day Zero still remains.
And the plan doesn’t indicate that lessons have been learnt. For example, an innovative Water Map used by the City of Cape Town was able to “name and shame” excessive water users, but some township users were exempt from restrictions while other wealthy users largely ignored the water restrictions because they could afford to pay the resulting fines.
This kind of behavioural analysis is important when it comes to equitable planning and water management, and provides a rich source of data for drought epidemiology – Cape Town knows more about how its residents use water than most cities.
Emerging from disaster
Over the next decades, it’s anticipated that southern Africa will experience both higher average annual temperatures, in particular in summer. It’s also expected to have more variable and somewhat lower rainfall. Collectively, these climatic changes will result in greater water insecurity, irrespective of any changes in population, water demand or capacity of water infrastructure.
A recent study shows that climate change has trebled drought risk in Cape Town. Future-proofing cities such as Cape Town to withstand water insecurity and drought conditions cannot be done without managing water infrastructure better. In South Africa, 56% of waste water treatment plants are not fully operational. This limits its ability to deliver on the future promises outlined in the City of Cape Town strategy document.
Water restrictions in Cape Town have eased over recent months. But persistent drought still exists elsewhere in the region, in small town rural communities where there’s a lack of water infrastructure, lack of access to dam water supplies and depleting aquifers. Addressing the future water problem for Cape Town should not be done at the expense of the wider region, and must be formulated as a national-scale strategy. This should be a government priority.
This article was originally published on The Conversation and has been republished under Creative Commons license.
By Jessica Eise and Natalie White, Purdue University
In Colombia’s coffee-producing region of Risaralda, small trees run along the sharp incline of the Andes Mountains, carefully tended in tidy rows. Thousands of green coffee berries turn brilliant red as they ripen, ready to be harvested by hand. The steep hills here prevent mechanized techniques.
Its unique geography makes Colombia one of the world’s greatest coffee-producing nations, selling US$2.64 billion of mild, high-altitude Arabica beans to countries around the world each year. Only Brazil and Vietnam export more coffee.
Despite their global reach, coffee farms in Colombia are generally family-owned and modest in size – perhaps 5 to 12 acres.
We asked 45 farmers questions that tapped into the farmers’ own conceptualization of climate change, such as “What is climate change?” and “How, if at all, has climate change affected you as a farmer?”
The results were stark.
Over 90 percent of the coffee farmers reported changes in average temperature. Seventy-four percent said droughts had gotten longer and worse, and 61 percent reported an increase in mountainside erosion and landslides because of more rain.
The farmers also perceived impacts of these environmental changes on their crops. Ninety-one percent reported changes in the flowering and fruiting cycles of the coffee plants. Seventy-five percent had noticed an increase in pests, and 59 percent reported an increase in crop disease.
These changes have created uncertainty about previously routine farming decisions.
Because the planting and harvesting seasons are no longer regular or predictable, for example, many farmers cannot rely on traditional seasonal indicators to guide them about the right time to plant, harvest or tend to their coffee crops.
Organizing labor to pick the coffee beans has also become a struggle because the trees often do not flower at the same time due to unstable seasonal conditions. New Colombian labor laws meant to decrease child labor make finding farmhands difficult, compounding the problem.
In short, the farmers saw climate change as nothing less than an existential threat.
“Our ability to counteract the effects of climate change is minimal,” one farmer told us. “It is a threat capable of greatly incapacitating us. So we must be very attentive to the little we can do to mitigate.”
Growing coffee in today’s climate
From 2008 to 2013, Colombia’s coffee production dropped approximately 33 percent due to the El Niño and La Niña inclement weather patterns, when rains, clouds and hot spells all increased.
The country has worked to increase its production since then, and this year Colombian coffee farmers are expected to produce 13.3 million bags of coffee beans – roughly 1.8 billion pounds – up about 23 percent from 2013 levels.
But they’re still short of the national production goals of 14.7 million bags, a shortfall the Colombian National Coffee Federation has attributed to excessive rain and cloudiness.
Even before climate change endangered their crop, Colombian coffee farmers were already operating on a very slim profit margin.
Most producers sell their coffee to the Colombian National Coffee Federation, a nonprofit cooperative founded in 1927 to represent Colombia’s coffee farmers nationally and internationally. It values Colombia’s coffee exports using a price scale tied to the New York Stock Exchange.
Since that price fluctuates daily, it is difficult to calculate an individual farmer’s exact income or losses, but most small farmers in Colombia barely break even.
Under such circumstances, even one crop failure can devastate the family farm.
Farmers struggle to adapt
To adapt to Colombia’s changing climate, some farmers have begun experimenting with new farming techniques they think might help offset its impacts.
Roughly one-third of the farmers we interviewed had planted trees on their farms to shade coffee plants during hot spells and to prevent soil erosion during big storms. Others were building water tanks to collect rainwater during droughts.
Some coffee farmers had also diversified their crops, adding banana and avocados trees to their farms to reduce the risks of any one crop’s failed harvest.
But fully one-third of all the coffee producers we spoke with – 14 of our interviewees – are still farming as their families have for centuries.
They’re not unconcerned about the environmental changes affecting their farms. Yet time pressures and lack of resources give them little choice but to focus on short-term demands like making payroll, paying debts and keeping food on the table.
Keeping Colombia’s coffee industry alive
Climate-related production challenges are a concern not just for the farmers we interviewed but also for Colombia’s economy.
Other developing countries where the coffee industry is being hit hard by climate change, such as Brazil and Tanzania, have tried some successful adaptation strategies. These include introducing new varieties of coffee beans, improving soil and water management and increasing access to loans and other financial services to help farmers weather failed crops or invest in new technologies.
That was the work we began to do in Risaralda. We hope our findings can help the Colombian government work with farmers to help them adapt their farming practices for a future of more extreme, unpredictable weather.
Farming in the face of climate change involves grappling with many complicated economic, informational, labor and business problems. Colombian coffee farmers want to succeed, but they’ll need help in all of these areas just to survive.
For the first time in its history, the World Ocean Summit was held in the Middle East. Last month, Abu Dhabi hosted the sixth edition of the event, which is organised each year by the Economist Group’s World Ocean Initiative. The three-day conference highlighted the threat posed by climate change to the world’s oceans, and drew attention to water-related climate risks to the United Arab Emirates (UAE) and other Gulf States.
Sea level rise in particular is a significant concern for the UAE, where almost seventy percent of the country’s gross domestic product is dependent on the ‘blue economy’ (including fisheries, maritime transport, renewable energy and tourism). “Any sea level rise is going affect a huge part of our coastal areas. Almost 80 percent of our population is living in coastal areas, so their communities are going to be destroyed,” said Thani Al Zeyoudi, the United Arab Emirates’ Minister of Climate Change and Environment, speaking to CNBC news last month.
The UAE is amongst the most vulnerable countries in the world to climate change. Over ninety percent of its infrastructure is coastal, and estimates suggest that the country could lose as much as 6 percent of its developed coastline by the end of the century. Al Zeyoudi also listed water scarcity as a major risk for the country. “Water scarcity here in the region and the droughts is affecting most of the sectors, especially agriculture, so that is why most of our food is imported from abroad,” he said.
Al Zeyoudi’s interpretation is supported by the UAE’s recently released, climate risk assessment, published in January buy the Ministry of Climate Change and Environment. The report says that the country faces very significant challenges to adapt to a climate that “may impose new and overwhelming pressures on the country’s environment, economy, and society”.
The climate risk assessment considered how climate change phenomena could affect four sectors – human health, energy (electricity and heat), infrastructure, and the environment. Ten priority climate risks were identified which were rated very high or high according to the risk assessment framework developed for the analysis.
The highly interconnected nature of the climate risks means that adaptation and resilience building measures need to be considered across all government departments and economic sectors. This will require increased ambition from the UAE’s in terms of its response to climate change. Its nationally determined contributions (NDC) to greenhouse gas emissions reductions made under the UNFCCC, were rated as ‘insufficient’ and its current policies on adaptation are not sufficient to protect the country from future climate shocks.
For the fourth year in a row, the United States has ranked 15th in the University of Notre Dame’s Global Adaptation Initiative (ND-GAIN) Country Index. The annual index ranks 181 countries on vulnerability to extreme climate events such as droughts, superstorms and other natural disasters as well as readiness to successfully implement adaptation solutions. Since the index launched in 1995, the U.S. has trended each year at or below its previous ranking, except for 2013.
This information comes on the heels of volume two of the fourth National Climate Assessment from the U.S. Global Change Research Program, which states that the country’s expanded mitigation and adaptation efforts over the years have not yet risen to the level necessary for avoiding substantial damages to the economy, environment and human health. Patrick Regan, associate director of the Environmental Change Initiative for ND-GAIN and professor of political science at Notre Dame, said the ND-GAIN Country Index’s data suggest that adaptation needs to take a much more central focus across our cities and towns.
“Although stability in the rankings is consistent among all developed countries, the index shows a similar trend to the latest National Climate Assessment — the U.S. national efforts to reduce climate vulnerability has plateaued,” said Regan. “Humans are the primary cause of climate change, and if the country wants to get serious about mitigation and adaptation, action needs to happen at the city level to address individual community vulnerabilities.”
To create the ND-GAIN Country Index, researchers measure common factors of successful adaptability to climate change, such as improved economies, access to resources including reliable drinking water, agricultural capacity and political stability. Because the index is measured at the country level, city-to-city vulnerabilities are impossible to discern with the ND-GAIN Country Index.
In 2018, ND-GAIN launched the Urban Adaptation Assessment (UAA) to support cities within the U.S. whose populations are above 100,000 in their prioritization of adaptation efforts. The UAA is a free, open-source measurement and analysis tool that explores a city’s ability and readiness to adapt to climate change. Through detailed visualization of adaptive capacities and social vulnerabilities at the sub-city or neighborhood level, the UAA can inform the development of strategies and adaptation preparedness across communities.
“Where the Country Index shows an overall ranking on a global scale, the UAA was created to be a starting point for U.S. cities by providing details with the projected cost and probability of climate-related hazards, such as drought, flooding and sea level rise, in 2040,” said Regan. “Now communities have this interactive tool to explore the connection between vulnerabilities and climate hazards, and help them decide which climate adaptation strategies to enact locally.”
ND-GAIN’s full country ranking, country profiles and visualization tools are available at gain.nd.edu/country, while the UAA database, funded by The Kresge Foundation, can be found at gain.nd.edu/urban.
The ND-GAIN Country Index aims to unlock global adaptation solutions that save lives and improve livelihoods while strengthening market positions in the private sector and policy decisions in the public sector. Measuring not only vulnerability but also the readiness to take on investment, it informs strategic, operational and reputational decisions regarding supply chains, capital projects and community engagements. The index includes 21 years of data across 45 indicators for 181 countries. ND-GAIN is housed in the Environmental Change Initiative of the University of Notre Dame.
March 8th is International Women’s Day, a time to reflect on how women are helping their communities overcome enormous challenges.
Byanyima: “Where I come from in Uganda, we are seeing the impacts of climate change already … droughts, flooding, droughts, flooding, farmers lose their crops.”
Winnie Byanyima, Executive Director of Oxfam International, says the effects of climate change often hit women the hardest. That’s because in many places, women are the ones responsible for farming and providing food for their families, frequently without much money.
But rather than talking about women as victims of climate change …
Byanyima: “I prefer to talk about women as providers of solutions to climate change.”
She says in many places, women collaborate and support one another as they adapt to more extreme weather.
Byanyima: “You see women forming communities to farm together, to lend each other money, adapting their farming methods or fishing methods, looking for ways to survive the impact of climate change, so I call them the climate heroes.”
Editor’s note:Kolkata and the Sundarbans face a deadly melange of climate change impacts: intensifying heat waves and rainfall extremes, an exceptionally rapid rise in sea levels and intensifying cyclones. Chirag Dhara, a climate physicist, visited Kolkata and the Sundarbans in November 2018. He interviewed a wide cross-section of people – college students and professionals, taxi drivers and street dwellers – on their experience of changes in their city’s climate.
He also spoke to experts and activists working in health, science and environment. This five-part series integrates public perception with expert opinion. It contextualizes local climate trends within country-wide and global trends, using photographs, videos, satellite imagery, infographics, concept schematics and the latest developments in climate research. Important scientific concepts have been simplified to better explain the causes and consequences of these changes. This is the third part of the series.
The photographs above of a school on the edge of Sagar Island, in the Indian Sundarbans, were taken less than four years apart. Classes were in full swing when Nagraj Adve, a climate change activist and writer, visited in early 2014. At the time, the school was a few hundred metres from the water line. While it was not uncommon even then for high tide waters in the monsoon to reach the school, waters in the Bay of Bengal have swelled so rapidly that the sea has now completely swallowed the school and intrudes a hundred metres beyond it.
The school has moved half a kilometre further inland as have families that chose to continue living on the island. Others have left, now effectively climate refugees. Sadly, the plight of the school is the rule, not the exception, in many parts of the Sundarbans.
The two overlaid images of the Sundarbans below were acquired by NASA satellites 19 years apart. A cursory visual inspection is all it takes to see how the coastline has eroded almost everywhere along the Bay-facing coastline. Some small islands have gone completely under.
The Indian Sundarbans images by NASA’s Landsat satellites 19 years apart. Left: November 2018. Right: November 1999. Note the erosion of the bay facing the coastline. Data access: https://landlook.usgs.gov/viewer.html
Why is the Sundarbans eroding away? What does its future hold? To what extent are we — humans — responsible for these children having lost their school?
Global sea levels are rising
Sea levels have been rising in all the world’s oceans for the past century. There are many natural reasons why sea levels change, but also two major ways in which human-induced global warming is impacting sea levels today.
For one, with rising temperatures, trillions of tonnes of ice have melted in the past century from glaciers and ice sheets on Greenland and Antarctica because of global warming, adding vast quantities of water to the oceans.
A time lapse of Earth for the past 32 years showing how glaciers are declining. Ice loss from Greenland and Antarctica are not evident in these images because these ice sheets are kilometres thick. Please see the Q&A section below for details. Data: NASA’s Landsat, ESA’s Sentinel 2A satellite imagery among others. Visualization: Google Earth Engine.
For another, water expands as it warms causing the same quantity of water to occupy more space. The combined effect of these two processes is a rise in global sea levels of about 3 mm/year on average.
Q&A: How are Greenland and Antarctica contributing to sea-level rise?
Greenland in the northern hemisphere and Antarctica at the south pole each hold enormous quantities of frozen fresh water in their kilometre(s)-thick ice sheets. As global temperatures rise, these ice sheets are rapidly melting, adding water to the world’s oceans.
Satellites monitoring ice thickness found that nearly 2 trillion tonnes of ice has melted from Antarctica while Greenland has shed nearly 4 trillion tonnes in 14 years of observation alone (2002 – 2016).
In addition, water expands as its temperature rises, as do most substances, in a process called thermal expansion. This causes the same mass of ocean water to occupy more space at a higher temperature contributing yet more to sea-level rise. Thermal expansion of water for even a small temperature rise so important that it is considered the single biggest cause of anthropogenic sea-level rise in the long run, even more important than ice-melt.
The combined effect of these phenomena has been to raise global sea-levels by about 3 mm/year on average in recent decades.
However, the seas are rising considerably faster in some of the world’s oceans than in others.
Sea levels are rising much faster along the Sundarbans’ coastline
Natural factors such as how heat is transported by ocean currents and periodic climatic phenomena such as El Niño are some major reasons for why regional differences in sea-level rise come about. Yet, global warming plays into this as well. Temperatures are rising faster in some parts of the world’s oceans than others. Consequently, water expands faster swelling the seas more rapidly in those regions.
Unhappily, physical features specific to the Sundarbans and extensive upstream damming of the rivers flowing into it has combined to make the situation even graver.
Q&A: Why should a few mm/year rise in sea level be of concern?
A sea-level rise of 3 mm per year may not seem like much. Yet, it can produce significantly greater inland sea water intrusion over time especially in low lying coastal areas.
The gently sloping area adjoining the coast is called the Continental Shelf, where the average downward slope is only about 0.1o. The 3 cm rise that would occurs in a decade, at current rates of sea-level rise, would cause sea levels to intrude further inland by a disproportionately larger 17 meters (65 feet).
Sea levels today are about 20c m higher than pre-industrial times (1850s) meaning that land has ceded about 115 metres to the sea in coastal areas with gentle elevation.
The Intergovernmental Panel on Climate Change (IPCC) special report released in October 2018 warns that sea levels may rise up to 77 cm by 2100 even if global temperatures rose “only” to 1.5 C in the next 80 years. The reality we are presently facing is far worse. We are currently on track for temperature rise of 3 to 4 C by 2100.
The sinking Sundarbans
Contours of river deltas are naturally dynamic being shaped by sediment deposition by the vast amounts of soft, fertile silt transported by the rivers constituting them. Land accretes by sedimentation, but is lost by silt compactification and coastal erosion. Sediment transport into the Sundarbans has been severely affected by upstream damming, especially the Farakka dam in West Bengal built on the Ganga in 1975. Dams trap sediment and greatly reduce downstream transport. As a result, subsidence have outpaced accretion on average in the Indian part of the Sundarbans and the Delta is sinking at a rate of about 2 to 4mm/year.
The combined effect of already high rate of sea-level rise in the Bay of Bengal and land subsidence has been an effective sea-level rise in the Sundarbans that is nearly three times as fast as the global average (~ 8mm/year), and as high as 12mm/year on Sagar Island.
These are facts that students and teachers of Boatkhali Kadambini School need little convincing about.
Impacts of sea-level rise on the Sundarbans
Higher sea levels have devastating impacts on low-lying coastal habitats, and the Sundarbans is one of the most densely populated yet biodiverse ones in the world.
Aside from the school on Sagar Island becoming permanently inundated in a space of merely four years, the entire stretch where there were houses and agricultural land has been swallowed by the sea. The large-scale destruction of Mangroves has exacerbated coastal erosion. The surging seas have turned fertile agricultural lands and groundwater increasingly saline.
Families are moving inland or leaving the island entirely, often to big cities like Kolkata, effectively becoming climate change refugees.
There is yet another tragedy in store for the Sundarbans. A study focusing on the Bangladeshi Sundarbans (contiguous with the Indian Sundarbans) found that the remaining Tiger habitat and population would be almost entirely wiped out for a 28 cm rise in sea levels above the 2000 levels, which is likely to happen in the next 50 to 90 years.