ESPA Deltas project publishes short film on creating a sustainable future for climate-vulnerable deltas

The Ecosystem Services for Poverty Alleviation Delta Project has just published a short film that highlights its findings in Bangladesh. The project was concerned with assessing health, livelihoods, ecosystems and poverty alleviation in populous deltas to provide knowledge and tools to enable policy-makers to evaluate the effects of policy decisions on people’s livelihoods.

A multidisciplinary and multi-national team of policy analysts, social and natural scientists and engineers collectively used a participatory approach to create a model to formally evaluate ecosystem services and poverty in the context of the wide range of changes that are occurring. In the film, DECCMA Principle Investigator Professor Robert Nicholls and researcher Dr Helen Adams talk about the environmental and social stresses facing delta populations, from salinity and subsidence to poverty and marginalisation.

“Climate change is triggering a migrant crisis in Vietnam” now published on The Conversation

by Alex Chapman, University of Southampton

DECCMA and ESPA Deltas researcher Dr Alex Chapman’s piece “Climate change is triggering a migrant crisis in Vietnam” has just been published on The Conversation UK. The article outlines how net out-migration of one million people from the delta – over double the national average – relates to a reduction in agricultural productivity and the effects of repeated exposure to cyclones that cause erosion of land and infrastructure.

Courtesy of The Conversation

Crucially, the article highlights that the creation of embankments, intended by the government to support in situ adaptation, actually often have the opposite effect. This is because in protecting the land, the embankments prevent “normal” flooding that replenishes soil nutrients and supports fishery-based livelihoods. Dr Chapman concludes by highlighting the importance of ensuring economic growth and adaptation supports all groups of the population to reduce a potential migrant crisis.


What does a 1.5⁰C increase in global temperature mean for deltas?

by Robert Nicholls

Deltas are a climate change hotspot, where the effects of climate change coincide with large numbers of people. Sea level rise is a major threat to deltas, bringing risks of flooding and erosion. As the world tries to limit the global temperature increase to 1.5⁰C, the DEltas, vulnerability and Climate Change: Migration and Adaptation (DECCMA) project has been looking at how deltas will be affected by increases in temperature of 1.5⁰C, 2⁰C or 3⁰C.

Volta delta mangroves (photo by Klaus Wohlmann)

Following the historic Paris Agreement, 1.5 ⁰C has become a hot topic.  The Paris Agreement commits developed and developing countries to global temperature increase to 2⁰C, with the aspiration to limit to 1.5⁰C.  These numbers are widely believed to be critical thresholds beyond which significant changes in the natural environment would be experienced (known as planetary boundaries).

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The issue of 1.5⁰C has recently been high on the political agenda again, as the 23rd Conference of the Parties to the UNFCCC met in Bonn to discuss a framework for reporting climate action to monitor the commitments made under the agreement.  Knowing the implications of a 1.5⁰C increase informs the “ambition mechanism”, whereby stocktakes of progress are due to be taken every 5 years, with a view to then revising and updating mitigation and adaptation commitments.  Improvements in science play a key input to ensuring that these commitments remain ambitious and on target to limit the damaging effects of climate change.

Deltas are home to 500 million people worldwide, as well as being natural environments that generate livelihoods, income and essential ecosystem services.  DECCMA has been investigating the effects of climate change in four study sites across three deltas across Africa and Asia: the Ganges-Brahmaputra-Meghna (GBM) megadelta in Bangladesh and the Indian Bengal component in India; and the smaller deltas of Mahanadi in India and Volta in Ghana.

Given the interest in 1.5⁰C, we have used our customised integrated assessment model –the Delta Dynamic Integrated Emulator Model – to look at the likely changes in flooding (in terms of depth of flood and area affected) and the impacts on population in the GBM in Bangladesh under three different scales of temperature increase: 1.5°C, 2.0°C and 3.0°C.

If we continue with relatively high rates of greenhouse gas emissions, models show that a 1.5°C increase could occur from 2011 to 2033.  Rates of temperature increase have already been significant and rapid.  Observed changes in temperature over the 20th century showed an increase in 0.7⁰C.  In comparison, in the readjustment period since the last ice age global temperatures have only increased by between 4-7c over 5000 years.

Sea level rise of 5-14cm is associated with an increase in global temperature of 1.5⁰C.  This may not seem a lot, and it is particularly difficult to find a reference period because sea levels have varied significantly over the last 20,000 years, reflecting glacial periods and the readjustment of land masses.  But, as an indication, sea levels rose by less than 2mm over the 20th century, so the projected increase is over 20 times more than that.

Until 2040 the differences that are likely from a 1.5⁰C increase and a 2⁰C increase are indistinguishable largely due to the year on year variability that is already characteristic of deltas.

If the temperature increase reaches 3⁰C, some of consequences more than double.  The area flooded under 3⁰C is more than 2.5 times that under 1.5⁰C of such sea level rise, for example.  Those at greatest risk are in the central regions and northeast, where there are fewer polders to protect the land.

The good news is that there is still time to implement adaptation – if we act now.  Our team has investigated adaptation and found 93 documented examples in our study deltas spanning agriculture, water management and disaster risk reduction.  We are now in the process of developing an integrated assessment model that will give us insights into adaptation needs and options under various future scenarios.

For more information, see:

Brown Sally, Nicholls Robert J, Lázár Attila, Hazra Sugata, Appeaning Addo Kwasi, Hornby Duncan D, Hill Chris, Haque Anisul, Caesar John and Tompkins Emma, What are the implications of sea-level rise for a 1.5°C, 2°C and 3°C rise in global mean temperatures in vulnerable deltas? Submitted to Regional Environmental Change.

(This blog is also published in the December edition of the CARIAA newsletter)

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Prizegiving for the enumerators of Bangladesh’s 1500 household survey

Certificates were awarded to 18 young researchers who acted as enumerators in DECCMA’s survey of migration and adaptation in 1500 households in Dhaka and Chittagong – two of the most influential cities in Bangladesh and the destination of many migrants.

The certificate award ceremony took place at the end of October at the Institute for Water and Flood Management at the Bangladesh University of Engineering and Technology. It coincided with a Bangladesh Country Team meeting, that brought together more than 80 researchers from the various partner organisations, including RMMRU, BIDS, TARA, CEGIS and SANEM.

Certificates were awarded at the Bangladesh Country Team meeting

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There were different categories of prize. One was for best supervisor of the DECCMA receiving area survey, two were available for best enumerators (one each for Dhaka and Chittagong) and  two for the best photography. Mr Md. Masum Ebne Haque and Muhammad Sehab Uddin got the prize for their valuable photos. Mr Md. Ataur Rahman and Ms Nahida Akter was selected as the best enumerators and Mr Robi Ray was selected for the best field supervisor. Congratulations to all!

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