Ahsan Uddin Ahmed’s research while affiliated with Laboratoire Interdisciplinaire de Recherches "Sociétés, Sensibilités, Soin" and other places

Climate change impacts in the mountains of the HKH are already substantive. Increased climate variability is already affecting water availability, ecosystem services, and agricultural production, and extreme weather is causing flash floods, landslides, and debris flow. Climate change is likely to have serious effects in the next decades in the mountains of the HKH (well established). By 2050, mountain temperatures across the region are projected to increase beyond 2 °C on average, and more at higher elevations. Mountain communities—especially remote ones—are more vulnerable to climate change impacts than non-mountain areas (established but incomplete). The high mountains are poorly served by life-saving and livelihood-supporting infrastructure. Access to climate information and support services is limited, as is the presence of government extension agencies. Weak institutional links hinder farmers from adopting technology that can contribute to adaptive capacity. For poor and marginalized groups, deep and pervasive structural inequalities make climate change adaptation even more difficult. Although the IPCC Fifth Assessment Report Working Group 2 had four chapters on adaptation, literature on mountain specifics was not prioritized. However, although still insufficient, scientific literature in the region is rapidly emerging, and there is a wealth of information emerging from ongoing adaptation action driven by HKH countries.

Climate change is predicted to have major consequences for South Asia. The South Asian region represents the most diverse ecosystems, topographies and climate regimes in the world. Incidences of droughts, floods, heat waves and cyclones have grown both in terms of intensity and frequency, impacting the lives and livelihoods of the most impoverished and vulnerable people of South Asia. The regional countries and respective governments have all exhibited high level of political will and urgency to tackle climate change by means of adaptation, while committing to contribute towards achieving global mitigation goal if they receive adequate international supports in terms of finance, technology transfer and capacity building. Though several climate change adaptation (CCA) efforts are in place at the national and subnational levels in South Asia, they have so far been fragmented and incoherent lacking a perspective that integrates technological, institutional, financial, capacity, information and policy needs. Focusing on key countries of the region, this review captures the trends, strategies and critical barriers in advancing the CCA agenda. It argues for a regional vision and underscores the importance of cross-sectoral coordination, stakeholder integration, democratic decision-making, building synergies with local government institutions and enhanced capacities to tap financial resources from bilateral and multilateral funding agencies.

Research on climate change and migration usually assesses the effects of natural hazards and/or creeping environmental degradation on people’s livelihoods and their migration. This chapter looks at changing rainfall patterns, local perception of these changes, and the decision to migrate, or not, to cope with rainfall variability and hunger. Based on empirical evidence from a case study undertaken in Kurigram District in northern Bangladesh, this chapter addresses four key questions: (1) Is the rural population sensitive to rainfall variability? (2) How is rainfall variability related to food security? (3) Which labour-migration systems can be used by the local people to cope with environmental shocks and adapt to change? and (4) Do people migrate for work to cope with and adapt to the effects of rainfall variability or because of food insecurity and social inequality? Although rainfall variability can play an important role in people’s decisions to migrate, we argue that migration from the region is not driven so much by climate changes as it is by the persistent local patterns of social inequality and food insecurity coupled with the structural economic disparities that exist in Bangladesh.

Various regions of South Asia experience high climate variability, both spatially and temporally. The hydrological regime of major parts of the region is predominantly influenced by monsoon, which brings 70-80% of total annual rainfall during early June to September. The post-monsoon months become dry and there is hardly any appreciable rainfall during winter months (December to February).

The environmental setting and possible influence of global environmental change, including that of climate change, have been presented for coastal and marine environments of South Asia. This has been dealt with in seven sections. In the first section biogeochemistry of the North Indian Ocean with emphasis on the reducing conditions and sensitivity of mid-ocean and coastal systems was presented. In the second, air-sea fluxes of climatically important gases from these marine ecosystems were assessed with particular reference to their contributions to total regional (that include anthropogenic) emissions. Coral reefs of Bangladesh, Sri Lanka and India and the impacts of El Nino and climate change on these systems were reviewed in the third. The Bengal delta, the Sundarbans and mangroves systems were dealt with in sections four to six, respectively. In the last section, impacts of climate change were assessed for the region.

CEGIS has conducted the study on “Adaptive Crop Agriculture Including Innovative Farming Practices in the Coastal Zone of Bangladesh” in Satkhira District, commissioned by the Climate Change Cell of Department of Environment (Component 4b, CDMP). The study has been conducted in partnership with BRRI, BARI, BARC and BUP. The main objective of the study was to find out suitable adaptation measures that have the potential to help farmers adapt to climate changes and to identify suitable varieties of crops that would be able to adapt to climate change. In order to assess and analyze the problems, the study team members appraised the existing findings from literature review and community consultation. An attempt was made to understand the present and future geo-physical environment of the study area. The CROPSUIT model developed by CEGIS was used to estimate the physical suitability of land for different types of land uses or crop cultivation. Physical suitability change under climate change scenarios was analyzed to assess potential threats to current landuse practices. Based on expert opinion, different types of rice crops and non-rice crops were selected for field-testing. For the boro season, BRRIdhan29, BRRIdhan45 and BRRIdhan47 were transplanted in the village of Roghurampur of Kaliganj Upazila. For the rabi season tomato, watermelon, okra and aroid were selected. For the T. Aman season, different varieties were selected such as BR23, BRRIdhan40, BRRIdhan41, and BRRIdhan33/39. From field experiments it was found that introduction of high yielding salt tolerant variety BRRIdhan47 could produce sustainable grain yield in the coastal regions. It was also observed that there was no salinity impact on rice production due to high rainfall during monsoon season. But in the later part, when the rainfall ceases, it was assumed that soil salinity might increase and go beyond the safe limit of rice crop (4 dS/m). So, salt tolerant T. Aman varieties like BR23, BRRIdhan40 and BRRIdhan41 may be the solution to overcome salinity impact at the later stage. Tomato, okra and aroid were grown successfully under improved management practices with raised bed and mulch in the medium saline soils of Satkhira. The existing cropping pattern of Fallow-T.Aman (Local)-Fallow or Fallow-T.Aman (Local)-Boro (Local/HYV) may be replaced with the pattern of Okra (Dharosh) - T.aman - Boro (HYV) or Okra (Dharosh) - T.aman - Tomato. Simulation experiments were conducted for five rice cultivars namely, BR23, BRRIdhan33, BRRIdhan39, BRRIdhan40, and BRRIdhan41 using two soils, Bajoa and Barisal series for transplanted aman season. Results of simulation experiments showed that the yields of all rice cultivars varied with soils and also with different climate change scenarios. Highest yield of 5839 kg ha-1 was obtained with BRRIdhan41, followed by BRRIdhan40 (4251 kg ha-1) and lowest yield of 2836 kg ha-1 with BR23. In general yield decrease was relatively small under HADC 50 scenario and large under UKTR 70 scenario. For boro season simulation experiments were conducted for five rice cultivars namely, BRRIdhan29, BRRIdhan45, and BRRIdhan47 using Bajoa series soil. Results of simulation experiments showed that the yields of all rice cultivars responded differently with different climate change scenarios. In general yield decrease was relatively small under GFDL 50 scenario and large under UKTR 50 scenario. Simulation runs were made for aroid at two locations with Barisal and Ishwardi series soils. Results showed that irrespective of GCMs and interval aroid yields increased from 2% to 9% in case of Barisal series soil. Lower yields were recorded for Ishwardi soil xiv series and also yield reduction of 4% to 13%. In case of tomato all the scenarios predicted 23% to 28% yields increase. It is difficult to confirm a crop as adaptive under climate change situations using only one season crop related data. At least three years of experimentation will be needed to confirm whether a crop is adaptive under climate change situations in the coastal region. The adapted rice and non-rice crop results along with their innovative farming practices may be expanded throughout the salt affected coastal zone of Bangladesh.

In an attempt to fill in a vital gap in understanding, the Centre for Global Change (CGC) embarked upon a basic study that generates information regarding livelihoods at risks and hazard-specific AEZ maps under two climate change scenarios. This report highlights the approach, methodology and the findings of the study.

Living in the downstream, as a total of 140 million are living in Bangladesh, is not easy. It is a part of the largest delta on Earth, created by the three mighty eastern Himalayan Rivers: the Ganges, the Brahmaputra, and the Meghna (GBM) (Figure 10.1). The lowlying delta has been created over millennia by the sediments carried by the water of the GBM systems, the combined flow of which is the second largest after the Amazon River. The monsoon circulation has generally brought moisture aplenty, while fertile lands have given adequate food grains for consumption and wealth creation. No wonder, several globe trotters have described the land the most prosperous country on Earth (Batuta, 1355). Simultaneously though, the happy going farming communities had to suffer through frequent water-related hazards, mostly in the form of floods. Then came a particular time in human civilization, which witnessed an unprecedented exploitation of earthly resources coupled with rapid growth in human population. As a by product of anthropogenic interference, the downstream areas of the GBM systems saw artificial obstacles to natural flows, created for the benefit of quick transportation of goods, cultivation in the lands that were designated as hazard-prone, and diversion of water from the river itself! The latter appeared to bring in the ultimate horror: hydrological balance denied, ecosystem destroyed, crop suitability perished, livelihoods at the brink of collapse and economy doomed. It is of little relevance now to invest large sums of money and to engage state-of the- art technologies to strive for development, the fruit of such thoughtful steps can no longer guarantee a quality living in Bangladesh. Safeguarding development processes and results has become the foremost challenge to policymakers. Living in downstream of GBM has already become a hazardous proposition to those hanging around.

Large scale inter-basin transfer (IBT) of water from one basin to the other is not a new phenomenon. In fact, large dams, and more broadly water transfer projects, have been integral in the development of “civilizations” for thousands of years. For example, Middle Eastern countries that share the waters of Nile River planned to divert water from the basin to replenish the Jordan River as early as 1902. Even now, in many places all over the world, water transfer projects have been implemented and many are continually being conceived.

A simulation study was conducted to assess the vulnerability of foodgrain production due to climate change in Bangladesh. Two general circulation models were used for development of climate scenarios. The experiments considered impact on three high yielding rice varieties and one high yielding wheat variety. Sensitivity to changes in temperature, moisture regime and carbon-di-oxide fertilisation was analysed against the baseline climate condition. The GFDL model predicted about 17 per cent decline in overall rice production and as high as 61 per cent decline in wheat production compared to the baseline situation. The highest impact would be on wheat followed by Aus variety. CCCM model predicted a significant, but much reduced shortfall in foodgrain production. It was found that increase in 4°C temperature would have severe impact on foodgrain production, especially for wheat production. On the other hand, carbondi-oxide fertilisation would facilitate foodgrain production. A rise in temperature cause significant decrease in production, some 28 and 68 per cent for rice and wheat, respectively. On the other hand, doubling of atmospheric concentration of CO2 in combination with a similar rise in temperature would result into an overall 20 per cent rise in rice production and 31 per cent decline in wheat production. It was found that Boro rice would enjoy good harvest under severe climate change scenario. The apparent increase in yield of Boro and other crops might be constrained by moisture stress. A 60 per cent moisture stress on top of other effects might cause as high as 32 per cent decline in Boro yield, instead of having an overall 20 per cent net increase. It is feared that moisture stress would be more intense during the dry season, which might force the Bangladeshi farmers to reduce the area for Boro cultivation. Shortfall in foodgrain production would severely threaten food security of the poverty ridden country.