Climate change adaptation involves many factors, including the likely social and economic impacts of adaptation measures themselves, and the political niceties of adaptation planning. This month, three research papers illustrate these issues nicely.

The millions of people that live and work along Vietnam's vast Mekong Delta are vulnerable to the impacts of sea-level rise, and the effects of upstream development. On page 167, Alex Smajgl and colleagues describe some of the difficult choices faced by the Vietnamese government in tackling these interrelated challenges, and some of the tensions and divisions that have emerged within the policy arena.

It seems that some Vietnamese policymakers favour investment in such things as the building of large-scale coastal defences — the so called 'hard' adaptation options. Others instead advocate 'softer' measures such as land use-related adaption options. Smajgl et al. argue that this disagreement between these two factions has resulted in 'political adaptation paralysis'. Based on their analysis, the researchers believe that a balance between hard and soft options is the way to go. The implications of their finding, its relevance to other parts of the world where coastal floodplains face similar problems, and the importance of recognizing political processes in climate adaptation are further discussed by Declan Conway on page 105. As he notes, in the case of the Mekong Delta, the political dimension also involves countries involved in development and water management upstream of the delta itself.

In a separate paper (page 153), Leslie Auerbach and colleagues consider the case of the Ganges–Brahmaputra tidal delta plain of southwest Bangladesh. Specifically, they show that, through reduced sedimentation, the landscape of a low-lying island in the delta experienced a net elevation loss in the years after embankments were constructed in the 1960s. When cyclone Aila breached the island's protective embankments in 2009, this loss of elevation caused major flooding and inundation. Based on their research, Auerbach and colleagues argue that human manipulation of the environment can itself amplify the threat posed by climate change to the region.

Orencia Duràn Vinent and Laura Moore (page 158) also consider the landscape response to climate change, in this case in relation to barrier islands protecting mainland shores. They demonstrate that the actual morphology of such islands can be bistable due to dynamical changes in the balance of competing effects of storm erosion, sea-level rise, and the aeolian and biological processes. This means that even seemingly mild storm conditions, for example, can cause rapid and catastrophic state transitions, making the impacts of sea-level rise much worse.

Between them, these studies should open eyes to some of the complexities of climate adaption planning for coastal regions.