Coastal cities can battle the climate crisis by adaptation
The key to coastal adaptation is the urgency for action. In coastal cities, where risks are high and increasing, delaying action reduces the choices they have to adapt
The Intergovernmental Panel on Climate Change (IPCC)'s latest report on Impacts, Adaptation and Vulnerability, released on Monday, discusses coastal cities in great detail. We know with certainty that globally, coastal cities and settlements are at the front line of the climate crisis, which will have a direct impact on people and infrastructure. They face sea-level rise (SLR), but also a host of other climate risks such as increasing saltwater intrusion, which can render groundwater and soil unusable; more severe cyclones, which are already having disastrous impacts on infrastructure and lives; frequent flooding due to heavier rainfall events; and in some places, growing water scarcity and more frequent heat waves.
We know from observation-based assessments that many of these risks occur concurrently in coastal cities — for example, tropical cyclones and storm surges coinciding with heat waves or urban drought — compounding the impacts of the climate crisis. Further, these climatic risks intersect with unsustainable and unequal urbanisation, exacerbating risks for low-income and marginalised communities within coastal cities.
It is also important to understand that what happens in coastal cities has a cascading effect on the hinterland because these places are critical nodes in global trade and food supply chains, house critical infrastructure, and are often sites with tremendous cultural and historical significance. India’s coastal cities — which range from the megapolises of Kolkata, Mumbai and Chennai to the crucial port cities of Kochi and Vishakhapatnam — are all expected to see increasing climate risk. While studies discuss how flooding, heat, and cyclones or SLR risks will change, there is relatively little evidence on how the natural and cultural heritage, and the socio-economic fabric of these iconic cities stand to change due to the climate crisis.
Coastal cities present a tremendous opportunity to anticipate and avoid climate risks, if locally relevant and hybrid interventions are rolled out. In the IPCC report, we wrote about a range of feasible adaptation options: Cities can choose to “advance” by reclaiming land or “protect” themselves by building seawalls or protecting mangroves that act as storm barriers. Such protection measures have been implemented across India over the past two decades with the government and civil society involvement, using bio-shields, geotextile tubes, and other site-specific designs with different degrees of effectiveness. Other options to manage and pre-empt climate risks include “accommodation” measures such as flood-proofing buildings or investing in passive cooling to improve ventilation and reduce extreme heat impacts. Finally, coastal cities and settlements can “retreat”. This means relocating specific population groups from hazard prone areas and moving critical infrastructure to avoid damage.
The key takeaway here is that coastal cities have multiple feasible adaptation options, and Indian cities also have a track record of investing in and implementing these measures. However, the question remains: How effective will these adaptation options be in the face of the climate crisis? And, more important, given how Indian cities are expanding (by area and population), how do we ensure these measures are enough?
The science shows that hybrid approaches, which combine infrastructural solutions such as seawalls, and ecosystem-based solutions, such as mangrove protection, are most effective at reducing risk. Nature-based solutions, in particular, have co-benefits for multiple sustainable development goals. It is imperative that these hybrid approaches are enabled by three other critical levers of change: Adequate finances, strong-yet-flexible governance, and local participation and behaviour change.
The key to coastal adaptation is the urgency for action. In coastal cities, where risks are high and increasing, delaying action reduces the choices they have to adapt. As cities expand and new infrastructure gets built, the space to conserve mangroves and accommodate more frequent floods or storm surges becomes narrower.
Indian cities are uniquely positioned because it is estimated that nearly 80% of its built infrastructure in 2030 is yet to be built. This provides a tremendous opportunity to make sure this infrastructure is climate-resilient and does not lock our cities onto unsustainable and risk-prone pathways. The Government of India’s Coalition for Disaster Resilient Infrastructure, a multinational effort led by India to share global knowledge about infrastructure risk management, financing and recovery mechanisms, is one such promising initiative.
What we need now is to acknowledge that multiple climate risks are coming together in Indian cities, that various feasible adaptation options exist, and combinations of options are more effective. Implementing these adaptation options needs strong governance and adequate finances, capacity-building and behavioural change. What the science is showing is that acting now is imperative.
Chandni Singh is senior researcher, School of Environment and Sustainability at the Indian Institute for Human Settlements. She works at the intersection of climate change adaptation and rural and urban development.
She is a lead author on the IPCC Working Group II Assessment Report 6 and was a contributing author on the IPCC Special Report on Global Warming of 1.5°C
The views expressed are personal