Three of our recent stories are closely interconnected. The World Meteorological Organization has reported that greenhouse gases that warm up the globe have reached the peak level since the pre-industrial times. A story by veteran journalist Darryl D’Monte talks about local concerns in Mumbai, where our office is located – scientists say the city could face coastal erosion and other hazards associated with climate change. Another story by Ajith Lawrence from Thiruvananthapuram talks about the problems associated with a common solution for coastal erosion – sea walls.
While there is worldwide concern about the gradual rise of the sea level and subsequent loss of the coasts, policymakers in India are resorting to hard solutions. They build sea walls, evict local people from the coasts and generally put in place techno-managerial quick-fixes. That is the bane of policy making in this country. Technocrats and bureaucrats believe they can manage impending disasters. It is an elitist notion that views people on the first mile of disasters as helpless victims, who need expert management of their environment and livelihoods. More often than not the problems these experts set out to address become worse.
The conundrum requires careful examination of the interrelated issues involved. First of all, in the face of global warming, as environmental features and natural hazard patterns shift, coasts become vulnerable to sea level rise, extreme weather events and changes in livelihood patterns. The UN climate panel predicts a temperature rise of 1.3 degree C to 6.4 degree C by 2100. Scientists project different scenarios of warming and associated impacts that include a global sea level rise of 18 to 59 cm by the end of the century. It could be even worse, some environmentalists argue – but there is no hard evidence for such fears.
In India, there has been sea level rise of 1.06 to 1.75 mm a year over the past 40 years as scientists at the National Institute of Oceanography have reported. A 4 cm rise in the sea level may not appear to be much – but its impact on the coast could be severe, exponential, speaking mathematically. For, coasts are not vertical terrains – but gradually slanting landscapes. So a single centimeter rise in the sea level could mean, in some cases, disappearance of 10 cm of the beach or close to even a metre. Then the coast erodes further as more sand is taken away by the waves.
Erosion of the coast is now widely found in east and west coasts. Houses and boats and entire hamlets could disappear. Such shrinking of the coast has happened in Pondicherry over the past few years – it was not sea level rise per se, but erosion worsened by a few unscientific structures on the coasts and in the sea. When the ocean moves landwards and the shoreline recedes – it is as simple as that.
What makes the future scenario even more fearsome is the possibility of intense storms, projected as a result of climate change. That could make wave attacks severe. Rising sea level can also amplify the impact of the waves and flooding. Besides, scientists have reported a rise in the frequency and intensity of extreme rainfall events and an increase in the number and proportion of cyclones in the Indian Ocean that cross a wind speed of 200 km per hour.
Here is the significance of the story about seawalls – they do not always protect the coast. Instead, they often contribute to the erosion by destroying or degrading the shores. They prevent the natural process of beach building. And they contribute to erosion on their sea-facing side and at their beginning, the end and the gaps in between. The waves are strong – they need a place to give vent to their fury. Eventually the wall sinks in the coastal sand and water in the natural processes of the waves, tide and sand deposit. Then more stones need to be laid. It is an unending process. The walls protect a stretch behind them – so they are popular among many local communities. But they just shift the problem in time and space. There is no sound scientific basis for much of the walls that have been built and allowed to sink .
At the same time more roads, industries and tourist resorts damage natural coastal barriers such as sand dunes. So coastal communities are facing attack from the sea and from the land, their space ever shrinking. Sandy beaches are necessary for their survival – for shore-based fishing, mending craft and gear, fish drying and safe landing and launching of catamarans and canoes.
The latest news is about geo-tubes or giant sand-filled sleeves that replace the granite walls as the story from Mumbai suggests. They are softer, allow the water to seep in, absorb the impact of the waves and tides and allow sand deposit and growth of organisms on them. While coastal erosion is a major problem and anything might be better than the sea walls, scientists still fear that such new, largely untested technological interventions here could simply shift the problem from one spot to another. It remains to be seen how geo-tubes that have been introduced in some parts of India, including in the Kovalam beach of Thiruvananthapuram, actually work.
Our concern is that traditional means of livelihoods are being undermined and people living on the coasts are seldom consulted before the government and other agencies introduce such techno-managerial interventions. There is a need for a paradigm shift in climate adaptation and disaster ‘management’ strategies that are being promoted in India – and elsewhere. The stress should be on promoting the resilience of local communities, instead of making them even more dependent on external, expensive technologies of dubious merit.