As a result of the unprecedented rise in the greenhouse gas (GHG) emissions and the resulting global warming phenomenon, there has been a steep rise in the extreme events such as devastating floods, cyclones, wildfires, heatwaves, drought, etc. While the frequency, intensity and the pattern of the rainfall and cyclones are changing and becoming more extreme, the heat waves and cold waves witnessed during different parts of the country are achieving record-breaking peaks.

This year at Davos, the World Economic Forum surveyed 1490 top leaders of the world attending the event and asked them about the Top Risks in 2024. Two third respondents (66%) selected “extreme events” as the extreme risk in 2024 (Fig 1) [1].

Fig 1 Current risk landscape (source: World Economic Forum) [1]

The climate-centric disasters are taking a heavy toll on the human society. An earlier report by UN Office for Disaster Risk Reduction (UNDRR) revealed that during the period 2000 to 2019, there were 7,348 major recorded disaster events claiming 1.23 million lives, affecting 4.2 billion people (many on more than one occasion), resulting in approximately US$ 2.97 trillion in global economic losses [2]. The same report reveals that India is ranked 3^rd amongst the top 10 ten countries in terms of the occurrence of number of disasters. A report from the State Bank of India observed that the country suffered a financial loss of Rs 13 lakh crore during 2001-21, which is equivalent to 6% loss in GDP [3]! An independent study carried out by two researchers showed that more than 80 % of India's population lives in districts highly vulnerable to extreme hydro-met disasters [4].

Besides affecting human lives, climate change has a profound impact on the infrastructure. The term infrastructure is a broad term. According to the Oxford dictionary definition, infrastructure en-compasses the basic systems and services that are necessary for a country or an organisation to run smoothly; for example buildings, transport and water, power supplies, etc. [5]. As far as the construction industry is concerned, it is involved in the planning, design, construction, maintenance, and repair, restoration and rehabilitation of the ‘physical infrastructure’ which includes roads and bridges, railways, airports, runways, ports, buildings, factories, schools, water and sewage system, etc.

What could be the possible damages to the infrastructure owing to climate change? It is indeed dif-ficult to predict possible damages; yet the potential threats can be identified. For example, tempera-ture extremes may result in melting of bituminous road surfaces, buckling of railway lines, perma-frost damages and a steep increase in cooling demand of residential and commercial buildings.

The changing pattern of precipitation – intense rainfall of short duration in some regions while drought conditions in others – may result in flooding of infrastructure and damage and disruption of the transport system, damage to inland waterways, reduced output from hydropower generation and the risk of widespread drought. The changing pattern and increasing frequency of storms may dam-age infrastructure assets including residential and commercial establishments. The one-in-hundred return period of floods and cyclones seems to be changing fast and is occurring more frequently.

Additionally, sea level rise is slowly swallowing land mass from seashore and this may permanently inundate roads, ports and airports. In view of the dwindling discharge of rivers into the sea, saline water from the sea tends to enter deep into the landmass, resulting in increasing the salinity of groundwater from wells located in the vicinity of seashore.

With the climate crises becoming more intense, it would indeed be challenging to predict the inten-sity and frequency of extreme events. While the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) warned that the Indian subcontinent would suffer more frequent and intense heat waves over the coming decade, the recent World bank report states that India could become one of the first places in the world to experience heat waves that break the human surviva-bility limit, which can jeopardise economic activities [6]. The World bank report further predicts that by 2030, India may account for 34 million job losses from heat stress associated productivity decline!

It is well known that over years, the per-capita availability of water has been declining in India. The uneven distribution monsoon and the flood-drought syndrome are not new for India. In recent years, the monsoon has been showing more erratic trends and its distribution pattern is tending to become more skewed. Further, as indicated by WRI research, India’s thermal power industry is highly dependent on freshwater cooling [7]. It is therefore likely that some of India’s energy sector may face high water stress in case of the failure of monsoon.

The experience from the last few years indicates that the frequency and intensity of storms and cy-clones visiting the east and the west coast of India is on the rise.

Climate resilience rests on three main pillars: preparedness, adaptation and recovery. As far as the physical infrastructure is concerned, the civil engineering fraternity need to re-examine as to whether such infrastructure in the country can resist the adverse effects of climate change. Here, we would like to make few suggestions for the consideration of professional engineers, specifiers and authorities:

• The preparedness for climate resilience starts from identifying areas which lie in the risk zones. It will be essential to undertake a quick survey of the critical physical infrastructure like roads, bridges, industrial structures, hospitals, schools, important public buildings, and telecom infrastructure network in the risk-prone areas. A structural health monitoring sur-vey may also be essential for some of the old structures. Based on such surveys it may be essential to undertake immediate strengthening/reconstruction of the essential infrastruc-ture to withstand the high winds during cyclones, possibility of damage during flooding, likelihood of submergence owing the rise in sea level, etc.
• It is also essential to re-visit some of our codes and standards, especially in respects of provi-sions about permissible temperatures and temperature gradients in structures, the return pe-riods of high floods and cyclones, etc.
• Since light-coloured surfaces return a large part of sunrays back to the atmosphere, it may be appropriate to create higher level of awareness amongst architects, builders, specifiers, etc. on the provision of ‘cool roof’ for buildings and other infrastructure and encourage use of materials having lower thermal conductivity for exposed surfaces. This will go a long way in reducing the heat-island effect in urban areas thereby rendering help in the mitigation of the adverse effects of climate change.
• Provisions should be made in the construction specifications of all new bridges, culverts, public buildings, toll plaza etc. to erect solar panel on the bridge top/ rooftop to tap the solar energy. Wherever possible, install solar panels on the existing bridges/culverts, public build-ings, etc.
• Wherever technically feasible, adopt nature-based solutions. For example, create water-storage ponds to act as cushions during heavy floods. This will also help in improving groundwater table in the nearby areas. Use of local materials, especially in rural and semi-urban areas should be encouraged in construction, repair/restoration, etc.

Considering the dangers posed by climate change to the physical infrastructure of the country it is suggested that a committee of experts from the civil and structural engineering fields should be formed to examine the issues mentioned above in greater depth and produce a white paper or a re-port on the subject, highlighting the mitigation efforts that can provide resilience to the physical infrastructure. The committee can take help from climate scientists and experts from the transport, energy, telecom, urban development and water resources sectors.

References