With the increase in the consequences of climate change, the global rise in average temperatures across the world is quite alarming. And the resultant increase in the intensity and the frequency in heatwaves are creating vulnerability among cities.
Especially in the northwestern, central and south-central regions of India. There has been an increase in severe heat waves in India in recent years. Cities are particularly vulnerable to these extreme heatwaves as their high built density absorbs and retains heat, leading to higher temperatures and causing whats called the heat island effect.
The north-western usually experiences high temperatures during the summer but recently cities elsewhere are also experiences these extreme heat temperatures.
Climate Change In The 21st Century
Climate change has now become the defining challenge in the 21st century, although it is widely accepted that the rapid rate is human-made.
A 2018. IPCC report concluded that many adverse impacts of climate change can be seen at the 1.5°C mark including extreme temperatures in most inhabited regions, heavy precipitation in many areas, a deficit of precipitations in many and a rise in sea levels among others.
Consequently there will also be huge impacts in the ecosystem and biodiversity including extinction and loss of a vast number of species. This could lead to climate-risks to health, livelihood, food security, water supply and resulting in damaging the economic growth.
A newfound study shows that the various parts of central, south-central India have emerged as heatwave hotspots. The study said climate change and the subsequent increase in heatwave trends have places a larger population at risk.
Heatwave Variations
Researchers analyzed monthly, seasonal and decadal variations along with long-term trends of heatwaves with some severe events for pre-monsoon and early monsoon.
The study suggests and links heatwaves with greater concern for the human health, agriculture and the natural ecosystem. Heatwaves are declared when a maximum temperature in the plains are above 40°C and at least. 4.5 notches above normal. A severe heatwave is declared if the normal temperature is more than 6.5°C, according to IMD.
Led by Professor RK Mall of Mahamana Centre of Excellence in Climate Change Research (MCECCR) at Banaras Hindu University (BHU), have found a shift in the patterns of heatwave events with an increasing trend in three prominent heatwave regions in northwestern, central and south-central India, the highest being in West Madhya Pradesh.
Changes In Heatwave Trends
There are continuous changes in the trends over eastern regions of the Gangetic West Bengal and Bihar to north-western, central and south-central regions.
Researchers said that the model developed to study heatwaves can also be used to predict future occurrences of such extreme trends and have just laid the ground for the preparation for a heatwave resilient future.
Parts of Delhi, Punjab, Haryana and Uttar Pradesh experienced one of the worst temperature spikes earlier this year. Even though these heatwaves have been extreme, India was not alone in reeling under them. Globally, the last twelve years have been the hottest in recorded history and the five hottest years have been the last five years.
What Is The Solution?
On a city-scale, solutions exist for a city to implement a few things to better adjust to the heated surroundings
Vegetation
Increasing the number of trees and vegetation around the city reduce the. Surface temperature by around 1-5°C. They do this by providing shade and cooling through evapotranspiration.
Green walls and roofs
Increasing and utilizing vegetation for roofs and walls around constructed building help reduce the temperature. While also bringing in biodiversity.
White roofs and cool roofs
Made from materials that reflect sunlight, they reduce the amount of heat absorbed and reflect the heat away from the building. High albedo materials are used for these heat mitigating practices.
Smart growth
These practices cover a wide range of development and conversation strategies that help protect the environment and at the same time make communities more attractive, economically stronger and more livable.
Water pavements
Wetting down buildings and surfaces before an extreme heatwave can be seen as an effective technique to reduce surface temperatures.
Building optimization
Buildings with a lot of thermal mass such as rocks, double-brick homes or concrete make sure that the inner surfaces have lower temperatures.
Shading structures
Installing structures that provide shade over streets and roofs help in reducing the surface temperature.
Conclusion
In conclusion, heat resilience is one of the most important issues that need to be dealt with today. We understand that a lot cannot be done by cities to mitigate heat, so it the responsibility of municipalities to embrace this challenge and make sure that they invest on adoption of future technologies towards the impacts of climate change and save energy and money.