Tags : GS Prelims Paper 1 GS Mains Paper 3 Prelims Facts Current events of national and international importance GS Mains Paper 1 General issues on Environmental ecology, Biodiversity and Climate Change Role of women and women’s organization, population and associated issues, poverty and developmental issues, urbanization, their problems and their remedies
If the impact of Urbanization due to migration to cities and resultant impact on climate is not managed in time, the city could transform to its dark twin, embodying vulnerability, inequity and instability.
  • As per the UNFPA (United Nations Population Fund) estimates, 4.2 billion people or 55% of the world’s population lives in cities.
  • By 2030, this will be over five billion. By 2050, 68% of the world will be urban.
  • The World Economic Forum finds 83. 6% Americans live in cities while 51% Asians were urban in 2020, compared to under 20% in 1950.
Cities are economic powerhouses
  • They contribute over 80% of gross national product worldwide — while being locales of miraculous possibilities. People find freedom, aspiration, camaraderie and dignity in cities globally.
  • At the same time, UN Habitat finds cities consume two-thirds of the world’s energy and generate 75% of global carbon emissions. Just 25 cities cause 52% of urban greenhouse gas emissions through electricity generation, transport and industry. These emissions have a dual impact. They intensify pollution within citiesWHO finds over 80% people in urban areas face unsafe air quality — while worsening climate change which is now impacting cities through extreme rain events, rising sea levels, water scarcity and heat stress. 
  • India has 43 of the world’s 100 most environmentally risky cities.
  • Climate change also impacts the urban socio-economy.
  • The UN estimates one in seven people on Earth is already a migrant. As climate change makes farming less viable, migration to cities will grow. Already over one billion people worldwide live in slums — by 2030, one in four could reside thus. Alongside, the UN finds 2. 9 billion people live in cities where income inequality is more pronounced than it was one generation ago. 
  • These factors have profound implications for the meaning of a city — if not managed in time, the city could transform to its dark twin, embodying vulnerability, inequity and instability. However, multiple mitigations can help create more sustainable cities
Sustainable City: 
  • This should be affordable and inclusive. Our ideas of a sustainable city draw from the West. We need to support more mixed traffic, mixed housing, walkable areas, etc. 
  • A sustainable city must be people-friendly.
The main impacts of climate change cities should prepare for: 
  • Building climate resilience is among the most important aspects of a city’s life
  • We are already seeing how every time it rains, cities flood.
  • Climate change will bring more extreme rain events. Cities face huge flooding risks. Alongside, they need water — so, local water harvesting is the must.
  • We should also increase urban sponges like green areas, lakes, ponds and wetlands. This will turn extreme rain events towards recharging our groundwater instead of becoming devastating floods. 
  • A city can then draw from local water systems rather than long-distance water transfers which are extremely expensive and break the back of every city’s water utility.
  • Climate change will also increase heat and we need green areas which bring down the temperature. Alongside, we need urban housing using the principles of passive architecture — this means building with nature and not against it. 
  • The traditional architecture of India planned for the sun — every home, for instance, had chajjas or visors to protect against the sun’s rays. Such building brought down the temperature substantially. 
  • As per CSE data, as soon as temperatures exceed 28 degrees, energy demand for cooling soars in cities. Thermal comfort at affordable prices needs urban design using passive architecture as opposed to more unsustainable glass facades with double-insulation, etc.
  • Historically, Indian urban planning respected ecology — Jaisalmer was built according to the sun and it harvested every drop of rain it received. It built courtyards, wind channels, water tanks and many innovations enabling sustainability.
Rise in climate migration to cities: 
  • In any Indian city, more people live in unauthorised areas. 
  • Every city is growing around its edges but owing to the lag in data, by the time city planners understand this occurrence, the complexity of the numbers is beyond their control.
  • Positive developments in authorised areas  also are a drop in the ocean — most people are living beyond these services. 
A case study of Cape Town and Chennai:
  • Cape Town had a Day Zero in 2018 when it practically ran out of water. 
  • Similarly, Chennai suffers from water scarcity — yet, every time it rains, Chennai is flooded. 
  • It is said to privilege a few, it destroyed its amazing water systems like the Buckingham Canal, the Cooum river, etc. , which managed water supply and drainage through lakes and ponds. 
  • Earlier, Cape Town also thought it was a city only for the elite —vast numbers living there have no access to water or sewage systems. But finally, even the rich faced a Day Zero because the city was dependent on long-distance water supply that dried up in a drought.