Climate Resilient Urban Development Strategies for a megacity: A Case of NCT of Delhi
Climate change is an undeniable global phenomenon. In the past decade, the onus of climate change discourse has shifted from global to urban level. Between 1970 to 2010 world’s population increased from 4 billion to 7 billion, an increase of 75 per cent, while the greenhouse gas emissions increased by 82 per cent, with an annual increase of 2.2 per cent in the last decade alone (IPCC 2015). Cities became critical for two reasons. First, they account for over 70 per cent of global greenhouse gas emissions. Second, they house over 50 per cent of the global population. Hence, cities and their activities are both victims as well as a primary reason for climate change.
Statistical data estimates population growth of Delhi from 4 lakh in 1901 to over 18 million in 2016 with an increase of 10 million since 1991. Simultaneously, the urban area of the city increased from 685 square kilometres in 1991 to over 1200 square kilometres by engulfing its rural counterparts and declining the annual agriculture production by 0.5 per cent. Also, the period saw a marked increase in its developed area density from 130 persons per hectare in 1991 to over 190 persons per hectare in 2011 (Census of India. 1981. 1991. 2001. 2011). At the same time, the climate of the city in terms of its temperature and precipitation has also changed. From 1901, the city’s annual average temperature has increased by 1.4 oC, with an increase of 0.93 oC in the past four decades. During the same period, the city’s precipitation pattern has changed with summers getting wetter, a number of rainy days reducing by 11 days and an increasing rainfall intensity. This trend of urbanization and climate variability in Delhi is further interlinked with the urban environment or loss of it and the three form a vicious cycle whereby urbanization is leading to loss or destruction of environmental resources and the combined forces of the two are adding up to the natural climate variability of the city.
This research develops a correlation model to study the impact of urbanization and urban planning on the climate variability and environment for a mega city of Delhi. The analysis in paper reveals that from 1986 to 2016, the city lost its heat sinks at an annual rate of 1.4 per cent with an increase in built-up area by 1.4 per cent and simultaneous increase in air and surface temperature by 0.3 per cent. The cumulative effect of these interactions is felt on the energy consumption, sale of consumer products that help regulate thermal comfort as well as on the health of citizens of Delhi. Moreover, the contribution to climate change and implications arising from the multiplier effect of climate change and urban development, are found to vary spatially within the city. It varies for different zones, planning divisions as well as population cohorts, with urban villagers living along floodplains of the city being at highest risk. Keeping in view the imminent climate change expected owing to urbanization patterns in Delhi the paper looks into a need for adopting climate resilient strategies in future planning efforts for development of Delhi.