By Satyaki Paul
On August 09, 2021 the Intergovernmental Panel on Climate Change (IPCC) released the first part of its Sixth Assessment Report. This is the sixth iteration of world review of climate change being conducted by IPCC. This report is momentous as its findings in due course mightcoerceother countries to ramp up their climate commitments in Glasgow climate summit of United Nations Framework Convention on Climate Change (UNFCCC).
The report observes that it is explicit that human interference i.e., certain anthropogenic causes has warmed the atmosphere, ocean and land. This has resulted in extensive and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred. These recent changes across the climate system are unprecedented over many thousands of years. Thus, human-induced climate change is already affecting many weather and climate extremes in every region across the globe. So, the world surface temperatures are now higher by 1.07 degrees Celsius over the pre-industrial level. Furthermore, the world surface temperature will continue to upsurge until at least the mid-century (current century) under all emissions scenarios considered. The threshold of global warming from 1.5°C to 2°C will be exceeded during the 21stcentury unless deep cuts are introduced in the emissions of carbon dioxide (CO2) and other greenhouse gas emissions in the near future.
What is the current situation of urbanised regions? In current context, the urban centres and cities are already warmer than surrounding rural areas due to urban heat island effect. This urban heat island effect results from numerous factors such as: reduced ventilation and heat trapping due to the close proximity of tall buildings, heat generated directly from human activities, the heat-absorbing properties of concrete and other urban building materials, and the limited amount of vegetation. The process of urbanisation alters the water cycle, generating increased precipitation over and downwind of cities and increasing surface runoff intensity. This results in phenomena such as the urban dryness island referring to conditions where lower humidity values are observed in cities relative to more rural locations, and to slower wind speed compared to adjacent suburbs and countryside. Thus, in a manner of speaking in spite of having aninsignificant impact on global annual mean surface-air warming urbanization has exacerbated the effects of global warming in cities.
What will be the consequence of urban centres? The future urbanisation will amplify projected air temperature change in cities. This will result in an increased frequency of extreme climate events such as heatwaves, with more heat days and warm nights adding to heat stress in cities. As redressals numerous measures should be undertaken such as: impact assessments and adaptation plan in cities require high-spatial-resolution climate projections. This involves change in urban geometry, reduction of heat from anthropocentric activities and intensifying rejuvenation of carbon sinks across the world. As a small step, to counter urban heat island effect small vegetation and water bodies can be nurtured.
What does India say on this report? The current Union Environment Minister Bhupender Yadav has hailed the report and opined that our country has taken many steps to decouple its economic growth from emissions. Further he has also added that this report is a clarion call for developed nations to gradually cut emissions and decarbonise their economies as soon as possible. Nonetheless, the union MoEFCC Secretary R.P. Gupta observed that, the Government of India is still considering what should be done on the issue of net zero neutrality commitment by Indian side. As because the developed countries have already appropriated more than their fair share of the global carbon budget due to early industrial revolution and growth. Thus, reaching net zero alone is not enough, as it is the cumulative emissions up to net zero that determine the temperatures that is reached. India’s cumulative and per capita current emissions are significantly low and far less than its fair share of global carbon budget.Thus, this report in one hand vindicates India’s position that historical cumulative emissions are the source of the climate crisis in current context. On the other hand, it rebukes that India needs to act in the same pace as that of the countries which are far more developed than India.