We are witnessing world’s biggest catastrophe in the form of zoonotic contagious virus named novel coronavirus (COVID-19/SARS-CoV-2). More than sixteen lakhs humans have already been infected by this COVID-19 and more than one lakh deaths related to coronavirus have been reported across the world till date. The current statistics of COVID-infections and accounted deaths clearly indicates the severity of situation. The world health organization (WHO) had already announced it as pandemic. Most of the world’s leading countries have announced national emergency and adopted partial or complete lockdown to control the transmission of infection. Indian population is no stranger to this highly contagious virus. Indian government has also taken some stringent and wise decisions to curb down the infection at its early stage. Nationwide lockdown (started since 22 March, 2020) is one of the important decisions taken by the central government to break the transmission chain and provide ample time to different institutions for preparation to face the future situation. Aside from the Coronavirus lockdown arresting the spread of the pandemic, it has also had an impact on the environment and there are certain lessons we must not ignore.
Impact of Coronavirus lockdown on air quality
Nationwide lockdown brings shutdown of all kinds of factories/industries, construction works and major transportation (public and personal vehicles) except necessary sectors across the country. Most of these sectors use fossil fuel based energy sources, which are the major source of anthropogenic pollutants and greenhouse gases, responsible for climate change. The forced restrictions on vehicular and industrial emissions are expected to results in better air quality. Within a week of the lockdown, the social media got flooded with various news/pictures/videos, showing twinkling stars in clear night sky, increased visibility during day and better air quality etc., as a result of lockdown. In fact, my scientific analysis using satellite observations also indicates a significant decrease in atmospheric particulate matter and gaseous pollution over India during lockdown period (see Figure). Satellite retrieved aerosol optical depth (AOD) and nitrogen dioxide (NO2) are used as proxies for air-borne particulate matter and anthropogenic gaseous pollutant, respectively. My study shows a significant decrease (about 20 – 60%) in AOD during lockdown as compared to past four years mean for the same period. As expected, the drop in concentration of particulate matter increases as a function of days in lockdown period. The gaseous pollutant (NO2) also shows a significant drop (about 20 – 40%) during entire month of March and early April, 2020.
Impact of Coronavirus lockdown on water quality
Coronavirus induced lockdown is not only benefiting in terms of air quality but also have greater impact on water quality and health of riverine systems. The discharge of chemical pollutants from factories and industries into rivers is completely closed, which accounts for a significant reduction in the pollution load of rivers flowing near urban agglomerates. However, there is no change in organic pollutants discharge through sewage from urban regions. In the absence of significant amount of chemical pollutants, self-cleansing capacities of rivers via dilution by natural runoff and natural degradation by microbial activities, may be able to deal with organic pollutants. Various social media posts and mainstream media articles show significant improvement in visible color and smell of water of Yamuna and Ganges as compared to past. However, scientific analysis results are yet to be seen before endorsing these claims.
The wild animals
Another important environmental aspect during lockdown period is related with increased frequency of spotting wild animals in residential/urban locations. Several Facebook’s and WhatsApp’s posts are displaying videos of elephant, deer and other animals roaming around in residential localities as per their claims. The marine animals are also frequently seen near coast during this period. Though a number of such claims are found to be false, these kinds of scenarios are natural in lockdown regulated silence zone of urban locations. The wild animals are claiming back their spaces and roaming freely while humans are sheltering in their houses during the lockdown period.
Coronavirus lockdown, the environment and lessons to be learnt
Better air quality, healthy riverine and flourishing ecosystems during lockdown give me a soothing touch as an environmentalist, but I can’t rejoice it. These environmental benefits are temporary and post-lockdown ‘as usual scenario’ may even pose greater threat to environment. These positive environmental changes are seen as a result of compulsive lockdown under the threat of pandemic outbreak, which have claimed a number of lives. This sudden lockdown has already costed lakhs of jobs, social security and mental peace of fellow citizens. Lakhs of poor and marginalized population are suffering despite the concerted efforts of states and central government’s machineries. Therefore, we can’t celebrate these temporary environmental benefits, but certainly can learn lessons from this lockdown.
This lockdown provides a natural laboratory condition of environment to gather baseline data for different environmental parameters. The academic/research institutions may use this scenario to build a nationwide baseline data for environment by collecting (with taking all necessary health precautions) measurements of various atmospheric, hydrological and ecosystem parameters. These baseline data can be helpful in determining the shares of different sectors in environmental pollution. Further, it can be used by stakeholders and policy makers to build a sustainable development model for the nation. In my view, this lockdown scenario gives us better understanding to differentiate between our needs and luxuries at individual levels. The goals of sustainable development can’t be achieved without balancing between ‘needs and luxuries’ at various scales such as individual, community, state and global levels. The lessons learned from lockdown can be used as arsenals in our fight for clean air, clean water and a healthy environment.