As of late June, India had the fourth-highest number of COVID-19 cases in the world, at more than 525,000. In May and June, the country also was hit by two destructive cyclones, just ahead of the onset of the monsoon season. India now faces the dual challenge of containing a pandemic in the face of natural disasters. Climate changes further complicate the process, as the intensity of natural hazards in general is forecast to increase.
Researchers say it is time to start a modeling effort that brings together these threats.
Bigger Storms, Bigger Problems
Two cyclones ripped through eastern and western India between mid-May and early June, felling electric poles and disrupting power to hospitals and quarantine centers.
First, Super Cyclone Amphan, with wind speeds reaching 260 kilometers per hour, pounded the states of Odisha and West Bengal in eastern India before moving on to Bangladesh. Two weeks later, Nisarga, a severe cyclone with wind speeds reaching 118 kilometers per hour, tore into Maharashtra in western India, blowing away the roof of a hospital just north of Mumbai. Maharashtra was already struggling with the country’s highest number of coronavirus cases.
The cyclones have heightened concerns about the coming monsoon. “The biggest worry is that we hit an unavoidable trade-off between emergency response and outbreak containment,” said Colin Carlson, a global change biologist at the Center for Global Health and Security at Georgetown University in Washington, D.C. “For example, when a cyclone hits, if we have to evacuate people from their homes and shelter them together, we might expect a localized outbreak to be basically inevitable. But we don’t have a great strategy for emergency response that prevents that.”
“Natural disasters can impact the [COVID-19] pandemic directly through disrupting health services and health infrastructure, as well as making social distancing more difficult among people displaced by a natural disaster,” said Christopher Trisos, director of the African Climate and Development Initiative at the University of Cape Town in South Africa.
Natural disasters could also impact COVID-19 control measures indirectly by disrupting clean water supplies and stretching government budgets already struggling to cope with the pandemic response, Trisos added. Trisos and Carlson are part of a team that authored a paper in Nature Climate Change on compound climate risks in the COVID-19 pandemic.
Although monsoon showers bring welcome relief to a Sun-scorched India, climate scientists have been cautioning that the rainfall pattern has become increasingly erratic in recent decades. This shift comes in tandem with a rise of 10%–30% in extreme rainfall events over the central Indian subcontinent, attributable to climate change.
“During monsoon season, this year we are expecting many heavy rainfall events and associated floods,” said Madhavan Nair Rajeevan, secretary of India’s Ministry of Earth Sciences. “This could hamper the COVID-19 activities.” Evacuation of people from disaster-hit areas to shelters could add more risk to COVID-19 spread, he added. Indeed, monsoon-triggered floods have already displaced hundreds of thousands of people in northeast India in 2020.
Expanding the Modeling Efforts
Indian climate scientists have developed several models to understand the impact of global warming on the country’s temperatures and rainfall, as well as the impact of climate change and monsoon on mosquito-borne diseases such as malaria and dengue. But they have yet to develop models to predict the impact of natural disasters on pandemics, specifically on COVID-19.
In May, India’s Department of Science and Technology (DST) launched an Indian National Supermodel initiative to serve as a common platform for future modeling efforts. Its priority is to create a composite robust model that can predict the spread of COVID-19, DST secretary Ashutosh Sharma said, and could eventually address natural disasters.
Although the combination of natural disasters and epidemics needs to be addressed, the focus at first should be “on making sure the COVID-19 model is as comprehensive and well benchmarked as possible,” said Gautam Menon, a professor of computational biology and biophysics at The Institute of Mathematical Sciences, Chennai.
Meanwhile, Menon’s team is developing India’s first large-scale “agent-based simulation model,” a dynamic system with inputs from different interacting entities, or agents, focused on COVID-19 in India. The researchers are partnering with Ashoka University, Sonipat, and the global software company ThoughtWorks.
“More detailed agent-based models have been used to model the consequences of natural disasters for disease spread abroad but not, so far as I know, in India,” Menon said, and not yet for coronavirus. Such models will help scientists compare different interventions, such as relief camps, a lockdown or a local quarantine, and even levels of individuals’ compliance to such control measures. Such models “will provide a powerful tool for decision-making,” Menon said.
India already has several “robust” models to forecast the impact of monsoon and other natural hazards on vector-borne diseases, said Rajan Patil, an epidemiologist at the SRM Institute of Science and Technology in Chennai. For example, links between monsoon, climate change, and vector-borne diseases (such as malaria, dengue, Japanese encephalitis, chikungunya, and visceral leishmaniasis) can be modeled as shifts in water and weather patterns influencing the life cycle of the bugs that carry the pathogens or the pathogens themselves.
Similarly, Indian scientists have developed models on the impact of natural hazards such as droughts, famine, and even earthquakes on vector-borne diseases. A few predictive models focus on more regular weather, such as winter conditions and respiratory diseases such as asthma, tuberculosis, and measles and the impact of summer weather on heat strokes and diarrhea, Patil said.
However, Patil cautioned that it is too early to talk of modeling the impact of the monsoon on COVID-19, as knowledge about the new virus is still evolving. “For the virus as well as for us as researchers, the coming monsoon is the first monsoon we will be facing with COVID-19,” he noted. He said that scientists need to observe how COVID-19 behaves during the monsoon for a minimum of 2 years to make future predictions. By then, the pandemic may be over—or continuing, making it even more urgent to incorporate coronavirus into climate and weather models.
—T. V. Padma (@tvpadma), Science Writer