India is Losing Sunlight

A new study by six Indian scientists has found that over the past three decades, sunshine hours—defined as the time direct sunlight reaches the Earth's surface—have steadily declined across most of India. This decline has been attributed to various factors including clouds, aerosols, and local weather conditions.

Data analyzed from 20 weather stations between 1988 and 2018 shows a consistent drop in sunshine hours throughout the country. The northeast region is an outlier with a slight seasonal improvement. The steepest declines were witnessed in northern regions, especially cities like Amritsar and Kolkata, and along the Himalayan belt and west coast, notably Mumbai.

India ranks among the world's top ten polluted countries, with the crisis largely stemming from rapid urbanization, industrial expansion, and land-use changes. These factors have intensified fossil fuel consumption, vehicle emissions, and biomass burning, leading to elevated aerosol levels that obstruct sunlight.

Impact of Air Pollution on Sunshine Hours

Aerosols—tiny particles from multiple sources—along with weather conditions have caused a significant reduction in solar radiation. It has been estimated that aerosols have decreased sunlight reaching the ground in India by about 13%, while clouds have further diminished it by 31% to 44% from 1993 to 2022.

This persistent reduction in sunlight is concerning for various sectors, especially agriculture and renewable energy. Cleaner air could potentially enhance solar energy production by up to 28 terawatt hours annually, enough to power millions of homes.

Global Context and Comparisons

India is not the only nation grappling with this issue. Similar trends have been observed globally, with air pollution leading to reduced sunlight in regions across Europe and China. However, the shift towards improved air quality has shown promise, signaling a potential reversal of the dimming effects observed in some parts of the world.

In conclusion, as India strives to increase its renewable energy capacity, addressing air pollution will be crucial to harnessing the full benefits of solar power and ensuring sustainable agricultural practices.