Polling begins in Rajasthan

New Delhi, Jun 27: Delhi Environment Minister Gopal Rai on Saturday called an emergency meeting here to discuss the situation following a locust attack in neighbouring Gurugram.

The minister also directed the administration to be alert, an official said.

"After the emergency meeting, an advisory will be issued on steps to be taken to deal with the situation," Rai told PTI.

He asked the officials of the Agriculture department to make field visits to areas close to Gurugram.

The development secretary, divisional commissioner, director, Agriculture department, and the district magistrates of South Delhi and West Delhi will attend the meeting, the official said.

Earlier in the day, the skies over many parts of Gurugram turned dark as swarms of locusts descended on the town.

However, the migratory pests are likely to spare the national capital for now, officials said.

The swarms of locusts, spread across two kilometres, moved from west to east. They entered Gurugram around 11.30 am, K L Gurjar of the Locust Warning Organisation, Ministry of Agriculture, told PTI.

The pests, he said, were headed towards Faridabad and Palwal in Haryana.

Alarmed at the invasion of the locusts, which settled on trees, rooftops and plants, many residents of Gurugram shared videos from their high-rise perches.

In May, India battled a devastating desert locust outbreak. The crop-destroying swarms first attacked Rajasthan and then spread to Punjab, Gujarat, Maharashtra and Madhya Pradesh.

According to experts, broadly four species of locusts are found in India – desert locust, migratory locust, Bombay locust and tree locust. The desert locust is considered the most destructive.

It multiplies very rapidly and is capable of covering 150 kilometers in a day.

This insect, a type of a grasshopper, can eat more than its body weight. A one square kilometer of locust swarm containing around 40 million locusts can in a day eat as much food as 35,000 people.

Experts blame the growing menace of desert locusts on climate change. They say breeding of locusts is directly related to soil moisture and food availability.

Washington, Apr 23: Air pollution over northern India has plummeted to a 20-year-low for this time of the year, according to satellite data published by US space agency National Aeronautics and Space Administration (NASA).
The US space agency's satellite sensors observed aerosol levels at a 20-year low post the countrywide lockdown, implemented to slow the spread of the novel coronavirus.

"We knew we would see changes in atmospheric composition in many places during the lockdown," said Pawan Gupta, a Universities Space Research Association (USRA) scientist at NASA''s Marshall Space Flight Center. "But I have never seen aerosol values so low in the Indo-Gangetic Plain at this time of year," added Mr Gupta.

Acting Assistant Secretary of State for South and Central Asia Alice G Wells tweeted, "These images from NASA were taken each spring starting in 2016 and show a 20-year low in airborne particle levels over India. When India and the world are ready to work and travel again, let's not forget that collaborative action can result in cleaner air."

The data published with maps show aerosol optical depth (AOD) in 2020 compared to the average for 2016-2019. Aerosol optical depth is a measure of how light is absorbed or reflected by airborne particles as it travels through the atmosphere.

If aerosols are concentrated near the surface, an optical depth of 1 or above indicates very hazy conditions. An optical depth, or thickness, of less than 0.1 over the entire atmospheric vertical column is considered "clean." The data were retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite.

In the first few days of the lockdown, it was difficult to observe a change in the pollution signature. "We saw an aerosol decrease in the first week of the shutdown, but that was due to a combination of rain and the lockdown," said Mr Gupta.

Around March 27, heavy rain poured over vast areas of northern India and helped clear the air of aerosols. Aerosol concentrations usually increase again after such heavy precipitation.

"After the rainfall, I was really impressed that aerosol levels did not go up and return to normal. We saw a gradual decrease and things have been staying at the level we might expect without anthropogenic emissions," Mr Gupta said.

On March 25, the Indian government placed its 1.3 billion citizens under a strict lockdown to reduce the spread of COVID-19. The countrywide mandate decreased activity at factories and severely reduced car, bus, truck and airplane traffic. Every year, aerosols from anthropogenic (human-made) sources contribute to unhealthy levels of air pollution in many Indian cities.

Aerosols are tiny solid and liquid particles suspended in the air that reduce visibility and can damage the human lungs and heart.

In southern India though, the story is a little hazier. Satellite data show aerosol levels have not yet decreased to the same extent. In fact, levels seem to be slightly higher than in the past four years. The reasons are unclear but could be related to recent weather patterns, agricultural fires, winds or other factors.

"This a model scientific experiment," Robert Levy, program leader for NASA's MODIS aerosol products, said about the lockdown and its effects on pollution.

"We have a unique opportunity to learn how the atmosphere reacts to sharp and sudden reductions in emissions from certain sectors. This can help us separate how natural and human sources of aerosols affect the atmosphere," Mr Levy added.