Down to Earth Magazine Analysis – 16 to 31st October 2021 Part 1

Table of Contents

BITS Global Terminology

Yezu:

Researchers in Japan have identified a novel virus named “Yezu” that can infect humans through tick bites. The symptoms of the virus include fever and reduced white blood cells and platelets that help fight disease, the scientists say in a Nature Communications study. Earliest known infections of Yezu virus so far are from 2014 in Japan.

Nobel Prizes (Dedicated to the Environment and Human Rights)

The chemistry Nobel went to scientists Benjamin List and David MacMillan for environment-friendly molecule building tools.
The physics Nobel to Syukuro Manabe, Klaus Hasselmann and Giorgio Parisi for their work on climate prediction.
The literature prize to novelist Abdulrazak Gurnah, who writes on refugee crises.
The Nobel Peace prize to journalists Maria Ressa and Dmitry Muratov for their efforts to protect freedom of speech.
The Nobel prize in physiology or medicine went to David Julius and Ardem Patapoutian for their work on temperature and touch receptors.

Ban on the use of packaged drinking water bottles

Sikkim Chief Minister P S Tamang on October 2 announced a ban on the use of packaged drinking water bottles in the state from January 1, 2022.
Apart from curbing plastic pollution, the move aims to promote the Himalayan state’s natural water resources. A similar ban is already in place in the state’s tourist hotspots like Lachen.

The September month usually gets the least rainfall as the monsoon winds prepare to retreat from the sub-continent.
This is also the month when rain-dependent agrarian communities eagerly wait for the harvest.
But things are changing.
This year, September received 35 per cent excess rainfall, while July and August, the two wettest monsoon months, remained drier than usual.

External Influence

There are at least four climatic phenomena that increased moisture levels and aided in the formation of low-pressure areas in September.
Starting August, the Indian Ocean Dipole (the oscillation of sea surface temperatures in the ocean) started entering into a negative phase. This means, waters in the eastern parts of the ocean near Indonesia were warmer and the western parts near Africa were cooler. This causes more rainfall in India. This phase intensified in September.
There were also colder than normal sea surface temperatures over the equatorial Pacific Ocean, which is associated with rainfall in India.
For most days of the month, the Madden-Julian Oscillation, an eastward moving pulse of cloud and rain responsible for sudden rainfall fluctuations on weekly to monthly time scales, was in a position that brought more moisture and aided the formation of low-pressure areas over the Bay of Bengal.
The Arctic ice loss this summer could have offered the final blow.
Reduced sea-ice in the Arctic during summer leads to high sea-level pressure over western Europe and north-eastern China, which steers planetary waves southeastward instead of their eastward trajectory. These waves enter India late in the season to produce circulation anomalies in the upper atmosphere, resulting in heavy rainfall in September.

Result

As a result, the Bay of Bengal saw five low-pressure areas through September.
- While the first, on September 6, ebbed before making landfall,
- the second on September 11 intensified into a deep depression and crossed the Odisha coast on September 13.
- Moving inland, it became a depression over Chhattisgarh, causing heavy rainfall along the way till September 15.
- This, accompanied by another low pressure system (September 17) over Gujarat, led to excess rainfall in the second week of September.

On September 26, cyclone Gulab made landfall in Andhra Pradesh. Over the next four days, it moved through Odisha, Chhattisgarh, Telangana, Maharashtra and Gujarat before entering the Arabian Sea.
While it was not unusually strong, high moisture levels over India kept it going. Around the same time, another low-pressure area over north Bay of Bengal brought a fair share of rainfall to West Bengal, Bihar and Jharkhand.

In the report of the Global Coral Reef Monitoring Network (gcrmn), a network of scientists and organisations that monitor the underwater ecosystems, “Status of Coral Reefs of the World 2020”, released after a gap of 13 years, the network estimates that the world has lost about 14 per cent of its coral reefs in the past decade.

What are Coral Reefs?

Coral reefs are large underwater structures composed of the skeletons of colonial marine invertebrates called coral.
The coral species that build reefs are known as hermatypic, or “hard,” corals because they extract calcium carbonate from seawater to create a hard, durable exoskeleton that protects their soft, sac-like bodies.
Other species of corals that are not involved in reef building are known as “soft” corals.
This is the sixth edition of the report, and the first since 2008. It is based on the quantitative analysis of a global dataset compiled from raw monitoring data of more than 300 members, spanning over four decades from 1978 to 2019.
Coral reefs occupy less than 1 per cent of the Earth’s ocean floor but benefit over 1 billion people and support at least 25 per cent of the world’s marine life, contributing trillions of dollars in trade and tourism. But they are under relentless stress from warming, says the report.
Marine heatwaves, coastal to ocean pollution (due to human effluents, agricultural runoff and industrial chemicals) and overfishing in the reef areas are also key drivers of declining corals. Diseases, overtourism and poor coastal management also play a role.
Bleaching occurs when hard corals or polyps lose their vibrant colour as they expel microscopic algae living inside their tissue, due to warm sea surface temperatures. A brief bleaching event does not always kill coral—but prolonged, severe bleaching can lead to disease and starvation.

First mass coral bleaching event: In 1998 (About 8% of the world’s corals killed)
- Now the trend seems to be reversing— there was 13.7 per cent less hard coral on reefs in 2015-19 compared with 2005-09.
- In contrast, since 2010, the amount of algae on the world’s coral reefs has increased by about 20 per cent.

Silver Lining in Asia

According to the region-specific status report, South Asia, which accounts for a little over 4 per cent of the world’s coral reefs, saw a decline in hard corals due to El Niño-related coral bleaching events in 1998 and 2016.
El Niño is the warm phase of the El Niño Southern Oscillation that affects ocean temperatures.
Coral reefs play a significant role in national economies, and in supporting livelihoods through fisheries and tourism, particularly in the Maldives, India and Sri Lanka.
Reef recovery is highly variable with better recovery on atolls along the Lakshadweep-Maldives-Chagos Ridge.
Atolls are ringshaped.

Coral reefs that encircle a lagoon. East Asia’s Coral Triangle that accounts for more than 30 per cent of the world’s reefs, has also been less impacted.
Despite a decline in hard coral cover during the last decade, on average, these reefs have more corals today than in 1983, when the first data were collected. Overall, on 2019, the world regained 2 per cent of coral cover.
This indicates that these critical ecosystems can recover if the pressure eases. They can even resuscitate to their pre-1998 health in 10 years.