Environment Current Affairs 2018

Global warming driving harmful algae growth: Study

Scientists have found that global warming is driving proliferation of Noctiluca algae (commonly known as sea tinkle), a harmful algae in Arabian Sea responsible for glowing of Mumbai’s beaches in dark. The study was jointly conducted by researchers from Indian National Centre for Ocean Information Services (INCOIS), a Ministry of Earth Sciences body and US National Oceanic and Atmospheric Administration (NOAA).

Key Facts

Noctiluca algae is parasite and occurs in patches or blooms in northern Arabian Sea. Its bioluminescence characteristic i.e. glow in dark has earned it name ‘sea sparkle’. The algae compete with fish for food and choke their supply. It devours one of most important planktonic organisms at base of fish-food chain, namely diatoms. It also excretes large amounts of ammonia, which causes massive fish mortality.

Significance of study

Earlier studies had linked increase in algal patches to coastal pollution from major Indian cities along west coast. However, in this study researchers found that global warming conditions are responsible their proliferation. Warming of oceans due to global is increasing temperature differences among layers of sea water.

This temperature differences has slowed the upward transport of nutrients like silicate from ocean bottom, lowering its concentration at surface. Diatoms growing in surface water which need both sunlight and silicate to build their glass skeletons, fail to thrive when silicate is in short supply. On other hand, Noctiluca algae remain unaffected by these changes and prey on remaining diatoms. Thus, the study shows that intensifying global warming conditions will disrupt fish-food chain and cause decline of fisheries in the region.

Month: Categories: Environment Current Affairs 2018

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14 of Indian cities figure in World’s 20 most polluted cities list: WHO

According to Global Urban Air Pollution database released by World Health Organisation (WHO), 14 Indian cities have figured in list of world’s 20 most polluted cities in terms of particulate matter PM2.5 levels in 2016. These 14 cities include Delhi, Varanasi, Kanpur, Faridabad, Gaya, Patna, Agra, Muzaffarpur, Srinagar, Gurgaon, Jaipur, Patiala and Jodhpur. They were followed by Ali Subah Al-Salem (Kuwait) and few cities in China and Mongolia. In terms of PM10 levels, 13 cities in India figured among the 20 most-polluted cities.

Background

The database measured levels of fine particulate matter (PM10 and PM2.5) from more than 4,300 cities in 108 countries. It estimates that around 7 million people die every year from exposure to fine particles in polluted air that penetrate deep into lungs and cardiovascular system. WHO recognises air pollution is critical risk factor for noncommunicable diseases (NCDs) as it causes diseases including stroke, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections, including pneumonia. Since 2016, over 1,000 additional cities are being added to WHO’s database, showing that more countries are measuring and taking action to reduce air pollution than ever before.

Key Facts

Pollution related Deaths: According to WHO database, ambient air pollution alone caused some 4.2 million deaths in 2016 across the globe, while household air pollution from cooking with polluting fuels and technologies has caused 3.8 million deaths in same period. It shows that 9 out of 10 people in the world breathe air containing high levels of pollutants.

Global Scenario: More than 90% of air pollution-related deaths occur in low- and middle-income countries (including India), mainly in Asia and Africa. It is followed by low-and middle-income countries of Eastern Mediterranean region, Europe and Americas. More than 80% of people living in urban areas are exposed to air quality levels that exceed WHO limits. While all regions of world are affected, populations in low-income cities are most impacted.

South Asia region: It alone accounts for 1.5 million (40%) deaths by household air pollution and 1.3 million (30%) global deaths due to ambient air pollution. Member-countries in Southeast Asia Region need to aggressively address double burden of household and ambient (outdoor) air pollution.

Lack of clean fuel: Around 3 billion people (more than 40% of the world’s population) still do not have access to clean cooking fuels and technologies in their homes, the main source of household air pollution.

Since 2016, over 1,000 additional cities have been added to WHO’s database, which shows more countries are measuring and taking action to reduce air pollution than ever before.

Month: Categories: Environment Current Affairs 2018

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