Global Warming Current Affairs

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.

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India at risk of food shortage due to climate change: Study    

According to recently published global study, India is among countries which are at greatest risk of food insecurity due to weather extremes caused by climate change. The study had examined how climate change could affect vulnerability of different countries mainly 122 developing and least-developed countries (mostly in Asia, Africa and South America) to food insecurity — when people lack access to sufficient quantity of affordable, nutritious food. It examined projected changes in weather extremes and their implications for freshwater availability and vulnerability to food insecurity.

Key Findings

Climate change caused by 2 degrees Celsius global warming is expected to lead to more extremes of both heavy rainfall and drought, with different effects in different parts of world. Such weather extremes will increase vulnerability to food insecurity. The countries at greatest vulnerability to food insecurity due to climate change are Oman, India, Bangladesh, Saudi Arabia and Brazil.

Global warming is expected to lead to wetter conditions on average causing floods and putting food production at risk. But agriculture may also get harmed by more frequent and prolonged droughts in some areas caused by climate change.

Wetter conditions are expected to have biggest impact in South and East Asia, with most extreme projections suggesting flow of River Ganges could more than double at 2 degrees Celsius global warming. Some areas are projected to see increase in flood event lengths of 4 days or more, particularly India and Bangladesh, for which such increases are projected in all ensemble members to some extent.

The areas worst affected by droughts are expected to be southern Africa and South America – where flows in Amazon River are projected to decline by up to 25%. Some climatic change is already unavoidable, but if global warming is limited to 1.5 degrees Celsius, this vulnerability is projected to remain smaller approximately 76% of developing countries than at 2 degrees Celsius

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