El Nino Current Affairs - 2019
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According to recent study conducted by scientists, the monster El Nino of 2014-16 caused over 3 billion tonnes of carbon to get released into the atmosphere, pushing carbon dioxide (CO2) concentration to record levels.
The study was based on analysis of data collected by NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite, which measures level of CO2 in the atmosphere. These are the first measurements for satellite tracking CO2 levels.
El Nino is a complex periodic climate event that causes waters to warm up in east-central Pacific Ocean. The warming of ocean causes huge changes in wind directions which bring less rain to south-east Asia and Indian subcontinent, while increasing rain in other parts of the world.
Key Highlights of study
The El Nino led to excessive carbon dioxide releases in three ways. They are (i) Hot weather and drought caused extensive wildfires in south-east Asia, (ii) Drought in the Amazon rainforest stunted plant growth, reducing the amount of carbon they absorb while growing (iii) Warmer weather and near normal rainfall in Africa caused forests to exhale more CO2.
The rate of growth of CO2 in the atmosphere had hit an all-time high of 2.94 parts per million per year in 2015 and slightly below that at 2.89 ppm per year in 2016. In other words, CO2 was being added to the atmosphere at a much higher rate than ever before even though carbon emissions were flat.
In 2014 and 2015, CO2 emissions from burning of fossil fuels had flattened out to about 36.2 billion tonnes. Projections for 2016 too indicated that emissions were still flat.
The industrialised countries do not appear to be on course to meet the targets that they pledged at the Paris Climate Accord of 2015. Emissions from European Union countries have actually increased in 2015, the rate at which emissions from US and Japan are declining does not comply with what they had pledged at Paris.
Tags: Climate Change • CO2 • El Nino • Environment • NASA
A study conducted by the University of Hyderabad and the Indian Institute of Technology – Bombay has found out that the extreme El Nino conditions and warming of the Bay of Bengal had resulted in unprecedented heavy rainfall in Chennai for three days between November 30th to December 2nd in 2015.
El Nino usually causes less than normal rainfall in the case of south-west monsoon. However, it does the reverse in the case of the northeast monsoon. It causes above-normal rainfall during the northeast monsoon. This is due to the difference in seasonal wind patterns between the two monsoons.
The researchers had carried out a simple linear correlation analysis that points out that the sea surface temperature at the Bay of Bengal is positively correlated with northeast monsoon rainfall. It has been found out that the magnitude of correlations of northeast monsoon rainfall with El Nino conditions and the Bay of Bengal warming to be almost same.
Based on several experiments, the scientists have attributed around 21% of the intensity of the extreme Chennai rainfall to the extreme El Nino condition
The consistent warming of the Bay of Bengal off the coast of Tamil Nadu and Andhra Pradesh is also considered as an important factor for the floods by the scientists.
However, scientists are yet to ascertain whether the contribution from the tropical Pacific to extreme rainfall during the northeast monsoon occurs only at the time of extreme El Nino or whether normal El Ninos too are capable of causing them.
El-Nino is a weather phenomenon, during which temperature at sea surface is warmer than normal sea-surface temperatures. El Nino is a warming of the Pacific Ocean between South America and the Date Line, centred directly on the Equator, and typically extending several degrees of latitude to either side of the equator. It accompanies high air surface pressure in the western Pacific. El Niño occurs when tropical Pacific Ocean trade winds die out and ocean temperatures become unusually warm