TNPSC Current Affairs July 2017
1.Earth’s sixth mass extinction is underway –
Scientist.
Scientist says that Earth is going to face sixth mass extinction and is more severe than
previously thought and humans are the
primary cause of massive loss.
The
new study published in the Proceedings of the National Academy of Sciences, argues
the loss of wildlife a "biological annihilation" that represents a
"frightening assault on the foundations of human civilisation".
About the Study:
- Scientist further said that Earth has gone through five mass extinctions, which has wiped out high proportion of life mainly due to natural forces like climate changes, huge volcanic eruptions or catastrophic meteor strikes
- But the 6th extinction which is underway would be the first to be driven by the activity of humans like such as deforestation, overpopulation, pollution, poaching etc.
- It is due to human overpopulation , continued population growth, overconsumption or greed especially by the rich .
- Scientist also warned there will be a huge wildlife loss if no changes is made within next 20 years.
Previous Mass Extinctions
443
million years ago(End Ordovician period)
Due
to sea level fall by 100 m, that wiped out 60-70 % of all species.
360
million years ago (Late Devonian Period)
Due
to prolonged climate change event, with shallow seas the worst affected areas,
nearly saw all corals disappearing.
250
million years ago(Permian Triassic period)
Third
mass extinction also known as the great dying, almost 96 % of species died, due
to Massive volcanic eruptions in Siberia which lead to global warming.
.
200
million years ago (Triassic-Jurassic)
Forth
mass extinction due to Climate change, an asteroid impact and flood basalt
65
million years ago( Cretaceous tertiary)
Fifth
Mass extinction, due to giant asteroid impact which saw the death of dinosaurs.
2.World population day – July 11
World population day is an annual event observed
on July 11 with focus attention on the urgency and importance of population
issues. This year it observed with the theme of “Family
Planning: Empowering People, Developing Nations”
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