Environment, GS-3, Uncategorized

Environment Digest – 29 May – 4 June 2016

[1]Nature’s answer to climate risk


  • Nature based solutions for climate and disaster risk.

Effect of climate change on coastal areas

  • Nearly half the world’s population lives near coasts.
  • As climate change exacerbates the effects of storms, flooding and erosion, the lives and livelihoods of hundreds of millions of those people will be at risk.
  • Coastal areas has to face economic losses as well owing to infrastructure damage and lost revenues from farming, fisheries and tourism.
  • Priorities of the governments worldwide
  • According to a report, failure to adapt to the effects of climate change is the single greatest risk, in terms of impact, to societies and economies around the world.
  • But, the international community currently spends on risk mitigation less than one-fifth of what it spends on natural-disaster response.

Priorities needs to be set

  • It is time to shift resources towards risk reduction.
  • Doing so will require national governments, industry, aid organizations and other NGOs to make the most of their investments.
  • And some of the most effective and cost-effective solutions are already available in nature.

Nature’s solutions

  • Coastal and marine ecosystems have considerable potential to mitigate the effects of storms and other risks, especially when combined with traditional built infrastructure
  • Mangroves can reduce wave height and  lower peak water levels during floods.
  • Coral reef  can reduce wave force by 97%, lessening the impact of storms and preventing erosion
  • These and other coastal ecosystems are the first line of defence for many cities around the world.


  • In the face of rising climate and disaster risk, investments in nature-based solutions can protect lives and safeguard prosperity in a cost-effective manner—all while preserving imperiled natural ecosystems around the world.
  • Paris climate agreement has also explicitly affirmed that ecosystems play a role in capturing greenhouse gases and helping communities adapt to the effects of climate change.
  • It is time for governments, business and NGOs alike to recognize that when it comes to fighting the effects of climate change and protecting coastal communities, preserving and restoring nature may be the smartest investment we can make.

[2] Harappa:older than we thought


  • According to some studies, climate change was probably not the sole cause for the collapse of the Harappan civilisation in the Indus-Ghaggar-Hakra river valleys and it is older than we thought of it.

Key findings in the study:-

  • Harappan civilisation itself was much older than thought — it is at least 8,000 years old.
  • Despite the monsoon decline, the civilisation did not disappear. The people changed their farming practices.
  • They switched from water-intensive crops when monsoon was stronger to drought-resistant crops when it was weaker.
  • Study suggests that other causes, like change in subsistence strategy, by shifting crop patterns rather than climate change was responsible for the Harappan collapse.
  • The findings come from a major excavated site of Bhirrana in Haryana that shows preservation of all cultural levels of this ancient civilisation from the pre-Harappan Hakra phase through the Early Mature Harappan to the Mature Harappan time.
  • Bhirrana was part of a high concentration of settlements along the now dried up mythical Vedic river ‘Saraswati’, an extension of Ghaggar river in the Thar desert.
  • To find out how old the civilisation is, the researchers dated pottery of the Early Mature Harappan time — by a technique called optically stimulated luminescence (OSL) — and found it to be nearly 6,000 years old, the oldest known pottery so far.
  • The levels of pre-Harappan Hakra phase have been dated as old as 8,000 years.

[3] Australia’s Great Barrier Reef , a third of coral killed due to bleaching

What happened?

  • Incidents of mass bleaching has killed more than a third of the coral in the northern and central parts of Australia’s Great Barrier Reef.

What are corals?

  • Coral organisms, called polyps, can live on their own, but are primarily associated with the spectacularly diverse limestone communities, or reefs, they construct.
  • Corals live in tropical waters throughout the world, generally close to the surface where the sun’s rays can reach the algae.
  • While corals get most of their nutrients from the byproducts of the algae’s photosynthesis, they also have barbed, venomous tentacles they can stick out, usually at night, to grab zooplankton and even small fish.

How coral reefs are formed?

  • Coral polyps are tiny, soft-bodied organisms related to sea anemones and jellyfish.
  • At their base is a hard, protective limestone skeleton called a calicle, which forms the structure of coral reefs.
  • Reefs begin when a polyp attaches itself to a rock on the sea floor, then divides, or buds, into thousands of clones.
  • The polyp calicles connect to one another, creating a colony that acts as a single organism.
  • As colonies grow over hundreds and thousands of years, they join with other colonies and become reefs.
  • Some of the coral reefs on the planet today began growing over 50 million years ago.

What is coral bleaching?

  • Warmer water temperatures can result in coral bleaching.
  • When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white.
  • This is called coral bleaching. When a coral bleaches, it is not dead.
  • Corals can survive a bleaching event, but they are under more stress and are subject to mortality.
  • Though bleached corals that haven’t died can recover if the water temperature drops, older corals take longer to bounce back and likely won’t have a chance to recover before the next bleaching event occurs.
  • Coral that has died is gone for good, which affects other creatures that rely on it for food and shelter.

What has triggered coral bleaching?

  • Experts say the bleaching has been triggered by global warming and El Nino, a warming of parts of the Pacific Ocean that changes weather worldwide.

[4] Two foot-long bug declared world’s longest insect


  • A bug, measuring over half-a-metre long, discovered in southern China has been declared the world’s longest insect.

About the bug

  • A stick insect measuring 62.4 centimetres found two years ago in the southern province of Guangxi has broken the record for length amongst the world’s 807,625 known insects.
  • The previous record-holder was a Malaysian 56.7-centimetre-long stick insect discovered in 2008 and now on display in London’s Natural History Museum.
  • The bug has been dubbed Phryganistria chinensis Zhao in his honour, and a paper about it will soon be published.

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