Is our world undergoing the sixth mass extinction?

There's proof we are increasingly losing species, and this is not good for us humans

What is mass extinction?

To be classified as a mass extinction, at least 75 % of all the species on Earth must go extinct within a short geological period of less than 2.8 million years. That timeframe seems long to us because modern humans have only existed for about 2,00,000 years so far.

Mass extinction is not new

Extinctions and speciations (species evolving over time) do not happen at uniform rates through time; instead, they tend to occur in large pulses interspersed by long periods of relative stability. These extinction pulses are what scientists refer to as mass extinction events. The Cambrian explosion was a burst of speciation some 540 million years ago. Since then, at least five mass extinction events have been identified in the fossil record (and probably scores of smaller ones). Arguably the most infamous of these was when a giant asteroid smashed into Earth about 66 million years ago in what is now the Gulf of Mexico. The collision vapourised species immediately within the blast zone. Species were killed off later by resultant climate change and volcanic activity too.

Are humans responsible for the current crisis?

Humans have been implicated in smaller extinction events going back to the late Pleistocene (around 50,000 years ago) to the early Holocene (around 12.000 years ago) when most of the megafauna, such as woolly mammoths, giant sloths. diprotodons, and cave bears, disappeared from nearly every continent over a few thousand years. Much later, the expansion of European colonists throughout the world from about the 14th Century precipitated an extinction cascade first on islands, and then to areas of continental mainland as the drive to exploit natural resources accelerated. Over the last 500 hundred years, there have been more than 700 documented extinctions of vertebrates and 600 plant species. These extinctions come nowhere near the 75 % threshold to include the modern era among the previous mass-extinction events. But those are just the extinctions humans have recorded. In fact. many species go extinct before they are even discovered- perhaps as many as 25 % of total extinctions are never noticed by humans. But it's not the total number of extinctions we should focus on; rather, it's the extinction rate. Even the most conservative estimates place the modern era well within the expected range to qualify as a mass extinction. If the current rate of extinction continues we could lose most species by 2200.

When species disappear

One may think that so long as the species that provide resources for modern societies survive, there's no reason to consider extinction a problem. The evidence suggests otherwise. Species loss also erodes the services biodiversity provides us. These include reduced carbon removal from atmosphere (which climate change), reduced pollination and increased soil degradation that compromise our food production, poorer water and air quality, more frequent and intense flooding and fires, and poorer human health. Even human diseases such as HIV/ AIDS, Ebola, and COVID-19 are the result of our collective indifference to the integrity of natural ecosystems.

There's still hope

We could potentially limit the damage if societies around the globe embraced certain fundamental, yet achievable, changes. We could abolish the goal of continuous economic growth, and force companies to restore the environment. We could limit undue corporate influence on political decision-making. Educating and empowering women would also help stem environmental destruction.

Did you know?

  • In the timeline of fossil evidence going right back to the first inkling of any life on Earth- over 3.5 billion years ago - almost 99 % of all species that have ever existed are now extinct. That means that as species evolve over time, they replace other species that go extinct.
  • When the giant asteroid hit our planet, about 76 % of all species around at the time went extinct, of which the disappearance of the dinosaurs is most well-known. But dinosaurs didn't disappear altogether-the survivors just evolved into birds.

Picture Credit : Google 

What is wind tree system?

Get to know about wind trees and how they help harness energy.

French innovator Jérôme Michaud-Larivière designed the Wind Tree as a sustainable energy-harnessing device that would also enhance urban landscapes. A wind tree is a tree-shaped structure that harnesses wind energy using small trembling wind turbines called 'aeroleaves’ that look exactly like leaves on a tree.  The micro-turbines work well even when there is little wind. Just a gentle breeze as light as 7 kmph is sufficient. This is something a conventional windmill cannot do.

French innovator Jérôme Michaud-Larivière designed the Wind Tree as an elegant, sustainable energy-harnessing device that would enhance urban landscapes. The first Wind Tree was a 3-m-tall structure with 72 aeroleaves. It produced 3.1kW of power. ‘Wind Bush’ is a combination of aeroleaves and photovoltaic petals that harnesses both wind and solar energy.

 For the Indian market, Larivière has created ‘Lotus’, an affordable wind tree minus the solar petals.

Picture credit : Google 

Where is world's Largest Solar Tree?

The largest solar tree in the world has been installed at the CSIR-CMERI Centre of Excellence for Farm Machinery in Ludhiana, Punjab.

A solar power tree is a device that is shaped like a tree with its steel branches holding the solar photovoltaic panels.

Just like a natural tree, the steel branches of the solar tree are arranged in such a fashion that every solar panel is properly exposed to the Sun. Moreover, the panels can be mechanically tilted east or west to derive maximum benefit of the Sun's position. The height of the tree is about 9-10 metres. One tree can produce about 5kW of power.

One of the main hurdles in installing solar power plants is the lack of availability of large spaces. Often, farmers are reluctant to sacrifice their cultivable land for solar power production. But a solar tree with its vertically arranged branches, occupies only four sqft of area, leaving almost the entire land free for cultivation. The energy generated can be used to run pumps, e-tractors and tillers as a green alternative to diesel.

India's first solar power tree was produced by Central Mechanical Engineering and Research Institute (CMERI), at Durgapur. The largest solar tree in the world has been installed at the CSIR-CMERI Centre of Excellence for Farm Machinery in Ludhiana. Its total solar PV panel surface area is 309.83 m2. CMERI hopes to install many such solar trees along highways and farmlands.

Picture Credit : Google 

What is the device of Ulta Chaata used for?

Ulta Chaata, a concave structure, collects rainwater in the monsoon and converts it into potable water. Find out how it's done.

Ulta Chaata, as the name suggests, resembles an inverted umbrella. It is a large concave structure that collects rainwater in the monsoon and converts it into potable water, while the solar panels fitted alongside the canopy, produce energy in the dry season.

The rainwater collected in the bowl of the Chaata, trickles down the stalk to reach a filtering unit of activated carbon where it is cleared of impurities. A duster of ten or more Ulta Chaatas is connected to a common device where the water undergoes further filtration to remove microorganisms, making it fit for drinking. A single unit can harvest as much as 100,000 litres of water every year.

The solar energy harnessed in the dry season is stored in the battery and is used not just to light up the Chaata, but also the premises. Unlike a typical rainwater harvesting unit, Ulta Chaata's attractive design lends itself well to the aesthetics of the surroundings, especially when lit up.

The device takes up to one sq. ft of area. Ulta Chaatas can be installed as sustainable workstations in open spaces. They can provide a green roof for reception areas, cafeterias, gazebos, car parks, bus stops and even railway stations.

Besides a number of corporates, Guntakal railway station in Andhra  Pradesh has installed six such structures on its premises.

Ulta Chaata is the brainchild of a Mumbai-based environmentally conscious couple Priya Vakil and Samit Choksy whose start-up ThinkPhi designs sustainable products.

Ulta Chaatas can be installed as sustainable workstations in open spaces. They can provide a green roof for reception areas, cafeterias, car parks, bus stops and even railway stations.

QUICK FACTS

  • A single unit of Ulta Chaata can harvest as much as 100,000. litres of water every year.
  •  Ulta Chaata's attractive design lends itself to the aesthetics of the surroundings.
  • The solar panels fitted alongside the canopy produce energy in the dry season.

Picture Credit : Google 

Why are astronomers concerned about light pollution?

Light pollution is very much a concern across the globe, something astronomers and skywatchers are trying to bring attention to. It not only takes away the right to enjoy the night skies and explore the celestial bodies with the naked eye but also affects the circadian rhythm of humans and wildlife.

Have you seen a sky spangled with stars winking at you from light years away? Have you ever spotted the Milky Way?

Well with the amount of artificial light strewn across the sky. it is a fact that dark skies that bring out the beauty of the cosmos are a rarity.

Light pollution is very much a concern across the globe, something astronomers and skywatchers are trying to bring attention to. It not only takes away the right to enjoy the night skies and explore the celestial bodies with the naked eye but also affects the circadian rhythm of humans and wildlife. So what is light pollution?

Light Pollution

Across the world, people have to deal with the nighttime glow caused by artificial light. This has been affecting humans, wildlife, and the environment equally. There is a global movement to reclaim the dark sky and reduce light pollution.

Sources of light pollution

The major cause of light pollution is misdirected light which scatters out into the open sky caused by human activities. From street lights to lights from buildings, boats, and outdoor advertising to illuminated sporting venues, every misdirected light leads to light pollution. High levels of sky glow mean fewer chances of seeing enough celestial bodies in the sky.

The circadian rhythm and light pollution

Artificial light can affect the circadian rhythm in both humans and animals. The circadian rhythm is the natural process regulating the sleep-wake cycle. The production of the hormone melatonin is linked to this. This sleep-inducing hormone gets released when it is dark. The presence of light inhibits it. If the ambient light is high at night, then it lowers the production of melatonin and leads to sleep deprivation, stress, fatigue, and anxiety.

Animal behaviour and light pollution

It has been proven that wildlife has also been affected badly by light pollution. The animal behaviours such as migration patterns and wake-sleep habits of animals have been affected. Birds and sea turtles have been found to lose their way and get confused due to the presence of increased ambient light. Light also affects the circadian rhythm of animals.

Picture Credit : Google