Why do plants go extinct?



A new international report from Royal Botanic Gardens, Kew, London, has estimated that 39.4% of plants are now threatened with extinction. That's two in five of the world's plant species. It's a jump from one in five plants thought to be at risk in Kew's 2016 report. The assessment of the State of the World's Plants and Fungi released in September 2020 is based on research from more than 200 scientists in 42 countries.



A study released last year found that the world's plants are going extinct at 500 times faster than they naturally should. The study published in journal Nature analysed the population of more than 3,30,000 sec bearing plants around the world. It found that almost 600 plant species have been lost from the wild in the last 250 years. It listed India as among the places with particularly high extinction rates. The other places included the islands of Hawaii, the Cape Provinces of South Africa, the island of Mauritius, Australia and Brazil.



The problem with our understanding of plants is there are a whole lot of them and many still remain unknown to science. Scientists suggest that there may be more plants that we don't know of at risk of extinction. After all about 2,000 plants are discovered every year Kew garden experts sail they are now in a race against time to find and identify species before they are lost.



Threats to plants



Some of the major threats to plants are habitat loss, fragmentation environmental degradation, pictures species pollination, and climate change.




  • Humor activities that lead to habitat loss include Cutting down of forest, urbanization and conversion of forests to agricultural land

  • People patterns of settlement, transportation, recreation, and use of natural resources directly or indirectly lead to environmental degradation.

  • Loss of pollinators such as insects, birds and small mammals leads to loss of plants and vice versa.

  • Over exploitation of plants (for horticulture and medicine) and trees (for construction and industries) can make it harder for species to rebound.

  • Introduction of invasive species when plants and animals that are not native to a region are introduced to the ecosystem, they can cause serious damage to the local plants and potentially contribute to their extinction.



Why do plants matter?




  • Directly or indirectly, all life on Earth depends on plants.

  • Plants provide the oxygen we breathe and the food we eat.

  • Plant extinctions can lead to a whole cascade of extinction in other organisms that rely on them.

  • We rely on plants to cure a wide range of ailments- from cancer to diarrhea. Plants have also inspired thousands of synthetic medicines over the last few decades.



Have you heard of plant blindness?



If we ask you to list some endangered species (or your favourite species for that matter) chances are you would remember more animals than plants. Although plants are far more important to us, the conservation of plants has not generated the sense of urgency that drives the conservation of animals.



Our tendency to underappreciate the flora around us is called Plant Blindness. Two US botanists Elisabeth Schussler and James Wandersee, coined the term in 1998. They described it as the inability to see or notice the plants in one's own environment.



 Plant blindness is a form of irrational bias. Scientists have suggested that the reason some people don't notice plants is because a majority of them are stationary and similarly colored, although some researchers have suggested that it is an influence of cultural practices. Urbanization could be driving this attitude. With less exposure to plants, one tends to acquire plant blindness. This is a matter of concern because plant blindness can affect the importance given to plant conservation.



 



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How do floods happen?


Many floods happen when it rains very heavily and rivers overflow. They burst their banks and flood the land all around. You also get floods in stormy weather when high tides or gigantic waves sweep on to the shore.



Amazing! The Thames Barrier was finished in 1984 to stop the River Thames flooding and drowning London. Ten huge steel gates swing up to make a massive dam.



What are flash floods?



Flash floods are floods which happen very suddenly, with no warning. Sometimes there isn’t time to evacuate buildings in the flood’s path. Flash floods can happen in the desert too, during a rare downpour of rain.



Is it true? Floods can wash whole buildings away.



Yes. In 1955, a flood in the USA washed a four-storey wooden hotel clean away. Imagine how surprised the guests were when they looked out of their windows!



Are some floods useful?



Yes, they are. The River Nile in Egypt used to flood every year, leaving rich mud on the fields. The mud made the soil ideal for farmers to grow bumper crops. The Nile doesn’t flood anymore because a large dam was built to store its water.



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From Kerala to Assam, floods cause widespread damage



The one word used repeatedly to describe several natural events across the world this year has been “unprecedented”. And it is no different for rains and subsequent floods. Be it Assam and Kerala in India, neighbours China, Bangladesh and Nepal or far away Africa and the U.S., the quantum of rain dumped so far has been unheard of, resulting in floods and landslides. And it did not help that these rains have come in the midst of the pandemic, rendering a twin blow to the people. According to new reports, monsoon rains this season have affected about 10 million people in South Asia alone, and this includes 1.3 million in Assam. In September, large areas of Africa witnessed rains with intensity not recorded earlier. In mere seven hours, Senegal recorded an amount of rain that usually takes an entire rainy season from July to September! Such a crisis causes loss of not just human lives but also of wildlife. Assam’s Kaziranga National Park lost more than a 100 wild animals, including about a dozen endangered one-horned rhinoceros in the recent floods. Rains and floods also damage or change landscapes permanently, in the process shrinking or destroying wildlife habitats and causing ecological imbalance. Experts point out that extreme weather event could be a result of human-induced climate change. This change is so swift and continuous that it does not allow for nature to heal or recover, threatening to trigger irrevocable consequences for the entire planet and all of its inhabitants.



Did you know?



This July, a few residents of Assam were greeted by an unusual visitor or two – one-horned rhinoceros (occasionally with a little one in tow) escaping Pobitora Wildlife Sanctuary, about 90% of it flooded by the swelling Brahmaputra. The sanctuary has the distinction of nurturing the highest density of rhinos in the world. But it also means these pachyderms jostle for space. And floods certainly don’t help. So the fortunate and smart among the lot moved to the fingers of the sanctuary and made themselves comfortable at the houses there – rent-free! While some residents were thrilled, some weren’t. However, no instances of human-animal conflict were reported.



 



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What are the causes of melting ice in Antarctica and Arctic?



This February, Antarctica witnessed its hottest temperature on record, resulting in widespread melting of nearby glaciers. During the period, images showed drastic changes in just nine days. Then came the news that Antarctica’s colossal Thwaites Glacier is melting fast. If the glacier were to collapse, it could lead to an increase in sea levels by around 64 cm. In mere two days, the Milne ice shelf lost over 40% of its ice over in July. And then, that ice shelf – the last intact one in the Canadian Arctic – collapsed into the Arctic Ocean. The month following this, residents of Italy’s Aosta valley were told to evacuate, fearing that a huge portion of the Mont Blanc glacier could collapse. The same month also brought in the worst news so far. A study – of nearly 40 years of satellite data – published in the journal “nature Communication Earth and Environment” said that Greenland’s glaciers have passed a tipping point of sorts. It means that glaciers on the islands have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking. The study said “the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from glaciers”. The melting of several glaciers globally has raised concerns on further sea-level increase. Throughout history, sea level have increased and decreased substantially. But the recent rise has crossed the average rate of the last few thousand years, and is increasing sharply and swiftly. If this tends to continue, it could lead to dramatic changes in coastlines the world over, caution experts.



Even as scientists and environmentalists the world over fret over melting glaciers, a new study in August appears to offer some solace. The study by Northumbria University, published in “Nature Geoscience”, revealed that the blanket of rock debris offers glaciers more protection from climate change than previously known. The expanse of rock debris on glaciers, a factor ignored in models of glacier melts and sea-level rise, could be significant, the study added.



 



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What has been the biggest bushfire in Australia?



After raging on for several months since the previous year, one of the worst Australian bushfires seasons and wildlife disasters came to an end in March 2020. The season was far worse than any prediction, and according to the BBC, “burned an area of land the size of South Korea”, killing or harming almost three billion animals. The wildfire events for the year did not end there – they have raged on in several regions of the world, destroying different kinds of ecosystems, ranging from tundra to rainforests. The Brazilian Amazon has lost large swathes of rainforests. In just the fire seven months of 2020, more than 13,000 sq.km. burned. The story is the same in the Pantanal wetland region of South America – by September, “fires had charred an estimated 24,000 square kilometers”. The tundra ecosystem of the Arctic region wasn’t spared either – in July and August, “abnormally warm temperatures spawned an intense fire season in eastern Siberia”, according to NASA. When the season waned, it had emitted 244 megatonnes of carbon dioxide. But the worst of all was yet to come – wildfires in the U.S. Even as the eastern part has been pounded by rains, the West has been battling a series of wildfires. By September, across 12 American States, as many as 100 large wildfires have burned 4.6 million acres. These include timber-dominated ecosystems. India too suffered its share of woes hen in May, forest fires in Uttarakhand left nearly 175 acres of land – part of forest ecosystems – destroyed. And today, we’re back to staring at Australia’s bushfire season. Experts say wildfires are a natural part of many ecosystems. But “the scale, intensity, speed, location, and timing of the recent infernos stand out”, perhaps warranting a closer study of global warming.



As wildfires continued to rage in Australia early this year, New South Wales (NSW) officials air-dropped more than 1,500 kg of sweet potatoes and carrots. These were for the endangered brush-tailed rock-wallabies. It is said that this was the largest such food drop ever done in NSW. The move was also important because most of the 15 species of wallabies are endangered. Sharing on social media an image of a wallaby nibbling on a carrot, an Australian minister called the marsupial “One happy customer.”



 



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Has the government diluted clearance norms for business benefits as claimed by the concerned public?



In the last few months, the new draft Environment Impact Assessment (EIA) 2020 proposed by the Centre has been drawing a lot of attention. EIA comes under the Environment (Protection) Act, 1986, and ensures projects, including industrial and infrastructural, are duly given or denied environmental clearance based on expert assessment. The first EIA norms were notified in 1994, and they were replaced with a modified version in 2006. The current government says it has redrafted this version to make the EIA “process more transparent and expedient”. However, the new draft has caused outrage among the media, activists, environmentalists and the public, and has raised the concerns of even the United Nations for various reasons. Among them are post facto clearance (projects can come up without environmental clearance); the exemption of several large industries and projects from public consultation; shortening the period of public consultation hearings; increasing validity of the clearances for mining projects and river valley projects. The draft is seen as giving more power to the government while diluting public involvement in protecting the environment. However, Prakash Javadekar, the Minister for Environment, Forest and Climate Change, has said that valid suggestions and objections raised on the draft EIA Notification 2020 will be considered on merit before finalising it. He also said “public consultations were still underway and suggestions can be sent up to 120 days from the date of publication of the draft”. He said it was wrong to assume that “ex-post facto environmental clearance will be given to the cases involving violation”. Similarly, the draft does not talk about diluting the process of public hearing, “instead it is stressing on making it more meaningful”, he said.



This May, gas leaked from a polymer plant in Vishakhapatnam, killing about a dozen people. It was discovered that the plant had been functioning for more than 20 years without clearances. The National Green Tribunal, the country’s top environmental court, has sought a high-level probe into the incident. The same month, due to lack of proper adherence to environment norms, the natural gas of an oil company in Assam had a blowout and caught fire. The oil field borders the Dibru Saikhowa National Park, putting “all life forms in the vicinity at risk”.



 



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How coronavirus taught us a gentle lesson?



The COVID-19 pandemic is easily the most defining aspect of 2020, altering lives and reshaping livelihoods globally. However, one of the few positive chapters in the COVID story is how the pandemic-induced lockdown showed us an improving environment the world over. According to a study published recently, as all types of “social, economic, industrial and urbanization activity suddenly shut off”, improvement in the quality of air, cleaner rivers, less noise pollution and undisturbed wildlife became evident. For instance, water from the Ganges at Haridwar and Rishikesh saw a “500% decrease in sewage and industrial effluents” after lockdown. Also, an IFS officer shared on social media that the Himalayas’ Dhauladhar mountain range in Himachal Pradesh – 200 km away – was seen after 30 years, from Jalandhar (Punjab) “after pollution drops to the lowest level in 30 years”. According to the Copernicus Atmosphere Monitoring Service of the European Union, a drop of approximately 20 to 30% of PM (particulate matter) 2.5 was observed in large parts of China in February. Meanwhile, there were many instances of animals and birds freely taking over space occupied hitherto by humans and human activity – think nilgai on Indian roads! And happily, with fever noisy vehicles on the road, sonorous bird calls became a lot more audible. But, this does not mean we can be complacent. The lockdown was only a pointer to how wonderfully our planet responds when we treat it gently.



The lockdown saw a spike not just in good air quality but also in rumours and “wild” imagination! Amidst (false) news of dolphins swimming merrily in Venetian canals, information about a critically endangered Malabar civet spotted in India for the first time since the 1990s was widely shared on social media. However, the creature sauntering on a Kerala road junction turned out to be its cousin, the small Indian civet – neither rare nor as endangered!



 



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Why do wildfires turn the skies orange-red?



News about the wildfires in San Francisco, U.S. dominated headlines in the first weeks of September 2020. The fires were raging, and the damage that went along with it was huge. And then, one morning, residents of the famed San Francisco Bay Area woke up to skies that were orange and red.



Not apocalypse



While those on social media quickly snapped pictures and captioned them in many ways, U.S.’ National Weather Service (NWS) and NASA tried to reassure people that apocalypse hadn’t arrived. And how did they do this? By explaining the science behind the phenomenon of course.



It was pretty clear to almost everyone that the skies’ strange hues were the result of the wildfire. What wasn’t well-known, however, was how exactly this was happening.



NWS went about their explanation by tweeting a picture of a satellite image that showed a thick layer of smoke above California. This smoke was filtering the energy coming from the sun. as a result, the temperatures were much cooler and the dark and dreary skies were the product of the skies shifting towards the red end of the spectrum.



Smoke blocks shorter wavelengths



NASA helped by going into more detail. They added that smoke particles block sunlight’s shorter wavelength colours – yellow, blue and green. They do, however, allow the longer wavelengths to pass through. As red and orange have longer wavelengths, they pass through the smoke and the skies therefore appear in these colours.



 



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