GS-3: Conservation, Environmental pollution and degradation, Environmental impact assessment

Key phrases: Climate change, Carbon sinks

Why in news:

Scientists are planning to map the world’s huge underground webs of fungi for the first time. This will help identify hotspots for protecting natural ecosystems and store carbon dioxide to help tackle climate change.

Analysis:

Key highlights:

• The world-first map will be used to identify sites with the potential to store more CO2, and withstand changes brought about by global heating.
• The project also includes identifying at-risk areas to improve conservation of below-ground biodiversity hotspots.
• The project is backed by a $3.5 million donation from the Jeremy and Hannelore Grantham Environmental Trust.
• The Society for the Protection of Underground Networks said it would collect 10,000 samples over the next 18 months from around the world, using machine learning to seek out the most biodiversity hotspots and map global fungal networks.
• The Society for the Protection of Underground Networks is a non-profit network whose members include scientists from the United States, Germany and Britain.

Fungal networks are an invaluable ally:

Underground fungal networks underpin the health of plants, trees and broader ecosystems by creating thread-like webs in soil that suck in CO2 and transport nutrients like phosphorus to plants.

What are Fungi?

• R.H. Whittaker (1969) proposed a Five Kingdom Classification. The kingdoms defined by him were named Monera, Protista, Fungi, Plantae and Animalia.
• Characteristics of Fungi
  • Eukaryotic cell type
  • Cell wall present within Chitin
  • Multicellular/ loose tissue body organisation
  • Heterotrophic (Saprophytic/ Parasitic)
  • Example: Mushrooms, Toadstool, Yeast, Penicillium, Mucor, Aspergillus, Agaricus
• Mucormycosis, commonly called black fungus, is a rare but serious fungal infection caused by a kind of fungus called mucormycetes, which is abundant in the environment.
•  Mucormycosis can lead to loss of the upper jaw and sometimes even the eye.

Threats to fungal networks:

Fungal networks, which store billions of tonnes of CO2, are under threat from factors including fertiliser use in agriculture, urbanisation and climate change.

Climate Change:

• Climate change refers to long-term shifts in temperatures and weather patterns.
• These shifts may be natural, such as through variations in the solar cycle. But since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas.
• Burning fossil fuels generates greenhouse gas emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat and raising temperatures.
• Examples of greenhouse gas emissions that are causing climate change include carbon dioxide and methane.

Causes for Climate change:

1. Fossil fuels: Gases such as carbon dioxide and methane trap heat in the Earth’s atmosphere. They are mostly created by humans burning fossil fuels – coal, oil, wood and natural gas.
2. Deforestation: Since about 1960, forests, soil and oceans have steadily absorbed 56 per cent of all the carbon dioxide humanity has put into the atmosphere, despite the 50 per cent rise in emissions.
3. Increasing livestock farming: Cows and sheep produce large amounts of methane when they digest their food, and this gas adds to the greenhouse effect on the Earth. Furthermore, animals need fields to graze on, and this leads to deforestation.
4. Fertilizers containing Nitrogen: fertilisers containing nitrogen produce nitrous oxide emissions, which increases the warming effect on the Earth’s atmosphere.
5. Fluorinated gases: These gases are emitted from equipment and products such as commercial and industrial refrigerators, air-conditioning systems and heat pumps. They are also used as blowing agents for foams, fire extinguishers, solvents and aerosol propellants. Such emissions have a very strong warming effect, up to 23,000 times greater than that of carbon dioxide.

Carbon Sinks:

A carbon sink is anything that absorbs more carbon from the atmosphere than it releases – for example, plants, the ocean and soil. The process by which carbon sinks remove carbon dioxide (CO2) from the atmosphere is known as carbon sequestration. Natural Carbon sinks: Grasslands, Agricultural Lands, Northern, boreal forests, Tropical Rainforests,Peat Bogs, Freshwater lakes and wetlands, Coastal ecosystems such as seagrass beds, kelp forests, fungal networks, salt marshes and swamps, Coral reefs.

• Plants grab carbon dioxide from the atmosphere to use in photosynthesis; some of this carbon is transferred to soil as plants die and decompose.
• The oceans are a major carbon storage system for carbon dioxide. Marine animals also take up the gas for photosynthesis, while some carbon dioxide simply dissolves in the seawater.

Artificial Carbon Sinks: The main artificial sinks are landfills and carbon capture and storage processes.

• Geological sequestration where the carbon dioxide is pumped into underground chambers such as old oil reservoirs, aquifers and coal seams that are unable to be mined.
• Ocean sequestration whereby carbon dioxide is injected deep into the ocean, forming lakes of CO2.
• Carbon captured and stored at source for example the factory chimneys.

Way forward

• Paris Agreement mandates to limit global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, compared to pre-industrial levels.
• To achieve these goals, it is very essential to limit the emissions of Greenhouse gases by capturing CO2 through carbon sinks both natural and artificial
• The recently proposed project can be very effective in storing CO2 by providing a natural carbon sink.

Source: Indian Express

Prelims question:

Which of the following is true about Fungi - a unique kingdom of heterotrophic organisms?

1. Some fungi are the source of antibiotics, e.g., Penicillium
2. Fungi are cosmopolitan and occur in air, water, soil and on animals and plants.
3. Yeast is a unicellular fungus.
4. Mucormycosis, commonly called black fungus, is a rare but serious fungal infection caused by a kind of fungus called mucormycetes.
5. They can also live as symbionts – in association with algae as lichens and with roots of higher plants as mycorrhiza.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 1, 2 and 3 only

(c) 1, 2, 3 and 4 only

(d) All 1, 2, 3, 4 and 5

Answer: (d)