Geography & Environment & Disaster management

Context: A modelling study has found methane emissions from fossil fuels declined between 1990 and the 2000s and have been stable since, whereas microbes have been producing more methane of late.

One reason could be an increase in cattle-rearing in Latin America and more emissions from waste in South and Southeast Asia.

Study on Methane Emissions

• Naveen Chandra has been conducting simulations at the Research Institute for Global Change in Japan for the past three years, focusing on recreating the earth's atmosphere over the last 50 years on a supercomputer.
• The concentration of methane in the atmosphere has been a subject of their research. Methane concentration increased until the 1990s, stabilized briefly, then started increasing again around 2007. Current estimates suggest methane levels are three times higher than 300 years ago.
• Methane is the second most abundant anthropogenic greenhouse gas after carbon dioxide (CO2) but it warms the planet more. Over a century, methane has a global warming potential 28-times greater than CO2, and even higher over shorter periods like two decades (GWP is around 80 over 20-year time period).
• Policymakers began focusing on methane recently, leading to initiatives like the 'Global Methane Pledge' at the U.N. climate talks in 2021.
• Recent research by Mr. Chandra's team suggests microbes, particularly archaea called methanogens, are the primary sources of atmospheric methane, not fossil fuel burning.

Sources of methane

• Scientists are increasingly recognising various sources of methane, most of which fit in two categories: biogenic and thermogenic. 
• When fossil fuels such as natural gas or oil are extracted from deep within the earth’s crust, thermogenic methane is released. 
• Biogenic methane comes from microbial action.
• The microbes that produce methane are archaea — single-celled microorganisms distinct from bacteria and eukaryotes — and are called methanogens. 
• They thrive in oxygen-deficient environments, such as the digestive tracts of animals, wetlands, rice paddies, landfills, and the sediments of lakes and oceans.
• Methanogens play a crucial role in the global carbon cycle by converting organic matter into methane. 
• While methane is a potent greenhouse gas, its production by methanogens is an essential part of natural ecosystems. But human activities like agriculture, dairy farming, and fossil fuel production have further increased methane emissions.
• Both biogenic and thermogenic activities produce different isotopes of methane. Tracking the isotopes is a way to track which sources are the most active. include biogenic (microbial action) and thermogenic (fossil fuel extraction) activities.

Measuring methane

• If there are fewer carbon-13 atoms than a certain level in a group of 1,000 methane molecules, the methane is from a biological source. If the methane is from thermogenic sources, such as trapped fossil fuels or geological activities, there will be more carbon-13 atoms in 1,000 molecules.
• Mr. Chandra and Mr. Patra, along with international scientists, collected data from 12 monitoring sites worldwide since the 1990s to recreate the atmosphere from 1980 to 2020 on a supercomputer.
• Finally, the team compared their own results with two emissions inventories, called EDGAR and GAINS, and found some discrepancies.
  • EDGAR had reported that methane emissions from oil and natural gas exploration had increased between 1990 and 2020. 
  • GAINS had recorded a large “unconventional” rise in emissions since 2006. Their findings disagreed with both inventories.
• Possible reasons for discrepancies include increased cattle-rearing in Latin America and more waste emissions in South and Southeast Asia, Latin America, and Africa, as well as an increase in global wetlands.
• The team's models indicated that methane emissions from fossil fuels declined between 1990 and the 2000s and have been stable since, with microbes producing more methane than fossil fuels.
• Ground models are needed to confirm interpretations of satellite data on methane emissions, as satellites rely on models and are prone to uncertainties.
• Anthropogenic activities such as waste and landfills, rice fields, enteric fermentation, and fossil fuel extraction contribute significantly to methane emissions and should be controlled to reduce methane levels.

Context: With a resolve to remove the Nilgiri Tahr (Nilgiritragus hylocrius) from the endangered status, the Tamil Nadu government will conduct a synchronised survey of the State animal.

The three-day exercise is being done to estimate the population of the Tahrs, which once roamed the length and breadth of the Anamalai and Nilgiris landscape

About Nilgiri Tahr

IUCN Status: Endangered

Wildlife Protection Act 1972- Schedule I

Endemic to Western Ghats

• The Nilgiri tahr is the only mountain ungulate in southern India amongst the 12 species present in India. 
• It is also the state animal of Tamil Nadu.
• Locally the animal is called ‘Varayaadu’.
• The Nilgiri tahr, or Nilgiri ibex of southern India, is dark brown with a grizzled saddle-shaped patch on its back; its body size is comparable to that of the Himalayan species. 
• The Arabian tahr is the smallest of the three species.

Distribution

• They inhabit the open montane grassland habitats at elevations from 1200 to 2600 m of the Southwestern Ghats. 
• Currently, the Nilgiri tahr distribution is along a narrow stretch of 400 km in the Western Ghats between Nilgiris in the north and Kanyakumari hills in the south of the region.
• There are smaller populations found in the Palani hills, Srivilliputtur, and the Meghamalai and Agasthiyar ranges.
• Only two well-protected, large populations are documented -- one from the Nilgiris and the other from the Anamalais, including the high ranges of Kerala.
• The Eravikulam National Park in Anamalai hills, Kerala, is home to the largest population of the Nilgiri tahr, with more than 700 individuals.

Reproductive behavior

• A grown-up male is known as 'saddle back'.
• The male would be bigger and darker than the female and has a silvery saddle like patch on its back.
• Mating takes place during the monsoon season and calving is during January-February.
• The female gestates for about 180 days and usually gives birth to one kid per pregnancy. Sexual maturity is achieved at around three years of age. 
• The average life expectancy for Nilgiri tahr in the wild is estimated to be only three or 3.5 years although the potential life span is at least 9 years.

Threats To Niligiri Tahr

• Habitat loss due to rampant deforestation, competition with domestic livestock, hydroelectric projects in Nilgiri tahr habitat, and monoculture plantations
• Occasional hunting for its meat and skin

As a result of extreme habitat fragmentation, its population has declined drastically in the last few years. Plantation activities affect the Nilgiri tahr habitat, which includes grasslands and sholas.

Conservation measures

• WWF India initiated its conservation work on Nilgiri tahr in 2008.
• In 2012, an assessment on Nilgiri Tahr’s status, threats faced, habitat, and population size was carried out in the Western Ghats. 
• WWF India published a report on the comprehensive study of the Nilgiri tahr population and its habitat in the hills of Tamil Nadu and Kerala in 2015.
• It was the first time such a comprehensive report had been made.

Context: The Supreme Court stopped the building of four dams in the Kalesar Wildlife Sanctuary in Haryana. They asked the government for explanations and said the dams could harm wildlife and people living there, as well as the environment. The court said no construction should happen until they make a final decision.

About Kalesar Wildlife Sanctuary

• Kalesar Wildlife Sanctuary is in Yamunanagar, Haryana, India.
• Found in the Shivalik foothills of the Himalayas.
• Named after the Kalesar forest and Kalesar Mahadev temple within it.
• Declared a national park on December 8, 2003.
• Historically used as hunting grounds by Mughal and British rulers, primarily for tigers.
• Houses historical Kalesar Fort, possibly built during Aurangzeb's reign, offering panoramic views
• The tiger population significantly declined around 1892, leading to a hunting ban in the early 20th century.
• Eastward lies the Yamuna River.
• Rajaji National Park is to the northeast, Simbalbara National Park to the north (bordering Himachal Pradesh), and Morni Hills to the west.

Flaura and Fauna

• Kalesar has 53% dense forest, 38% open forest, 9% scrub. Total forest cover is about 71%.
• Home to various animals like leopards, deer, hyenas, jackals, porcupines, pangolins, and langurs.
• Diverse bird species including red junglefowl, grey partridge, peafowl, and kingfisher.
• Known for its scenic beauty with dense Sal tree cover.