India has expressed its concern over the draft decision text to implement the Koronivia Joint Work on Agriculture.

What is the news?

• India said developed countries are blocking a pro-poor and pro-farmer decision by insisting on expanding the scope for mitigation to agriculture.
• Developed countries are thereby compromising the very foundation of food security in the world.

What is the Koronivia Joint Work?

• The KJWA is a decision under the United Nations Framework Convention on Climate Change (UNFCCC).
• It seeks to recognize the unique potential of agriculture in tackling climate change.
• It emphasizes reducing emissions of greenhouse gases due to the agriculture sector.
• The Koronivia decision addresses six interrelated topics on soils, nutrient use, water, livestock, methods for assessing adaptation, and the socio-economic and food security dimensions of climate change across the agricultural sectors.

India’s arguments against Koronivia joint work

• India said that agricultural emissions are not “luxury” emissions but “survival” emissions of the poor.
• The world is facing a climate crisis today because of the excessive historic cumulative emissions by the developed nations.
• These nations are unable to reduce their emissions domestically by any worthwhile change in their lifestyles.
• Rather, they are searching for cheaper solutions abroad.
• In most developing countries across the world, agriculture is done by small and marginal farmers who toil hard and brave the vagaries of extreme weather and climate variability to ensure food security.

Back2Basics: Agricultural Emissions

• Farms emitted 6 billion tonnes of GHGs in 2011, or about 13 percent of total global emissions.
• That makes the agricultural sector the world’s second-largest emitter, after the energy sector (which includes emissions from power generation and transport).
• Most farm-related emissions come in the form of methane (CH4) and nitrous oxide (N2O).
• Cattle belching (CH4) and the addition of natural or synthetic fertilizers and wastes to soils (N2O) represent the largest sources, making up 65 percent of agricultural emissions globally.
• Smaller sources include manure management, rice cultivation, field burning of crop residues, and fuel use on farms.

(Click) FREE1-to-1 on-call Mentorship by IAS-IPS officers | Discuss doubts, strategy, sources, and more

The super-cyclone Amphan is said to have been triggered by Marine Heatwaves.

What is the news?

• A study has found the presence of a strong MHW beneath the track of the cyclone with an extremely high anomalous sea surface temperature of more than 2.5°C.
• This coincided with the cyclone track and facilitated its rapid intensification in a short period.

What are Marine Heatwaves?

• We know that heatwaves occur in the atmosphere. We are all familiar with these extended periods of excessively hot weather.
• However, heatwaves can also occur in the ocean and these are known as marine heatwaves, or MHWs.
• These marine heatwaves, when ocean temperatures are extremely warm for an extended period of time can have significant impacts on marine ecosystems and industries.

When do they occur?

• Heatwaves can happen in summer and also in winter, where they are known as “winter warm-spells”.
• These winter events can have important impacts, such as in the southeast of Australia where the spiny sea urchin can only colonize further south when winter temperatures are above 12 °C.

What causes marine heatwaves?

• Marine heatwaves can be caused by a whole range of factors, and not all factors are important for each event.
• The most common drivers of marine heatwaves include ocean currents which can build up areas of warm water and air-sea heat flux, or warming through the ocean surface from the atmosphere.
• Winds can enhance or suppress the warming in a marine heatwave, and climate modes like El Niño can change the likelihood of events occurring in certain regions.
• MHWs can be caused due to large-scale drivers of the Earth’s climate like the El Niño Southern Oscillation (ENSO).

Impacts of the MHWs

• Marine heatwaves affect ecosystem structure, by supporting certain species and suppressing others.
• For example, after the 2011 marine heatwave in Western Australia, the fish communities had a much more “tropical” nature than previously and switched from kelp forests to seaweed turfs.
• Marine heatwaves can cause economic losses through impacts on fisheries and aquaculture.
• Temperature-sensitive species such as corals are especially vulnerable to MHWs. In 2016, marine heatwaves across northern Australia led to severe bleaching of the Great Barrier Reef.

How do we measure marine heatwaves?

• A marine heatwave occurs when seawater temperatures exceed a seasonally-varying threshold (usually the 90th percentile) for at least 5 consecutive days.
• Successive heatwaves with gaps of 2 days or less are considered part of the same event.

Why study MHWs?

• MHWs are increasing in frequency due to climate change. MHWs increased by 54 per cent in the last 30 years.
• MHW has severe socio-economic consequences such as fish mortality, and coral bleaching, and also has the potential to interact and modify other extreme events such as tropical cyclones.

Way Forward

• Marine heatwaves clearly have the potential to devastate marine ecosystems and cause economic losses in fisheries, aquaculture, and ecotourism industries.
• However, their effects are often hidden from view under the waves until it is too late.
• By raising general awareness of these phenomena, and by improving our scientific understanding of their physical properties and ecological impacts, we can better predict future conditions and protect vulnerable marine habitats and resources.

UPSC 2023 countdown has begun! Get your personal guidance plan now! (Click here)

Several parts of the country are reeling under heat wave conditions. Cities, especially, are a lot hotter than rural areas. This is due to a phenomenon called an “urban heat island”.

Urban Heat Island

• An urban heat island is a local and temporary phenomenon experienced when certain pockets within a city experience higher heat load than surrounding or neighbouring areas on the same day.
• The variations are mainly due to heat remaining trapped within locations that often resemble concrete jungles.
• The temperature variation can range between 3 to 5 degrees Celsius.

Why are cities hotter than rural areas?

• Green cover: Rural areas have relatively larger green cover in the form of plantations, farmlands, forests and trees as compared to urban spaces.
• Transpiration: Transpiration is a natural way of heat regulation. This is the scientific process of roots absorbing water from the soil, storing it in the leaves and stems of plants, before processing it and releasing it in the form of water vapour.
• Heat-regulation: Urban areas are often developed with high-rise buildings, roads, parking spaces, pavements and transit routes for public transport. As a result, heat regulation is either completely absent or man-made.
• Construction: Cities usually have buildings constructed with glass, bricks, cement and concrete all of which are dark-coloured materials, meaning they attract and absorb higher heat content.

This forms temporary islands within cities where the heat remains trapped.

How can urban heat islands be reduced?

• The main way to cut heat load within urban areas is increasing the green cover; filling open spaces with trees and plants.
• Other ways of heat mitigation include appropriate choice of construction materials, promoting terrace and kitchen gardens, and painting white or light colours on terraces wherever possible to reflect heat.

What has NASA said on urban heat islands in India?

• NASA recently pointed out heat islands in urban parts of Delhi, where temperatures were far higher than nearby agricultural lands.
• It used its Ecosystem Spaceborne Thermal Radiometer Experiment (Ecostress) on the International Space Station.

UPSC 2023 countdown has begun! Get your personal guidance plan now! (Click here)

India is gripped in the wrath of a long spell of heatwaves that too in the early month of April.

What is a Heatwave and when is it declared?

• Heatwaves occur over India between March and June.
• IMD declares a heatwave event when the maximum (day) temperature for a location in the plains crosses 40 degrees Celsius.
• Over the hills, the threshold temperature is 30 degrees Celsius.

How are they formed?

• Heatwaves form when high pressure aloft (3,000–7,600 metres) strengthens and remains over a region for several days up to several weeks.
• This is common in summer (in both Northern and Southern Hemispheres) as the jet stream ‘follows the sun’.
• On the equator side of the jet stream, in the upper layers of the atmosphere, is the high pressure area.
• Summertime weather patterns are generally slower to change than in winter. As a result, this upper level high pressure also moves slowly.
• Under high pressure, the air subsides (sinks) toward the surface, warming and drying adiabatically, inhibiting convection and preventing the formation of clouds.
• Reduction of clouds increases shortwave radiation reaching the surface.
• A low pressure at the surface leads to surface wind from lower latitudes that brings warm air, enhancing the warming.
• Alternatively, the surface winds could blow from the hot continental interior towards the coastal zone, leading to heat waves.

Following criteria are used to declare heatwave:

To declare heatwave, the below criteria should be met at least in 2 stations in a Meteorological subdivision for at least two consecutive days and it will be declared on the second day.

1. a) Based on Departure from Normal

• Heat Wave: Departure from normal is 4.5°C to 6.4°C
• Severe Heat Wave: Departure from normal is >6.4°C

1. b) Based on Actual Maximum Temperature (for plains only)

• Heat Wave: When actual maximum temperature ≥ 45°C
• Severe Heat Wave: When actual maximum temperature ≥47°C

How long can a heatwave spell last?

• A heatwave spell generally lasts for a minimum of four days. On some occasions, it can extend up to seven or ten days.
• The longest recorded heatwave spell, in recent years, was between 18 and 31 May 2015.

Impact of Heat Waves:

Heat Strokes: The very high temperatures or humid conditions pose an elevated risk of heat stroke or heat exhaustion.

Older people and people with chronic illness such as heart disease, respiratory disease, and diabetes are more susceptible to heatstroke, as the body’s ability to regulate heat deteriorates with age.

Increased Healthcare Costs: Effects from extreme heat are also associated with increased hospitalisations and emergency room visits, increased deaths from cardio-respiratory and other diseases, mental health issues, adverse pregnancy and birth outcomes, etc.

Lessens Workers’ Productivity: Extreme heat also lessens worker productivity, especially among the more than 1 billion workers who are exposed to high heat on a regular basis. These workers often report reduced work output due to heat stress.

Risk of Wildfires: The heat domes act as fuel to wildfires, which destroys a lot of land area every year in countries like the US.

Prevents Cloud Formation: The condition also prevents clouds from forming, allowing for more radiation from the sun to hit the ground.

Effect on Vegetation: The trapping of heat can also damage crops, dry out vegetation and result in droughts.

Increased Energy Demands: The sweltering heat wave also leads to rise in energy demand, especially electricity, leading to pushing up rates.

Power Related Issues: Heat waves are often high mortality disasters.

Avoiding heat-related disasters depends on the resilience of the electrical grid, which can fail if electricity demand due to air conditioning use exceeds supply.

As a result, there is the double risk of infrastructure failure and health impacts.

• Initiatives Taken:
  • Global:
    • Global forums dealing with climate change issues—such as the World Health Organization, World Economic Forum, First Global Forum on Heat and Health, and the Global Forum for Environment-OECD—also focus on heat waves by investing in research on health risks of extreme heat, climate and weather information, advice on surviving heat waves, partnerships and capacity building, and communications and outreach.
  • Indian:
    • The National Disaster Management Authority (NDMA) has issued guidelines on dealing with heatwaves.
      • However, India does not recognise heatwaves as a disasterunder its Disaster Management Act (2005).

Way Forward

• Adopting A More Sensitive Approach: The impact of such excessive heat needs to be understood from the point of view of common people — daily labourers; farmers; traders; fishermen etc.
  • Beyond numbers and graphs that capture the impact of the climate crisis, the human experience of living in oppressive heat needs to be understood by policymakers and measures should be taken accordingly.
• Cooling Shelters: The government should come out with a policy to deal with the suffering and disability caused by heat extremes in different parts of the country.
  • Water kiosks, staggered outdoor work hours, cool roofs for buildings and homes are certain things that should be put in place immediately.
  • A number of emergency cooling shelters can be opened so that people without domestic air conditioning units can escape the heat.
    • Portable air-conditioning units, along with fans and even ice are also useful.
• Passive Cooling to Reduce Urban Heat Islands: Passive cooling technology, a widely-used strategy to create naturally ventilated buildings, can be a vital alternative to address the urban heat island for residential and commercial buildings.
  • The IPCC report cites ancient Indian building designs that have used this technology, which could be adapted to modern facilities in the context of global warming.
• Action Plans Similar to Ahmedabad: As per the IPCC Report, Ahmedabad has shown the way to combat heat extremes by heat-proofing buildings.
  • After the heat action plan was implemented in 2013 in Ahmedabad, heat-related mortality reduced by 30% to 40% over the years. Similar plans like that of Ahmedabad can be implemented in vulnerable regions.
• Replacing Dark Roofs: A big reason that cities are so much hotter than rural areas is that they are covered by dark roofs, roads and parking lots that absorb and retain heat.
  • One of the long term solutions can be replacing the dark surfaces with lighter and more reflective materials; it will result in a comparatively cooler environment.

The Brihanmumbai Municipal Corporation (BMC) inspected a bungalow owned by a Union Minister for alleged violation of Coastal Regulation Zone (CRZ) norms.

What is the news?

• The Union Minister’s bungalow named has been illicitly constructed within 50 metres of the sea in violation of the CRZ rules.
• The crackdown assumes significance in the escalating verbal spats between the two political rivals (which were allies for years).

What are CRZ norms?

• In India, the CRZ Rules govern human and industrial activity close to the coastline, in order to protect the fragile ecosystems near the sea.
• They restrict certain kinds of activities — like large constructions, setting up of new industries, storage or disposal of hazardous material, mining, reclamation and bunding — within a certain distance from the coastline.
• After the passing of the Environment Protection Act in 1986, CRZ Rules were first framed in 1991.
• After these were found to be restrictive, the Centre notified new Rules in 2011, which also included exemptions for the construction of the Navi Mumbai airport and for projects of the Department of Atomic Energy.
• While the CRZ Rules are made by the Union environment ministry, implementation is to be ensured by state governments through their Coastal Zone Management Authorities.

Where do they apply?

• In all Rules, the regulation zone has been defined as the area up to 500 m from the high-tide line.
• The restrictions depend on criteria such as the population of the area, the ecological sensitivity, the distance from the shore, and whether the area had been designated as a natural park or wildlife zone.
• The latest Rules have a no-development zone of 20 m for all islands close to the mainland coast, and for all backwater islands in the mainland.

New Rules under CRZ regulations

• The government notified new CRZ Rules with the stated objectives of promoting sustainable development and conserving coastal environments.
• For the so-called CRZ-III (Rural) areas, two separate categories have been stipulated.
• In the densely populated rural areas (CRZ-IIIA) with a population density of 2,161 per sq km as per the 2011 Census, the no-development zone is now 50 m from the high-tide level, as against the 200 m stipulated earlier.
• In the CRZ-IIIB category (rural areas with population density below 2,161 per sq km) continue to have a no-development zone extending up to 200 m from the high-tide line.
• The new Rules have a no-development zone of 20 m for all islands close to the mainland coast, and for all backwater islands in the mainland.

UPSC 2022 countdown has begun! Get your personal guidance plan now! (Click here)

The latest IPCC report has warned that increasing global warming will result in reductions in Arctic permafrost and the thawing of the ground is expected to release greenhouse gases like methane and carbon dioxide.

What is Permafrost?

• ‘Permafrost’ or permanently frozen ground is land that has been frozen at or below 0 degrees Celsius for two or more consecutive years.
• A staggering 17 per cent of Earth’s entire exposed land surface is comprised of permafrost.
• Composed of rock, sediments, dead plant and animal matter, soil, and varying degrees of ice, permafrost is mainly found near the poles, covering parts of Greenland, Alaska, Northern Canada, Siberia and Scandinavia.
• The Arctic region is a vast ocean, covered by thick ice on the surface (called sea ice), surrounded by land masses that are also covered with snow and ice.

Permafrost thawing

• When permafrost thaws, water from the melted ice makes its way to the caves along with ground sediments, and deposits on the rocks.
• In other words, when permafrost thaws, the rocks grow and when permafrost is stable and frozen, they do not grow.

Why thawing?

• The link between the Siberian permafrost and Arctic sea ice can be explained by two factors:
• One is heat transport from the open Arctic Ocean into Siberia, making the Siberian climate warmer.
• The second is moisture transport from open seawater into Siberia, leading to thicker snow cover that insulates the ground from cold winter air, contributing to its warming.
• This is drastically different from the situation just a couple of decades ago when the sea ice acted as a protective layer, maintaining cold temperatures in the region and shielding the permafrost from the moisture from the ocean.
• If sea ice (in the summer) is gone, permafrost start thawing.

Impact on Climate Change

• Due to relentlessly rising temperatures in the region, since the late-twentieth century, the Arctic sea ice and surrounding land ice are melting at accelerating rates.
• When permafrost thaws due to rising temperatures, the microbes in the soil decompose the dead organic matter (plants and animals) to produce methane (CH4) and carbon dioxide (CO2), both potent greenhouse gases.
• CH4 is at least 80 times more powerful than CO2 on a decadal timescale and around 25 times more powerful on a century timescale.
• The greenhouse gases produced from thawing permafrost will further increase temperatures which will, in turn, lead to more permafrost thawing, forming an unstoppable and irreversible self-reinforcing feedback loop.
• Experts believe this process may have already begun. Giant craters and ponds of water (called ‘thermokarst lakes’) formed due to thawing have been recorded in the Arctic region. Some are so big that they can be seen from space.

Why a matter of concern?

• An estimated 1,700 billion tonnes — twice the amount currently present in the atmosphere — of carbon is locked in all of the world’s permafrost.
• Even if half of that were to be released to the atmosphere, it would be game over for the climate.
• Scientific estimates suggest that the Arctic Ocean could be largely sea ice-free in the summer months by as early as 2030, based on observational trends, or as late as 2050, based on climate model projections.

Potential to cause another pandemic

Ans. Permafrost has many secrets.

• When the permafrost was formed thousands of years ago, there weren’t many humans who lived in that region which was necessarily very cold.
• Researchers recently found mammoths in the permafrost in Russia.
• And some of these mammoth carcasses when they begin to degrade again may reveal bacteria that were frozen thousands of years ago.
• So there will be surprises. But whether they will be lethal surprises is just not possible to say.

UPSC 2022 countdown has begun! Get your personal guidance plan now! (Click here)

The Brihanmumbai Municipal Corporation (BMC) is drafting a Mumbai Climate Action Plan (MCAP) in a bid to tackle climate challenges.

What is the Mumbai Climate Action Plan?

• Amid warnings of climate change leading to extreme weather events in the city, the civic body has started preparing the Mumbai Climate Action Plan (MCAP).
• It will look at climate resilience with mitigation and adaptation strategies by focusing on six areas —

1. Sustainable waste management
2. Urban greening and Biodiversity
3. Urban flooding and Water Resource Management
4. Building Energy Efficiency
5. Air Quality and
6. Sustainable Mobility

• The plan is expected to be ready by November ahead of the United Nations Climate Change (COP26) conference at Glasgow, Scotland.

Why does Mumbai need a climate action plan?

Mumbai’s climate action plan will help set a vision and implement strategies to fight these climate challenges with mitigation and adaptation steps.

• Flash floods: As per a study conducted by the World Resource Institute (WRI) India, the city will face two major climate challenges — the rise in temperature, and extreme rain events which will lead to flooding.
• Temperature rise: The city has seen a constant rise in temperature after 2007, and a substantial increase in intense rainfall and storm events in the last five years.
• Sea level rise: A recent report from the IPCC has warned that at least 12 Indian coastal cities including Mumbai will face a sea rise of 0.1 metres to 0.3 metres in the next three decades due to climate change.

What is the greenhouse gas emission of the city?

• The data show that Mumbai’s greenhouse gas emission was 34.3 million tonnes in 2019, and of which 24.23 million tonnes or 71 per cent came from the energy sector which is mainly based on coal.
• At least 24 per cent or 82,21,902 tonnes is from transport, and the remaining 5 per cent or 18,53,741 tonnes from solid waste management.
• The maximum contribution from the energy sector was mainly due to domestic and commercial usage of electricity.
• As per the data, 95 percent of Mumbai’s electricity is coal-based and needs to be shifted to renewable energy to bring down emissions.

UPSC 2022 countdown has begun! Get your personal guidance plan now! (Click here)

According to the IPCC’s Report (AR6), the Atlantic Meridional Overturning Circulation (AMOC), is losing its stability.

What is AMOC?

• The AMOC is a large system of ocean currents.
• It is the Atlantic branch of the ocean conveyor belt or Thermohaline circulation (THC), and distributes heat and nutrients throughout the world’s ocean basins.
• AMOC carries warm surface waters from the tropics towards the Northern Hemisphere, where it cools and sinks.
• It then returns to the tropics and then to the South Atlantic as a bottom current. From there it is distributed to all ocean basins via the Antarctic circumpolar current.
• Gulf Stream, a part of the AMOC, is a warm current responsible for mild climate at the Eastern coast of North America as well as Europe.

What happens if AMOC collapses?

• Colder Europe: Without a proper AMOC and Gulf Stream, Europe will be very cold.
• Rainfall decline: Modelling studies have shown that an AMOC shutdown would cool the northern hemisphere and decrease rainfall over Europe.
• El-Nino trigger: It can also have an effect on the El Nino.
• Cooling of Atlantic: AMOC collapse could bring about large, markedly different climate responses: a prominent cooling over the northern North Atlantic and neighboring areas.
• Weaker thermohaline: Freshwater from melting Greenland ice sheets and the Arctic region can make circulation weaker as it is not as dense as salt water and doesn’t sink to the bottom.

Has the AMOC weakened before?

• AMOC and THC strength has always been fluctuating, mainly if you look at the late Pleistocene time period (last 1 million years).
• The extreme glacial stages have seen weaker circulation and slowdown in AMOC, while the glacial terminations have shown a stronger AMOC and circulation.
• AMOC has been relatively stable until the late 19th century.
• With the end of the little ice age in about 1850, the ocean currents began to decline, with a second, more drastic decline following since the mid-20th century.

Why is the AMOC slowing down?

• Climate models have long predicted that global warming can cause a weakening of the major ocean systems of the world.
• Last month researchers noted that a part of the Arctic’s ice called “Last Ice Area” has also melted.
• The freshwater from the melting ice reduces the salinity and density of the water. Now, the water is unable to sink as it used to and weakens the AMOC flow.

Influence of Indian Ocean

• Another study suggested that the Indian Ocean may also be helping the slowing down of AMOC.
• As the Indian Ocean warms faster and faster, it generates additional precipitation.
• With so much precipitation in the Indian Ocean, there will be less precipitation in the Atlantic Ocean, leading to higher salinity in the waters of the tropical portion of the Atlantic.
• This saltier water in the Atlantic, as it comes north via AMOC, will get cold much quicker than usual and sink faster.
• This acts as a jump start for AMOC, intensifying the circulation.

Now try this:

Q.With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct? (CSP 2020)

1. OMT is measured up to a depth of 26ºC isotherm which is 129 meters in the south-western Indian Ocean during January-March.
2. OMT collected during January-March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Post your answers here:

2

Please leave a feedback on thisx

Back2Basics:  Ocean Currents

A US city has recorded the highest temperatures as high as 46-degree Celsius part due to the historic heatwave that lasted as a result of a phenomenon referred to as a “heat dome”.

What is a Heat Dome?

• To understand what causes a heat dome, one should liken the Pacific Ocean to a large swimming pool in which the heater is turned on.
• Once the heater is on, the portions of the pool close to the heating jets will warm up faster and therefore, the temperature in that area will be higher.
• In the same way, the western Pacific ocean’s temperatures have increased in the past few decades and are relatively more than the temperature in the eastern Pacific.
• This strong change in ocean temperature from the west to the east is what a team of scientists believe is the reason for the heat dome.
• This occurs when the atmosphere traps heat at the surface, which encourages the formation of a heatwave.
• To compare, the reason that the planet Venus is the hottest in the Solar System is that its thick, dense cloud cover traps the heat at the surface, leading to temperatures as high as 471 degrees Celsius.

Is this heat wave a result of climate change?

• It cannot be said for sure if the heatwave is a direct result of global warming.
• Scientists are usually wary of linking climate change to any contemporary event mainly because of the difficulty in completely ruling out the possibility of the event having been caused by some other reason.
• Similarly, scientists who have been studying the climate tend to agree that the heat waves occurring today are more likely to be a result of climate change for which humans are responsible.

Answer this PYQ in the comment box:

Q.Consider the following statements:

1. Jet streams occur in the Northern Hemisphere only.
2. Only some cyclones develop an eye.
3. The temperature inside the eye of a cyclone is nearly 100C lesser than that of the surroundings.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(c) 2 only

(d) 1 and 3 only