Extreme Weather Event

Context: Recently, in July, 2023, all seven of Earth’s continents have experienced extraordinary extreme weather events. About Extreme Weather Events
  • Definition: When the weather conditions show significant differences than the usual weather, this is termed as extreme weather or severe weather.
    • The extreme weather conditions may last for a while or sometimes it may take just one or two days to become normal.
  • Impact: According to the World Meteorological Organisation (WMO), extreme weather, climate and water-related events caused 11,778 reported disasters globally, leading to more than two million deaths and USD 4.3 trillion in economic losses between 1970 and 2021.
    • Over 90 per cent of the reported deaths worldwide occurred in developing countries.
    • In India, 573 disasters occurred between 1970 and 2021, that claimed 1,38,377 lives,
  • Types of Extreme Weather Events
Events Description Example
Heatwaves
  • A heatwave occurs when the maximum and the minimum temperatures are unusually hot over a three-day period at a location. This is considered in relation to the local climate and past weather at the location.
  • In India, Heat Waves typically occur between March and June, and in some rare cases even extend till July.
  • According to the  European Space Agency in june 2023, Italy’s islands of Sicily and Sardinia could experience their hottest-ever temperature, with a predicted high of 48 degrees Celsius (118F)  — potentially the hottest temperatures ever recorded in Europe.
  • In the middle of April a heatwave swept over China, India, Thailand, Laos, Bangladesh, and more countries across the Asian continent, with temperatures ranging from 38 degrees to 45 degrees Celsius — breaking temperature records in over a dozen countries.
Wildfire
  • Wildfire, also called forest, bush or vegetation fire, can be described as any uncontrolled and non-prescribed combustion or burning of plants in a natural setting such as a forest, grassland, brush land or tundra, which consumes the natural fuels and spreads based on environmental conditions (e.g., wind, topography).
  • Canada: Canada is currently experiencing its worst ever wildfire season, largely due to an extreme dry period followed by a heatwave.
  Droughts
  • Drought is a prolonged dry period in the natural climate cycle that can occur anywhere in the world.
  • It is a slow-onset disaster characterized by the lack of precipitation, resulting in a water shortage.
  • From North America to Europe to China, vast swaths of the Northern Hemisphere experienced extreme drought in the summer of 2022, straining water resources, ruining crops, and priming the landscape for perilous wildfires.
  • Horn of Africa drought, 2020-2023: A three-year drought in the Horn of Africa, one of the world’s most impoverished regions, has caused crops to wither, water to disappear, and livestock to starve in large parts of Kenya, Somalia and Ethiopia.
  Cold Snaps
  • A cold snap is a very sudden drop in temperature as opposed to a cold spell (Spell means a length of time), and a cold wave (a wave comes gradually and grows till it breaks).
  • It have a multifaceted impact on not just human lives, but the Earth’s systems as a whole.
  •  Indian Meteorological Department (IMD) declares a cold wave when the minimum temperature is equal to or less than 10 degrees Celsius at a weather station in the plains and is 4.5-to 6.4 degrees Celsius below the normal temperature for that period.
  • In 2023, temperatures in the city of Mohe in northern China plummeted to minus 53 degrees Celsius (minus 63.4 degrees Fahrenheit), the lowest temperature the country has ever recorded.
  Tropical Cyclones
  • A tropical cyclone is a rapid rotating storm originating over tropical oceans from where it draws the energy to develop.
  • It has a low pressure centre and clouds spiraling towards the eyewall surrounding the “eye“, the central part of the system where the weather is normally calm and free of clouds.
  • According to the IPCC, these have become more frequent over the last four decades. Furthermore, they are proving more destructive as they result in higher category hurricanes.
  • Tropical Storm ‘Mawar’ affected Guam, the Philippines, Taiwan, and Japan at the end of May and early June.
    • It is reported as the strongest tropical cyclone globally so far in 2023 and the strongest northern hemisphere cyclone ever recorded in May.
  • Cyclone Mocha Myanmar: It proved to be one of the strongest cyclones to ever hit the region.
    • The storm led to immense destruction, killing an estimated 145 people.
    • According to the UN, the cyclone impacted 800,000 people overall.
Torrential rains
  • Torrential rain, or a torrential downpour, is any amount of rain that is considered especially heavy.
  • Asia in 2023 has been hit by extreme weather conditions, with South Korea facing heavy rains causing floods and landslides, resulting in 37 deaths and nine people missing.
  • Northern Japan also experienced deadly floods, claiming the life of a man in a submerged vehicle.
  • In northern India, relentless monsoon rains have killed at least 90 individuals, exacerbating the region’s already scorching heat.
Flood and Flash Flood
  • Flood: An overflow of water onto normally dry land. The inundation of a normally dry area caused by rising water in an existing waterway, such as a river, stream, or drainage ditch. Ponding of water at or near the point where the rain fell.
  • Flash flood: A flood caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Flash floods are usually characterized by raging torrents after heavy rains that rip through river beds, urban streets, or mountain canyons sweeping everything before them.
  • Flooding is a longer-term event than flash flooding: it may last days or weeks.
  • Pakistan floods, 2022: Major flooding caused by record monsoon rains claimed the lives of nearly 1,500 people during the summer of 2022, with millions more affected by clean water and food shortages.
    • The floods left a third of Pakistan underwater. 
    • The country received more than three times its usual rainfall in August, making it the wettest August since 1961. 
    • Increases in both extreme precipitation and total precipitation have contributed to increases in severe flooding events in certain regions.
  Extreme Weather Events are influenced by many factors
  • Anthropogenic Factors: Human activity is causing rapid changes to our global climate that are contributing to extreme weather conditions.
    • When fossil fuels are burned for electricity, heat, and transportation, carbon dioxide, a greenhouse gas that traps solar radiation, is released into our atmosphere.
    • These greenhouse gas emissions and land use change were a key factor in extreme climate change events around the world.
    • Climate change has increased the instability in the atmosphere, leading to an increase in convective activity — thunderstorms, lightning and heavy rain events.
    • Cyclonic storms in the Bay of Bengal and the Arabian Sea are also intensifying rapidly and retaining their intensity for a longer duration due to global warming.
  • Global Warming: Global warming is the long-term warming of the planet’s overall temperature.
    • It can contribute to the intensity of heat waves by increasing the chances of very hot days and nights.
    • Warming air also boosts evaporation, which can worsen drought. 
    • More drought creates dry fields and forests that are prone to catching fire, and increasing temperatures mean a longer wildfire season.
    • It increases water vapor in the atmosphere, which can lead to more frequent heavy rain and snowstorms.
    • It causes sea level to rise, which increases the amount of seawater, along with more rainfall, that is pushed on to shore during coastal storms.
    • That seawater, along with more rainfall, can result in destructive flooding.
    • It causes climate change, which poses a serious threat to life on Earth in the forms of widespread flooding and extreme weather.
  • Natural Climate Patterns: El Nino is a natural climate cycle that occurs every three to seven years, characterized by warmer than usual ocean surface temperatures in the central and eastern tropical Pacific.
    • This phenomenon, known as the El Nino-Southern Oscillation (ENSO), has far-reaching effects on weather conditions across the globe.
    • This warming disrupts the normal atmospheric circulation, leading to changes in weather patterns worldwide.
    • The warmer waters cause the Pacific jet stream to move south of its neutral position. With this shift, areas in the northern U.S. and Canada are dryer and warmer than usual.
    • The changes in climate due to El Niño mean more natural disasters for climate-vulnerable countries to contend with amid a climate crisis that is already decimating lives.
    • La Nina: It represents a cooling effect, with colder ocean temperatures in the equatorial Pacific.
    • During La Niña events, trade winds are even stronger than usual, pushing more warm water toward Asia.
    • This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada
  • High Atmospheric Winds: The jet stream is found where the cold air from Earth’s poles meets with warm tropical air.
    • These winds help to continue and control the weather system from west to east in the northern hemisphere and from east to west in the southern hemisphere.
    • Sometimes these winds bring unpleasant weather with them which may lead to the formation of a tornado.
Extreme Weather Events in India
  • In India, the year 2023 has witnessed a series of unprecedented climatic phenomena, indicating a disturbing new normal caused by climate change.
    • Onset of 2023 was marked by scorching temperatures that shattered a 123-year-old record in February.
    • Cyclonic Event: Arabian Sea witnessed the formation of cyclone Biparjoy, which lasted a staggering 13 days, becoming the longest-duration cyclone since 1977.
  • According to India Meteorological Department (IMD), India experienced extreme weather events on 314 of the 365 days in 2022. 
    • Human Lives Lost: Erratic weather conditions expose millions of Indians to climate disasters, kill thousands every year and increase economic hardships by eroding farm productivity.
    • The events claimed 3,026 lives and damaged 1.96 million hectares (ha) crop area.
  • IPCC assessments in 2023 also provided convincing evidence that global warming is triggering severe climate-related occurrences like non-stop rainfall.
  • Financial Implication: India is already losing 3-5% of its GDP due to climate change and this number could rise to as much as 10% if the warming is not limited to below 2 degrees Celsius.”
  • Shift in monsoon patterns: It is characterized by prolonged deficit rainfall periods followed by intense downpours occurring over a few days.
    • This pattern has been strengthening over the past several decades. 
    • The combination of warmer temperatures, increased moisture in the air, and the southwest monsoon’s impact is resulting in heavy rainfall concentrated within a short span of time.
    • Recent heavy rainfall in northern India can be attributed to the interaction between a low-pressure weather system known as the western disturbance and the southwest monsoon.
    • According to a report by Indian Institute of Technology, Gandhinagar, the frequency of extreme weather events such as floods and heatwaves is projected to rise manifold in India in the future due to climate change.

Image Credit: TOI

Way Forward
  • Climate Resilient Infra for Cities: Implementing strategies to lessen the effects of flooding is necessary when creating flood-resistant infrastructure and cities. 
    • Important techniques include proper urban design, efficient drainage systems, floodwater storage facilities, and flood-resistant construction materials.
    • Urban areas must incorporate efficient waste management systems, green areas, and renewable energy sources to lower carbon emissions and improve sustainability.
    • Cities must also incorporate climate resilience into their long-term urban development plans to adapt to shifting climatic trends.
  • Himalayas: A Safety-First Approach: This strategy entails establishing reliable monitoring systems that use cutting-edge monitoring tools, including satellite imaging, ground sensors, and remote sensing.
    • Strict land-use rules must stop construction on perilous slopes and locations susceptible to flooding.
  • Adopting Greener Alternative: Move beyond fossil fuels, by keeping fossil fuels in the ground and cleaning up pollution.
    • Switching to clean energy, by setting ambitious climate goals, removing barriers to clean energy, and electrifying our economy.
    • Protecting climate forests, promoting climate-smart agriculture, and stopping the petrochemical buildout.
  • Strengthening early warning systems: Need for improved forecasting techniques, smarter infrastructure design, and adopting a safety-first philosophy to lessen the effects of catastrophic catastrophes.
    • Efficient and reliable forecasting methods are essential to warn communities and authorities about oncoming extreme weather occurrences.
    • Satellite images, localised doppler radars, weather models, and data analytics are examples of modern meteorological technology that can assist in predicting rainfall patterns more accurately, identifying possible flood-prone locations and offering timely warnings.
  • Collaborative Strategies: Collaboration between government, academic institutions, engineering firms, urban planners, and local communities is required if we are to address the problems caused by extreme weather occurrences. 
  • Climate Justice: Centering environmental justice and expanding access to clean energy in every community.
  • Local Solution: Need for micro-action plans at the local level to identify vulnerable areas and develop customized disaster management strategies.
  • Awareness: Campaigns for public education, evacuation strategies, and community training programmes ensure that locals are prepared for flood situations and can act quickly to save themselves and be effective first responders. 
World Meteorological Organisation (WMO):
  • It is a specialized agency of the United Nations (UN).
  • It is the UN system’s authoritative voice on the state and behavior of the Earth’s atmosphere, its interaction with the oceans, the climate it produces, and the resulting distribution of water resources.
About India Meteorological Department (IMD)
  • It was established in 1875.
  • It is an agency of the Ministry of Earth Sciences of the Government of India.
  • It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
  • IMD is also one of the six Regional Specialized Meteorological Centres of the World Meteorological Organization.
 News Source: The Hindu 

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