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Rainfall changes could impact global manufacturing, services sectors: Study

  • Posted By
    10Pointer
  • Categories
    Geography
  • Published
    28th Jan, 2022
  • Context

    Increases in the number and days of rainfall and severity of downpour, due to human-induced climate change, may deal a blow to global economic growth, as per a new study.

    • These changes are likely to take a higher toll on the manufacturing and services sectors.
  • Background

    Rainfall pattern means the distribution of rain geographically, temporally, and seasonally.

    • The study (conducted by researchers from Potsdam Institute for Climate Impact Research) looked at how rainfall patterns hurt the economy.
    • The group compared daily rainfall data with subnational economic output from 77 countries between 1979 and 2019.
    • It made the following revelations:
      • An increase in the number of days with rainfall exceeding one millimetre led to a substantial decline in growth rates. A rise in extreme rainfall days contributed further to this loss.
      • Extreme daily rainfall is the annual total of rain on days that exceed the 99.9th percentile of the distribution of daily rainfall between 1979 and 2019.
      • Increases in both the number and severity of extreme rainfall days within a given year reduce economic productivity.
      • Increasing wet days and extreme rainfall will likely hit prosperous countries harder. This is because these countries rely more on the manufacturing and services sectors.
  • Why the rainfall pattern is changing?

    • Global warming: Global warming leads to a near-term collapse of the ocean's thermohaline circulation. 

    Thermohaline circulation is a global ocean circulation pattern that distributes water and heat both vertically, through the water column, and horizontally across the globe.

    • Due to this collapse of thermohaline circulation, warm surface waters move from the tropics to the North Atlantic and extra-warm water surfaces in the Pacific Ocean surrounding the equator.
    • Thus, Western Europe, some parts of Asia, and many parts of the Americas get warmer than normal, and some parts of Europe get cooler rapidly.
      • El Niño and La Niña are examples of this.
    • This latest deviant trend generates dramatic weather impacts, such as
      • rapid cooling in some parts of the world
      • greatly diminished rainfall in agricultural and urban areas
    • Shift in global wind pattern: UNESCO and other studies found that changes in rainfall pattern could be attributed to the shifts in global wind pattern. These shifts are due to the changes in the ocean surface temperature.
    • Human activity: Effect of human activity on the surface vegetation is also causing rainfall pattern variation.
    • Deforestation: Widespread deforestation in parts of Africa and Asia is causing scarce rainfall and subsequent drought.

    The set pattern of rainfall in India

    • The normal date for monsoon onset over India is June 1 and for monsoon withdrawal is October 15.
    • The India Meteorological Department (IMD) closes its monsoon seasonal data on September 30. The rainfall that happens after this period is post-monsoon rainfall.
    • This means that for the last 10 years, India’s monsoon rainfall pattern has been largely skewed.
    • Monsoon is said to withdraw from a region when the following criteria are met:
    • Rainfall activity ceases over the area for five continuous days
    • an anti-cyclone establishes in the lower troposphere around 1.5 kilometres above sea level
    • moisture content reduces
    • Similar criteria are followed for the declaration of monsoon withdrawal from the country. The wind patterns over the country change from south-westerly direction to a more westerly direction when the monsoon retreats.
  • What are the consequences of changed rainfall?

    • Affected agricultural sector: The world's agriculture, especially third world agriculture, depends upon the seasonal rainfall pattern.
    • Food insecurity: Recent erratic changes in rainfall pattern lead toward low agriculture production, thus creating food insecurity for an ever-increasing world population.
    • Migration: Rainfall pattern variability would certainly cause mass human migration.
    • Increased disasters: Flood, drought, and famine are the consequences of these changing patterns.
  • Why this study assumes significance for India?

    • The study offers important lessons for India as the country aims to become a manufacturing hub.
      • The sector currently contributes roughly 17 per centto GDP.
      • Its share in employment was 7.3 per cent in 2020-2021.
    • According to India Brand Equity Foundation projections, India can add more than $500 billion annuallyto the global economy.
    • But the manufacturing sector is vulnerable to climate change. The sector is heavily dependent on supply chains and supply chains are heavily disrupted during extreme weather events.
  • Why manufacturing industry is itself a climate criminal?

    • Manufacturing – especially of the cheap construction staples steel and cement – accounts for about a third of global greenhouse gas emissions.
    • That makes manufacturing more polluting than the power or transportation sectors, which receive far more attention in policies and investments.
    • And the manufacturing sector is set to grow, as the global population climbs and countries further develop.
  • Way forward

    If this trend of changed rainfall pattern continued, environmental managers need to make new decisions about the management of water and land. They need to accurately understand the inter-annual variability of rainfall and a possibility of runs of dry and wet years, which may cause important changes in runoff, sedimentation, soil erosion, or changes in communities of vegetation and animals, and of the viability of large water resource developments.

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