Oceans are heating up at a quickening pace, say scientists

Oceans are heating up at a quickening pace, say scientists

News:

World’s Oceans Are Warming Faster, Fueling Storms and Sea Rise

Important Facts:

  • Oceans are heating up 40% faster on average than a United Nations panel estimated five years ago.
  • A warmer ocean is contributing to increasingly destructive weather patterns around the world
  • More than 90 percent of the excess heat from greenhouse gas emissions has been absorbed into the oceans
  • Ocean temperatures are much less variable than surface temperatures, which can swing greatly from year to year, and therefore give a clearer signal of global warming

Consequences of Ocean Warming:

  • On Climate:
    • The implication of faster ocean warming is that the effect of carbon dioxide on global warming is greater than it was expected. It is already known that adding CO2 to the air was warming the world very rapidly.
    • Greater warming will mean increased water demand for crops and forests and pastures, more stress on irrigation and urban water supplies, and reduced food production.
    • More water demand means more forest fires and smoke, shorter winters with less mountain snowpack, and increased stress on ecosystems, cities and the world economy.
  • Higher Sea Levels
    • When water heats up, it expands. Thus, the most readily apparent consequence of higher sea temperatures is a rapid rise in sea level.
    • Sea level rise causes inundation of coastal habitats for humans as well as plants and animals, shoreline erosion, and more powerful storm surges that can devastate low-lying areas.
  • Stronger Storms
    • The effects of higher ocean temperatures in the form of stronger and more frequent tropical storms and hurricanes/cyclones is already seen in Indian oceans recently. Warmer surface water dissipates more readily into vapor, making it easier for small ocean storms to escalate into larger, more powerful systems.
  • On Ocean organism:
    • Ocean organism most vulnerable to temperature change.
    • Ocean warming leads to deoxygenation – a reduction in the amount of oxygen dissolved in the ocean – and sea-level rise – resulting from the thermal expansion of sea water and continental ice melting. The rising temperatures, coupled with ocean acidification (the decrease in pH of the ocean due to its uptake of CO2), affect marine species and ecosystems
    • Due to temperature change reef bleaching will start. Bleaching slows coral growth, makes them susceptible to disease, and can lead to large-scale reef die-off.
    • Other organisms affected by temperature change include krill, an extremely important link at the base of the food chain
    • Research has shown that krill reproduce in significantly smaller numbers when ocean temperatures rise. This can have a cascading effect by disrupting the life cycle of krill eaters, such as penguins and seals—which in turn causes food shortages for higher predators.
  • Other Consequences
    • Warmer sea temperatures are also associated with the spread of invasive species and marine diseases.
    • If an ecosystem becomes warmer, it can create an opportunity where outside species or bacteria can suddenly thrive where they were once excluded. This can lead to forced migrations and even species extinctions.
    • Warmer seas also lead to melting from below of polar ice shelves, compromising their structural integrity and leading to spectacular shelf collapse
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