Rising Antarctic ice melt to dramatically slow global ocean flows

Research found that rapidly melting Antarctic ice is dramatically slowing down the flow of water through the world’s oceans.

Key-highlights of the study:

• Rapidly melting Antarctic ice is slowing down the flow of water through the world’s oceans.
• It could have a disastrous impact on global climate, the marine food chain and even the stability of ice shelves.
• As temperatures rise, freshwater from Antarctica’s melting ice enters the ocean, reducing the salinity and density of the surface water and diminishing that downward flow to the sea’s bottom.
• The study found that deep-water circulation in the Antarctic could weaken at twice the rate of decline in the North Atlantic.
• Disruption the base of food chain: Ocean overturning allows nutrients to rise up from the bottom, with the Southern Ocean supporting about three-quarters of global phytoplankton production, the base of the food chain.
• Leaving more CO2 in the atmosphere: Study suggest that the ocean would not be able to absorb as much carbon dioxide as its upper layers become more stratified, leaving more CO2 in the atmosphere.

What is Global Ocean Circulation?

• Earth's oceans have a worldwide circulation system that moves ocean water in an endless loop around the planet (that could take a thousand years to complete). The global ocean circulation pattern is sometimes referred to as a conveyor belt.
• The "overturning circulation" of the oceans is driven by the movement of denser water towards the sea floor.
• Significance:
  • Heat distribution: The patterns of global ocean circulation distribute heat around the planet. 
  • Bringing stability: The Ocean and the atmosphere are closely connected and are responsible for maintaining Earth's relatively stable climate, providing a hospitable environment for life.
  • Key regulator of climate: Ocean circulation is a key regulator of climate by storing and transporting heat, carbon, oxygen, nutrients and freshwater all around the world.

What factors are responsible for climate change?

•  Co₂ emission on rise:According to the Global Carbon Project, CO2 emissions are on rise by 0.6% in 2019 (2.1% in 2018). The reductions are not enough to stop global warming.
• • Despite a significant decline in coal consumption in US and Europe, the higher global emissions are attributed to growth in natural gas and oil usage.
• Industrial heat:Manufacturing industrial products (essential to construction, infrastructure and manufacturing) requires a lot of heat that emits more carbon dioxide than all the world’s cars and planes.
• Land degradation:Land degradation, mainly due to human activities like deforestation, mining/quarrying, construction, roads, other infrastructure for economic development, human settlements for increasing population, etc., is a contributing factor to climate change.
• Meat consumption:IPCC report ‘Climate Change and Land’ emphasises the ever-increasing global meat consumption and the resulting distorted land-use pattern to meet this requirement, as a cause contributing to climate change.
• Disregard for ocean health: Overfishing, plastic pollution, micro-plastics, flow of fertilisers and chemicals etc. is suffocating fish and damaging ocean health.
  • More than 1 billion people depend on the oceans. Ocean health is vital to biodiversity, healthy fisheries and to regulate the climate.

New-age measures adopted/suggestions to control climate damage:

• Carbon markets: Creation of ‘carbon markets’ under the Paris Agreement allows countries, or industries, to earn carbon credits for emission reductions they make in excess of what is required of them.
• Climate- Neutral Europe: In a ‘Green Deal’, Europe has vowed to become the first ‘climate-neutral’ continent by 2050, as it aims to eliminate its net discharges of greenhouse gases.
  • This will be done through creating single set of definitions, to determine what economic activities are sustainable and should count as green, in areas ranging from finance to design of cities.
• Carbon capture: Carbon capture, use and storage (CCUS) is essential to reducing carbon emissions from heavy industry, especially cement and steel production. It is more affordable than most other option—far cheaper and more readily available than electrical heating or burning biomass.
• New Climate Economy: Studies suggest that shifting to a low-carbon economy represents USD 26 trillion growth opportunity that could create 65 million new jobs by 2030.