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RSTV: THE BIG PICTURE- RISING OCEANS, SINKING CITIES


RSTV: THE BIG PICTURE- RISING OCEANS, SINKING CITIES


Introduction:

             Oceans act as a sponge for the ill effects of the climate change by absorbing heat and CO2 generated by greenhouse gas emissions. However these same oceans are likely to unleash their wrath on a global scale. According to a draft report of United Nations Intergovernmental Penal on Climate Change destructive changes have already been set in motion. The draft report says that even with most optimistic emission reduction scenario , by the year 2050 many low lying megacities and small island nations will experience extreme sea level events every year. Report says that the big four – United States of America, China, India and European Union will face most devastating fall out of the ocean and ice related impacts of climate change.

 

IPCC:

  • The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations, dedicated to providing the world with an objective, scientific view of climate change, its natural, political and economic impacts and risks, and possible response options.
  • The IPCC was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) and was later endorsed by the United Nations General Assembly.
  • Membership is open to all members of the WMO and UN.
  • The IPCC produces reports that contribute to the work of the United Nations Framework Convention on Climate Change (UNFCCC), the main international treaty on climate change.
  • The objective of the UNFCCC is to “stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (human-induced) interference with the climate system”.
  • The IPCC’s Fifth Assessment Report was a critical scientific input into the UNFCCC’s Paris Agreement in 2015.
  • IPCC reports cover the “scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.”
  • The IPCC does not carry out original research, nor does it monitor climate or related phenomena itself. Rather, it assesses published literature including peer-reviewed and non-peer-reviewed sources.

 

Key Highlights of the draft report:

  • The Earth could witness a dramatic decline in fish stocks, a 100-fold increase in the damage caused by superstorms and millions of people displaced by rising seas, if humanity does not reduce greenhouse gas emissions.
  • The report concludes that humanity must overhaul the way it produces and consumes almost everything to avoid the worst ravages of climate change and environmental degradation.
  • It is due to be the fourth in a series of UN reports in recent months on the effects of climate change and specifically focuses on the planet’s oceans and cryosphere – areas composed of frozen water.
  • {articleGUID}The destructive changes have already been set in motion, according to the report.
  • Melting glaciers will first give too much, causing widespread flooding, and then too little, bringing drought, to billions who depend on them for freshwater, the report finds.
  • Without cuts to man-made emissions, at least 30 percent of the northern hemisphere’s surface permafrost could melt by the end of the 21st century, unleashing billions of tonnes of carbon and accelerating global warming even more, the study says.
  • The draft report concludes that even with the most optimistic emission-reduction scenarios, by 2050, many low-lying megacities and small island nations will experience “extreme sea-level events” every year.
  • By the year 2100, “annual flood damages are expected to increase by two to three orders of magnitude”, or 100- to 1,000-fold, the summary for policymakers says.
  • Even if the world manages to cap global warming at 2C, the global ocean waterline will rise enough to displace more than a quarter of a billion people, the report says.
  • Earth’s two ice sheets, sitting atop Greenland and Antarctica, have lost roughly 400 billion tonnes of mass each year in the decade to 2015, becoming the main driver of the rising sea levels, the draft report’s summary says.
  • “Even if the number is 100 or 50 million [displaced people] by 2100, that’s still a major disruption and a lot of human misery.

 

What is the 1.5-degree question?

  • Since 1990s, countries started discussing climate change and began negotiating an international arrangement for tackling it together.
  • The objective has been to limit rising global average temperatures to within 2°C from pre-industrial times.
  • Periodic Assessment Reports produced by IPCC, suggest that the impacts of climate change could be “irreversible” and “catastrophic” if the rise in temperature was allowed to go beyond the 2°C ceiling.
  • Small island states and the least developed nations, are likely to suffer the worst consequences of climate change.
  • These countries asked that the goal should be to restrict the temperature rise within 1.5°C from pre-industrial times.
  • A 1.5°C target demanded much deeper emission cuts from the big emitters, which in turn required massive deployment of financial and technological resources.
  • The Paris Agreement ‘hold’ the increase in global average temperature to “well below” 2°C, it also promised to keep “pursuing efforts” to attain the 1.5°C target.
  • Incidentally, the global average temperature has already risen by more than 1°C from pre-industrial times.
  • At the current rate, the 1.5°C limit could be crossed as early as 2040.

 

So what happens at 2°C that does not happen at 1.5°C?

  • Research found that limiting global warming to 1.5°C could prevent around 3.3 million cases of dengue every year in Latin America and the Caribbean alone.
  • According to World Bank report, additional 150 million people could be at risk from malaria if the temperature was allowed to increase beyond 2°C.
  • The world could have 25 million fewer undernourished people by the end of the century, if the 1.5°C goal was achieved.
  • 350 million additional people could be exposed to deadly heat waves if the warming increased to 2°C as compared to 1.5°C.
  • 5°C could prevent 153 million premature deaths due to air pollution by 2100, as compared to the 2°C scenario.
  • The world could be 3% wealthier by 2100 in a 1.5°C scenario compared to a 2°C scenario.
  • A UNDP report in 2016 claimed that a 1.5°C strategy could create double the number of jobs in the energy sector by 2050.
  • Extreme weather events such as heavy rainfall and heat waves are likely to become more severe and frequent, and freshwater supply could fall sharply, in a 2°C world.

 

The change in sea levels is linked to three primary factors, all induced by ongoing global climate change:

  • Thermal expansion: When water heats up, it expands. About half of the sea-level rise over the past 25 years is attributable to warmer oceans simply occupying more space.
  • Melting glaciers: Large ice formations such as mountain glaciers naturally melt a bit each summer. In the winter, snows, primarily from evaporated seawater, are generally sufficient to balance out the melting. Recently, though, persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs. That creates an imbalance between runoff and ocean evaporation, causing sea levels to rise.
  • Loss of Greenland and Antarctica’s ice sheets: As with mountain glaciers, increased heat is causing the massive ice sheets that cover Greenland and Antarctica to melt more quickly Scientists also believe that meltwater from above and seawater from below is seeping beneath Greenland’s ice sheets, effectively lubricating ice streams and causing them to move more quickly into the sea. While melting in West Antarctica has drawn considerable focus from scientists, especially with the 2017 break in the Larsen C ice shelf, glaciers in East Antarctica are also showing signs of destabilizing.

 

Consequences:

  • These rising sea levels pose a major threat to island nations and coastal areas meaning that these areas could be swamped and submerged by water anytime in the future.
  • In countries like the United States, where almost 40 percent of the population resides in coastal areas, the flooding due to sea-level rise is expected to create adverse effects.
  • Additionally, because of global warming and the resultant rising sea levels, there is a threat of extinction of several types of plants and animals which need and thrive only in the cold climate.
  • Besides these, the rise in sea level would also make an impact on the lives on beaches.
  • Animals are facing the threat of extinction, then humans living in coastal areas and island nations also face the threat of getting submerged in case a deluge happens.
  • Rising sea levels could cause the water levels to increase and invade in the residential areas thus causing a lot of problem to the locales.
  • And unlike other natural calamities, where migration could solve problems, in the case of rising sea levels and the expectant troubles, migration to other parts of the world will be futile because every land form in the globe is bordered by in one way or the other.
  • Contamination of freshwater sources would also affect irrigation and farming, eventually leading us to a food crisis.
  • One of the immediate impacts of the increasing sea level on the economy would be the threat posed the tourism industry.
  • Since the total concentration of the water-bodies being more than two. Every day, little-by-little the glaciers in the Arctic and the Antarctic are melting thus giving way to rising sea levels and a little less chance to experience living for the future generation.

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