The cryosphere, comprising the Earth’s frozen water bodies such as glaciers, ice caps, and sea ice, is undergoing profound changes due to the warming climate, a phenomenon often referred to as Arctic amplification (PA). This amplification is most pronounced in the Arctic region, where temperatures are rising at more than twice the global average rate. As a result, the once expansive icy landscapes of the Arctic are rapidly shrinking, leading to cascading effects on global climate systems and sea levels. The loss of sea ice not only disrupts the delicate balance of regional ecosystems but also contributes to the rise in sea levels worldwide, presenting significant challenges for coastal communities and biodiversity. Understanding and mitigating these changes are imperative as we navigate the complex interplay between climate, cryosphere dynamics, and their far-reaching consequences.
SHRINKING CRYOSPHERE
- The cryosphere encompasses the segment of the Earth’s climate system that comprises solid forms of precipitation, including snow, sea ice, lake and river ice, icebergs, glaciers and ice caps, ice sheets, ice shelves, permafrost, and seasonally frozen ground.
- The term “cryosphere” finds its etymological roots in the Greek word ‘kryos,’ signifying frost or ice cold.
- This cryospheric domain extends globally, persisting either seasonally or perennially across various latitudes, not confined solely to the Arctic, Antarctic, and mountainous regions but spanning approximately one hundred countries.
- The largest continental ice sheets are notably located in Antarctica.
- A significant portion, around 70%, of the Earth’s freshwater exists in the form of snow or ice within the cryosphere.
MELTING OF CRYOSPHERE – LOSS OF CRYOSPHERE
- The melting of the cryosphere has far-reaching consequences, particularly in its impact on the volume of water in the oceans.
- Alterations to the water cycle resulting from this melting process have a profound effect on the global energy and heat budget, consequently influencing the overall global climate.
- Furthermore, the melting of the cryosphere contributes to the emission of greenhouse gases (GHGs) and induces changes in albedo.
- Projections indicate that these factors, especially in the context of a melting Arctic, are anticipated to more than double the region’s contribution to global warming by the year 2100.
IMPACT OF CRYOSPHERE ON CLIMATE
Albedo:
- The concept of albedo refers to the reflective properties of surfaces, with snow and ice exhibiting high albedo.
- These surfaces reflect a significant portion of incoming sunlight without absorbing it, contributing to the cooling of the Earth.
- Consequently, the presence or absence of snow and ice plays a crucial role in influencing the heating and cooling of the Earth’s surface, impacting the overall energy balance of the planet.
Feedback Loop:
- The melting of ice initiates a feedback loop with notable implications. As ice melts, the once-reflective surface diminishes, and the darker-colored ocean and land areas absorb more solar radiation, subsequently releasing heat into the atmosphere. This process results in additional warming, leading to further ice melt. This cyclical relationship is known as a feedback loop.
Permafrost:
- Permafrost, prevalent in polar regions, holds significant amounts of methane and carbon dioxide.
- This frozen ground contains tons of carbon within its soil. If the feedback loop intensifies, the release of carbon occurs in the form of methane—a potent greenhouse gas—contributing to global warming. Permafrost houses approximately 1,400 to 1,600 billion tons of carbon.
- In terms of carbon budgets, under the 1.5°C climate warming scenario, the melting of permafrost is estimated to result in emissions ranging from 150–200 Gt CO2-eq.
- By 2100, in a 2+°C warming scenario, this could escalate to approximately 220–300 Gt CO2-eq. These emissions levels are comparable to the total emissions of entire countries, such as Canada or the entire European Union.
ARCTIC AMPLIFICATION
- Arctic amplification, also known as Polar amplification, is a phenomenon that arises from atmospheric changes, leading to an increased temperature differential between the Earth’s north and south poles compared to the rest of the planet.
- Global warming, attributed to anthropogenic causes or human activities, has resulted in a substantial rise in the Earth’s average temperature, recording a 1.1-degree Celsius increase since pre-industrial times.
- While the impacts of global warming are observable worldwide, the most significant effects on surface air temperature and net radiation balance are particularly pronounced in the polar regions.
- The term “Polar amplification” is used to describe this phenomenon.
- Arctic amplification is more prominently observed at higher latitudes and occurs as elevated greenhouse gas levels impact the net radiation balance of the atmosphere.
- A notable study conducted by researchers from the Finnish Meteorological Institute in August 2022 revealed that the Arctic is experiencing warming at a rate four times faster than the global average.
- The intensified warming is particularly concentrated in the Eurasian Arctic, with the Barents Sea north of Russia and Norway experiencing alarming rates of warming – seven times faster than the world average.
- This observation underscores the accelerated and disproportionate impact of climate change on the Arctic region, emphasizing the urgency of addressing global warming to mitigate its adverse effects.
GLOBAL CONSEQUENCE OF ARCTIC AMPLIFICATION
- Greenland Ice Sheet Thinning:
- The Greenland ice sheet is experiencing accelerated melting, with a significant decrease in sea ice formation since 2000.
- Unusually high summer temperatures have led to a rapid ice sheet melt, reaching 6 billion tonnes per day and totaling 18 billion tonnes in three days.
- This melt rate has the potential to submerge areas like West Virginia under a foot of water.
- Sea Level Rise:
- The Greenland ice sheet, second only to Antarctica in ice volume, plays a crucial role in regulating sea levels.
- In 2019, it contributed significantly to a 1.5-meter rise in sea levels.
- A complete melt of the ice sheet could lead to a seven-meter rise in sea levels, posing threats to island nations and coastal cities.
- Impact on Biodiversity:
- Warming of the Arctic Ocean and surrounding seas, changes in water acidity, and altered salt levels are affecting biodiversity, particularly marine and dependent species.
- Increased rainfall frequency is impacting the availability of lichens, affecting reindeer populations and causing severe famine and mortality among Arctic wildlife.
- Permafrost Thawing:
- Permafrost in the Arctic is thawing, releasing significant amounts of carbon and methane, major greenhouse gases contributing to global warming.
- Thawing may release dormant germs and viruses, potentially causing health issues, as seen in the 2016 Siberian anthrax epidemic that killed around 200,000 reindeer.
- Connectivity:
- Melting Arctic ice and its strategic location will create the shortest maritime route connecting America, Europe, and North East Asia.
- This transformation is expected to revolutionize global maritime commerce, challenging the conventional East-West routes via the Malacca Strait and the Suez Canal.
- Monsoons:
- The changing Arctic conditions are increasingly linked to monsoons in India, crucial for water and food security in the country.
- Mineral Resources:
- The Arctic region is rich in coal, gypsum, diamonds, zinc, lead, placer gold, and quartz.
- Greenland alone holds more than a fifth of the world’s rare earth deposits.
- Geopolitics:
- Melting Arctic ice is leading to increased geopolitical tensions.
- Major players, including the United States, China, Russia, and NATO, are vying for position and influence in the region, driven by the opening of maritime routes and the potential for expanded resource exploitation. China, in particular, has identified itself as a ‘Near-Arctic State’ in its Arctic strategy.
SEA LEVEL CHANGE
- As per the World Meteorological Organization’s (WMO) report titled “Global Sea-level Rise and Implications,” India, China, Bangladesh, and the Netherlands are identified as facing the most significant threat of sea-level rise on a global scale.
- The report emphasizes that numerous major cities across all continents are under the imminent threat of rising sea levels.
- Among these vulnerable cities are Shanghai, Dhaka, Bangkok, Jakarta, Mumbai, Maputo, Lagos, Cairo, London, Copenhagen, New York, Los Angeles, Buenos Aires, and Santiago.
- The rising sea levels pose a substantial risk to the coastal regions of these cities, highlighting the urgent need for global attention and collaborative efforts to address and mitigate the impacts of climate change on vulnerable areas.
TRENDS AND PROJECTIONS
- Over the period from 2013 to 2022, the global mean sea level exhibited an average rise of 4.5 mm per year, with human influence identified as the likely primary driver of these increases since at least 1971.
- Examining the historical context, global mean sea level rose by 0.20 meters between 1901 and 2018.
- This increase manifested at a rate of 1.3 mm per year during the period from 1901 to 1971, accelerated to 1.9 mm per year from 1971 to 2006, and experienced a further acceleration to 3.7 mm per year between 2006 and 2018.
- It is crucial to note that even if efforts successfully limit global heating to a 1.5 degrees Celsius increase over pre-industrial levels, a substantial rise in sea levels is still anticipated.
- However, every incremental degree matters significantly. In the scenario where temperatures rise by 2 degrees, the projected sea level rise could potentially double.
- Moreover, any further increases in temperature beyond that point might result in exponential rises in sea levels, emphasizing the critical importance of addressing and mitigating global climate change.
FAQs: SHRINKING CRYOSPHERE, ARCTIC AMPLIFICATION, SEA LEVEL CHANGE
1-What is the cryosphere?
A: The cryosphere refers to the Earth’s climate system component encompassing solid forms of precipitation, such as snow, sea ice, glaciers, ice sheets, permafrost, and more. It plays a crucial role in regulating global climate patterns.
2-Why is it called the “cryosphere”?
A: The term “cryosphere” originates from the Greek word ‘kryos,’ meaning frost or ice cold, reflecting the frozen nature of the components within this Earth system.
3-Where does the cryosphere exist globally?
A: The cryosphere extends globally, persisting seasonally or perennially in various latitudes, not limited to the Arctic, Antarctic, or mountainous regions but spanning approximately one hundred countries.
4-What is the significance of the cryosphere in terms of freshwater?
A: Around 70% of the Earth’s freshwater exists in the form of snow or ice within the cryosphere, highlighting its vital role in global water resources.
5-How does the melting of the cryosphere impact oceans and the climate?
A: The melting of the cryosphere influences the volume of water in oceans, leading to changes in the water cycle. This, in turn, affects the global energy and heat budget, influencing the overall climate.
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