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Rising sea level may become a serious threat in the coming decades

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By Nithin Sridhar

A latest study by NASA scientists using satellite data suggests that a rise of up to 1 meter in the global sea level may become inevitable. NASA scientists used a series of highly sensitive altimeters to measure the ocean height from the space.

photo credit: lima.nasa.gov
photo credit: lima.nasa.gov

The study further reveals that there has been an average increase of 8 centimeters in the sea levels since 1992. Scientists add that the sea levels have been rising at a faster rate than they were half a decade ago and this rate is going to further increase over coming decades.

Previously, United Nations Intergovernmental Panel on Climate Change (IPCC) had predicted in 2013 that the sea level rise would be in the order of 0.3 to 0.9 meters by the end of the century.

IPCC

If these predictions turn out to be true, then they may lead to serious disasters across the world. Let us try to understand why sea level rises and what are its likely consequences.

Why does the sea level rise?

A sea-level basically refers to the average level of the surface of water in the ocean. Many factors like ocean currents, ocean density, and water and ice mass exchange between land and ocean influence the sea-level. But, the major factors behind sea level rise are thermal expansion of water and melting of ice caps and glaciers.

Thermal expansion of water refers to the property of water to expand, i.e. increase in volume when there is an increase in temperature. Therefore, even a slight increase in temperature can cause a large increase in the volume of water resulting in sea level change.

The melting polar ice-caps and glaciers are another contributing factor. Melting of polar ice caps and glaciers during summer season is a natural phenomenon. This used to be more or less compensated by the re-formation of ice caps and the falling snow during winter seasons. But, the ever increasing global temperature has induced a rapid melting of ice during summer and a decreased falling of snow during winter. This has in-turn led to an increase in the net quantity of water in the ocean. This phenomenon has occurred even in case of ice-sheets of Greenland and West Antarctica. The ice-sheets are melting at a very faster pace with each passing year.

photo credit: www.whoi.edu
photo credit: www.whoi.edu

One report on sea level change states: “Observations since 1971 indicate that thermal expansion and glaciers (excluding Antarcticglaciers peripheral to the ice sheet) explain75% of the observed rise (high confidence). The contribution of theGreenland and Antarctic ice sheets has increased since the early 1990s, partly from increased outflow induced by warming of the immediately adjacent ocean.

Therefore, global warming that leads to increase in temperature across the world (causing both increased thermal expansion and the melting of ice caps) is the main culprit behind sea level rise. In other words, all those human actions that contribute toward global warming and heat-stress also contribute towards sea level rise.

What are the consequences of sea level rise?

Increase in sea level may have wide change of consequences. Various small island nations and low-lying islands are especially at risk. For example, an estimate released by Copenhagen International Climate Congress has forecasted that many of the islands in the Maldives may get swallowed by the sea by 2100, making the whole country of small islands uninhabitable. Therefore, many low-lying islands are at the risk of getting completely submerged. Other Islands may face severe floods and storms as well.

The coastal areas across the world including India may face various risks. Increased sea-level may cause erosion of soil, increased risks of flooding, cyclones, contamination of agricultural soil, pollution of fresh-water sources etc. Further, people living along the coastline will face increased threat to their life and property. In case of India, sea-level increase may induce cyclones in Bay of Bengal and may cause severe damage to islands like Andaman apart from causing various damages along the coastal area.

photo credit: www.austradesecure.com
photo credit: www.austradesecure.com

 

 

It is high time that the efforts at fighting global warming and climate change are escalated to prevent massive natural crisis that may result from climate change.

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Use Every Resources To Help in Climate Change: Scientists

Individuals and civic groups have a big role to play in pushing governments to tackle climate threats.

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Climate change, Australia
The coal-fired Plant Scherer, one of the nation's top carbon dioxide emitters, stands in the distance in Juliette, Georgia. VOA

Last-ditch efforts to hold climate change to the most ambitious target set by governments will likely require using every available technique rather than picking and choosing the most attractive ones, climate scientists said on Monday.

Dramatically reducing the use of coal, planting huge swaths of land with carbon-absorbing forest or powering most transport with electricity are no longer sufficient to bring about the swift transition needed, they said, with warming expected to pass the 1.5 degree Celsius (2.7 degrees Fahrenheit) mark in as little as 12 years.

“We can make choices about how much of each option to choose, but the idea you can leave anything out is impossible,” said Jim Skea, who jointly led a major scientific report analyzing the feasibility of holding global average temperature rise to 1.5 degrees C above pre-industrial levels, the most ambitious goal of the 2015 Paris Agreement.

The Intergovernmental Panel on Climate Change (IPCC) report, requested by governments, was issued ahead of a U.N. conference in December in Poland that will consider how to increase country ambitions to cut emissions and manage climate risks better.

Current government commitments to curb climate change under the Paris pact, even if fully met, would still leave the world on track for about 3 degrees of warming, scientists said.

Climate change
Waves from Hurricane Florence pound the Bogue Inlet Pier in Emerald Isle, N.C. VOA

To have a chance of meeting the 1.5 degrees goal, climate-changing emissions would have to plunge 45 percent by 2030 compared to 2010 levels, the report said.

As that would be an “unprecedented” rate of decline, it is more likely the world will overshoot the target, then try to return to it by sucking carbon from the air, scientists said.

Such “carbon removal” might happen by developing better technology to take out carbon dioxide from the atmosphere – now an extremely expensive process – or by planting many more forests that could be harvested and burned for energy, with emissions pumped into underground storage.

“We have not identified any pathways that get to 1.5 degrees Celsius without some kind of carbon dioxide removal,” Skea said.

But turning over much more land for energy production “could have implications for food security, ecosystems and biodiversity,” the British scientist warned, as competition for land grows.

Climate change
Traffic moves as smoke emits from the chimney of a factory on the outskirts of Gauhati, India. VOA

All on board

Swiftly reducing emissions – even with carbon removal – will also require unprecedented levels of international cooperation, a particular challenge as some national governments, like that in the United States, look increasingly inward.

Making the needed emissions changes “is within the scope of what humans can achieve”, said Hans-Otto Portner, a German climate scientist and IPCC report co-chair.

But success “depends on political leadership,” he added.

Henri Waisman, a senior researcher at Paris-based think tank IDDRI and one of 91 report authors, said the report’s aim was to set out the types of transformation required as clearly as possible to inform discussions at U.N. climate talks and beyond.

Delaying action on climate change “is something that is explicitly contradicted in the report,” he told the Thomson Reuters Foundation.

Climate change
Climate Change Fuels California Fires. Flickr

If governments fail to ramp up their ambition to reduce heat-trapping emissions over the next two years, they will have consciously abandoned the 1.5 degree goal, he added.

Action in cities – which consume more than two-thirds of energy globally and account for about three-quarters of carbon emissions – are pivotal to meeting the target, said report author William Solecki, a professor at Hunter College-City University of New York.

That’s particularly true because most population growth in coming years “is going to be in urban areas – a lot of it particularly in small and medium-sized cities … in the global south,” he said.

Those cities will need more support to develop cleanly, prevent disasters and adapt to climate shifts, he added.

Climate change
The connection between Antarctic Volcanic Eruptions and abrupt Climate Change. Pixabay

The scientists said the report was intended to guide more than just governments, however, and that action by everyone – including individuals and businesses – would be required to hold the line on climate change.

“There’s a lot we can do individually or within our communities,” said Debora Ley, a report author who works on adaptation and renewable energy in Latin America.

Also Read: UN IPCC Will Meet To Consider On A Global Warming Impact Report

Personal changes might include everything from eating less meat to using energy-efficient appliances and reducing air travel, said Patricia Pinho, a Brazilian climate scientist and report author.

Individuals and civic groups have a big role to play in pushing governments to tackle climate threats, and are stepping up pressure as recognition of the danger grows, she said.

“We have to live our lives in a way that makes a difference. “Our life on this planet, our kids are at risk,” she said. (VOA)