Written by Ayushi Bhatt | Header image: National Geographic
It can be easily said that 2020 has been a disastrous year, especially for the Gen Z. But hold your horses! It may be the worst year as of now, but it won’t be the worst one forever. We are on the path to face enemies with no nuclear weapons, but equally deadly. All thanks to climate change.
Around 40% of the world’s population lives within 100 km of the coast. That is a large enough population to seriously worry about, which is going to be affected as more and more of our ice sheets melt. Sea level rise is one of the most catastrophic consequences of climate change. It has a long term impact that may not be felt immediately. But make no mistake, it is happening and it is certainly damaging. It shouldn’t be news that the Antarctic ice sheet, which holds around 90% of Earth’s freshwater, is melting at alarming rates. Antarctica recorded
its highest temperature on record on February 6, 2020. What do scientists predict? According to IPCC’s fifth assessment report, sea level will have risen by 26 to 54 cm, relative to 1985-2005 levels, by 2100. But this will happen only when emissions are cut drastically after 2020. Under the business as usual scenario, where emissions continue to rise rapidly, sea level will increase by 45 to 82 cm. Prediction of ice loss from Antarctica has been difficult. While some parts on the surface are gaining mass by snow accumulation, parts of the Antarctic Peninsula and West Antarctica continue to lose ice. Overall, the sea level is projected to rise by 5 cm by the end of the century due to Antarctic ice loss.
Some new developments have led scientists to believe that this figure could be much higher. “Marine ice-cliff instability” could trigger an irreversible collapse of an entire ice sheet if the ice shelves at the edges melt away. However, it has not been observed at a significant scale in Antarctica yet. Thwaites glacier is pivotal to Antarctica’s future. It is retreating at an accelerating rate and is losing
double the amount of ice than it did 30 years ago. Its total retreat could lead to the complete discharge of West Antarctic ice into the ocean causing more than 3 meters rise in global sea level. Why should we be worried? Flooding of low lying coastal
areas is the most obvious impact of rising sea levels. The intensity and frequency of these floods will increase. Some lands could be permanently submerged. A 3 meters rise in sea level could submerge southern Bangladesh and even parts of New York City. As seawater penetrates inward, it will lead to salinization of ground and surface water, causing a shortage of already depleting freshwater. Erosion and salt contamination will make soil unfit for agriculture. People will be forced to migrate. Habitat loss and ecosystem changes will have direr consequences. The endangered sea turtles, for example, will be hard hit. It will be a huge blow to the economy when beaches and other touristy areas near the coast get washed away. The phenomenon of melting of the Thwaites glacier and subsequent collapse of the West Antarctic ice sheet could play out in the next few centuries. But it could be slowed down or even stopped. That requires extreme measures to be taken to curb greenhouse gas emissions. Paris Agreement is not enough, but for now, it needs to be strictly adhered to, which most countries are not doing.
In 2019, A NASA study found a 300 meters cavity growing at the bottom of the Thwaites glacier. As warm ocean water flows into it, it will melt the glacier from below, triggering an even rapid loss. No one knows for certain if and how soon the Thwaites glacier will give away. But once it does crumble, there is no going back.