Scientists have sounded the alarm: the world must take immediate and drastic action to halt global warming and prevent the melting of ice sheets which will lead to rising sea levels that could threaten millions of people. Moderate action is no longer enough as this would fail to prevent the increase in sea levels. Moreover, a recent study indicates that Antarctic sea ice has hit an all-time low, suggesting that the climate system is responding to global warming.
A recent study suggests that we need to limit human-caused global warming to 1.5°C or less to prevent the melting of the world’s ice sheets and rising sea levels. Even if emissions are limited to a moderate amount, sea levels will continue to rise until at least 2150 because of the delayed reaction of the Greenland and Antarctic ice sheets. For instance, achieving the Paris Agreement’s goal of limiting warming to 2°C would not be sufficient to slow down the rise in global sea levels and only the most dramatic cuts in emissions can achieve this. However, the world is not currently taking enough action.
The study, published in Nature, addresses the problem of melting ice sheets and their effect on ocean processes by utilizing an updated ‘coupled’ computer model that includes the interactions between the atmosphere, ocean, ice sheets, and ice shelves. The model takes into account delayed and unpredictable responses from ice sheets to atmospheric and oceanic warming, and the feedback effects from ocean processes. The projections for the rise in sea levels by 2150 range from 20 cm to 1.4 m, and the study notes that these are probably conservative estimates due to the model’s sensitivity to increased greenhouse gas concentrations.
Even if the world was to slow down global warming by around the year 2100, the melting of the world’s ice sheets would continue to speed up. The melting of the Greenland ice sheet and large parts of Antarctica is like a runaway train that is hard to stop. The resultant rise in sea levels will create more flooding during storms and high tides, events that are already affecting communities living near the coast.
Scientists have stated that the most recent measurements show the lowest recorded overall extent of Antarctic sea ice since satellite monitoring began in the late 1970s.
The images of Antarctica show several areas with lower levels of sea ice concentration that appear as darker blue areas encircling the continent which means that the extent of ice is expected to reduce in the near future. On February 13, 2023, the extent of sea ice in Antarctica was 1.91 million square kilometers (737,000 square miles) as shown by the blue line which also shows the typical extent for the same day between 1981 to 2010.
Fig.1. A new record low in Antarctic sea ice extent. Five-day average sea ice extent
Source: The Washington Post
International organizations have warned of the effects of rising levels with UN Secretary-General Antonio Guterres stating that these “are sinking futures” and that they will have “dramatic implications” for global peace and security.
Addressing the Security Council Debate on “Sea-level Rise: Implications for International Peace and Security”, he warned that should the world fail to limit global warming to 1.5°C above pre-industrial levels, many countries such as Bangladesh, China, India, and the Netherlands, as well as major cities such as Cairo, Lagos, and New York, will be at risk of serious impacts. Nearly 900 million people who live in coastal zones at low elevations, which is 1 out of 10 people on earth, are particularly vulnerable.
Guterres said: “For the hundreds of millions of people living in small island developing states and other low-lying coastal areas around the world, sea-level rise is a torrent of trouble. Rising seas threaten lives, and jeopardize access to water, food and healthcare. Saltwater intrusion can decimate jobs and entire economies in key industries like agriculture, fisheries and tourism. It can damage or destroy vital infrastructure — including transportation systems, hospitals and schools, especially when combined with extreme weather events linked to the climate crisis. And rising seas threaten the very existence of some low-lying communities and even countries.”