6. Understanding Why Antarctic Ice Loss Matters
Antarctica may seem like another world—cold, distant, and forgotten—but what goes on there is already beginning to affect Antarctica may be remote, but what happens there is already affecting coastlines around the globe. Picture it as Earth’s deep freeze—one with enough frozen water to raise global sea levels more than 58 meters if it were to fully thaw. Luckily, that isn’t happening overnight. But even small levels of melting can have catastrophic consequences. The Intergovernmental Panel on Climate Change says that about 680 million people currently inhabit low-lying coastal areas, and as many as more than 1 billion might by 2050. That is to say, the future and livelihood of millions depend on the cold south.
5. Land Ice vs. Sea Ice
Here’s a telling fact: all ice does not act the same way on sea level. Land ice—such as glaciers and the giant ice sheets of Antarctica and Greenland—sits on solid ground. When it melts, it contributes additional water to the ocean, increasing sealevels.Sea ice, however, is already floating on the ocean. When it melts, it’s rather like ice in a glass of water—it doesn’t really change volume much. NASA’s Jet Propulsion Laboratory simplifies it this way: sea level is rising, partly because melting land is adding more water to the world’s oceans.
4. How Antarctic Ice Sheets Are Changing
Antarctica’s ice isn’t melting—it’s melting more than ever. Although some areas of the continent are receiving additional snowfall (which contributes to ice), on balance, it’s losing much more than it’s gaining. Indeed, Antarctica’s ice loss has accelerated sixfold in the last 30 years. The West Antarctic Ice Sheet is particularly precarious. Some of its glaciers are accelerating, and scientists fear that they might reach a tipping point—i.e., the loss of ice could become irretrievable. Even the East Antarctic Ice Sheet, previously considered secure and stable, is now exhibiting problems, with important glaciers such as Totten melting at rates significantly higher than predicted.
3. Ice Shelves’ Function: Calving, Thinning, and Unstability
Ice shelves are floating ice edges of the ice sheet, and they have a very important function: they function like giant brakes, slowing the rate at which land ice flows into the ocean. When ice shelves thin or split apart—a process referred to as calving—that braking effect is reduced, and more land ice can move into the ocean. Warmer air and ocean temperatures are reducing ice shelves from above and below, causing them to become weaker and more prone to breakage, says NASA’s Nicole Schlegel. It’s a feedback process: thinning causes more land ice movement, which causes more thinning, and so on. Include calving, and the loss is even greater.
2. Where Sea Level Will Rise the Most—and Why
Sea level rise does not occur uniformly everywhere. Ironically, regions close to Antarctica may experience less rise—or even a fall—since the gravitational pull of all that ice keeps ocean water in closer proximity. When that ice melts, the attraction dissipates, and the water moves elsewhere. Consequently, the fastest sea level rise will occur in the tropics and mid-latitudes—regions such as the Pacific and Indian Ocean coastlines. In the US, the Gulf Coast and Southeast are particularly vulnerable. Some of that is exacerbated by the ground itself subsiding—a slow-motion aftermath of the most recent ice age that continues to unfold today.
1. The Human Impact: Coastal Communities and Global Risks
It’s not merely a matter of moving coastlines or rearranging maps. Rising seas threaten actual communities. Houses flood. Freshwater can be contaminated with salt. The land can be too salty to till. Even a few feet of sea level rise would displace hundreds of millions of individuals. Antarctica stores approximately 90 percent of its freshwater, and its destiny is directly linked with the destiny of our cities, economies, and ecosystems. As the ice continues to melt, the pressure to act for our health, safety, and way of life only intensifies.