One of the most significant impacts of climate change is sea level rise, which can not only flood islands and coastal regions, but it can cause birds, fish, and plants to lose their habitats. It also induces soil erosion and contaminates agricultural and aquifer soil with salt. In fact, because much of the non-water resistant infrastructure of the Internet lies over the seas, the Internet could be drowned out within 15 years!
Within the last century, global sea level has risen by 0.2m, however, since the 1960s, sea level rise has started to accelerate. In fact, in the direction we're currently heading, due to temperatures warming 1.5 °C, sea level could rise over 2m this century!
What could be responsible for the sudden upsurge in the rate that the sea rises? One of the main factors is the thermal expansion of water. As seawater gets hotter, it becomes less dense and expands, which leads to rising oceans. Due to the sheer amount of global warming in our modern world, Earth's oceans have risen 19mm from thermal expansion between 1993 and 2010, over one-third of the total sea level increase of 54mm!
In addition to thermal expansion, some other causes for the acceleration of sea level rise include the melting of glaciers and ice sheets. In fact, if all the ice currently on Earth melted, it would raise sea level by a whopping 216 feet, which could cause entire states and countries to become submerged! This scenario is not likely, but could be possible in the future if we kept burning fossil fuels.
Furthermore, if it weren't for an increase of the water being stored on land, the already staggering increase in the acceleration of sea level rise could become even higher! When rain falls on land, it gets held in soil, wetlands, groundwater, lakes, and reservoirs as it travels back to the oceans. Humans speed up this cycle by extracting water, but also slow it down at the same time by building dams and reservoirs. However, the rate at which we speed it up far exceeds the rate at which we slow it down. As a result of this, 0.38mm of land water ends up in the oceans each year for the past 20 years! This may not sound like a significant amount, but it all accumulates to a gradual, yet drastic, rise in sea level.
To sum it all up, according to a 2011 study by Church and White, from 1901-1990, the main cause for sea level rise was the melting of glaciers. From 1993-2010, in addition to the melting of glaciers, ice sheets began to melt as well. Thermal expansion and human activity on land water were also significant causes for this acceleration. In the future, thermal expansion is projected to be the main cause of the acceleration of sea level rise, showing how big of a role it plays in current trends.
What can we, as humans, do to stop or slow the further acceleration of sea level rise? Well, as scientists are busy refining their models predicting the rates of future sea level acceleration, countries can work together to limit their use of greenhouse gases. Similarly, on a smaller scale, we can be less dependent on fossil fuels, for example, by switching to electric cars, turning out the lights or TV when not using it, and take public transportation.
References:
https://www.carbonbrief.org/water-stored-on-land-stopped-recent-sea-level-rise-being-up-to-22-higher
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