Scientists have been monitoring the world’s sea levels for several decades, and have realized that the rate at which they are rising has significantly increased. The analysis of 25 years of satellite data shows that the height of most oceans will continue to rise by at least 4 inches each decade, if global changes aren’t implemented. This means that by the end of the century the sea levels will be over two feet above measurements taken in 2005. The 25 years of evidence was published in Proceedings of the National Academy of Science, and demonstrated in 3D.
Although these figures don’t seem that devastating at first glance, even a small increase in sea levels causes great destruction in coastal areas. As water comes further inland, it causes erosion, loss of habitat for aquatic and coastal animals and plants, flooding and soil contamination. Higher sea levels also mean that storms will cause more damage. Flooding is currently the leading cause of death by natural disaster. Hundreds of millions of people are now living in areas that are becoming increasing susceptible to flooding. As the sea levels continue to rise many of them will be forced to relocate, and low-lying islands may be completely submerged.
There are three primary factors, all resulting from global warming, which are contributing to the rising levels of the world’s major water bodies.
Thermal Expansion – As the Earth’s atmosphere gets hotter, the oceans’ water also increases in temperature and begins to expand. This causes the sea levels to rise as the water can only expand upwards.
Ice Loss from Greenland and West Antarctica – Increased heat on the planet is also causing the ice sheets that cover these regions to melt at a faster pace. Research has shown where meltwater from above, and seawater from below, is seeping in between the sheets, causing the ice streams to move more quickly into the sea. Higher sea temperatures also result in the ice shelves, extending from Antarctica, to melt.
Melting Glaciers and Polar Ice Caps – Each summer, large ice formations melt, and are normally replaced in winter by snow. This natural balance worked to maintain sea levels for centuries. The higher temperatures, caused by global warming, means that more ice has begun to melt each summer. In addition, winter is coming later each year, and spring starts earlier, meaning that there is significantly less snowfall to replace the amount lost each summer.
The rising sea levels are already affecting countries all over the world, including the United States. The US Geological Survey recently conducted a study which shows that without human intervention, a large percentage of Southern California beaches will become completely eroded. This will both threaten one of the state’s main sources of income, and make inland communities more susceptible to flooding. The overall study shows where a global effort needs to be made to control the rising sea levels, as soon as we possibly can.