题目：The problems caused by sea level rise
In the past of 30 years, sea level has been rising faster than ever. Carbon dioxide causes melting glaciers, global warming, and rising sea levels. This is not a good thing, because global warming has caused many animals to no longer adapt to the natural environment and become extinct. Research shows that the global sea level has risen by 10 to 20 centimeters in the past 100 years, and it is expected to accelerate in the future. However, the actual sea level change in a certain area of the world is also affected by the local land vertical movement—slow crustal elevation and local ground subsidence. The sum of the global sea level rise plus the local land elevation value is the relative sea level change in the areas . Therefore, it is meaningful to study the sea level rise in a certain area only by studying its relative sea level rise.
