Global Warming
Global warming is caused by the greenhouse gas effect, which is exacerbated by human activities. The most abundant greenhouse gas is carbon dioxide(CO2), which is being admitted by humans at an alarming rate. Today, CO2 concentration is 380 ppm(). The rate of increase is about 2 ppm per year, and is expected to accelerate. If we maintain this course, we could cross the 450 ppm tipping point before 2050. Global warming is the root cause of the the other two main reasons for the rising of the sea level: glacial melting and thermal expansion. (2)
Glacial Melting
As global warming speeds up the growth of world’s tempurature, glaciers and ice caps have been deteriorating, this is a major problem adding to the rise in sea level. In 2002, the northern section of the Larsen B ice shelf, located in Antarctica and bigger than Rhode Island, collapsed. This ice shelf alone greatly added to the sea’s level, ever since the collapse the area around the once existing Larsen B has melted by 40% (3). Since the 1960’s, According to NASA, the thickness of the arctic ice has gone down by 40%, as well as the polar ice cap decreasing at around 9% per decade. Without the presence of global warming the glaciers and ice caps would not be in danger of noticeably melting as they are today. At the rate the atmosphere is heating, by 2070 it is predicted that the glaciers located in Glacier National Park will be completely gone. (3)
Glacial Melting Continued...
Greenland and Antarctica have successfully held stable sea levels until the late 19th century. As the atmosphere heats it causes both of these to melt, although naturally they melt slightly in the summer and rebuild in the winter the increase of greenhouse gasses has caused these two continents to melt faster than they are able to rebuild. In the ten years between 1993 and 2003 Greenland alone has lost 50 to 100 billion tons of ice due to melting. If Greenland and Antarctica were to fully melt the world’s sea level will rise 64m. If the temperatures continue to rise as they are today, it won’t be long until both Greenland and Antarctica no longer exist.