For years, scientists have carried out research to determine the causes of the current rise in global temperatures. While many have pointed to the fact that the Earth has experienced previous cycles of heating and cooling, what many cannot deny is the current rate of warming have had help from humans.
We live on a planet where human activity in one part influences processes occurring in another part. This relationship has been evident long before increased technological advancement has led to globalization and increased connectivity among the planet’s inhabitants. What this means is that little changes in one part of the planet can lead to severe changes in other parts.
An example of this interconnection is the relationship between polar ice sheets at the northern and southern poles. Despite being thousands of miles apart, researchers have discovered that whatever happens in one part have a direct effect on the other.
Analysis by Dr Natalya Gomez, Harvard professor Jerry X. Mitrovica shows that changes in the Antarctic ice sheet were as a result of melting in the northern hemisphere. The researchers developed models which show how this ‘seesaw effect’ works. Results indicate that when the northern hemisphere ice sheets were frozen in the last Ice Age (20,000 – 26,000 years ago), there was a decline in the sea level at the southern hemisphere and a growth of the ice sheet there. As soon as the climate started warming the northern ice sheets began to melt leading to sea-level rise in the Southern hemisphere. As a result, the Ice sheet in Antarctica began to melt as well.
This research has helped answer the question of what has caused the Antarctic ice sheet to melt rapidly during our present warming period. As this research indicates, antarctic ice sheet melting is not as due to local activities occurring there. As the northern ice sheets melt, the southern sea level rises and cause the overlying ice sheets to melt.
Currently, the northern hemisphere ice sheets are rapidly declining as the Arctic warms three times faster than the rest of the world. We lose more ice during the summer months that can be replenished by snowfall during winter. Scientist predicts that if we do not cut back on global greenhouse emissions, the Arctic will have warmed by 4oC by 2050.
According to the researchers, this work has helped improve our understanding of ice sheets and sea levels. It provides a better appreciation of the workings of Earth’s system and could help predict future changes to the ice sheets as well as periods of stability.
Read the research here.