Every day, humans are engaged in countless activities that emit greenhouse gases which contribute to the dramatic global sea level rise. Even if the day will come when humans have completely stopped emitting these gases into the atmosphere, its effect will still linger in the world for centuries afterwards.

With the improvement of human technology, the greenhouse gases that is emitted by these activities also multiplied. As the temperature rises, the global sea level also rises and this phenomenon is called "Thermal Expansion."

The science behind the thermal expansion is relatively simple. As explained by Washington Post, the process starts when greenhouse gases go into the atmosphere. This, then, causes the air temperature to rise.

Some of the heat would end up being absorbed into the oceans, thus, causing the water to expand in volume. This process is simply a basic physics by which our planet cannot escape from.

Furthermore, a new study published in the Proceedings of the National Academy of Sciences, written by Susan Solomon and colleagues Kirsten Zickfeld of Simon Fraser University and Daniel Gilford of MIT, reported that short-lived greenhouse gases such as methane can have a long term effect in expanding the oceans even if the pollutants have already been cleared from the atmosphere.

In order to arrive at an answer about the long-term effects of the short-lived gases, Solomon, together with her co-researchers conducted a study using an Earth System Model of Intermediate Complexity, or EMIC, a computationally efficient climate model. In this model, the researchers calculated the average global temperature and sea level rise due to the emission of carbon dioxide, methane, chlorofluorocarbons, and hydrofluorocarbons.

In their findings, unlike carbon dioxide, methane gas has quickly disappeared from the atmosphere which decreases the atmospheric warming. However, its effect lingers in the ocean. This means that even if greenhouse emissions were to stop by 2050, methane will continue to contribute in the rising of the sea level. This effect is surely irreversible and we are going to live with it for a very long time, as per Phys.org.

This phenomenon is really alarming. The rise of sea level must be seriously considered, and this indicates that we should give a primary importance to our further actions that will lessen the problem in the future.