The biggest uncertainty in forecasting sea level rise is determining how quickly the polar ice sheets will melt in response to warming temperatures.
The biggest uncertainty in forecasting sea level rise is determining how quickly the polar ice sheets will melt in response to warming temperatures.
MELTING: Nasa says global warming is responsible for sea level rise in two ways: first because warmer air increases the rate of glacial melting and, second, because the ocean is absorbing most of the extra heat trapped by greenhouse gases. Warmer seas take up more space than colder seas. Picture: AP
MELTING: Nasa says global warming is responsible for sea level rise in two ways: first because warmer air increases the rate of glacial melting and, second, because the ocean is absorbing most of the extra heat trapped by greenhouse gases. Warmer seas take up more space than colder seas. Picture: AP
Nasa described ice shelves as the 'gatekeepers' for glaciers flowing from Antarctica towards the ocean.
Nasa described ice shelves as the 'gatekeepers' for glaciers flowing from Antarctica towards the ocean.
CAPTION
The floating tongue of an Antarctic glacier is terminating in the ocean.
CREDIT
[Credit: Alba Martin-Español]
CAPTION The floating tongue of an Antarctic glacier is terminating in the ocean. CREDIT [Credit: Alba Martin-Español]

WASHINGTON, DC -  Nasa scientists have developed a new tool that can pinpoint which glaciers and ice sheets are contributing to changing sea levels in almost 300 coastal cities including South Africa's Cape Town and Durban. 

This comes as global warming intensifies and sea levels rise. According to a climate change report, the US government revealed that sea levels have risen by between seven and eight inches since 1900.

The tool known as the Gradient Fingerprint Mapping Simulation allows users to spin a virtual globe and select one of the hundreds of coastal cities. Using the data, it then shows you which cities will be, and when it will be flooded, by the ocean and which specific ice sheets will cause it to happen.

Clicking on Miami reveals that the city is affected by ice that melts in Greenland, Alaska and Antarctica and they will be the primary contributors to the rise in sea level near the city.

The data revealed by using this tool will aid planners to understand whether or not they need sea walls and other measures to prevent flooding.

According to the tool:

1.  Cape Town - Will be affected by ice that melts in the Antartic and sub-antarctic. It contributes to 0.38mm (11.8%) to the rise in sea level 

2. Durban - It will contribute to 0.38mm (12.1%).

- BUSINESS REPORT ONLINE