Developing nations at low elevation will bear the brunt of climate change, as sea levels rise. Already, rising sea levels are causing regular and more catastrophic flooding in such countries, but as these countries are often poor, they are less able to take mitigating actions, and generally are not responsible for the carbon emissions which have increased the greenhouse-effect to the levels responsible for increasing the rate of ice melt.
The melting of floating ice – such as that over the North Pole has a minimal effect on seal levels, as 90% of that ice is below the waterline already, due to the fact that ice is only very slightly less dense than water. However, ice sheets laid over land – such as glaciers, and the ice sheets over land in Antartica, and Greenland will have a much more serious effect when melted. This is because the ice is laid up over land – 2km thick over Antartica, and 3km thick over Greenland. If this ice melts, it will drain into the sea causing seal levels to dramatically rise. Unfortunately, the process is subject to various positive feedback mechanisms, which cause it to accelerate, or to occur very suddenly – such as the recent disintegrations of the floating ice shelf off the Greenland coasts. If the Antarctic ice sheets melted, seal levels would rise by 3.3m. If Greenland’s ice sheets melted, they would add another 7.4m to sea levels. If all the ice sheets melted, sea levels would rise by approximately 70 metres!
Whereas there are disagreements over how fast this melting will occur (Greenland’s ice sheets are in fact melting 100 times faster than previously thought), there is no uncertainty about the outcome. The attached image shows how the UK and Ireland would be transformed into smaller islands. Low European countries such as Denmark, Germany and The Netherlands, would lose vast areas of land to the sea, and the USA would lose Florida as well as large tracts of land along the Eastern Seaboard.