The Rising Tide

Originally published in the Informanté newspaper on Thursday, 3 December, 2015.

This week, the nations of the world descended upon Paris. But unlike a month ago, when France was in the spotlight due to terrorist attacks, this time it is a matter of grave importance to the entire world. This, of course, is the 2015 United Nations Climate Change Conference, running from 30 November to 11 December. The conference aims to achieve a legally binding and universal agreement on climate change from all the nations of the world.

Here in Namibia, of course, we have been feeling the effects of climate change quite a bit over the past few years. The increase in temperatures globally has led to increasing weather abnormalities. In particular, atmospheric circulation, which greatly determines precipitation, or rainfall. 

Specifically, atmospheric conditions are determined by three circular patterns of winds that determine cloud movements and rainfall. The first of these is called the Hadley cell, named after George Hadley, who explained the trade winds that blow towards the equator low in the atmosphere (where the rainclouds are), whereafter it heats up, and thus rises high up, cools down, and has high atmospheric winds blowing outwards from the equator. 

Similarly, the polar cells operate in the opposite direction. Hot air from the 60^th latitude line rises, and is blown high in the atmosphere to the poles. There the air cools down, drops, and results in low atmospheric winds blowing out from the poles, with the attendant snow storms etc. that is common near the polar regions.

The third cell, named the Ferrel cell after William Ferrel, who theorized it in the 19^th century, exists in between the polar and Hadley cell, in the sub-tropical semi-arid regions such as Namibia. This cell, however, is not a closed loop like the other cells, and depends on them. And unlike those cell that have north-south winds, the Ferrel cell is characterised by westerly winds. It is from these winds that break away from the Hadley cell, that we get our rainfall.

The increases in global temperature is causing the polar and Ferrel cells to weaken, and cause the Hadley cell to grow. In effect, this causes dry regions to become even drier, with wet regions becoming wetter, with more storms.

Unfortunately, the Climate Change Conference only has a stated aim of trying to limit global temperature increases to 2 °C. This in itself will still cause devastation, as that will still entail the global sea level rising between 3 and 6 meters. Even in Namibia, this will displace between 2 000 and 28 000 people along the coast. Without this agreement, temperatures could rise by 4 °C, raising sea levels by 7 to 10 meters. Along the coast, that will displace 48 000 to 56 000 Namibian citizens. 

http://sealevel.climatecentral.org/

At the conference, President Geingob stated, "We must be decisive without further delay and adopt a legally binding agreement that will limit the average global temperature below two degrees Celsius. In the absence of the required political will and concrete actions, future generations will judge us harshly." I cannot agree more.