Entries by Moritz Hartmann

Flashfloods in Accra. Facts and outlook. Ghana's capital is a city of 2 Million inhabitants sited directly at the Gulf of Guinea. The highest elevation is 46 m above sea level but the most part of Accra is below 5 m - some parts even below sea level. Somehow it is like a bowl, a plain surrounded by hills.
 Since 1877 it‘s the capital and by far its economic and cultural centre. Although it‘s part of the wet tropics it is located in Ghana‘s coastal savannah, a zone covered with low scrubs and few trees and palms. It receives not more than 850 mm of precipitation in the annual average with a strong peak in May/June and a little peak in October; the mean temperature here is at 26.9˚C with highest rates in the dry season from November now on to April.

Although it‘s one of Ghana‘s driest places it suffers from severe flashfloods nearly every year due to heavy rainfall events, poor sanitation and growing population pressure on flood prone areas. This year a township of Accra called Kaneshie got flooded after getting 313 mm of rain in 10 hours! That’s more than a third of the annual precipitation in a single rainfall event! Seven people lost their lives, 20 000 were affected. The flood caused a damage of over 10 Million $. Similar cases can be reported from the years 1995, 1997, 2001, 2002 and 2007, with over 150 people left dead and ten thousands homeless. Hardly anyone is insured in Accra due to high rates and low availability.

By an increase of 2 degrees the basic factors for these floods will even grow stronger: First of all the amount of water coming down in single rainfall events is going to increase (and already did in the past years), although there will be a general decline in the mean rainfall amounts. That means rarer but even heavier rainfalls. 
Second, the population density here is going to increase due to climate change: Agriculture employs close to 70% of Ghanaians, mostly in small holder farms that are rain-fed. But there is and will be a decrease in rainfall and a growth in precipitation variability in these parts of Ghana too. Food production is getting more and more insecure, the economic basis of the farmers erodes. The consequence is that they move to Accra to get one of the few jobs. These people are the most vulnerable to natural disasters, because of their low ability to adapt even if it just means to find some shelter. Other consequences of urbanization on flooding are the decrease of infiltration rates in the soils (which also means a decrease of time to the peak of flooding) and a higher pressure on sanitation, sewerage and drainage systems, all leading to a decrease of channel carriage capacities.
Third, the level of Accras recipient will rise. All water in Accra drains into the Gulf of Guinea. When the sea level is going to rise due to expanding water volume and melting ice caps this means (in addition to the threads of inundation, coastal erosion and salinization of drinking water resources) that the capacity of Accras drainage system will turn down.
To bring it down to a few words: temperature rise of 2˚C means for the flood situation in Accra more extreme rainfall events, less drainage and more people in flood prone areas. That’s far from good news…

Posted by Ingo Haltermann, Associate Junior Fellow, KWI Essen

After its last minute invitation to the 17th APEC leaders’ meeting in Singapur, the Danish prime minister Lars Rasmussen adressed a breakfast gathering of the present leaders in order to formulate the importance of signing a post-Kioto protocol at COP 15 in Copenhagen.
Although his views were supported by all 21 participants, including China, afterwards Rasmussen stated that countries agreed to sign a document setting out commitments of emission reductions until 2020, but which would not have legal force but which would be ’politically binding’.
Considering the linguistic acrobatics of diplomatic negotiations: What exactly means ’politically binding’? Are ’political’ reduction commitments measurable? And with regard to climate change issues, is the international (governmental and non-governmental) community meanwhile powerful enough to restrain governments not to break ’politically binding’ commitments?

Everywhere we continually hear about the climate. Actually, there isn’t really any climate unto itself. Climate basically means a summary of weather conditions, the average of these conditions. However, the subsequent creation of an average always leads to the disappearance of the highs and lows of weather processes.

Therefore, regarding the formula of the 2°C limit of global warming, it’s worth it to take a look at the socio-cultural dimension of single environmental phenomena and weather changes. And certainly not out of global, but regional and local perspectives. Here the implication of a possible temperature increase of 2°C applies not only for certain regions and cities, but also for the transforming conditions of crops, supply, transportation routes and environmental perception.

In the next few months, young scholars from the KWI will report about local environmental observations from their research trips to the USA, China, Ghana, Chile and Europe – and always with the view of the meaning of climate change and the 2°C guiding limitation for local communities, for local Climate Worlds.