Is there a problem with Africa’s weather monitoring system?
The current networks of weather stations in Africa - and their spatial coverage - are insufficient for monitoring structural changes in rainfall patterns and therefore inadequate for dealing with climate change. In addition, most of these stations are located near airports, because historically aviation was the first sector that gathered weather data. However, meteorological information from airports cannot be applied to distant locations due to the high variability of rainfall.
Could you explain why this is a problem?
To make informed predictions of climate changes in future, and their impact on rural communities, we need weather records that span at least 30 years. Such a historical database is indispensable for determining whether what is being observed is actual climate change or just climate variability. Variability refers to the normal changes in climate patterns in a region, while climate change implies a distinct difference either in temperature or rainfall from one period to another.
Is this a particular problem for Africa, in terms of climate change?
Of course. The greatest impacts of climate change, according to the Intergovernmental Panel on Climate Change (IPCC), will be felt in the semi-arid regions of Africa. Here, rain is concentrated in three to four month seasons each year and is barely sufficient to grow rain-fed crops. The anticipated climate changes in these regions will result in a greater frequency of droughts, but also of heavy storms that cause erosion, flooding, soil loss, and land degradation.
A key problem facing rural communities is the lack of information. Communities can deal with the impacts of climate change, but only if they have information that will enable them to take appropriate action, and in a timely manner. If I know with certainty that there is going to be a drought this rainy season, I can plan for it. I can change my crop or I may decide not to sow as much seed as I would normally do. I might even try to find a supplemental water supply for my crops or to leave parts of my land fallow. So farmers can apply various strategies - but only as long as they have access to quality information!
What needs to be done to fix the problem of Africa’s deteriorating weather stations?
At the WMO, we advocate that the meteorological networks in Africa should be improved. First, there should be more stations in areas that are critical for a country’s food security. Using GIS technology, we can quickly analyse many layers of information on crops, soils, physical infrastructure and so on, and identify communities that are most at risk. Then we need expand the number of stations to provide sufficient spatial coverage more generally. Next, we need to put in place a system that ensures that collected data are analyzed and disseminated to farming communities without delay.
Last November, just ahead of the UN Climate Change Conference in Nairobi, the WMO’s Secretary-General, Michel Jarraud said that 200 automatic weather monitoring units were needed across Africa. How much would this cost?
Automatic weather monitoring units are equipped with small data loggers that can record information in units of one minute, 15 minutes or every hour– whatever is needed. Typically, an automatic weather unit with just the basic sensors for temperature, rainfall, humidity and radiation would cost €3000. A network of 30 units would translate into a base cost of around €90-100,000. However we cannot just put up these units and then forget about them. Each unit needs to be physically inspected about once every three months to make sure that the sensors are functioning properly. A further ten to 15 per cent of the set up costs should be allocated for maintenance on an annual basis.
I admit that this is not loose change for a developing country. However, these units speed up the process of providing reliable weather forecasts to rural communities. We can receive the data from the monitoring units via satellite or telephone, analyze them and pass this information on to radio or TV stations, who can then pass them on to farmers in the form of bulletins. Moreover, as the data are collected in digital format, they can be fed into computer models to generate climate change scenarios.
Meteorological networks should be treated in the same way as a country’s health system, with its network of hospitals. Dealing with climate change is no different and just as important for our survival, if not more so. We need to invest in networks that collect the weather data and provide the information when we need it.
More information: World Meteorologial Organisation.
Dr Mannava V. K. Sivakumar is chief of the agricultural meteorology division at the World Meteorological Organization (WMO).