Climate change and the Great Green Wall

Last Tuesday there was the story on the VRT television news about Belgian entrepreneurs who “stop the desert” in Burkina Faso (Dutch). They take part in what is called “The Great Green Wall” across Africa, planting trees and crops in plowed open land just before the rain season. During the rain season those fill with water and then the seeds will grow to trees, grasses and crops.

Screen cap VRT television news June 30, 2015 Source: http://deredactie.be/cm/vrtnieuws/videozone/programmas/journaal/2.39737

Screen cap VRT television news June 30, 2015
Source: http://deredactie.be/cm/vrtnieuws/videozone/programmas/journaal/2.39737

That forest keeps the desert from taking the land and also provide some new income for the people (who for example can weave mats or baskets that can be sold at local markets, providing some additional money).

If those trees keep the desert away and are a new source of income, I can only applaud such an initiative. It is a great idea and it rightfully laudable.

But two thoughts crossed my mind when hearing this success story. First, the journalist mentioned that:

Because of climate change, the Sahara is dangerously advancing in the Sahel region, also in Burkina Faso.

There we go again…

Second, there was also that green band across Africa … I have seen that somewhere else …

So I started looking for information about that Great Green Wall across Africa. The idea of a Green Wall existed already a long time, it was re-emerged in 2002 and finally approved in 2005. The Belgian entrepreneurs started their work in Burkina Faso in 2009.

Overall trends in vegetation greenness throughout the period 1982-2003 based on monthly AVHRR Normalized Difference Vegetation Index (NVDI) time series. Percentages express changes in average NDVI between 1982 and 2003. (Hermann et al., 2005)

Overall trends in vegetation greenness throughout the period 1982-2003 based on monthly AVHRR Normalized Difference Vegetation Index (NVDI) time series. Percentages express changes in average NDVI between 1982 and 2003. (Hermann et al., 2005)

Then I found the image that I was looking for. It was the depiction of the overall trends in vegetation greenness throughout the period 1982-2003 from Herrmann et al., 2005. The greening band is seen in the area that will become that Great Green Wall. It also partially covers Burkina Faso.

I remember the surprise the first time I saw this image a couple years ago. I remember when I was a kid, we were bombarded with scary images of the effects of droughts in for example Biafra (Nigeria), at that time worsened by a civil war. There were indeed serious and prolonged droughts in the Sahel during the 1960s until the 1980s. In the meanwhile rainfall increased again in the region and start “greening” again.

Those droughts seems to be cyclical events. It happened numerous times in the past and there is little doubt that it will happen numerous times in the future as well.

This is typical for one-sided reporting. The droughts were widely reported in the 1970s, the subsequent increasing rainfall and greening didn’t even get the news. So until some years ago I thought desertification was still on the rise in the Sahel, while in fact the opposite was true!

So if this area was already greening BEFORE the project began, I don’t understand why the VRT journalist blames “climate change” as the cause of “rapid” desertification, when there was actually greening of several decades preceding today…

By the way, if there really was climate change between the 1980s and 2003 (whether anthropogenic or not) it did THE EXACT OPPOSITE of what he is claiming. In other words, whatever climate change there has been in the last decades, it has led to more rainfall and increased greenery in de Sahel.

I have some issues with this news report. For example, what does he mean by “climate change”. Apparently overall there is increased rainfall. There is nonetheless a large annual variability which still can give droughts. If this is what he means? In that case, he could probably better talk about “weather change” because in the last decades the overall effect is greening.

Also, there are numerous reasons for desertification like population growth, expansion of urban areas, deforestation, over-cultivation, over-grazing, over-use of land, lack of irrigation, social elements like poverty and wars, variations in seasonal rainfall,… Some of those are human caused, others natural. NONE of them were even mentioned. Only “climate change” had the dubious honor to be explained away as the cause of desertification.

If he meant “catastrophic anthropogenic climate change” (as a result of our emissions), then he even took the least likely candidate for which there is no direct evidence. Contrary to the other causes.

There a problem with definitions here. As with many things in climate communication, in the current news reporting the term “climate change” can mean everything between a “change in weather”, over a “long term natural trend” and “cyclical events” to “Catastrophic Anthropogenic Climate Change”. Confusion about what is actually meant when someone uses the term is not favorable for clear understanding of the issue.

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2 thoughts on “Climate change and the Great Green Wall

  1. Hugh

    [I]n the current news reporting the term “climate change” can mean everything between a “change in weather”, over a “long term natural trend” and “cyclical events” to “Catastrophic Anthropogenic Climate Change”. Confusion about what is actually meant when someone uses the term is not favorable for clear understanding of the issue.

    I have come to a conclusion that the lack of clarity is partly a chosen strategy to bring up an important issue.

    What is interesting, is the role of CO2 in greening. It has direct effect by reducing the amount of water needed by plants. CO2 could increase rainfall as well, but it is fairly difficult to know if this has happened. The year-by-year and decade-by-decade variability dominates in Sahel.

    Reply
    1. trustyetverify Post author

      Thanks for passing by and commenting, Hugh.

      I think the journalist meant well, but he obviously didn’t check what he said about climate change or didn’t use some critical thinking. In fact the strong statements he used in this news report were largely copied from the company he covered.

      From the company I am not really sure whether they chose to make it vague. It is possible/likely they have more background of the situation, but making that clear to the public is not in their interest, on the contrary (that subject was planned to make for the next post, but some other interesting things popped up – maybe I should finish the post and put it online).

      CO2 can be a factor in the greening, but I think it will be rather small. It indeed causes plants to release less water to the atmosphere, but that will not be much of use when there is insufficient rainfall. The Sahel is a arid region and water will be the driving factor for greening. As far as I remember this is tied to the ocean surface temperatures in the Gulf of Guinea. When the gulf cools, there is generally more rainfall in the region, when it warms less. It indeed would be rather difficult to attribute this to CO2. 😉

      Reply

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