My occasional series, dependent on Guardian articles distorting the facts to blame the “climate crisis” for events with lots of other probably more significant explanations, now continues. Earlier pieces include The Gambia Gambit; Niger Negatives; Volte-Face; The Cancun Con; and Malawian Mystery. The latest Guardian article to set my antennae twitching, has the dramatic headline “How global heating supercharged floods in West Africa, displacing thousands” and sub-title: “Adaptation to frightening new normal and reducing emissions further and faster is critical, scientists warn”.

The article focuses on the Gulf of Guinea coast of west Africa and discusses recent heavy rains there. As usual it features a quote from Friedericke Otto, who on this occasion is described as “a professor of climate science at Imperial College London”, which is true of course, though we regularly see her quotes appearing in her guise as a leading member of World Weather Attribution (WWA) which she co-founded in 2014. Indeed, its no surprise to see on the WWA website an article on the same topic as the Guardian article. Interestingly, while the Guardian article does nothing but scaremonger about climate change, the WWA article does acknowledge, even withing the article’s title (“Climate Change and urban pressures intensify flood risk on the Gulf of Guinea coast”) that other factors may be at work. Both the Guardian and WWA are in turn referencing a study in which researchers from Côte d’Ivoire, Ghana, Kenya, the Netherlands, Sweden, the United States and the UK undertook an attribution study on the 3-day event of the heaviest rainfall in the most impacted region. WWA does at least have the good grace to acknowledge that:

The floods affected a very densely populated region where rapid urbanisation and the expansion of formal and informal settlements into floodplains and conversion of natural vegetation to croplands have reduced natural drainage capacity and increased exposure to flooding. Population growth is projected to continue its upward trajectory in this region, further increasing exposure in the decades to come…

…This year’s flooding is part of a pattern of similar floods that periodically occur in this region, eroding people’s assets and ability to recover…

Inevitably, nevertheless the finger is pointed at climate change, despite the additional findings that:

Overall, the available climate models indicate only a very small increase in the likelihood of an event such as the one under study with about 4% increase in intensity. While the majority of the models show a trend toward more extreme precipitation events, they systematically underestimate the observed increase. While most models show an increase in 3-day rainfall, supporting the conclusion that the observed increase is attributable, confidence in the estimated magnitude of the attributed change is constrained by the models’ limited performance and by the fact that none were developed or calibrated specifically for the African continent. Consequently, combining model- and observation-based estimates to derive a single quantitative attribution result is not meaningful.

Equally inevitably, the Guardian articles mentions no such caveats or alternative explanations for the flooding, save very obliquely, and in a way that makes the case it always seeks to make, regardless of the facts:

Joyce Kimutai, who researches extreme weather and climate change at Imperial College London, was the lead author on the study. She said:

“Climate models typically struggle to capture the full scale of tropical precipitation trends when we look at extreme events like this one.

“As such, the fact that we found such a role for climate change is significant. Combined with the very wetter trend in the observational-based data, it’s clear that human-caused warming made this event worse, and wetter, with devastating impacts.

“This study is a clear example of the need for international cooperation on climate justice. Industrialised nations have a responsibility to help nations like Togo, Côte d’Ivoire and Ghana to adapt to a worsening problem that they didn’t cause.”

A worsening problem that they didn’t cause? That’s always the claim, but is it true? Well, the UK Centre for Ecology & Hydrology has a piece titled “Vegetation effects on rainfall in West Africa (2015-2019)”, which can be found here. It says:

Much of West Africa was deforested throughout the 20th century, a process driven by agriculture, international trade in goods like cocoa, and the displacement of people by conflict. The rapid growth of cities, particularly along the coast, is also leading to deforestation in the region. This project revealed that deforestation in West Africa has made storms more frequent and thus increased the risk of disastrous flash flooding in the region’s coastal cities.

In collaborative work with the University of Leeds we used data from satellites and the latest weather and climate models to get to the heart of how vegetation affects rainfall. Focusing on West Africa, we examined cloud and vegetation observations from the last 30 years to detect where deforestation has changed rainfall, and how the rapid greening of the savannah each year affects the monsoon rains. We found from analysis of satellite observations that deforestation in southern West Africa has enhanced storm frequency over the last 30 years. The effect is particularly strong in coastal areas, where post-deforestation warming enhances land-sea breezes which are a key driver of storms.

Maybe, then, they have caused, or at least contributed to, the problem. But is the problem getting worse? The African Economic History Network has provided an interesting study titled “Climate Shocks and Conflict: Evidence from Colonial Nigeria”. It explores the connection between climate shocks and conflict, and is useful because although it is arguably part of the panoply of “climate crisis” studies, it does rely on data from a period (1912-1945, before the end of the Second World War) when man-made climate change is generally supposed to have had a very limited, if any, effect. We are told that “The data was collected from 36 meteorological stations across Nigeria on a provincial level documented in the Administration Annual Reports.” It is clear that Nigeria during this period experienced a great number of “climate shocks” which I have no doubt would be attributed to the supposedly man-made “climate crisis” if they occurred today:

For the period 1912–1945, we documented 203 shocks in the whole of colonial Nigeria; 97 of these were owing to excessive rainfall, and 107 were due to mild, moderate or extreme droughts. There were six climatic shocks per year on average. Naturally, these shocks were not evenly spread out. In 1916, 1929 and 1935 there were no shocks of any serious magnitude. In 1913, on the other hand, the situation was disastrous, with extreme droughts extending across large parts of West Africa…..

97 shocks, due to excessive rainfall, in just a third of a century. I suggest that would take some beating today.

A 2018 study that is more specifically focussed on rainfall is titled “Rainfall over the African continent from the 19th through the 21st century”. Section 3.1.2. deals with West Africa:

The most striking aspects of the time series are the abrupt decline in rainfall in 1968 and the long run of generally wet years from the 1920s through the 1960s. Wettest conditions occurred in the 1870s and 1880s and in the 1950s and early 1960s. Since that time rainfall has reached or exceeded the mean in very few years…

Section 3.1.3. deals with Western equatorial Africa:

In Cameroon the annual rainfall trends tend to mimic those in the Sahel and Guinea Coast: good rainfall in the 1950s and early 1960s, then an abrupt reduction of rainfall in 1968 and a continuation of dryness to the present, with little recovery. Relatively wet conditions did occur in 1999, 2002, 2009, 2010, and 2012. Most of those years were relatively wet in the Sahel and Guinea Coast as well. Overall the wettest period in the Cameroon region was in the 1920s.

In the Congo/Gabon region, annual anomalies were primarily negative from the 1860s until around 1920, in contrast to the strong positive anomalies prevailing then in the Sahel. As in the Sahel, wetter conditions prevailed between then and the early 1960s. In contrast to the Sahel, year-to-year variability was quite large and many very dry years occurred within this time, resulting in an opposition between the two regions. After circa 1961 year-to-year variability was quite weak with alternating wet and dry years. However, rainfall has generally been above or near the long-term mean since about 1980…

Section 3.2.3. deals specifically with seasonality on the Guinea coast:

Wettest conditions occurred from the 1920s until the early 1970s, with some very dry seasons occurring during this interval. Western equatorial Africa and eastern equatorial Africa were also relatively wet at this same time, but dry years were nevertheless common. The rainfall fluctuations along the Guinea Coast during October–November are similar to those during March–April–May. In both there has been an upward trend since the early 1980s. However, rainfall remained generally below the long-term mean during March–April–May, but as of the mid-1990s most October–November seasons have been relatively wet.

There is little here to support the Guardian’s scaremongering. Speaking of which, it is worth noting that the Guardian article is replete with photographs of floods in Lagos, seeking (presumably) to provide visual justification of the claims made. There is, however, a significant problem here, which is well exemplified by a very interesting study titled “Troubled waters: rewriting environmental histories of Lagos, 1882–1921”. Lagos was always an island in a lagoon – or perhaps more accurately, a number of islands in several lagoons – and the British colonial authorities carried out major works that, in the words of the abstract, had dramatic effects:

The filling of the lagoons and creeks that framed the city and island of Lagos changed the relationship between people, power, land and the water at the turn of the nineteenth century.

More precisely:

…Between 1882 and 1921, a system of canals, bridges and new roads in Lagos was constructed…The Lagos government reclaimed approximately 1,000 acres of swamp between 1905 and 1946…The old cemetery used to be on the western edge of the city, but was now [1914] in the centre. Additionally, a new district named Lafiaji had been reclaimed from the forest and swamp, while construction of the harbour moles improved the crossing of the bar…Most of the infrastructural work was dedicated to dredging and deepening the entrance to Lagos to improve the port.

By 1921, the population of this small island had grown to 99,690 people, with the mainland and islands combined.…

The result, we learn, is inevitable:

…Every year at the start of the summertime rainy season, metropolitan Lagos experiences devastating floods.

On Eko or Lagos Island – the site of the original settlement of the city – while the flooding patterns are aggressive and destructive, they also inscribe and follow a historical geography that the city has tried for decades to hide. The flooding persists and is often worst at the site of the old lagoons, creeks and lakes covered up at the turn of the twentieth century. Decades of infrastructural neglect plague Lagosians: the city is low-lying, still flood-prone and densely populated, with many areas still lacking the proper drainage infrastructure necessary to control the after-effects of torrential rain fall and erosion from rising sea levels via climate change…

The final reference to climate change is accompanied by a footnote, which links to an article on the CNN website, dating to 2021. It seems the situation is more complicated than simply rising sea levels caused by climate change. Among other things, the CNN article tells us that:

…Sand mining for construction is a major contributor to shoreline erosion in Lagos …In Victoria Island, an affluent Lagos neighborhood – an entirely new coastal city christened ‘Eko Atlantic’ – is being built on land reclaimed from the Atlantic Ocean …Beyond Lagos’ vulnerability to climate change, poor drainage systems and clogged street gutters in large swathes of the city are believed to have escalated its flooding challenges….“As much as climate change plays a part in rising sea levels, what you can see in this video is predominantly a drainage system issue,” a social media user tweeted while reacting to a video of the recent flooding in Lagos.

As so often seems to be the case, it’s complicated. Humankind in west Africa may have affected the climate by deforestation, we have changed the shape of islands, ongoing mining for sand is having a deleterious effect, drainage isn’t maintained, properties are built on land reclaimed from the sea. Urbanisation is an ongoing problem. As for whether the climate is becoming much wetter, that’s clearly a matter for debate. The historical record shows great natural variability over the decades and centuries since records began, and there seems to be legitimate doubt regarding the reliability of climate models relating to the area. Whatever the truth of it, the Guardian claim of “global heating supercharg[ing] floods in West Africa” seems to be at best an exaggeration and at worst unjustified.