Tag Archives: Climate Change


From Chapter 3, p. 197, Box 3.1 | Sub-Saharan Africa: Changes in Temperature and Precipitation Extremes,

Sub-Saharan Africa has experienced the dramatic consequences of climate extremes becoming more frequent and more intense over the past decades (Paeth et al., 2010; Taylor et al., 2017).

In order to join international efforts to reduce climate change, all African countries signed the Paris Agreement. In particular, through their nationally determined contributions (NDCs), they committed to contribute to the global effort to mitigate greenhouse gas (GHG) emissions with the aim to constrain global temperature increases to ‘well below 2°C’ and to pursue efforts to limit warming to ‘1.5°C above pre-industrial levels’. The target of limiting global warming to 1.5°C above pre-industrial levels is useful for conveying the urgency of the situation. However, it focuses the climate change debate on a temperature threshold (Section 3.3.2), while the potential impacts of these global warming levels on key sectors at local to regional scales, such as agriculture, energy and health, remain uncertain in most regions and counries of Africa (Sections 3.3.3, 3.3.4, 3.3.5 and 3.3.6).

Weber et al. (2018) found that at regional scales, temperature increases in sub-Saharan Africa are projected to be higher than the global mean temperature increase (at global warming of 1.5°C and at 2°C; see Section 3.3.2 for further background and analyses of climate model projections).

Even if the mean global temperature anomaly is kept below 1.5°C, regions between 15°S and 15°N are projected to experience an increase in hot nights, as well as longer and more frequent heatwaves (e.g., Kharin et al., 2018). Increases would be even larger if the global mean temperature were to reach 2°C of global warming, with significant changes in the occurrence and intensity of temperature extremes in all sub-Saharan regions (Sections 3.3.1 and 3.3.2; Figures 3.4, 3.5 and 3.8).

West and Central Africa are projected to display particularly large increases in the number of hot days, both at 1.5°C and 2°C of global warming (Section 3.3.2). This is due to the relatively small interannual present-day variability in this region, which implies that climate-change signals can be detected earlier there (Section 3.3.2; Mahlstein et al., 2011).

Projected changes in total precipitation exhibit uncertainties, mainly in the Sahel (Section 3.3.3 and Figure 3.8; Diedhiou et al., 2018). In the Guinea Coast and Central Africa, only a small change in total precipitation is projected, although most models (70%) indicate a decrease in the length of wet periods and a slight increase in heavy rainfall. Western Sahel is projected by most models (80%) to experience the strongest drying, with a significant increase in the maximum length of dry spells (Diedhiou et al., 2018). Above 2°C, this region could become more vulnerable to drought and could face serious food security issues (Cross-Chapter Box 6 and Section 3.4.6 in this chapter; Salem et al., 2017; Parkes et al., 2018). West Africa has thus been identified as a climate-change hotspot with negative impacts from climate change on crop yields and production (Cross-Chapter Box 6 and Section 3.4.6; Sultan and Gaetani, 2016; Palazzo et al., 2017). Despite uncertainty in projections for precipitation in West Africa, which is essential for rain-fed agriculture, robust evidence of yield loss might emerge. This yield loss is expected to be mainly driven by increased mean temperature, while potential wetter or drier conditions – as well as elevated CO2 concentrations – could modulate this effect (Roudier et al., 2011; see also Cross-Chapter Box 6 and Section 3.4.6).

Using Representative Concentration Pathway (RCP)8.5 Coordinated Regional Climate Downscaling Experiment (CORDEX) scenarios from 25 regional climate models (RCMs) forced with different general circulation models (GCMs), Klutse et al. (2018) noted a decrease in mean rainfall over West Africa in models with stronger warming for this region at 1.5°C of global warming (Section 3.3.4). Mba et al. (2018) used a similar approach and found a lack of consensus in the changes in precipitation over Central Africa (Figure 3.8 and Section 3.3.4), although there was a tendency towards a decrease in the maximum number of consecutive wet days (CWD) and a significant increase in the maximum number of consecutive dry days (CDD).Over southern Africa, models agree on a positive sign of change for temperature, with temperature rising faster at 2°C (1.5°C–2.5°C) as compared to 1.5°C (0.5°C–1.5°C) of global warming.

Areas in the south-western region, especially in South Africa and parts of Namibia and Botswana, are expected to experience the largest increases in temperature (Section 3.3.2; Engelbrecht et al., 2015; Maúre et al., 2018). The western part of southern Africa is projected to become drier with increasing drought frequency and number of heatwaves towards the end of the 21st century (Section 3.3.4; Engelbrecht et al., 2015; Dosio, 2017; Maúre et al., 2018). At 1.5°C, a robust signal of precipitation reduction is found over the Limpopo basin and smaller areas of the Zambezi basin in Zambia, as well as over parts of Western Cape in South Africa, while an increase is projected over central and western South Africa, as well as in southern Namibia (Section 3.3.4). At 2°C, the region is projected to face robust precipitation decreases of about 10–20% and increases in the number of CDD, with longer dry spells projected over Namibia, Botswana, northern Zimbabwe and southern Zambia. Conversely, the number of CWD is projected to decrease, with robust signals over Western Cape Maúre et al., 2018). Projected reductions in stream flow of 5–10% in the Zambezi River basin have been associated with increased evaporation and transpiration rates resulting from a rise in temperature ( Section 3.3.5; Kling et al., 2014), with issues for hydroelectric power across the region of southern Africa.

For Eastern Africa, Osima et al. (2018) found that annual rainfall projections show a robust increase in precipitation over Somalia and a less robust decrease over central and northern Ethiopia (Section 3.3.3). The number of CDD and CWD are projected to increase and decrease, respectively (Section 3.3.4). These projected changes could impact the agricultural and water sectors in the region (Cross-Chapter Box 6 in this chapter and Section 3.4.6).

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Africa and Climate Change: New Evidence of Damage

Africa and Climate Change: New Evidence of Damage


     by Steven Langdon, Adjunct Research Professor of Economics, Carleton University


 When the Intergovernmental Panel on Climate Change (IPCC) presented its most recent Assessment Report in 2014,  the consensus of the thousands of scientists involved was that global warming was taking place at a rate that could cause “irreversible detrimental impacts.”  More than fifty percent of this was caused by human activity,  the Report indicated,  especially the high rate of emissions of carbon dioxide and other Greenhouse Gases resulting from fossil fuel consumption, cement production and gas flaring.

These trends have continued since 2014 and are widely recognized by global climate observers,  as illustrated in 2017 by the National Aeronautical and Space Agency (NASA) in the United States.

The IPCC Assessment Report concluded that Africa would be especially impacted by global climate change,  with temperatures very likely to rise by more than the world average in West and Southern Africa,  and higher chances of extreme rainfall and heat events in East Africa and elsewhere. Rising sea levels also threaten low-level coastal areas in many parts of the continent.

As discussed in the book we have just published (Langdon, Ritter and Samy, 2018, African Economic Development, Abingdon and New York: Routledge,)  this demonstrates how negative environmental externalities from global carbon emissions damage African populations despite limited emissions within Africa itself. We also point out in the book the more constricted capacity for African countries to finance adaptation and mitigation measures to counter these trends.  Data reported by the Economist,  and already posted in this blog,  show that increasing variability in temperatures is affecting Sub-Saharan Africa more than other parts of the world.

Evidence of climate change damage in Africa has been growing since the IPCC Report – ranging from drought in Southern Africa to bleaching of coral reefs in East Africa and subsequent reductions in fish stocks.  The accompanying article from the New York Times (May 24, 2018) provides another example of such damaging effects,  in this case associated with rising sea-coast levels in northern Senegal.  It also describes adaptation efforts in the community to counter these rising levels.


“Wrath of Coastal Erosion” is Devouring a Senegal Fishing Hub

ByAurelien Breeden

  • May 23, 2018

SAINT-LOUIS, Senegal — Houses on the shore seem to have been ripped open by a giant claw. The corner of an abandoned school is gutted, leaving what looks like a gigantic bite mark. All that is left of a nearby mosque is a flattened pile of concrete blocks and twisted iron rods.

The culprit behind this destruction in Saint-Louis, on the northern edge of Senegal’s Atlantic Coast, is not some mythical sea monster, but the ocean itself.

At a rate that is increasingly worrying to residents and officials, waves are lapping at buildings on the shoreline, pulling sand away and eroding foundations until walls collapse and floors cave in.

On a recent morning, Massamba Diaw, 70, showed a jumble of ruins in the sand.

“Two months ago, we were standing here, under a roof,” he said. Like most men in his neighborhood, Mr. Diaw was a fisherman. Like many of his neighbors’, his house is now crumbling.

About 80,000 people live in the poorer neighborhoods of Saint-Louis, where coastal erosion is an immediate threat.


“We all feel really sad, and threatened,” Mr. Diaw said, pulling his grandchildren away from the edge of his first floor, which is now exposed to wind and rain. “What will these kids do in the future?”

Eroding shorelinesare a globalproblem, made worse by the rising sea levels that result from climate change.

But the impact is particularly stark in Saint-Louis, especially on the Langue de Barbarie, or Barbary Tongue, a thin, sandy peninsula that extends over a dozen miles further south and acts as a natural buffer with the ocean.

“For the past decade, people here have really started to suffer the wrath of coastal erosion,” said Latyr Fall, the city’s deputy mayor for economic issues.

Saint-Louis, a city of over 232,000 that was first settled by the French in the 17th century, was the colonial capital of French West Africa until 1902.

It is split in two by the Senegal River, which snakes down from the north, forming a natural border with Mauritania. Eastward, on the mainland, is most of modern Saint-Louis. Westward is the Langue de Barbarie, which separates the river from the ocean until the two meet.

In the middle is an island best known to tourists for its preserved 19th-century colonial architecture — low, pastel-colored houses with vivid shutters and wrought-iron balconies, some renovated and turned into elegant guesthouses, others slowly crumbling but still graceful.

The island became a Unesco World Heritage sitein 2000, and is host to cultural events like annual jazzand contemporary dancefestivals. Erosion isn’t discussed much, said Staffan Martikainen, a Finn who runs an artistic residency programthere.

“It’s surprising, in view of the fact that both the fisherman’s peninsula and the island might be gone in two generations, that real estate prices don’t go down,” he said.

But across the bridge that spans the small arm of the Senegal River, in the poorer neighborhoods on the Langue de Barbarie, coastal erosion is an immediate threat. About 80,000 people live there, on a stretch of land that is barely 600 feet wide in some places.

Crowds of children race the streets, jumping out of the way of horse-pulled carriages and sputtering minibuses. Green fishing nets lie tangled on the sidewalk while tethered goats munch on trash in sandy side alleys.

Many in these neighborhoods are from the Lebou ethnic group, traditionally a fishing community. The ocean might have destroyed their homes, but it was also a source of food, income and community.

“In Saint-Louis, if fishing thrives, everything thrives,” said Mr. Fall, the deputy mayor. “But if fishing hurts, then everything hurts.”

Fishing is now harder than ever for about 250 families that have lost their homes to erosion. Most of them — roughly 850 people — were resettled by the local authorities in a temporary camp several miles inland.

Abdou Gueye, 42, is one of them. His house was destroyed during a storm surge in August and his family was brought in October to the temporary settlement, a mix of small concrete houses and tents known as the Khar Yalla camp, in an empty field far from downtown.

It has several outdoor showers and toilets, and some outside lighting, but lacks proper access to water and to waste management, and it is prone to flooding.

Still, it is the distance to the coast that ails these fishermen the most.

“Now we have to pay for transportation to the ocean,” Mr. Gueye said, sitting under a pitched white tarp to avoid the sun. In the bustling fishing district, neighbors conveyed reports of a brewing storm, or of a good catch. “Now we are far away from all that information,” he added.

Nearby, Yaram Sène, 20, said leaving was on everybody’s mind. “There is nothing here, no police, no health facility, no school,” she said.

Mr. Gueye said each family had received about $900 from the authorities when their houses were destroyed, but nothing since. Few can afford to move elsewhere.

For those who still live on the Langue de Barbarie, Senegal is paying the French construction company Eiffage to build an embankment that shields houses from the ocean swell.

Made of giant five-ton bags of sand topped with rock-filled cages, it will run for about two miles down the coast until it reaches parts of an old colonial-era sea wall that are still standing.

But officials stress that the embankment is an emergency buffer to protect houses from immediate destruction, not a permanent fix for the erosion. Longer-term solutions have been proposed: building breakwaters or a new sea wall, resanding the beaches or clearing them to create a buffer zone.

The authorities are still waiting for results from continuing engineering studies to determine what to do. President Emmanuel Macron of France recently promisednearly $18 million to help, adding to existing funds from the World Bank.

Some, like 53-year-old Ahmet Diagne, are taking matters into their own hands.

Mr. Diagne used to live in Doun Baba Dièye, a village of fishermen, cattle breeders and farmers just south of Saint-Louis. But in 2003, scrambling to evacuate floodwaters swelling around the city, the Senegalese authorities hastily dug a channel in the Langue de Barbarie.

The breach quickly grew, bringing erosion to villages that had previously been shielded from it, and submerging Doun Baba Dièye. In 2009, residents started moving inland.

From his fishing boat, early on a recent morning, Mr. Diagne pointed to what was left of his former village: a few ruins on the shore, and a sunken tree covered with cormorants that used to be in the town square.

For the past several years, with financial help from the government and international organizations, he and his community have planted thousands of mangroves and pine trees known as filaos, to halt erosion and reclaim land then used to farm and sell cassava, cabbages, melons, sweet potatoes and other produce.

Mr. Diagne became a local expert of sorts on coastal erosion, even for those in Saint-Louis who had previously derided his warnings that they, too, would soon face his village’s fate.

“It was a bit hard for me in the beginning,” he said. “I received calls from people telling me: ‘Stop talking nonsense. You did not attend school. Who are you to talk about erosion and rising sea levels?’”

“But now,” he said, “people are calling me back.”


Follow Aurelien Breeden on Twitter @aurelienbrd.

A version of this article appears in print on May 24, 2018, on Page A8 of the New York edition with the headline: ‘Wrath of Coastal Erosion’ Devours a Fishing Hub in Senegal. Order Reprints| Today’s Paper| Subscribe

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Temperatures in tropical climates will become far more variable.

Original Article: Climate Change and Africa

By THE DATA TEAM, The Economist, May 9th 2018

GLOBAL warming is often used as a synonym for climate change, and most discussions of the topic focus on the expected increase in average global temperatures. However, the frequency and severity of individual, catastrophic weather events depend heavily on the variability of temperatures as well as their mean. The larger the swings, the more often extremely hot or cold conditions can wreak havoc.

Unfortunately, according to a new study by Sebastian Bathiany of Wageningen University and three other scientists, poor countries are not only predicted to bear the brunt of the increase in average temperatures, but also to suffer from higher variation. Their paper finds that, as the planet warms, soil in areas near the equator will dry up, reducing its ability to dampen temperature swings. This problem is expected to be especially acute in the Amazon rainforest. Consequently, the authors expect the standard deviation of monthly temperatures to increase by nearly 20% in Brazil.

In contrast, countries in the northern latitudes, which are mostly rich, will not be affected nearly as much by changes in soil moisture. Far from the equator, countries will actually see smaller temperature fluctuations, because of changing atmospheric patterns. In terms of both means and variances, the countries that bear the most historical responsibility for climate change are likely to be the ones least harmed by its consequences.

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