Fact Sheet: The IPCC’s Sixth Assessment Report: Impacts, Adaptation Options and Investment Areas for a Climate-Resilient West Africa

Introduction

West Africa has already experienced widespread losses and damages from climate change. The climate has warmed at rates “unprecedented in at least 2,000 years” due to human activity,finds the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Most African countries have contributed among the least to global greenhouse gas emissions causing climate change, yet have already experienced widespread losses and damages attributable to human-induced climate change. West Africa is no different and is already facing loss of lives and impacts on human health, reduced economic growth, water shortages, reduced food production, biodiversity loss, and adverse impacts on human settlements and infrastructure as a result of human-induced climate change. Transformative adaptation – which includes climate risk reduction in every sphere of development – will contribute to achieving climate resilience in West Africa.

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This CDKN Factsheet is part of a series of factsheets summarising what the IPCC AR6 report means for Africa. Other factsheets in the series cover Southern Africa, East Africa, North Africa, and Central Africa

This weADAPT article is an abridged version of the original text, which can be downloaded from the right-hand column. Please access the original text for more detail, research purposes, full references, or to quote text.

How West Africa’s Climate is Changing

The Earth’s average surface temperature has already warmed by 1.09°C since pre-industrial times (1850–1900).However, West Africa’s climate has warmed even more than the global average in the past few decades.

Temperature: West Africa’s average annual and seasonal surface temperatures have increased 1–3°C since the mid-1970s, with the highest increases in the Sahara and Sahel.

Heat waves: In the 21st century, heatwaves in West Africa have become hotter and longer compared to the last two decades of the 20th century. Between 1961–2014, the frequency of very hot days (over 35°C) increased by 1–9 days per decade and tropical nights (minimum temperature above 20°C) by 4–13 nights per decade. Cold nights have become less frequent.

Marine heat waves: Climate change has doubled the probability of heatwaves in the ocean around most of Africa.

Rainfall: West Africa has been getting wetter since the mid-1990s, accompanied by fewer but more intense rainfall events.

Extreme rainfall and flooding: Extreme rainfall increased from 1981–2010, increasing flows in large Sahelian rivers and catchments, leading to flooding.Between 1981–2014, the Gulf of Guinea and the Sahel experienced more intense rainfall and the frequency of convective storms tripled.

Drought: Meteorological, agricultural and hydrological drought have increased in frequency since the 1950s. Multi-year droughts have become more frequent.

West Africa’s Future Climate

Temperature: At 1.5°C, 2°C and 3°C global warming, average annual surface temperatures in West Africa are projected to be higher than the global average.

Extreme heat and heat waves: In West Africa, the number of potentially lethal heat days reaches 50–150 per year at 1.6°C global warming and 100–250 per year at 2.5°C global warming, with the highest increases in coastal regions.Children born in West Africa in 2020 will, under 1.5°C global warming, be exposed to 4–6 times more heatwaves in their lifetimes than those born in 1960. Over tropical West Africa, heat-related mortality risk is 6–9 times higher than the 1950–2005 average at 2°C global warming. Increasing urbanisation means cities are particularly exposed, such as Lagos, Niamey, Kano and Dakar.

Marine heat waves: Increases in frequency, intensity, spatial extent and length of marine heatwaves are projected for all coastal zones of Africa.

Rainfall: Rainfall is projected to decrease in the west and increase in the east in West Africa. A reduction in length of the rainy season is projected over the western Sahel through delayed rainfall onset by 4 to 6 days at global warming levels of 1.5°C and 2°C.

Extreme rainfall: Heavy rainfall events will become more frequent and intense with mid to high emissions, increasing exposure to flooding.

Drought: At 2°C global warming, West Africa is projected to experience a drier, more drought-prone and arid climate, especially in the last decades of the 21st century.Above 3°C global warming, meteorological drought frequency will increase, and length will double from approximately 2 months to 4 months in the western Sahel.

Climate Change Impacts We Have Already Seen in West Africa

The multiple dimensions of poverty and wellbeing – people’s health, nutrition, education, security of food, water and shelter, and economic development – are now all affected by climate change. The natural environment is also deeply affected. Addressing climate change effectively depends on viewing climate, people and biodiversity as interlinked systems. Some impacts already seen are listed below. The factsheet includes impacts and future risks in the categories of human life and health, ecosystems and biodiversity, food systems, water for people, education, human settlements and infrastructure, migration, economies, heritage, and compound risks

• Recorded death rates have been above normal on days with raised temperatures in Burkina Faso and Ghana – most commonly because of cardiovascular disease. Respiratory, stroke and non-communicable diseases have also been linked with heat.

• Climate conditions that support wildfires have increased in West Africa. However, vegetation fragmentation due to cropland expansion and the spread of trees and shrubs into savannas both reduce fire activity.

• Climate change is reducing crop productivity in West Africa. Maize and wheat yields decreased on average 5.8% and 2.3% respectively across sub-Saharan Africa from 1974–2008, due to climate change.Climate change has slowed the growth of agricultural productivity in Africa by 34% since the 1960s, the highest impact of any region. Two thirds of people across Africa perceive that climate conditions for agricultural production have worsened over the past ten years.Africans are disproportionately employed in climate-exposed sectors: 55–62% of the sub-Saharan workforce employed is in agriculture and 95% of cropland is rainfed.

• Rainfall and river discharge have been extremely variable in West Africa recently, as in the rest of Africa – between 50% above and 50% below historic levels. In West Africa, declines in river flows have been attributed to declining rainfall and increasing temperature, drought frequency and water demand. This has caused deep and mostly negative impacts across waterdependent sectors: from freshwater supply to people and agriculture, to availability of water for hydropower and tourism.

• West Africa’s human settlements are particularly exposed to floods (from rain and river flows), droughts and heat waves. Other climate hazards are sea level rise and storm surges in coastal areas and thunderstorms.

• Over 2.6 million and 3.4 million new weather-related displacements occurred in sub-Saharan Africa in 2018 and 2019, with West Africa (798,000) a hotspot in 2018.

Future Climate Risks in West Africa

West Africa will experience a multitude of impacts from climate change. Some of these are:

• Epidemics of dengue and yellow fever are projected to expand further into the Sahel region of West Africa under future global warming scenarios.Studies estimate that malaria vector hotspots and prevalence are projected to increase in the Sahel under mid to high-warming scenarios by 2030 and thereafter. However, in other parts of West Africa malaria hotspots are projected to diminish.

• Over 40% losses in rangeland productivity are projected for western, sub-Saharan Africa at global warming over 2°C (which could occur by 2050 under a mid-to high-warming scenario). By 3.75°C, severe heat stress may be near year-round for cattle across tropical Africa.

• Towns and cities are growing so rapidly in West, Central and East Africa that the area of urban land exposed to arid climate conditions will increase 700% between 2000–2030, even without further climate change. The urban area exposed to high-frequency flooding will increase by 2,600% in the same period.

• West Africa has the highest levels of projected climaterelated internal migrants (moving within countries), potentially reaching more than 50 million by 2050 for 2.5°C global warming.This suggests that climate impacts will have a particularly pronounced impact on future migration in the region.

• There is increasing demand for water for agricultural and energy production in West Africa. Governments are responding with ambitious plans to expand irrigation and hydropower infrastructure – especially in the Niger and Senegal river basins. Climate change introduces significant risks to these plans: future levels of rainfall, evaporation and runoff will have a substantial impact. However, climate models disagree on whether climates will become wetter or dryer in each river basin.

West Africa’s Potential to Adapt

• In agriculture, there is potential to boost farmers’ and pastoralists’ resilience to climate shocks and stresses; for example, through the introduction of drought- and pest-tolerant crop and livestock varieties. Often farmers with the lowest incomes cannot afford these without assistance. However, adaptation limits for crops in Africa will increasingly be reached for global warming of 2°C, and in tropical Africa may already be reached at current levels of global warming. The risk of no available genetic varieties of maize for adaptation is higher for East Africa and southern Africa than for Central or West Africa.

• There is a need to manage the competition among different water uses – for example, among household users, farmers and energy producers (the ‘water-energy-food nexus’). Effective approaches include working at river basin level to research and quantify the future sensitivity of crops and dams to changing rainfall, runoff, evaporation and drought. Integrating these perspectives and identifying cross-cutting adaptation options work better when decision making involves a wide range of actors affected by decisions.

• Effective adaptation in human settlements relies on addressing climate risks throughout planning and infrastructure development and can provide net financial savings. This needs to be done in an integrated, cross-cutting way. There is scope for governments to better harness the role of the informal sector in mitigation and adaptation – through multi-level governance. This could include, for example, service providers, such as informal water and sanitation networks.

• Early warning systems, targeting weather and climate information to specific users and sectors, can be effective for disaster risk reduction, social protection programmes, and managing risks to health and food systems (such as vector-borne disease and crops).

Key investment areas for a climate resilient West Africa

The IPCC’s Sixth Assessment Report identifies key areas for enabling climate-resilient development in Africa, where investment would have a catalytic effect on the continent’s resilience to current and future climate change. These areas are finance, climate services literacy and research, and governance. A summary is provided here, while more information can be found in the fact sheet.

• Increasing public and private finance flows by billions of dollars per year, enhancing direct access to multilateral funds, strengthening project pipelines, and shifting more finance to implementation would help realise transformative adaptation in Africa.
• Investing in climate information services that are demand-driven and context-specific, combined with climate change literacy, can enable informed adaptation responses.
• Increased funding for African partners, and direct control of research design and resources can provide more actionable insights on adaptation in Africa.
• Robust legislative frameworks that develop or amend laws are an important basis for mainstreaming climate change across government and society
• Working across sectors and at transboundary levels can ensure that adaptation and mitigation actions in one sector don’t exacerbate risks in other sectors, and cause maladaptation.
• Governance for climate-resilient development includes integrating climate resilience into long-term planning and investment decisions, all-of-government approaches, transboundary cooperation and benefit sharing, development pathways that increase adaptation and mitigation and reduce inequality, and implementing Nationally Determined Contributions (NDCs).