Climate change is going to affect all aspects of the water cycle. The quantity and distribution of precipitation, the frequencies and duration of droughts, as well as evaporation rates and the water balance at plot level will be impacted by climate change. The African monsoon, which regulates the lives of 300 million West Africans, is evolving: the monsoon’s year-to-year variability will increase, as will the occurrence of extreme rainfall. Agricultural activity will be more or less strongly affected by this change depending on the agro-ecological zone and particular economic activity. The main scientific studies concur: mean annual runoff and groundwater recharge will decrease and competition for water will be exacerbated by growing demand for water by other uses, such as hydro-electric generation. Studies conducted by the African Monsoon Multidisciplinary Analysis (AMMA) are clear in stating that the variability in precipitation both in space and in time will be a real constraint on farm production. Society will need to adapt. Yet we should not underestimate the complexity of any given approach; thus, irrigation schemes should be consulted and agreed upon by all downstream principals and water users involved, even from a neighbouring country. Many methods and their local variations exist to mitigate the vagaries of water availability. Most try to increase production while at the same time reducing dependence on, and vulnerability to, inputs and limiting their negative effects on the environment. Techniques include water saving methods and methods to conserve biomass and soil fertility.

The United Nations Framework Convention on Climate Change (UNFCCC) offers the developing countries some tools to evaluate their vulnerabilities to climate changes, to plan and to implement adaptation and mitigation policies and measures. Among them, National Action Plans for Adaptation (NAPAs) and National Communications are of particular importance, especially for West Africa. NAPAs identify urgent adaptation actions to be supported by international climate finance, after a participatory process aiming at identifying present and future vulnerabilities, as well as existing or innovative adaptation measures, and hierarchizing priorities. National Communications present national inventories of Greenhouse Gases (GHG) emissions and removals, as well as countries’ vulnerabilities in terms of climate changes, thus identifying adaptation and mitigation policies and measures. All Least Developed Countries (LDCs) of the CILSS/ECOWAS area have developed at least a NAPA or a National Communication; most have developed these two documents. However, the action of the West African countries is not limited to these tools. For over a decade, many national policies, particularly those relating to rural development and agriculture, have taken climate change into account and have planned specific actions on adaptation. In the case of Burkina-Faso, these include the National Action Programme to Combat Desertification (PAN-LCD), dealing with the prevention and management of climate hazards, the National Agriculture Investment Programme (PNIA) which addresses sustainable management of land, and the National Programme for the Rural Sector (PNSR), which includes the PNIA and provides for the adaptation of forest and agricultural resources, and the improvement of knowledge in terms of vulnerability and adaptation. In Niger, the PAN-LCD identifies climate as the first driver of desertification and focuses on the analysis and monitoring of climate changes. The PNIA aims at reducing the dependence of farming systems to climate hazards and the 3-N initiative ("Nigeriens feed Nigeriens"), which largely relies on the PNIA, quotes adaptation as one of the five challenges to food security.

The picture is bleak for food security in West Africa, due to the expected impacts of climate changes. Indeed, increased intensity of extreme weather events, droughts and water stress, warming of water and decreasing fish production, land degradation, changes in the distribution of animal and human vector-borne diseases, etc. are anticipated (IPCC, 2013). These effects are aggravated by a significant degradation of land and natural resources by human activities. Despite a possible increase in precipitation in some areas, West Africa is in a delicate situation because of its environmental, economic, and political vulnerabilities. Among others, key vulnerabilities are dependence on agriculture, low incomes, and the already significant variability in climate. Crops in West Africa are already affected by drought and depletion of water resources. Pests and diseases are common, and livestock is affected by regular outbreaks. Pastures rarely produce enough forage. People are dependent on markets and thus undergo changes in local and global food prices. The diet of the population is generally poor in animal proteins, sometimes in vegetables. According farming systems, specificities emerge in terms of vulnerability, such as: • Risks of significant flooding in irrigated farming system; • Low adaptation investments in farming systems based on tubers and cereals; • Isolation, high land degradation, and silting up of ponds in agro-pastoral farming systems based on millet and sorghum; • Drying up of water sources, bush fires, conflicts, and adverse terms of trade for cattle ranchers in pastoral farming system; • Shortages of drinking water in urban and peri-urban areas. Successful adaptation practices do exist. Some of them are presented in another note

Published late 2013, the latest IPCC report demonstrates that the link between human activities and increasing temperatures observed since 1950 is very likely. These activities are manifested by massive emissions of Greenhouse Gases (GHGs) in the atmosphere, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Responsibilities are shared unequally between countries, but effects apply to everyone, especially African countries, particularly subSaharan ones. Yet, the African continent as a whole represents only 3.4& of global GHGs emissions and the CILSS/ECOWAS countries all together less than 1& of global emissions. At the global level, since the early 20th century, the temperature of the surface of the earth has increased by 0.8°C and sea levels rose from 19 cm. Each of the last three decades has been successively warmer than all previous decades since 1850! At the level of sub-Saharan Africa, climate changes are also important and disrupt farming activities, backbone of the economy: increase in the frequency of hot days and nights, heat waves, rainfall anomalies (annual and monthly volumes, heavy rains, consecutive dry days, start and end of the rainy season, etc.), increase in extreme weather events, etc. The example of the rainfall is striking: after experiencing an unprecedented drought in the world since the 1970s, West Africa has benefited from increased rainfall since the beginning of the 1990s, but with a strong interannual variability and more frequent episodes of heavy rains. The duration of the rainy season has decreased, while the frequency of flooding has increased. The impacts of climate changes are perceived by the West African populations, but their causes are not well understood. Informing these populations on climate changes, which will grow worse, is therefore an urgent challenge.

The struggle against desertification and the protection of their natural resources has been a recurring theme since the 1970s in the policy documents of the West African States marked by the droughts of the Sahel. More recently, issues related to adaptation to climate change and its corollaries, how to adapt agriculture and maintain food security, have begun to be discussed even at the subregional level. Thus, many political and/or economic regional groupings of countries have defined strategic programmes or adopted legal instruments that allow them to integrate environmental questions into their action plans. It is not always easy to navigate the various programs and legal instruments. The regional and sub-regional institutions are many and often overlap thematically or geographically. Introduction The first section of this review presents policies and strategies on the environment and agriculture implemented on the African continent and in West Africa by a variety of institutions: the African Union (AU), the African Ministerial Conference on the Environment (AMCEN), the Economic Community of West African States (ECOWAS), the West African Economic and Monetary Union (UEMOA), and the Permanent Interstates Committee for Drought Control in the Sahel (CILSS). However difficult it may be to understand and to coordinate between these regional and sub-regional programmes, their very proliferation affirms the growing importance that the environment and its interdisciplinary nature has come to occupy since the Millenium Summit in 2000, where it was treated in isolation as one of the eight Millenium Development Goals (MDG). However, going beyond mere words, regional and sub-regional institutions, as well as the Member States themselves, have already taken action and have since the early 2000s begun to implement huge field actions involving efforts against desertification and land degradation, sustainable land and water use, reforestation, etc. We present only three field actions in this review but the list is much longer. This clearly demonstrates how the environment has become a cornerstone of sustainable development and a major concern of West African countries

Although they are low emitters, West African countries are invited, like all Parties to the UNFCCC, to reduce their Greenhouse Gases (GHGs) emissions, according to their national capacities and circumstances. Mitigation in developing countries is promoted by the UNFCCC with three tools: Nationally Appropriate Mitigation Actions (NAMAs), Clean Development Mechanism (CDM), and Intended Nationally Determined Contributions (INDCs). NAMAs are voluntary for developing countries and can cover a variety of sectors: energy, transport, forestry, etc. They are published by the UNFCCC, with the objective to attract funding from the international community. However, so far, they are no specific guidelines neither dedicated funding. Up to now, only 15 countries have submitted NAMAs to the UNFCCC, and among them, Mali is the only one from the CILSS/ECOWAS area. The CDM allows developed countries to meet part of their commitments by financing emission reduction projects in developing countries. Many limitations explain that these projects have benefited little to Africa: carbon price fluctuations, complexity of the procedures, high transaction costs, complicated rules for reforestation, etc. Finally, the concept of INDC is very recent and it is not yet clear how these contributions will be supported. The opportunities offered by the UNFCCC for financing adaptation and mitigation actions are tenuous: the target of 100 billion US$/year by 2020 is not credible in the absence of short-term financing and the Green Climate Fund, key element of the financial mechanism of the UNFCCC, is still not operational. However, outside of the UNFCCC, fundings are available for mitigation, especially in the agriculture and forest sectors: Forest Carbon Partnership Facility (FCPF), Forest Investment Programme (FIP), Global Alliance against Climate Change (GCCA), International Climate Initiative of Germany (ICI), and Japan Initiative for Fast-Start Actions. In the short term, the West African countries could better benefit from the CDM, by advocating for its adaptation to their national circumstances, as well as from the NAMAs, by requesting the development of guidelines and dedicated funding. In the medium and long term, in the absence of tangible prospects under the UNFCCC, the integration of mitigation-related goals in the "traditional" projects of donors would probably remain the most obvious opportunity to finance the mitigation in West Africa.

Already handicapped by increasing land pressure and continued land degradation, West African farmers face an additional challenge: to adapt their farming practices to climate changes. In West Africa, these changes should lead to increased water stress, the extension of arid areas and, ultimately, lower crop yields (IPCC, 2013). Cereal yields are expected to fall by 10 to 15& by 2025, while 20& of the population is already structurally vulnerable and food crises are regular (CILSS, 2013). The situation is difficult, but simple and effective techniques can be implemented to adapt farming practices. This means that, with few resources, the farmer may be able to improve its yields, while preserving its natural capital (the soil), and taking into account the future climate changes in West Africa. This involves making the best use of agricultural water, using collection techniques that aim at maintaining as long as possible the water in the fields. It also means combatting erosion due to the wind or heavy rains, introducing physical barriers in the fields. Finally, this implies to better manage physical and chemical soils properties, in order to maintain or restore their fertility. These techniques must be implemented in a complementary manner. Despite having shown very good results at plot level, their widespread adoption remains a challenge for West Africa. Restoration costs of degraded land in the CILSS/ECOWAS countries demonstrate the importance of this challenge: up to 100 million US$ per country (CILSS, 2013)

More than in other places, millions of people in West Africa depend in large part on natural resources which continue to deteriorate. Each year more than 4 million ha of forest are lost in Africa and 80& of the forests in West Africa disappeared in the last century (FAO, 2010). 34 countries like Angola, Ethiopia, Gabon, and Mali continue to suffer a loss of biodiversity (UNEP, 2008). Genetic erosion in sub-Saharan Africa is accelerating and local food-producing seeds are disappearing at an alarming rate (FAO, 2012). Soil degradation affects almost 500 million people in Africa and two thirds of the arable land is exposed to degradation. The situation concerning water resources is just as troubling. Introduction The first part of this report gives a brief overview of the principles and mandates of the UNCBD and its two Protocols, Cartagena and Nagoya, and then presents its main bodies. The second section introduces how far the UNCBD has been implemented and discusses specific aspects of agrodiversity and bio-security in the African context, then at the sub-regional West African level, and finally at the level of the individual countries of West Africa. Never before have the humid zones and the bodies of water in West Africa been under such a strain. The area covered by Lake Chad, for example, has fallen from 25,000 ha to only 2,500 in 40 years. The direct pressures are aggravated by changes in the climate whose effects will be all the more damaging because West Africa is already so vulnerable. The objective of UNCBD and its additional Protocols of Nagoya and Cartagena is to maintain biological diversity, stop genetic erosion and ensure a just and equitable sharing of the benefits from the use of genetic resources. Nevertheless, while humanity is going through its 6th biodiversity crisis, the objective for 2010 – reduce the rate of biodiversity loss – has not been achieved and the national implementation of UNCBD’s measures remains limited in West Africa.

UNCCD took effect in 1996 and was conceived of "to forge a global partnership to reverse and prevent desertification/land degradation and to mitigate the effects of drought in affected areas in order to support poverty reduction and environmental sustainability." Bringing together at the same time countries affected in whole or in part by desertification and land degradation, and developed countries expected to support the affected countries, the UNCCD has struggled since its creation to mobilise the necessary political will and funding. But, nearly 20 years on, the UNCCD has reset itself with the adoption of a 10-year Strategy (2008-2018) to combat land degradation and desertification. This recent change of tack is sorely needed in West Africa, where the agricultural sector accounts for 35& of GDP and occupies a very extensive part of the working population. It is handicapped by poor soils and the encroaching desert. These phenomena are exacerbated by already very perceptible changes to the climate and powerful demographic pressures. The key issues of UNCCD for Africa, in particular West Africa, are clear: Introduction Land degradation and desertification are major constraints to economic and social development. Inspired by that realisation, African, Latin American, and Mediterranean leaders called into being the UN Convention to Combat Desertification (UNCCD). Translation: Peter Gaechter, SOS Sahel  Sharply increased funding for sustainable land management (SLM) is essential in order to scale up: at least 2 billion US$ would be necessary to manage land sustainably in the 17 CILSS/CEDEAO countries ;  The Global Mechanism should be implemented and, as underlined in the 10year Strategy, “the sources and mechanisms of innovative funding, in particular from the private sector should be identified ”;  The implementation of a scheme of Zero Net Land Degradation should be explored, which aims at compensating degraded land by an equal quantity of restored land and to achieve a balance. Indeed, this scheme would allow degraded land to be restored and contribute to combating degradation and desertification, the protection of biodiversity, reducing climate change, and improving adaptation to it, as well as, obviously, food security;  The recent process of setting up a subsidiary body, the Science-Policy Interface (SPI), requires it to become quickly more operational and to work on strategic investment frameworks in SLM.

After the publication of the Brundtland Report in 1987, alerting the international community about the dangers of global changes, including climate changes, the Intergovernmental Panel of Experts on Climate Change (IPCC) is established in 1988. Soon after, at the Rio Earth Summit in 1992, the UNFCCC is created. It adopts an armed wing in 1997, the Kyoto Protocol, which enters into force in 2005. The first commitment period of the Protocol (2008-2012) did not address the issue, covering less than a third of global Greenhouse Gases (GHG) emissions and setting a modest target in terms of GHG emissions reduction (-5.2& in 2008-2012 compared to 1990). The opposition of the United States to any reduction of their GHG emissions ("The American way of life is not negotiable!" - George Bush, 1992) has often been put forward to explain the low ambition of the Protocol. The reality is less simple: the climate negotiations involve more than 190 countries with diverse interests and have become complex, far exceeding climate and abuting on geopolitical or even philosophical issues. This Protocol was supposed to be strengthened in 2009 at the Climate Conference in Copenhagen. Political tension was high before this Conference: "No plan B in case of failure" (Barroso, 2009). Five years later, the Plan B is still under negotiation... Agreeing on a multilateral treaty on the post2020 climate regime - by 2015 at the COP21 in Paris - is even more urgent that all signals are red, as evidenced by the last IPCC Report (2013). In addition, the last to pollute will be the first affected: developing countries that have low GHG emissions compared to industrialised countries already bear the brunt of the effects of climate change and will suffer even more. In this context, the West African countries ardently defend their positions: • Applying the principles of "Common But Differentiated Responsibility" (CBDR) and "Transparency" and asking the developed countries to be exemplary; • Increasing greatly climate finance in particular for adaptation; • Integrating agroforestry in the Clean Development Mechanism (CDM); • Operationalising the “Loss and Damage Mechanism”.