Authors : Carlo Buontempo, Kirsty Lewis
Affiliated organisation : Sahel and West Africa Club (SWAC) of the Organisation for Economic Co-operation and Development (OECD)
Site of publication : oecd-ilibrary.org
Type of publication : Research paper
Date of publication : August 2016
Climate and climate projections for the Sahel and West Africa
Most of the Sahelian region receives precipitation in only one or two seasons a year and thus one deficient season could well have devastating effects on local livelihoods and economies. Recent observations in the region (Dong and Sutton, 2015) point toward a moderate recovery of precipitation, which is still below the levels that characterised the relatively humid period of the 1960s.
Given the challenge climate change represents for human kind, and in particular the precarious balance between human needs and natural resources that characterises West Africa, it is all too natural that scientists have looked at this region with particular interest. Climate models represent one of the best tools to understand what the future climate holds. They also provide a fundamental machinery to understand the processes that underpin the variability and the long-term change in key meteorological parametres such as precipitation and temperature.
Climate services: working with users
Climate scientists had a crucial role in sounding the alarm when it first became clear what the consequences of a warming planet could be for humankind and the natural world. However, climate scientists might not necessarily be in the best position to have the insight required to provide information on climate change which could form the basis for action to prepare for these consequences.
Combining user- and systems-led approaches could be a way of increasing users’ understanding of the system, and potentially help users to identify the questions that need answering. The most obvious way to do this is to include users in the analysis of the wider system, going beyond their own decision-making experiences in response to weather events, so that they can also consider the context in which their activities sit
Uncertainty in projections, as well as lower temporal and spatial resolution of climate models in comparison to weather data, means that climate information is not equivalent to a forecast for the long-term. Climate models explore the behaviours and statistics of the climate system over average regions and time periods. While these are useful for understanding the direction and scale of change, and for evaluating changing risk, they are not what most users familiar with meteorological data might expect and therefore demand.
In order to address the discrepancy between the nature of climate information and the expectation of users, the climate services community developed a new approach to identify users’ needs. Understanding the users’ universe, including their needs, issues, and priorities can give developers of climate services new information to identify the most relevant aspects of climate information for the user.
In a region like the Sahel and West Africa, where projections are not robust (or at least not robust for all parameters) the identification and communication of what is actually known, and not just focusing on uncertainty, is extremely important. Climate model projections for the Sahel and West Africa do not provide a consistent message on whether precipitation will increase or decrease.
Beyond the user: adopting a systems-based approach to climate change
Many user groups, such as farmers, who recognise the importance of climate information and thus are most likely to engage with climate services, do so because of the operational experience they have of the impacts of weather on their activities. For this group of stakeholders, who are direct users of weather and climate information, the focus is often on the near- to medium-term.
Long-term climate change will have profound impacts across society, but aside from specific questions on engineering resilience, users of long-term climate information can be difficult to identify. This makes a user-led approach to evaluating climate model projections a less effective tool for understanding and communicating the impacts of long-term climate change.
In a region like the Sahel and West Africa, where projections are not robust (or at least not robust for all parameters) the identification and communication of what is actually known, and not just focusing on uncertainty, is extremely important. Climate model projections for the Sahel and West Africa do not provide a consistent message on whether precipitation will increase or decrease
Despite the range of possible temperature change associated with different greenhouse gas concentration scenarios, the levels of change expected in the coming decades indicate a climate radically different from that experienced since the start of the industrial revolution.
Providing information about the impacts of climate change in a way that engages with long-term planners requires some understanding about the ways in which weather and climate have the potential to affect outcomes. Climate change is also about the changes in variability and extremes, and the potential to threaten human security by impacting food, water, energy, transport, trade, livelihoods and assets. It requires looking beyond the user to the whole human-environment system and its dynamical responses to long-term changes.
Taking a systems approach to the long-term view of human security involves evaluating the way in which systems work and, from a climate-science perspective, the way these human systems interact with weather and climate.
This approach requires a multi-disciplinary evaluation of the system, mapping what is relevant from a variety of expertise, and then exploring the sensitivities of that system to weather and climate. Understanding and responding to climate change is not just about knowing more and in greater detail what the future weather and climate will be. It is also about the inter- action between changes in climate with all other changes in, for example, population, urbanisation, technology, infrastructure and so on, that will take place over the decades to come.
Combining user-led climate service and systems approaches
Starting with the system and the decision maker may be a way out of the paralysis of uncertainty that can come from the huge amounts of data generated by climate models, or from relying on climate scientists alone to determine what is important to communicate and how.
Taking a systems approach to the long-term view of human security involves evaluating the way in which systems work and, from a climate-science perspective, the way these human systems interact with weather and climate
Combining user- and systems-led approaches could be a way of increasing users’ understanding of the system, and potentially help users to identify the questions that need answering. The most obvious way to do this is to include users in the analysis of the wider system, going beyond their own decision-making experiences in response to weather events, so that they can also consider the context in which their activities sit.
In the Sahel and West Africa, farmers are important users of weather and climate infor- mation. They may already receive weather forecasts from their local meteorological services, and be open to engage in stakeholder workshops to develop climate services for seasonal climate outlooks.
The climate change projections for the Sahel and West Africa are complex and there is a high degree of uncertainty, but there is enough information within climate projections to inform robust, no regrets responses to the challenges that a changing climate brings. The key is to look beyond climate science numbers and to engage with individual users not only at the local and near-term levels, but also across the wider system, both globally and in the long-term.
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