ABSTRACT
The United Nations Water Conference 2023 highlighted the need for concrete actions to boost integrated water resources management for achieving the Sustainable Development Goals and called for strategies to enhance cooperation among stakeholders. Technical cooperation between countries and institutions in transboundary systems, e.g., on environmental data collection, is an effective way to promote international diplomacy and prevent disputes between riparian states. Still, establishing collaborations to inform bilateral dialogues on the identification of environmental challenges, their causes, and development priorities may be a difficult task in itself. This is particularly true in the African context because of limited resources and lack of data. In this paper, we analyse the case of nine transboundary river basins in Sub-Saharan Africa to identify which water-management challenges are perceived as most important by the different riparian countries from a policy and scientific perspective. Our insights are based on the most up-to-date scientific papers, open access reports and technical literature, river basin authority's strategy papers, projects' summary reports, and national policy documents. We also complement these sources with the pieces of information we gained through collaborations with regional and local experts, and management bodies (such as river basin authorities). We highlight the current water-related conflicts and the gap between the priorities identified by the scientific community and different riparian countries on how to tackle hydro-climatic change and improve food and energy security, human and environmental health. Based on our experience, we discuss some keys to building trust among stakeholders, strengthening cooperation, and identifying shared water-governance measures in transboundary river basins. They are: (i) connect science and policy to provide sound knowledge for the right questions, (ii) value local knowledge and exploit the complementarity of different perspectives, (iii) consider multiple spatial scales and multi-level stakeholders to leave no one behind, (iv) promote a culture which values trade-offs and handles complexity, and (v) co-create data and knowledge to facilitate stakeholder dialogue from problem definition to intervention identification.
ABSTRACT
We estimate changes in forest cover (deforestation and forest regrowth) in the tropics for the two last decades (1990-2000 and 2000-2010) based on a sample of 4000 units of 10 ×10 km size. Forest cover is interpreted from satellite imagery at 30 × 30 m resolution. Forest cover changes are then combined with pan-tropical biomass maps to estimate carbon losses. We show that there was a gross loss of tropical forests of 8.0 million ha yr(-1) in the 1990s and 7.6 million ha yr(-1) in the 2000s (0.49% annual rate), with no statistically significant difference. Humid forests account for 64% of the total forest cover in 2010 and 54% of the net forest loss during second study decade. Losses of forest cover and Other Wooded Land (OWL) cover result in estimates of carbon losses which are similar for 1990s and 2000s at 887 MtC yr(-1) (range: 646-1238) and 880 MtC yr(-1) (range: 602-1237) respectively, with humid regions contributing two-thirds. The estimates of forest area changes have small statistical standard errors due to large sample size. We also reduce uncertainties of previous estimates of carbon losses and removals. Our estimates of forest area change are significantly lower as compared to national survey data. We reconcile recent low estimates of carbon emissions from tropical deforestation for early 2000s and show that carbon loss rates did not change between the two last decades. Carbon losses from deforestation represent circa 10% of Carbon emissions from fossil fuel combustion and cement production during the last decade (2000-2010). Our estimates of annual removals of carbon from forest regrowth at 115 MtC yr(-1) (range: 61-168) and 97 MtC yr(-1) (53-141) for the 1990s and 2000s respectively are five to fifteen times lower than earlier published estimates.
