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Wetlands provide numerous ecosystem services essential for biodiversity conservation, climate change mitigation, and human well-being. Nevertheless, there are still no complete and uniform wetland maps providing information on the location, distribution, size, and changing status of wetlands in Africa. In this study, we used 130,000 Landsat satellite images and 270,000 sampling points evenly distributed across Africa to classify wetlands with a random forest classifier based on the Google Earth Engine (GEE) cloud platform. This resulted in the first systematic and comprehensive map of existing wetlands in Africa that quantified the area and distribution of these wetlands at a spatial resolution of 30 m, with an overall wetland producer accuracy of 90.22 % and user accuracy of 95.74 %. To address the seasonal variation in African wetlands, we used a dynamic threshold segmentation method based on the Otsu method, which can extract the extent of wetlands under different periods more accurately based on Landsat time series and African phenology data. Our results show that the total African existing wetlands extent from 2019 to 2021 (here in 2020), was approximately 1,341,500 km2, excluding shallow marine waters, comprises 3.98 % of Africa's total land area. Of these wetlands, inland wetlands account for 81 %, and coastal wetlands account for 19 %. The wetlands in Africa were symmetrically distributed around the equator and decreased with increasing latitude, accounting for 97 % of the total wetland area being within the 20°N and 20°S latitudes. African marshes were highly dynamic, expanding by 92.22 % from the dry to wet season. Our study demonstrates the substantial potential of large data samples, multiple wetland classification features (spectral-temporal, topographic, and hydrological features), and random forest classification in GEE for large-scale wetland mapping. The resulting wetland maps provide new baseline data for large-scale monitoring of seasonal dynamics and long-term trends in African wetlands. [ABSTRACT FROM AUTHOR]

Efforts to avoid the acceleration of global warming have tended to focus on countries with high CO 2 emissions levels and large populations, with a high level of economic development or industrialization. African countries, which often do not conform to such criteria, are more vulnerable to climate change due to their dependence on climate-sensitive industries and their limited infrastructure and technological capacity to cope with its impacts. The long-term economic growth rates projected for Africa's rapid development period will, further, make Africa a potential emission hotspot in the near future. Here, for the first time, we built an energy-related emissions inventory for 19 African countries for 2010–2019, which addresses emissions from 47 economic sectors and 5 energy types, making it the most comprehensive of its kind. The degree of decoupling of economy and emissions, and drivers of CO 2 emission changes are also examined. Most African countries experienced rapid growth in CO 2 emissions, with an average annual growth rate of 5.5% for fossil fuel-related CO 2 emissions and 6.0% for unsustainable biomass-related CO 2 emissions. Only two countries, South Africa and Tanzania, have achieved a strong decoupling of economic growth from CO 2 emissions. Economic and population are the most important drivers of emissions, while energy intensity has been identified as a key factor in mitigating CO 2 emissions, especially for those countries that have reached strong or weak decoupling. The findings from this study provide essential insights that could guide the development of low-carbon policies and strategies in Africa. • We provide energy-related emission inventories for 19 African countries from 2010 to 2019. • African countries experienced rapid growth in CO2 emissions. • Two countries achieved strong decoupling of GDP from CO2 emissions. • Economic and population growth are the most important drivers of emissions. [ABSTRACT FROM AUTHOR]

Local governments are expected now more than ever to lead climate action planning as climate change intensifies and urbanization increases rapidly. However, studies indicate limitations in the comprehensiveness and level of integration of adaptation and mitigation in existing climate action plans. To develop suitable climate action plans that are comprehensive and consistent with globally accepted standards and benchmarks, this study proposed an Urban Climate Action Planning framework and pilot-tested it with 257 urban climate action plans. Overall, 43 criteria are included in the framework across three stages of climate planning. The pilot test revealed that more than half of the sampled plans have a medium level of suitability, with 39% having a weak level of suitability. About 51% of plans from Europe have a weak level of suitability. Surprisingly, none of the plans sampled from Africa and Latin America achieved a weak level of suitability despite lacking a significant share of global climate research and development funding. A Kruskal-Wallis test shows a statistically significant association between stages of climate planning and (a) city types (p-value of 0.004326) and (b) year of adoption or publication of climate plans and suitability scores (p-value of 0.0001027). Urban climate action plans adopted or published more recently (2018–2022) are likely more suitable than those adopted or published earlier. The sampled urban climate action plans from the Global South had higher average suitability scores than those from the Global North. The study presents key findings and considerations for urban climate action planning and future research. [Display omitted] • A framework for assessing the suitability of Climate Action Plans (CAPs) is proposed. • The framework is used to pilot-test the suitability of 257 urban CAPs. • Suitability analysis is done across city types, regions, and the global divide. • Most sampled plans achieved a medium level of suitability. • The CAPs lack criteria related to implementation and monitoring. [ABSTRACT FROM AUTHOR]

• Conservation Agriculture is able to mitigate climate change in Africa. • Both annual and perennial crops are able to contribute to C sequestration. • Potential estimate of C sequestration is 145 Mt per year, which is 533 Mt CO 2. • This figure represents about 95 times the current sequestration figure. Africa is the smallest contributor to global greenhouse gas emissions among the continents, but the most vulnerable to the impacts of climate change. The effects will not be limited to a rising average temperature and changing rainfall patterns, but also to increasing severity and frequency in droughts, heat stress and floods. Agriculture is not only impacted upon by climate change but also contributes to global warming. However, not all agricultural systems affect negatively climate change. Conservation Agriculture (CA) is a farming system that promotes continuous no or minimum soil disturbance (i.e. no tillage), maintenance of a permanent soil mulch cover, and diversification of plant species. Through these principles it enhances biodiversity and natural biological processes above and below the ground surface, so contributing to increased water and nutrient use efficiency and productivity, to more resilient cropping systems, and to improved and sustained crop production. Conservation Agriculture is based on the practical application of three interlinked principles along with complementary good agricultural practice. The characteristics of CA make it one of the systems best able to contribute to climate change mitigation by reducing atmospheric greenhouse gas concentration. In this article, the carbon sequestration potential of CA is assessed, both in annual and perennial crops, in the different agro-climatic regions of Africa. In total, the potential estimate of annual carbon sequestration in African agricultural soils through CA amounts to 143 Tg of C per year, that is 524 Tg of CO 2 per year. This figure represents about 93 times the current sequestration figure. [ABSTRACT FROM AUTHOR]

The ongoing global warming is projected to persist throughout the entire century if effective mitigation measures are not put in place. The warming is associated with occurrence of extreme climate events that are prone over Africa. This study uses model data from 24 CMIP6 modeling centers to investigate future changes in extreme climate events over Africa under 1.5 °C, 2.0 °C and 3.0 °C global warming levels (GWLs). The amplified impact in extreme climate events by additional is computed relative to GWL1.5 °C. The models generally simulate observed climate extremes well, with the ensemble mean minimizing data uncertainties. The entire continent is projected to get warmer with the Sahara, Kalahari and parts of the Mediterranean depicting relatively higher temperatures. Both Rx1day and Rx5day are projected to increase over the continent except for the northern and southern regions of the continent. Rx5day is projected to increase by 4–10% for GWL1.5 and GWL3.0 °C. In comparison, an additional 0.5 °C warming between GWL2.0 °C and GWL1.5 °C will lead to an increase of about 43% impact for the climate extremes. An additional GWL1.5 °C (GWL3.0 °C) could result in about 68% increment in climate extremes. The amplified impact of global warming will result in devastating socioeconomic impacts over Africa. This stresses the need of formulating and implementing more ambitious climate change mitigation measures in effort to limit global warming to 1.5 °C. • Future changes in extreme climate are projected over Sahara, Kalahari and parts of the Mediterranean region. • Higher increase in Rx5day compared to Rx1day is projected for GWL1.5 – GWL3.0 °C. • Additional 0.5 °C (GWL1.5 °C) warming will lead to an increase of about 43% (68%) impact for the climate extremes. [ABSTRACT FROM AUTHOR]

• Amplification effects of higher air temperature on the range of changes in flood frequency and magnitude are projected. • Southeast Eurasia, Africa, and South America are hotspots with higher flood defense pressures. • Most watersheds worldwide would face increasing pressures from current flood defense standards in warming climates. Floods usually threaten human lives and cause serious economic losses, which can be more severe with global warming. Therefore, it is a salient challenge to find out how global flood characteristic changes and whether current flood protection standards will face more pressures. This study aims to characterize changes in global floods and explicit flood defense pressures in warming climates of 1.5–3.0 °C above pre-industrial levels by running four well-calibrated lumped hydrological models using bias-corrected Global Climate Model (GCM) simulations for 9045 watersheds worldwide. The results show that global warming from 1.5 to 3.0 °C has increasingly dominated all continents, with amplification effects on changes of flood frequency and magnitude. Southeast Eurasia, Africa, and South America are hotspots of changes for significant proportions of watersheds with larger flood patterns and greater changing extents than others. For example, for the 3.0 °C warming period under the combination of shared socioeconomic pathway 2 and representative concentration pathway 4.5 (SSP245) scenario, the regionally averaged 50-year flood magnitude will increase by 25.6 %, 30.6 %, and 16.4 % for these regions, respectively. The increases in occurrence and magnitude indicate that current flood protection standards will face increasing pressures in future warming climates. The design-level flood frequency is projected to increase for about 47 %, 55 %, 70 %, and 74 % of watersheds in 1.5, 2.0, 2.5, and 3.0 °C warming periods under the SSP245 scenario. However, large uncertainty are observed for the change of flood characteristics dominated by GCMs and their interactions with SSP scenarios and hydrological models. This study implies that the current flood defense standards should be enhanced and climate adaptation and mitigation strategies should be proposed to cope the change of future flood. Floods usually threaten human lives and cause serious economic losses, which can be more severe in the context of global warming. It is a salient challenge to find out how global flood risk changes and whether current flood protection standards will face more pressures. This study aims to characterize changes in global floods and explicit flood defense pressures in warming climates of 1.5, 2.0, 2.5, and 3.0 °C above pre-industrial levels. Here we show that amplification effects of higher air temperature on the range of changes in flood frequency and magnitude are projected. Southeast Eurasia, Africa, and South America are hotspots of changes for significant proportions of watersheds with larger flood patterns and greater changing extents than others. Most watersheds worldwide is likely to face increasing flood defense pressures in warming climates. Our findings could improve the understanding of future flood conditions under the warming climates and provide information to mitigation and adaptation policymaking. [ABSTRACT FROM AUTHOR]

Despite renewed efforts to combat climate change, it remains uncertain how economies will achieve emission reduction by 2050. Among different decarbonisation strategies, knowledge about the potential role and contributions of social movements to curbing carbon emissions has been limited. This study aims to shed light on the diverse contributions of social movements to staying within the global carbon budget, as well as on the specific outcomes and strategies employed in protests against hydrocarbon activities. For this purpose, we conduct a systematic literature review of 57 empirical cases of social movements contesting fossil fuel projects in 29 countries. Based on an exploratory approach, we identify a series of different movement strategies and a range of qualitative contributions that support staying within the carbon budget. These include raising awareness of risks and strategies, enhancing corporate responsibility, being informed about policy changes, laws and regulations, fostering just energy transitions, energy democracy, divestment, alternative market solutions, and forcing the postponement or cancellation of targeted hydrocarbon activities. While the institutional means are widely used and seem to support policy change and regulation, these strategies are not used to deliver awareness or postponement outcomes. Similarly, while movements tend to rely on civil disobedience to stop hydrocarbon projects in the short term, they rely on multiple strategies to cancel them in the longer term. Our study also indicates significant knowledge gaps in the literature, particularly, cases in Africa and Central Asia, women's participation in these movements, in addition to more quantitative assessments of the actual emissions reduced by social movements. [ABSTRACT FROM AUTHOR]

Abstract: The estimation of above ground biomass in forests is critical for carbon cycle modeling and climate change mitigation programs. Small footprint lidar provides accurate biomass estimates, but its application in tropical forests has been limited, particularly in Africa. Hyperspectral data record canopy spectral information that is potentially related to forest biomass. To assess lidar ability to retrieve biomass in an African forest and the usefulness of including hyperspectral information, we modeled biomass using small footprint lidar metrics as well as airborne hyperspectral bands and derived vegetation indexes. Partial Least Square Regression (PLSR) was adopted to cope with multiple inputs and multicollinearity issues; the Variable of Importance in the Projection was calculated to evaluate importance of individual predictors for biomass. Our findings showed that the integration of hyperspectral bands (R 2 =0.70) improved the model based on lidar alone (R 2 =0.64), this encouraging result call for additional research to clarify the possible role of hyperspectral data in tropical regions. Replacing the hyperspectral bands with vegetation indexes resulted in a smaller improvement (R 2 =0.67). Hyperspectral bands had limited predictive power (R 2 =0.36) when used alone. This analysis proves the efficiency of using PLSR with small-footprint lidar and high resolution hyperspectral data in tropical forests for biomass estimation. Results also suggest that high quality ground truth data is crucial for lidar-based AGB estimates in tropical African forests, especially if airborne lidar is used as an intermediate step of upscaling field-measured AGB to a larger area. [Copyright &y& Elsevier]

Formally adopting climate change mitigation policies does not necessarily translate to tangible change on the ground. Here, we analyse 31 semi-structured interviews with climate policy government officials and consultants from 11 low-income and lower-middle income countries (LMICs) as well as the respective climate policy context, and find high average degrees of perceived discrepancies between formally adopted climate change mitigation policies and their actual implementation. Our results suggest that for our LMIC sample, both the global political process to limit climate change and domestic environmental threats have been key to drive the formal adoption of climate change mitigation policies, but have had limited effect on implementation. By contrast, momentum for implementation of climate change mitigation initiatives and projects on the ground emerges where climate policies are firmly embedded within economic and social development policies, the economy and society are comparably well-positioned to embrace the associated change, and where they have been governed by cross-ministerial institutions capable of implementing wider climate-compatible development pathways. Thus, to help translate climate policy into action, national LMIC governments and the international community need to find context-specific ways to successfully integrate climate with economic and social development policies, identify and build on feasible opportunities and competitive advantages through which the local economy can benefit from green growth, build adequate social capital, and actively create institutional spaces and processes for well-equipped and meaningful cross-ministerial co-benefit governance. The importance of unlocking co-benefits for implementing climate policies underlines both the urgency with which the international community needs to increase finance for LMICs for climate change mitigation, as well as the associated development opportunities. [ABSTRACT FROM AUTHOR]

Crassulacean Acid Metabolism (CAM) plants have the potential to provide future-proof biomass growth under increasingly stressed climatic conditions. Using active cultivation and anaerobic digestion, CAM plants can be grown and fermented to produce biogas or hydrolysed to extract valuable volatile fatty acids (VFAs) which can be applied to a range of uses: energy provision, protein and bioplastic production, carbon sequestration. However, an understanding of the spatial potential for CAM plants to be actively grown and harvested for bio-economic uses across Africa is unknown. A combined conservative assessment which incorporates three key dimensions is lacking from the literature: i) where can CAM plants physiologically grow? ii) where can CAM plants be cultivated without competing with existing land use? and iii) where lies the greatest energy demand? Answering these three questions and mapping the spatial variability between these aspects is essential to the future bioplastics/protein sector and opportunity to capitalise on generating sustainable energy which can connect off-grid rural and peri-urban communities whilst also achieving climate change mitigation targets. Using Opuntia ficus-indica as an example, this study compares two measures of land suitability estimation based on ecophysiological requirements and social, environmental and land-use masks. Focusing on abandoned land, conservative baseline estimates suggest that c.28–55 million hectares of land may be suitable for active CAM cultivation, with the potential to repurpose degraded lands and provide alternative bio-economic livelihoods to communities across semi-arid regions of Africa. [ABSTRACT FROM AUTHOR]

The interactive dynamics in the food, water, and energy system as a nexus (FWEN) are critical to the sustainable development of global cities, and they can be mediated by green and blue infrastructure (GBI) in the urban area. Here we provide a comprehensive literature review to examine how GBI affects FWEN in urban centers, an area which is currently understudied. In order to do this, we undertake a systematic review of the literature using a meta-analytic approach and topic modelling. Based on our synthesis, we develop a conceptual framework of the key links between urban GBI and FWEN and the direction and magnitude of the relationship. We found that GBIs can benefit food supply, energy saving, and climate change mitigation but at a price of food safety and water contamination. Well-designed urban construction can help curb the negative effects. Therefore, we need to make deliberate and integrative policy to link GBI with each element in urban FWEN. Moreover, the focus of studies on GBIFWEN links is also heterogeneous across cities: urban agriculture and food security are priorities in cities located in Africa and Asia as well as in lower income and larger cities (but not metropolitan areas), while the cooling effect of green space has been a focus for cities of middle or high income. Finally, current research focuses on isolated analysis, lacking integrated studies needed for decision making supporting tools. While isolated analyses lead to connectivity failures and can result in adverse impacts, integrated analyses can identify interdependencies of environmental resources between parts of a cycle and across different scales, which can increase resource efficiency and minimize environmental degradation. Therefore, our key findings point out the importance of linking the effects of GBI on each component of FWEN in both research and policy making. • Studies exploring the effect of GBI on FWEN in cities are rare. • GBI-FWEN links mainly focus on food and green infrastructure. • GBI can have positive and negative effects on urban FWEN. • GBI-FWEN links are heterogenous in global cities (size, location and income level). • The management of urban GBI-FWEN should guide the development of a goal-based framework. [ABSTRACT FROM AUTHOR]

Transformation in the smallholder agricultural sector towards more sustainable and cleaner production systems is needed in Southern Africa. Climate-smart agriculture could be an opportunity in this respect. The paper presents a cost-benefit analysis of the public investment program to promote climate-smart agriculture in Lesotho. Economic profitability of investing in such program in nationwide crop, livestock and aquaculture smallholders' production is assessed, considering costs and benefits at private level and those that accrue to society. Given uncertainty about the future, a development pathway commercially oriented is compared with a pathway aimed at increasing households' capacity to adapt their farming systems to the changing climate. Investment returns are above the opportunity cost of capital, under both pathways, indicating the convenience for farmers and the whole society in investing in climate-smart agriculture. The program also leads to a decrease in the greenhouse gas emissions' intensity, positively contributing to climate change mitigation. The economic evaluation of the carbon-balance increases societal profitability of the investment program. • Climate-smart farming increases smallholder households' income in Southern Africa. • Investing in climate-smart production generates profitable returns to the society. • Benefit-cost analysis can orient climate-smart agriculture policy planning. • Including economic evaluation of Carbon-benefits increases societal convenience. • Farmers actualize agriculture sector's sustainable transformation and development. [ABSTRACT FROM AUTHOR]

Climate change mitigation is a topical issue with growing debate in the context of the renewable energy transition, global partnership, governance, and economic growth. The complexness of climate change makes it difficult to predict relationships and formulate policies across varied countries. Motivated by the core mandate of the Kyoto Protocol, we examined the individual, combined and interactive impact of growth in income, renewable energy, foreign direct investment, and governance on greenhouse gas emissions. We decomposed the relationships to account for the theories of scale effect, composition effect and technique effect. The study utilized a dynamic heterogeneous estimation technique with a panel data from 1990 to 2017 in 47 Sub-Saharan African countries. Our adopted empirical framework made it possible to account for heterogeneity, a situation that may be prevalent in countries with varied economic and environmental policies. The empirical results revealed that increasing the share of renewable energy by 1% declines greenhouse gas emissions by as much as 35.32% (95% Confidence interval) while a 1% increase in the coupling effect of income level, governance, and renewable energy consumption intensifies climate change by 0.79%. The interactive effects of scale, composition, and technique indicators were found to worsen climate change. The decoupling effect revealed that while foreign direct investment, income level, and governance exacerbate climate change, renewable energy consumption lessens climate change and its impact. From a policy perspective, the magnitude of the technique effect of renewable energy consumption depends on, inter alia , its share in the energy portfolio, technological innovation, and country-specific policy instruments. The study demonstrated that decoupling renewable energy from economic growth propels the transition from fossil fuels, leading to energy efficiency— explaining the decline in GHG emissions. • Dynamic heterogeneous method is used to develop 13 conceptual tools for mitigating climate change. • Climate change is decomposed into scale, composition and technique effects. • Increasing renewable energy consumption reduces climate change in Sub-Saharan African. • Income level exacerbates pollution intensities which affect climate change and its impact. • The study confirmed the validity of the Pollution Haven Hypotheses in Africa. [ABSTRACT FROM AUTHOR]

• Carbon sequestration potential through CA in Africa was overestimated with a factor of 10. • CA should be promoted for climate resilience benefits rather than for climate change mitigation. [ABSTRACT FROM AUTHOR]