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Lianas are common in tropical forests, where they influence forest dynamics, thus impacting the global carbon sink, with implications for climate change mitigation. Despite their increasing competitiveness with trees at the global scale, robust measurements of liana aboveground biomass (AGB) have been limited. Here we use data from destructive sampling to develop two separate allometric equations for estimating liana AGB from stem diameter in old-growth (n = 15 lianas) and secondary forests (n = 22 lianas). We compared estimates of AGB using our equations for 3141 lianas (≥ 1 cm diameter) in Tanzania's Kilombero Valley against estimates from previously published equations in other tropical regions. Our equations demonstrated stronger correlations between diameter and destructively measured AGB, than those from previously published equations (R2 = 0.86–0.89, versus R2 = 0.82–0.88). Across all stems, the average stem-level liana AGB estimated using the equation for old-growth forests was 52 % higher than that estimated by the equation for secondary forests, showing that lianas have lower biomass per unit diameter in forests impacted by disturbance. In such forests, liana stems are damaged, deformed, or cannot reach maximum height due to reduced structural support. At the scale of the forest stand, our equations estimated a mean liana AGB of 3.25 Mg ha−1 (95 % Confidence Interval: 1.52–6.96) in old-growth forests and 10.19 Mg ha−1 (5.91–17.64) in secondary forests. These estimates roughly aligned with estimates from other equations, although there was considerable variation. Depending on the equation used, mean stand-level estimates of liana AGB ranged from 2.49–9.76 Mg ha−1 in old-growth forests and 10.19–20.74 Mg ha−1 in secondary forests. Our findings show the variability in liana allometry and AGB with disturbance and successional stage, further underscoring a need for caution when comparing estimates of liana biomass across studies and regions. • New allometric models were built to predict liana aboveground biomass from diameter. • Stem-level AGB estimates were 52% higher for old-growth than for secondary forests. • Our models were more accurate in predicting biomass in our region than previous ones. • Model efficacy for estimating liana biomass differed significantly between forests. • Forest disturbance had the greatest influence on variations in liana AGB estimation. [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]

Climate change is a complex and wicked problem, which needs to be addressed through relevant climate change education. However, the preconditions for combatting climate change differ in different parts of the world, depending on physical, cultural and social circumstances. The diversity of circumstances also influences the implementation of climate change in education. Therefore, in this article we have chosen to examine climate change education (CCE) based on an interview study in two distinct school contexts. More specifically, the cases aim to explore Finnish and Tanzanian primary students' views on climate change. A hermeneutical approach guided the analysis, and a significant result was that most of the students understood the severity of climate change. Nevertheless, some misconceptions regarding both causes, consequences and mitigation of climate change were also obvious. In addition, the analysis revealed interesting variations in the students' reasoning, which relate to their different contexts. Unquestionably, the sample size in this study is limited, and further research is needed for a more detailed picture of Finnish and Tanzanian students' views. [ABSTRACT FROM AUTHOR]

Expansion of urban fabric on carbon storages is estimated to cause loss of 1.38 Pg of Above-Ground Carbon (AGC) in pan-tropics between 2000 and 2030. This would be approximately 5% of all emissions caused by tropical land use changes. Despite the significance of the phenomenon, these emissions are rarely measured, monitored, or addressed in climate change mitigation plans, especially in Sub-Saharan Africa. Therefore, we demonstrated a state-of-the-art approach predicting AGC loss of Zanzibar City Region under multiple alternative urban planning scenarios between 2013 and 2030. The AGC information was modeled based on field measured forest inventory sample plots and RapidEye satellite data from 2013, while the future urban expansion model was calibrated with data of happened expansion between 2004, 2009 and 2013, and geospatial independent variables influencing the expansion patterns. This model was then projected until 2030, while alternative urban planning scenarios were integrated to the model by modifying the geospatial variables. The combination of these two models indicates that 42,000 Mg or 15% of total AGC in Zanzibar City Region can be anticipated to be lost by 2030 due to urban expansion. Majority of the loss will take place in the agroforest and fruit tree plantations surrounding the city, while natural forest face limited impacts. None of the tested alternative urban planning scenarios significantly impact the loss of AGC compared to the business-as-usual scenario. Therefore, alternative policies and plans are seriously needed to address the issue in Zanzibar. These could include promoting urban densification, directing urban expansion to low carbon areas, improving soil carbon management, and preparing an urban forestry and greenery strategy. All in all, the study indicates that data and methods are available for monitoring and predicting the phenomenon in Sub-Saharan Africa. Research based on a comparable methodology should be produced from all the main cities in the region that are surrounded by significant carbon storages and facing high urban expansion rates to support climate change mitigation. • There is a knowledge gap related to direct loss of carbon storages caused by urban expansion in the Global South. • Expansion of Zanzibar City will cause direct loss of 42,400 Mg of AGC in 2013–2030. • This will be 15% of the total AGC of the city region and 3% of the whole Unguja island. • None of the tested alternative urban growth scenarios significantly reduced the AGC loss. • Alternative mitigation solutions are needed to reduce the impacts of this rising source of carbon emissions. [ABSTRACT FROM AUTHOR]

Climate change is projected to cause significant reductions in global fisheries catch during the 21st Century. Yet, little is understood of climate change impacts on tropical fisheries, which support many livelihoods, as is the case in the Western Indian Ocean region (WIO). Here, we focus on two central WIO countries ― Kenya and Tanzania ― and run a multi-species fish model (Size Spectrum Dynamic Bio-climate Envelope Model; SS-DBEM) for 43 species of commercial and artisanal importance, to investigate the effects of climate change. We include both national Exclusive Economic Zones (EEZs) as domains. The model was forced by data from a biogeochemical model (NEMO-MEDUSA), run under the high emissions scenario Representative Concentration Pathway (RCP) 8.5, until the end of the 21st century. Impacts of fisheries and climate change were investigated by running SS-DBEM under five scenarios of fishing pressures to predict a range of possible future scenarios. Fishing pressure was represented as the Maximum Sustainable Yield (MSY), expressed as MSY0, MSY1, MSY2, MSY3 and MSY4 representing fishing mortality of 0, 1, 2, 3 and 4 times MSY, respectively. Large reductions in average fish biomass were projected over the 21st Century, with median reductions of fish species biomass of 63–76% and 56–69% for the Kenyan and Tanzanian EEZs respectively across the fishing scenarios. Tunas were particularly impacted by future climate change, with the six modelled species exhibiting biomass reductions of at least 70% in both EEZs for all fishing scenarios during the 21st Century. Reductions in fish biomass were much more severe during the second half of the 21st Century, highlighting the benefits to tropical fisheries of global action on climate change. [Display omitted] • Projection of impact of climate change (under RCP8.5) on 43 key species. • Focus on two central WIO countries: Kenya and Tanzania. • Large reductions in average fish biomass with median reductions of up to 76%. • Reductions in fish biomass more severe during the second half of the 21st Century. [ABSTRACT FROM AUTHOR]