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• The nexus between forest-based climate mitigation and health is poorly researched. • This scoping review identified exposure pathways and health co-benefits from forests. • There is potential for synergies between forest management and health benefits. • Interdisciplinary efforts are required for advancement of research and understanding. Climate change is a pressing global challenge with profound implications for human health. Forest-based climate change mitigation strategies, such as afforestation, reforestation, and sustainable forest management, offer promising solutions to mitigate climate change and simultaneously yield substantial co-benefits for human health. The objective of this scoping review was to examine research trends related to the interdisciplinary nexus between forests as carbon sinks and human health co-benefits. We developed a conceptual framework model, supporting the inclusion of exposure pathways, such as recreational opportunities or aesthetic experiences, in the co-benefit context. We used a scoping review methodology to identify the proportion of European research on forest-based mitigation strategies that acknowledge the interconnection between mitigation strategies and human impacts. We also aimed to assess whether synergies and trade-offs between forest-based carbon sink capacity and human co-benefits has been analysed and quantified. From the initial 4,062 records retrieved, 349 reports analysed European forest management principles and factors related to climate change mitigation capacity. Of those, 97 studies acknowledged human co-benefits and 13 studies quantified the impacts on exposure pathways or health co-benefits and were included for full review. Our analysis demonstrates that there is potential for synergies related to optimising carbon sink capacity together with human co-benefits, but there is currently a lack of holistic research approaches assessing these interrelationships. We suggest enhanced interdisciplinary efforts, using for example multideterminant modelling approaches, to advance evidence and understanding of the forest and health nexus in the context of climate change mitigation. [ABSTRACT FROM AUTHOR]

Marine primary productivity is a critical driver of functioning marine ecosystems, providing a foundation for biological diversity and associated economic productivity, and a key component of the oceanic carbon sink. However, it is largely under-represented within the global marine protected area estate and has been widely ignored in global priority assessments for marine conservation. Using global high-resolution data on marine primary productivity and human cumulative impact to marine systems, more than 18.6 million km² of high productivity-low impact areas in the global ocean were identified. These areas occur across all ocean basins and represent the vast majority of marine provinces and ecoregions. Over 80% of these highly productive waters with low levels of human impact lies within national jurisdictions and yet only 11% of the overall identified area is currently safeguarded within designated marine protected areas or sustainable management initiatives, leaving more than 16.5 million km2 of high productivity-low impact areas without those forms of formal protection. The multifaceted contribution of these areas to preserve biodiversity, support human welfare and help mitigating climate change suggest they are an essential, but currently overlooked, conservation priority for consideration in both global nature conservation and human wellbeing policy fora. ● Over 18 million km2 of highly productive waters with low human impact exist globally. ● These areas exist across all ocean basins and most marine provinces and ecoregions. ● Only 11% of these areas lie within marine protected areas and OECMs. ● Over 15 million km2 of these areas occur in waters of national jurisdiction. ● About 3.5 million km2 of these areas occur in areas beyond national jurisdiction. [ABSTRACT FROM AUTHOR]

[Display omitted] • CO 2 fluxes were measured in three subtropical mangroves for 16 site years. • VPD stress inhibits mangrove productivity during both exposed and inundated periods. • Meteorological factors and VPD have interactive effects on mangrove productivity. • Tides have independent effects on mangrove productivity through salinity changes. • The threshold effect range of VPD stress on mangrove productivity is 2.50–2.95 kPa. Subtropical mangroves have great potential to sequester atmospheric carbon dioxide (CO 2) and thus significantly contribute to climate change mitigation. Meanwhile, the carbon cycling processes in subtropical mangroves are vulnerable to the changing climatic conditions, such as the warming-induced vapor pressure deficit (VPD) increases. However, the impacts of VPD on net ecosystem production (NEP) in subtropical mangroves remain poorly understood due to a lack of detailed assessment of NEP responses to VPD among different mangrove forests over a long-term observational period. In this study, we deployed eddy-covariance systems to measure net ecosystem CO 2 exchange at three subtropical mangrove forests for 16 site-years, comprising two natural and one artificial forests. We employed a state-of-the-art data-driven modeling approach (i.e., Shapley additive explanations (SHAP) framework based on extreme gradient boosting model), which enabled us to explore the interactive effects of meteorological and tidal factors (e.g. salinity) with VPD on the mangrove NEP. We revealed that air temperature, global solar radiation (GR) and wind speed have significant interactions on the response of NEP to VPD stress in subtropical mangroves. For instance, when GR was high, the SHAP interaction values of VPD and GR on NEP decreased with increasing VPD, but when GR was low, the trends were the opposite. However, instead of identifying interactive effects between tidal salinity and VPD on mangrove NEP, we came across potential independent influence of salinity on the same. SHAP analysis was also able to disentangle the impact of VPD from other abiotic drivers. Thus, we evaluated the threshold effect of VPD stress on NEP loss in subtropical mangroves and observed a range of 2.50–2.95 kPa. Above this range, VPD stress leveled off. The subtropical mangrove responses to VPD should be therefore considered in the dynamic global vegetation models to increase the accuracy in carbon cycle simulations in the future. [ABSTRACT FROM AUTHOR]

Carbon emission reduction in China matters to global climate change mitigation. China has been experiencing extensive land changes, which profoundly influence terrestrial ecosystem carbon storage (TECS) and carbon emissions. Scholars have predicted influences of land changes on TECS in China with scenarios obtained from global integrated assessment models (IAMs), which lack national details. Moreover, universally existing variations in land-use intensity have not been considered when estimating influences on TECS. This study simulated changes of land-use intensity of China from 2000 to 2050 using CLUMondo under China-specified policies for sustainable development modeled by a national IAM named Threshold21-China. We proposed a more precise TECS estimation method by distinguishing land-vegetation and land-soil types. Results demonstrated that under scenario with preceding policies, the total TECS can increase by 865.5 Tg C from 2000 to 2050. Through implementing preceding policies, TECS loss by conversions from cultivated land to artificial surfaces can decline by 82 Tg C, and new TECS accumulated by increased and densified forests can increase by 73 Tg C. Mountainous and rapidly urbanizing regions are sensitively influenced and need more restrict land change management policies. This study demonstrates the significance of sustainable development policies for TECS conservation and indicates specific critical regions. • Introducing national IAM into land change simulation. • Considering land-use intensities in land change simulation. • Proposing an improved TECS estimation method. • Estimating influences of land changes on China's TECS. • TECS accumulation could be improved under sustainable policies. [ABSTRACT FROM AUTHOR]

• Carbon footprint at the UBI consumption level is 4.8 tCO 2 -eq per capita. • UBI carbon footprint is around half of the average carbon footprint in Finland. • Downscaling consumption alone is not enough to achieve sustainable lifestyles. • Additional mitigation solutions are needed alongside downscaling. • At a societal level, downscaling is hard to reconcile with high social security. Human economic activities and following carbon emissions have been recognized to be a real threat to the environment. The current levels of consumption-based carbon footprints in all developed economies grossly exceed the sustainable level. Scientists have concluded that in addition to technological solutions, downscaling of consumption and far-reaching changes in lifestyles will be needed to achieve environmental sustainability. In this study, we provide a tangible real-world example that reveals the scale of the needed change from a perspective of a European welfare state citizen. Universal basic income (UBI) represents an income that is just enough to fulfil basic needs, such as food, shelter, and medication. In our case country, Finland, UBI is in practice at the same level as the income of the lowest income decile. The purpose of this study is to present and analyse the carbon footprints at a consumption level that corresponds to UBI. We compare the carbon footprints at this low-income level to average Finnish carbon footprints and discuss their sustainability in the light of global carbon budgets. We use an input-output approach based on the Finnish ENVIMAT model. The average carbon footprint at the UBI level is 4.8 tCO 2 -eq and it focuses on necessities. It's significantly lower than the average carbon footprint in Finland, 9.4 tCO 2 -eq, but still far from the level compatible with the current climate change mitigation targets. The results emphasize how challenging it is to find true low-carbon solutions for living in affluent countries. Lifestyle changes and technological leaps need to be combined and fostered by legislation. [ABSTRACT FROM AUTHOR]

As interest in natural climate mitigation solutions continues to grow, there is an essential role for coastal and ocean ecosystems ("blue carbon") to play. To meet mitigation targets, however, it is crucial that human actions to protect or restore blue carbon sinks are based on solid science and actionable human management opportunities to increase sinks and reduce emissions from ecosystem loss. Here, we reaffirm the role of coastal wetlands in climate mitigation opportunities. We update the state of the science regarding existing blue carbon pathways and explore expanding the blue carbon opportunities to new systems. Specifically, we analyze new science for those blue carbon pathways we categorize as "emerging" (e.g., management interventions involving macroalgae - both cultivated and wild, tidal flats, and marine sediments) where human action may be able to increase these sinks, but we currently have insufficient information to ensure that their climate mitigation benefit is additional. We revisit those that are "non-actionable" (e.g., management interventions involving calcifying organisms and marine fauna) where the scientific evidence is clear that there is no mitigation benefit, or the science is too uncertain to claim that human action can definitively increase these carbon sinks. With limited funding for climate action, it is critical that efforts focus on projects with the most mitigation potential. Blue carbon management is only one piece in the climate mitigation challenge, but it is an important one. Continued scientific research and investment in developing policy pathways is warranted for these actionable and emerging systems. At the same time, the world must continue to work to decrease emissions rapidly, invest in other natural climate solutions, and scale renewable energy technologies. [ABSTRACT FROM AUTHOR]

• Most country long-term climate strategies envision reliance on NETs. • Most countries emphasize NETs that enhance natural carbon sinks. • Few countries explicitly envision slowing down short-term mitigation measures. • Countries estimate huge carbon sink potentials despite pervasive uncertainties. • This may set in motion a spiral of delay as uncertainties are sought to be reduced. In order to address the pressing challenge of climate change, countries are now submitting long-term climate strategies to the United Nations Framework Convention on Climate Change (UNFCCC) process. These strategies include within them potential future use of 'negative emissions technologies' (NETs). NETs are interventions that remove carbon from the atmosphere, ranging from large-scale terrestrial carbon sequestration in forests, wetlands and soils, to use of carbon capture and storage technologies. We assess here how NETs are discussed in 29 long-term climate strategies, in order to ascertain the risk that including the promise of future NETs may delay the taking of short-term mitigation actions. Our analysis shows that almost all countries plan to rely on NETs, particularly enhanced use of natural carbon sinks, even as a wide array of challenges and trade-offs in doing so are highlighted. Many strategies call for improved accounting systems and market incentives in realizing future NETs. While no strategy explicitly suggests that NETs can be a substitute for short-term mitigation, most estimate substantial potential for future use of NETs even in the face of acknowledged uncertainties. This, we suggest, may have the consequence of resulting in what we describe here as 'a spiral of delay' characterized by the promise of future NET options juxtaposed with the simultaneous uncertainty around these future options. Our analysis highlights that this inter-connected delaying dynamic may be intrinsic to what we term 'governing-by-aspiration' within global climate politics, wherein the voicing of lofty future ambition risks replacing current action and accountability. [ABSTRACT FROM AUTHOR]

Blue carbon ecosystems (BCE) include mangrove forests, tidal marshes, and seagrass meadows, all of which are currently under threat, putting their contribution to mitigating climate change at risk. Although certain challenges and trade-offs exist, remote sensing offers a promising avenue for transparent, replicable, and cost-effective accounting of many BCE at unprecedented temporal and spatial scales. The United Nations Framework Convention on Climate Change (UNFCCC) has issued guidelines for developing blue carbon inventories to incorporate into Nationally Determined Contributions (NDCs). Yet, there is little guidance on remote sensing techniques for monitoring, reporting, and verifying blue carbon assets. This review constructs a unified roadmap for applying remote sensing technologies to develop cost-effective carbon inventories for BCE – from local to global scales. We summarise and discuss (1) current standard guidelines for blue carbon inventories; (2) traditional and cutting-edge remote sensing technologies for mapping blue carbon habitats; (3) methods for translating habitat maps into carbon estimates; and (4) a decision tree to assist users in determining the most suitable approach depending on their areas of interest, budget, and required accuracy of blue carbon assessment. We designed this work to support UNFCCC-approved IPCC guidelines with specific recommendations on remote sensing techniques for GHG inventories. Overall, remote sensing technologies are robust and cost-effective tools for monitoring, reporting, and verifying blue carbon assets and projects. Increased appreciation of these techniques can promote a technological shift towards greater policy and industry uptake, enhancing the scalability of blue carbon as a Natural Climate Solution worldwide. • Blue carbon ecosystems (BCE) play a key role in climate change mitigation. • Remote sensing techniques are cost-effective for monitoring BCE extent and carbon stocks. • A tradeoff exists between spatial resolution and historical coverage of remotely sensed data. • New technologies can facilitate the inclusion of BCE in national inventories and Nationally Determined Contributions (NDCs). • Our decision tree guides the choice of remote sensing methods for monitoring BCE. [ABSTRACT FROM AUTHOR]

• Large uncertainties are associated with the future magnitude and stability of the forest carbon sink. • Business-as-usual management practices might already be close-to-optimum for supporting forest carbon uptake and storage. • Increases in management intensity have the potential to lower forest carbon sequestration and stocking capacity. • Forest management practices are as important as climate change to regulatethe carbon sink and stock size. Forest management practices might act as nature-based methods to remove CO 2 from the atmosphere and slow anthropogenic climate change and thus support an EU forest-based climate change mitigation strategy. However, the extent to which diversified management actions could lead to quantitatively important changes in carbon sequestration and stocking capacity at the tree level remains to be thoroughly assessed. To that end, we used a state-of-the-science bio-geochemically based forest growth model to simulate effects of multiple forest management scenarios on net primary productivity (NPP) and potential carbon woody stocks (pCWS) under twenty scenarios of climate change in a suite of observed and virtual forest stands in temperate and boreal European forests. Previous modelling experiments indicated that the capacity of forests to assimilate and store atmospheric CO 2 in woody biomass is already being attained under business-as-usual forest management practices across a range of climate change scenarios. Nevertheless, we find that on the long-term, with increasing atmospheric CO 2 concentration and warming, managed forests show both higher productivity capacity and a larger potential pool size of stored carbon than unmanaged forests as long as thinning and tree harvesting are of moderate intensity. [Display omitted] [ABSTRACT FROM AUTHOR]

This study examines empirically climate change related vulnerability impacts, and remedial options as an optimal and applicable strategy by prioritizing needs in climate change mitigation over 95 years. An Empirical Downscaling Dynamic Integrated model of Climate and the Economy (EDDICE) is deployed using an optimal scenario for Malaysia against a baseline scenario of existing conditions following the top-down disaggregation strategy recommended by other studies. The model takes account of various climatic variables, including, temperature, carbon cycle, carbon emission, climatic damage, carbon control, and carbon concentration, which was adapted from observational records of climatic changes caused by global warming from 2010 to 2105. The results are interesting in prioritizing climate change mitigation for the future. Whereas the cumulative cost of climatic damage over the period 2010–2105 will amount to MYR40,128.1 billion under the present climatic regime in Malaysia, it will fall to MYR5263.7 billion under the optimal regime. In addition, the government would have collected revenue from carbon taxes amounting to MYR9535.4 billion over the 95 years. [ABSTRACT FROM AUTHOR]

At present, global warming is an indisputable fact, and more and more attention has been paid to the impacts of climate warming on global ecological environments. Forests play increasing significant roles in regulating global carbon balance and mitigating climate change. Therefore, to understand the response mechanisms of the carbon budget of global forest ecosystems to future climate change, an improved version of the FORest ecosystem Carbon budget model for CHiNa (FORCCHN) and future Representative Concentration Pathway (RCP) scenario RCP4.5 and RCP8.5 were applied in this study. The results demonstrated that the global forest ecosystems will play a major role in the carbon sink under the future two climate change scenarios. In particular, the average carbon budget of global forest ecosystems under RCP4.5 scenario was estimated to be 0.017 kg(C)·m−2·yr−1 from 2007 to 2100. The future carbon sink areas of global forest ecosystems will increase significantly. Under RCP4.5 and RCP8.5 climate scenarios, the carbon sink areas of global forest ecosystems during 2026–2100 would be significantly been expanded than those in 2007–2025, with increases of 83.16–87.26% and 23.53–29.70%, respectively. The impacts of future climate change on carbon budget of global forest ecosystems will significantly vary between different regions. The carbon budget of forests will be enhanced in the northern hemisphere and significantly weakened in the southern hemisphere under the future two climate change scenarios. The carbon sink regions of global forests will be mainly distributed in the middle and high latitudes of the northern hemisphere. In particular, the forests' carbon budget in northeastern and central Asia, northern Europe and western North America will increase by 40% ~ 80%. However, the carbon budget of forests will decrease by 20% ~ 40% in the most regions of the southern hemisphere. In northern South America and central Africa, the forests' carbon budget will be reduced by more than 40%. In the future, in some areas of southern hemisphere, where the forests' carbon budget was predicted to be reduced, some measures for improving forest carbon sink, such as strengthening forest tending, enforcing prohibiting deforestation laws and scientific forest management, and so on, should be implemented to ensure immediate mitigation and adaptation to climate change. • We quantitatively evaluated the role of global forest in terrestrial carbon cycle. • We explored the spatial-temporal dynamics of future global forest carbon budget. • We simulated the responses of global forest carbon budget to future climate change. • Individual-based carbon budget model FORCCHN and remote sensing outputs were used. [ABSTRACT FROM AUTHOR]

The African Sahel-Sudano-Guinean region is one of the largest water limited environments in the world, thus making it highly vulnerable to climate change. Recent studies have shown vegetation greening in the region, but few have investigated the impact of this greening on carbon and water cycles. We used a combination of earth observation (EO) data and a diagnostic model to evaluate the extent of the vegetation greening and its impacts on carbon sequestration potential (i.e., Gross Primary Productivity-GPP) and the water cycle (i.e., Evapotranspiration-ET and Water Use Efficiency-WUE) from 1982 to 2015. Additionally, we evaluated the influence of key climatic variables (i.e., precipitation, temperature, and solar radiation) on vegetation greening, carbon sequestration potential and the water cycle. Our results showed widespread vegetation greening during the first half of the study period (1982–2000), driven mainly by increase in precipitation. However, the rate of greening reduced or became stagnant during the latter half of the study (2000–2015), but did not revert to pre-greening levels of 1980s, implying a persistent ecosystem change. The vegetation greening and increased precipitation resulted in a ~ 17.95% increase in GPP (from ~3.9 PgC/year in 1982 to ~4.6 PgC/year in 2000) and a ~ 21.28% increase in ET (from ~47 mm/year in 1982 to ~57 mm/year in 2015). The WUE showed an overall reduction, mainly attributed to large increases in ET not matched by similar magnitude of increases in GPP. Currently, there is lack of consensus on the magnitude of the contribution of drylands to the global carbon and water cycle. This study shows that drylands undergoing ecosystem change, coupled with climate change, may in future become important contributors to the global carbon and water cycle. Therefore, they could play a key role in future global warming and climate change mitigation strategies. • Widespread vegetation greening from 1982 to 2000, which stagnates from 2000 to 2015 • Precipitation dynamics was the key driver to vegetation greening. • Greening led to increases in gross primary productivity and evapotranspiration. • Overall reduction in water use efficiency was observed in the region. • Potential changes in future role of drylands in the global carbon and water cycle. [ABSTRACT FROM AUTHOR]

• This sugarcane agro-system was a carbon sink. • The NEE of CO 2 fluxes (assimilation versus respiration) dominated the balances. • The N 2 O and CH 4 emitted totals were offset by the C gain. The sustainability of sugarcane farming for biofuel has recently become a subject of debate, because its expansion may contribute significantly to global climate change mitigation. Here we report greenhouse gases (GHG) fluxes, measured by the eddy covariance method, from a commercial scale rain-fed sugarcane plantation representative of the leading bioethanol production area in southeast Brazil. The measurements covered two harvests, during which the field received nitrogen fertilization and trash was not removed. The cumulative fluxes for nitrous oxide (N 2 O) (62.4 ± 1.3 and 52.3 ± 1.8 g N 2 O CO 2 eq. m−2 for the first and second years, respectively) and methane (CH 4) (12.1 ± 1.7 and 10.4 ± 2.3 g CH 4 CO 2 eq. m−2 for the first and second years, respectively) were minor sources to the atmosphere in comparison with the net ecosystem exchange (NEE) of carbon dioxide (CO 2), whose sink dominated the balances (−7643. ± 129. and -4615. ± 124. g CO 2 m−2 for the first and second years, respectively). Compared to the first year, the observed NEE in the second year decreased by 40%, as it covered the first re-growth from the stubble (ratoon) and exhibited a shorter growth cycle than the first year (304 versus 390 days). The second year also included the partial decomposition of the trash remaining on the soil after the first harvest (1581 ± 301 g CO 2 m−2). The net ecosystem carbon balances (NECB), obtained as the cumulative fluxes of GHGs and the stalk dry biomass removed in the harvests (4923 ± 459 and 3929 ± 352 g CO 2 m−2 for the first and second years, respectively) were -2646 ± 459 and -623 ± 352 g CO 2 m−2 for the first and second years, respectively. Although the yields in stalk fresh weight (SFW) were representative of the region (9.9 and 8.2 kg SFW m−2, in the first and second year respectively) other factors caused a decrease of 76% in NECB, stressing the importance of the CO 2 balance (assimilation versus respiration). Nevertheless, this sugarcane agro-system was an overall carbon sink with the N 2 O and CH 4 emitted totals being offset by the net carbon gain. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Climate change mitigation in rapidly growing developing countries is receiving increased global attention, especially after the 2016 Paris Agreement. In Bangladesh, the government has initiated some climate change policies to reduce its greenhouse gas emissions in the last decade. However, the rate of emissions has been increasing recently, which questions the emissions reduction potential of these policies. Therefore, this study has utilized relevant indicators to evaluate the extent to which the policies are mitigating climate change, and of their synergy with national development goals. The findings indicate that the policies have limited impacts on energy decarbonization, energy demand management, and emissions sink improvement. Although policies on renewable energy, energy efficiency and demand management, and afforestation are aligned with national development goals, the policies on electricity generation from coal and forest biomass have little synergy with the goals. By quantitatively evaluating the effects of its climate change policies in enhancing socioeconomic, and environmental benefits, this study can assist Bangladesh's policymakers to understand the impact of the policies on climate change mitigation and their level of integration with national development goals. Also, other developing countries can adopt the study methodology to evaluate their climate change policies and track their progress. Image 10614 • Customized indicators were used to evaluate the effects of climate policies. • Bangladesh's energy efficiency measures have achieved some success in recent years. • Decarbonization, energy demand management and carbon sink options are inadequate. • Increased use of coal and biomass hinders achieving the national development goals. • Renewables and afforestation programs have synergy with national development goals. [ABSTRACT FROM AUTHOR]

• Molecular analysis of 3200 yr Posidonia australis seagrass soil record (Australia). • Tracing diagenetic effects on sheaths and root/rhizome detritus. • Ageing-induced selective degradation of polysaccharides and enrichment of lignin. • Minor constituents cutin, suberin and tannin also preferentially depleted. • Overall C storage capacity associated with lignocellulose chemical recalcitrance. Seagrass ecosystems are recognised for their role in climate change mitigation, due to their capacity to form organic-rich sediments. The chemical recalcitrance of seagrass organs is one characteristic driving carbon storage, but the molecular background of this feature is poorly understood. We assessed molecular composition changes of Posidonia australis sheaths (SH) and roots plus rhizomes (RR) along a sediment core, encompassing 3200 cal. yr BP, by means of nuclear magnetic resonance spectroscopy (13C NMR), conventional analytical pyrolysis (Py-GC–MS) and thermally assisted hydrolysis and methylation (THM-GC–MS). Significant trends with depth (age) in the composition of both SH and RR remains of P. australis were observed from all methods. In general terms, polysaccharides become depleted (degraded) and lignin enriched (selectively preserved) as age increases, and the minor constituents cutin, suberin and condensed tannin are also preferentially depleted during ageing in both fractions. Molecular changes with ageing were smaller in SH, especially regarding polysaccharides, indicative of a superior stability compared to RR. The molecular changes observed are most pronounced within the first 75 cm of the record, which reflects the recalcitrance of P. australis detritus once it is buried below that depth (corresponding to approximately 700 cal. yr BP). The capacity of P. australis to act as a long-term carbon sink seems to be mainly related to the resistance of buried lignocellulose materials to decomposition. The results on diagenetic effects on the molecular fingerprint of seagrass detritus contribute to our understanding of carbon sequestration in Blue Carbon ecosystems. Furthermore, data comparison of the methods applied using principal component analysis (PCA) allowed us to identify consistencies, discrepancies and complementarities. [ABSTRACT FROM AUTHOR]