Brazilian Mangroves: Blue Carbon Hotspots of National and Global Relevance to Natural Climate Solutions

Mangroves are known for large carbon stocks and high sequestration rates in biomass and soils, making these intertidal wetlands a cost-effective strategy for some nations to compensate for a portion of their carbon dioxide (CO2) emissions. However, few countries have the national-level inventories required to support the inclusion of mangroves into national carbon credit markets. This is the case for Brazil, home of the second largest mangrove area in the world but lacking an integrated mangrove carbon inventory that captures the diversity of coastline types and climatic zones in which mangroves are present. Here we reviewed published datasets to derive the first integrated assessment of carbon stocks, carbon sequestration rates and potential CO2eq emissions across Brazilian mangroves. We found that Brazilian mangroves hold 8.5% of the global mangrove carbon stocks (biomass and soils combined). When compared to other Brazilian vegetated biomes, mangroves store up to 4.3 times more carbon in the top meter of soil and are second in biomass carbon stocks only to the Amazon forest. Moreover, organic carbon sequestration rates in Brazilian mangroves soils are 15–30% higher than recent global estimates; and integrated over the country’s area, they account for 13.5% of the carbon buried in world’s mangroves annually. Carbon sequestration in Brazilian mangroves woody biomass is 10% of carbon accumulation in mangrove woody biomass globally. Our study identifies Brazilian mangroves as a major global blue carbon hotspot and suggest that their loss could potentially release substantial amounts of CO2. This research provides a robust baseline for the consideration of mangroves into strategies to meet Brazil’s intended Nationally Determined Contributions.

Clapping From the Arena

Climate change is a serious global issue and concern that is attributed to change. A change of climate that is directly or indirectly related to human activity, that which alters the composition of the global atmosphere and which in addition to natural climate variability observed over comparable time periods. There is therefore no doubt that the earth is warming, and the climate changing. Despotism and the rule of despots as agents of democracy has created a rift in the issue of climate change on its citizenry in the southern zone of Plateau State in the area of health, water shortages, cutting meals due to the economic recession in Nigeria. Research has shown that climate change can create a conflict, and it does have a direct effect on scarce resources required to sustain life. Water is at the heart of human existence. Global warming has a major impact on global water cycle, hence on rainfall, soil moisture, rivers, and sea levels. If climate change is not tackled urgently, the calamity will be enormous.

Adaptive, Resilient Urban Underground Space (UUS)-Subsidence and Economic Impact Spatial Planning Model (USEM): The Extent Development Impact via Cause-Effect Analysis Circa 1980-2050 in Shanghai Megacity

There are multiple factors determined causing the land subsidence (e.g. man-made and natural-climate change) which have impact on the urban built environment economic spectrum e.g. buildings, properties, infrastructures and land. This paper presents the cause-effect investigation of the causing factors which influence the direct-indirect impacting urban economic factor via multi-regression analysis using Shanghai megacity as case study. Factors are selected based on existing UUS-subsidence-economic impact (USEM) framework as well as modification and adaptation from Shanghai Masterplan 2017-2035 (SM 2035) and Sustainable Development Goals (SDGs) 2030. Data are gathered secondarily via open sources e.g. scientific journal articles and reports. The results are parallel to previous studies on the current trend for rapid and unconscious UUS exploration development including tunneling seepage and leakage as leading causes for further land subsidence in Shanghai. A further concrete multi-integrated macro-scale USEM’s awareness and knowledge is needed to avoid future costlier damage. The highly regressed causing factors include increasing population, UUS-induced subsidence, underground tunnel leakage, cumulative UUS development and subsidence whereas building prices, reconstruction area ratio, land price, green buildings, tunnel settlement, loss of arable land, number of death and government revenue are the among the most impacted. Officials in Shanghai may further consider results for future USEM masterplans to prevent further unsustainability. It is also found that developing megacity may possess different factors according to their distinct condition.

What influences the implementation of natural climate solutions? A systematic map and review of the evidence

Emerging research points to large greenhouse gas mitigation opportunities for activities that are focused on the preservation and maintenance of ecosystems, also known as natural climate solutions (NCS). Despite large quantifications of the potential biophysical and carbon benefits of these activities, these estimates hold large uncertainties and few capture the socio-economic bounds. Furthermore, the uptake of NCS remains slow and information on the enabling factors needed for successful implementation, co-benefits, and trade-offs of these activities remain underrepresented at scale. As such, we present a systematic review that synthesizes and maps the bottom-up evidence on the contextual factors that influence the implementation of NCS in the peer-reviewed literature. Drawing from a large global collection of (primarily case study-based, N=211) research, this study (1) clarifies the definition of NCS, including in the context of nature-based solutions and other ecosystem-based approaches to addressing climate change; (2) provides an overview of the current state of literature, including research trends, opportunities, gaps, and biases; and (3) critically reflects on factors that may affect implementation in different geographies. We find that the content of the reviewed studies overwhelmingly focuses on tropical regions and activities in forest landscapes. We observe that implementation of NCS rely, not on one factor, but a suite of interlinked enabling factors. Specifically, engagement of indigenous peoples and local communities (IPLC), performance-based finance, and technical assistance are important drivers of NCS implementation. While the broad categories of factors mentioned in the literature are similar across regions, the combination of factors and how and for whom they are taken up remains heterogeneous globally, and even within countries. Thus our results highlight the need to better understand what trends may be generalizable to inform best practices in policy discussions and where more nuance may be needed for interpreting research findings and applying them outside of their study contexts.

Remote sensing reveals multi-decadal losses of tree cover in California driven by increasing fire disturbance and climate stress

Forests provide natural climate solutions for sequestering carbon and mitigating climate change yet are threatened by increasing temperatures and disturbance. Accurate information on vegetation dynamics is lacking in some regions with forest carbon offset programs and dense forests like California. To address this, we combined remote sensing observations with geospatial databases to develop annual maps of vegetation cover (tree, shrub, herbaceous) and disturbance type (fires, harvest, and forest die-off) in California at 30 m resolution from 1985 to 2021. California lost 3783 km2 of its tree cover area (5.5% relative to initial cover). Early gains in tree cover area were more than offset by fire-driven declines, resulting in greater shrub and herbaceous cover area. Fires and tree cover area loss occurred where temperatures were high or increasing, whereas tree cover gain occurred in cooler areas. Disturbance and warming are threatening the integrity of California's forests and its carbon offsets program.

Recent natural variability in global warming weakened phenological mismatch and selection on seasonal timing in great tits ( Parus major )

Climate change has led to phenological shifts in many species, but with large variation in magnitude among species and trophic levels. The poster child example of the resulting phenological mismatches between the phenology of predators and their prey is the great tit ( Parus major ), where this mismatch led to directional selection for earlier seasonal breeding. Natural climate variability can obscure the impacts of climate change over certain periods, weakening phenological mismatching and selection. Here, we show that selection on seasonal timing indeed weakened significantly over the past two decades as increases in late spring temperatures have slowed down. Consequently, there has been no further advancement in the date of peak caterpillar food abundance, while great tit phenology has continued to advance, thereby weakening the phenological mismatch. We thus show that the relationships between temperature, phenologies of prey and predator, and selection on predator phenology are robust, also in times of a slowdown of warming. Using projected temperatures from a large ensemble of climate simulations that take natural climate variability into account, we show that prey phenology is again projected to advance faster than great tit phenology in the coming decades, and therefore that long-term global warming will intensify phenological mismatches.

Temporary Nature-based Carbon Removal Can Lower Peak Warming in a Well-below 2°C Scenario

There is growing recognition that meeting the climate objectives of the Paris Agreement will require the world to achieve net-zero carbon dioxide emissions around or before mid-century1–4. Natural climate solutions (NCS), which aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems5,6, are increasingly being evoked as a potential contributor to net-zero emissions targets7,8. However, there is a risk that any carbon that we succeed in storing in land-based systems could be subsequently lost back to the atmosphere as a result of either climate-related or human-caused disturbances such as wildfire or deforestation9–12. Here, we show that temporary NCS-based carbon sequestration has the potential to decrease the peak temperature increase, but only if implemented alongside an ambitious mitigation scenario where fossil fuel CO2 emissions were decreased to net-zero during the time that NCS-sequestered carbon remained stored. We also demonstrate the importance of non-CO2 climate effects of NCS implementation, which have the potential to counter a substantial portion of the climate effect of carbon sequestration. Our results suggest that there is some climate benefit associated with temporary NCS, but only if implemented as a complement (and not an alternative) to ambitious fossil fuel CO2 emissions reductions.