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Emissions reduction is not enough
Abstract
In their Review “Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios” (Reviews, 3 July, p. 45), J.-P. Gattuso et al. write that anthropogenic greenhouse gas (GHG) emissions must be drastically reduced to avoid “massive and effectively irreversible
... As an effort to mitigate climate warming, a global political action plan was set in place to limit the global temperature increase to 2°C by reducing C emissions (UNFCCC, 2015). However, emission-cuts alone will not be sufficient to keep global warming below 2°C (Rau & Greene, 2015). Efforts to reduce atmospheric CO 2 through conservation, restoration, and improved land management need to be undertaken, which includes the identification and quantification of natural carbon sinks (Griscom et al., 2017). ...
The identification and quantification of natural carbon (C) sinks is critical to global climate change mitigation efforts. Tropical coastal wetlands are considered important in this context, yet knowledge of their dynamics and quantitative data are still scarce. In order to quantify the C accumulation rate and understand how it is influenced by land use and climate change, a palaeoecological study was conducted in the mangrove-fringed Segara Anakan Lagoon (SAL) in Java, Indonesia. A sediment core was age-dated and analyzed for its pollen and spore, elemental and biogeochemical compositions. The results indicate that environmental dynamics in the SAL and its C accumulation over the past 400 years were controlled mainly by climate oscillations and anthropogenic activities. The interaction of these two factors changed the lagoon's sediment supply and salinity, which consequently altered the organic matter composition and deposition in the lagoon. Four phases with varying climates were identified. While autochthonous mangrove C was a significant contributor to carbon accumulation in SAL sediments throughout all four phases, varying admixtures of terrestrial C from the hinterland also contributed, with natural mixed forest C predominating in the early phases and agriculture soil C predominating in the later phases. In this context, climate-related precipitation changes are an overarching control, as surface water transport through rivers serves as the "delivery agent" for the outcomes of the anthropogenic impact in the catchment area into the lagoon. Amongst mangrove-dominated ecosystems globally, the SAL is one of the most effective C sinks due to high mangrove carbon input in combination with a high allochthonous carbon input from anthropogenically enhanced sediment from the hinterland and increased preservation. Given the substantial C sequestration capacity of the SAL and other mangrove-fringed coastal lagoons, conservation and restoration of these ecosystems is vitally important for climate change mitigation. K E Y W O R D S carbon accumulation rate, climate change, estuary, land use change, mangrove, palaeoecology, watershed, XRF
... Perhaps in response to this inattention as well as the need to address more community based priorities, areas within the state have undertaken initiatives in planning teXas Climate Change Planning at a glanCe a statewide mandatory plan, efforts for climate change mitigation, including greenhouse gas reduction, are often executed at the city or county level. For example, the City of Houston developed the "Emissions Reduction Plan" in 2008, outlining baseline emissions inventory, as well as measures and 2010 emissions goals for the following areas: building and structures, mobile sources, and waste (Green Houston, 2008). This plan has facilitated the development of more than 20 projects in the city and estimates that they have curbed more than 1.5 million tons of greenhouse gas emissions. ...
The study represents a unique effort, which for the first time, brings together many levels of information on health, climate and socio-cultural factors drawing on research, data analysis, Geographic Information Systems (GIS) mapping, policy review and one-on-one interviews with state and local government leaders, academicians, and community-based representatives. Findings reveal that communities of color are especially susceptible to climate change threats, particularly those already burdened by poor health conditions, lack of health care access, low socioeconomic status and lack of integration into planning.
Concerns over the massive increase in CO2 emissions induced by overconsumption of fossil fuels have driven the rapid development of CO2 valorization techniques. Carbon capture and utilization (CCU) technology, which emerged as a promising strategy to relieve increasing environmental concerns and create more carbon feedstocks simultaneously, hold great promise to close the anthropogenic chemical carbon cycle. Herein, recent breakthroughs related to the two predominant techniques involved in returning CO2 into a useful state, namely CO2 capture and CO2 conversion are systematically overviewed. Initially, CO2 capture principles, recent advances, as well as future challenges of state-of-the-art absorbents/adsorbents and membrane separation technology are summarized. Furthermore, innovative catalysts related to the CO2 conversion technologies (including thermo-driven CO2 hydrogenation, photo-and electrochemical CO2 reduction, and enzymatic CO2 conversion) are discussed, emphasis is focused on the catalytic performance, design principles, and economic efficiency. Finally, a perspective regarding the future research opportunities toward CCU technologies is provided. This review aims to stimulate innovation and accelerate interdisciplinary integrations toward CCU related technologies via a discussion of fundamental mechanisms, recent breakthroughs, current associated difficulties as well as future directions.
The county is the basic economic spatial unit in China, and is also an integrated spatial carbon emitter. Focusing on a county, especially the developed counties in the Yangtze River Delta, it is of typical significance and enlightenment to conduct an in-depth and detailed dissection. The spatialization of a county's carbon emissions is crucial for exploring the spatial pattern of carbon emissions, which is fundamental information needed to reduce carbon emissions through the optimization or reorganization of the spatial pattern. This study systematically calculated the carbon emissions of Changxing county from four aspects (including energy; industrial processes and product use; agriculture, forestry, and other land use; and wastes), based on a combination of bottom-up and top-down approaches. Subsequently, we constructed ten carbon emission spatial datasets with a resolution of 50–500 meters (m). According to landscape metrics and the information loss evaluation model, we analyzed the scale effect of carbon emissions at different resolutions and determined the optimal resolution of the spatial carbon emissions at the county scale to be a 200 m × 200 m grid. A reasonable scale of spatial carbon emission data provides support for low-carbon spatial planning and emission reduction policymaking.
The historically unprecedented threats to the marine environment posed by increasing atmospheric carbon dioxide will probably require the use of unconventional, non-passive methods to conserve marine ecosystems. Soliciting such approaches and evaluating their cost, safety and effectiveness must be part of a robust ocean conservation and management plan going forward.
Lunar Prospector (LP) electron reflectometer measurements show that
surface fields are generally weak in the large mare basalt filled impact
basins on the near side but are stronger over highland terranes,
especially those lying antipodal to young large impact basins. Between
the Imbrium and Nectaris basins, many anomalies correlate with the
Cayley and Descartes Formations. Statistical analyses show that the most
strongly magnetic nearside terranes are Cayley-type light plains, terra
materials, and pre-Imbrian craters. Light plains and terrae include
basin impact ejecta as a major component, suggesting that magnetization
effects from basin-forming impacts were involved in their formation. The
magnetization of pre-Imbrian craters, however, may be evidence of early
thermal remanence. Relatively strong, small-scale magnetic anomalies are
present over the Reiner Gamma feature on western Oceanus Procellarum and
over the Rima Sirsalis rille on the southwestern border of Procellarum.
Both Apollo subsatellite and LP data show that the latter anomaly is
nearly aligned with the rille, though LP magnetometer and reflectometer
data show that the anomaly peak is actually centered over a light plains
unit. This anomaly and the Reiner Gamma anomaly are approximately
radially aligned with the center of Imbrium, suggesting an association
with ejecta from this basin.
The equivalent of about 1/4 of annual anthropogenic CO2 emissions is absorbed and stored by the ocean, and the sea plays the primary role in naturally removing excess atmospheric CO2 on geologic timescales. Ways of safely enhancing or augmenting this carbon uptake and storage therefore have the potential to contribute significantly to atmospheric CO2 stabilization efforts. Various physical, chemical, biological, and hybrid strategies of increasing ocean CO2 uptake or reducing CO2 leakage have been proposed. Further research is needed to better determine the full range of options and their costs, benefits, impacts, and overall desirability as CO2 mitigation methods.
To limit global warming to <2 °C we must reduce the net amount of CO2 we release into the atmosphere, either by producing less CO2 (conventional mitigation) or by capturing more CO2 (negative emissions). Here, using state-of-the-art carbon-climate models, we quantify the trade-off between these two options in RCP2.6: an Intergovernmental Panel on Climate Change scenario likely to limit global warming below 2 °C. In our best-case illustrative assumption of conventional mitigation, negative emissions of 0.5-3 Gt C (gigatonnes of carbon) per year and storage capacity of 50-250 Gt C are required. In our worst case, those requirements are 7-11 Gt C per year and 1,000-1,600 Gt C, respectively. Because these figures have not been shown to be feasible, we conclude that development of negative emission technologies should be accelerated, but also that conventional mitigation must remain a substantial part of any climate policy aiming at the 2-°C target.
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