Social and ecological effectiveness of large marine protected areas

Large marine protected areas are increasingly being established to meet global conservation targets and promote sustainable use of resources. Although the factors affecting the performance of small-scale marine protected areas are relatively well studied, there is no such body of knowledge for large marine protected areas. We conducted a global meta-analysis to systematically investigate social, ecological, and governance characteristics of successful large marine protected areas with respect to several social and ecological outcomes. We included all large (>10,000 km²), implemented (>5 years of active management) marine protected areas that had sufficient data for analysis, for a total of twelve cases. We used the Social-Ecological Systems Meta-Analysis Database, and a consistent protocol for using secondary data and key informant interviews, to code proxies for fisheries, ecosystem health, and the wellbeing of user groups (mainly fishers). We tested four sets of hypotheses derived from the literature on small-scale marine protected areas and common-pool resources: (i) the attributes of species and ecosystems to be managed in the marine protected area, (ii) adherence to principles for designing small-scale marine protected areas, (iii) adherence to the design principles for common-pool resource management, and (iv) stakeholder participation. We found varying levels of support for these hypotheses. Improved fisheries were associated with older marine protected areas, and higher levels of enforcement. Declining fisheries were associated with several ecological and economic factors, including low productivity, high mobility, and high market value. High levels of participation were correlated with improvements in wellbeing and ecosystem health trends. Overall, this study constitutes an important first step in identifying factors affecting social wellbeing and ecological performance of large marine protected areas.     

Impacts and adaptation to climate change in European economies

This paper evaluates the impacts of climate change to European economies under an increase in global mean temperature at +2 °C and +4 °C. It is based on a summary of conclusions from available studies of how climate change may affect various sectors of the economies in different countries. We apply a macroeconomic general equilibrium model, which integrates impacts of climate change on different activities of the economies. Agents adapt by responding to the changes in market conditions following the climatic changes, thus bringing consistency between economic behaviour and adaptation to climate change. Europe is divided into 85 sub-regions in order to capture climate variability and variations in vulnerabilities within countries. We find that the impacts in the +2 °C are moderate throughout Europe, with positive impacts on GDP in some sub-regions and negative impacts down to 0.1 per cent per year in others. At +4 °C, GDP is negatively affected throughout Europe, and most substantially in the southern parts, where it falls by up to 0.7 per cent per year in some sub-regions. We also find that climate change causes differentiations in wages across Europe, which may cause migration from southern parts of Europe to northern parts, especially to the Nordic countries.     

Drivers,constraints and trade-offs associated with recultivating abandoned cropland in Russia,Ukraine and Kazakhstan

Further cropland expansion might be unavoidable to satisfy the growing demand for land-based products and ecosystem services. A crucial issue is thus to assess the trade-offs between social and ecological impacts and the benefits of converting additional land to cropland. In the former Soviet Union countries, where the transition from state-command to market-driven economies resulted in widespread agricultural land abandonment, cropland expansion may incur relatively low costs, especially compared with tropical regions.Our objectives were to quantify the drivers, constraints and trade-offs associated with recultivating abandoned cropland to assess the potentially available cropland in European Russia, western Siberia, Ukraine and Kazakhstan—the region where the vast majority of post-Soviet cropland abandonment took place. Using spatial panel regressions, we characterized the socio-economic determinants of cropland abandonment and recultivation. We then used recent maps of changes in cropland to (i) spatially characterize the socio-economic, accessibility and soil constraints associated with the recultivation of abandoned croplands and (ii) investigate the environmental trade-offs regarding carbon stocks and habitat for biodiversity.Less cropland abandonment and more recultivation after 2000 occurred in areas with an increasing rural population and a younger labor force, but also improved yields. Synergies were observed between cropland recultivation and intensification over the 2000s. From 47.3 million hectares (Mha) of cropland abandoned in 2009, we identified only 8.5 (7.1–17.4) Mha of potentially available cropland with low environmental trade-offs and low to moderate socio-economic or accessibility constraints that were located on high-quality soils (Chernozems). These areas represented an annual wheat production potential of ∼14.3 (9.6–19.5) million tons (Mt). Conversely, 8.5 (4.2–12.4) Mha had high carbon or biodiversity trade-offs, of which ∼10% might be attractive for cropland expansion and thus would require protection from recultivation. Agro-environmental, accessibility, and socio-economic constraints suggested that the remaining 30.6 (25.7–30.6) Mha of abandoned croplands were unlikely to provide important contributions to future crop production at current wheat prices but could provide various ecosystem services, and some could support extensive livestock production. Political and institutional support could foster recultivation by supporting investments in agriculture and rural demographic revitalization. Reclaiming potentially available cropland in the study region could provide a notable contribution to global grain production, with relatively low environmental trade-offs compared with tropical frontiers, but is not a panacea to address global issues of food security or reduce land-use pressure on tropical ecosystems.     

Circulation analysis in the northwest Indian Ocean using ARGO floats and surface drifter observations,and SODA reanalysis output

This study incorporates observations from Array of Real-time Geostrophic Oceanography (ARGO) floats and surface drifters to identify seasonal circulation patterns at the surface, 1000 m, 1500 m, and 2000 m in the northwest Indian Ocean, and quantify velocities associated with them. A skill comparison of the Simple Ocean Data Assimilation (SODA) reanalysis output was also performed to contribute to the understanding of the circulation dynamics in this region.Subsurface currents were quantified and validated using the ARGO float data. Surface currents were identified using surface drifter data and compared to the subsurface observations to enhance our previous understanding of surface circulations. Quantified Southwest Monsoon surface currents include the Somali Current (v_max = 179.5 cm/s), the East Arabian Current (v_max = 52.3 cm/s), and the Southwest Monsoon Current (v_max = 51.2 cm/s). Northeastward flow along the Somali coast is also observed at 1000 m (v_max = 26.1 cm/s) and 1500 m (v_max = 12.7 cm/s). Currents associated with the Great Whirl are observed at the surface (v_max = 161.4 cm/s) and at 1000 m (v_max = 16.2 cm/s). In contrast to previous studies, both ARGO and surface drifter data show the Great Whirl can form as early as the boreal Spring intermonsoon, lasting until the boreal Fall intermonsoon. The Arabian Sea exhibits eastward/southeastward flow at the surface, 1000 m, 1500 m, and 2000 m. Quantified Northeast Monsoon surface currents include the Somali Current (v_max = 97.3 cm/s), Northeast Monsoon Current (v_max = 30.0 cm/s), and the North Equatorial Current (v_max = 28.5 cm/s). Southwestward flow along the Somali coast extends as deep as 1500 m.Point-by-point vector and scalar correlations of SODA output to ARGO and surface drifter data showed that surface SODA output and surface drifter data generally produced a strong correlation attributed to surface currents strongly controlled by the monsoons, while subsurface correlations of SODA output and ARGO were mostly insignificant due to variability associated with intermonsoonal transitions. SODA output produced overall smaller velocities than both observational datasets. Assimilating ARGO velocities into the SODA reanalysis could improve subsurface velocity assimilation, especially during the boreal fall and spring when ARGO observations suggest that flow is highly variable.     

Scientists’ views on economic growth versus the environment: a questionnaire survey among economists and non-economists

The academic debate on economic growth, the environment and prosperity has continued for many decades now. In 2015, we conducted an online survey of researchers’ views on various aspects of this debate, such as the compatibility of global GDP growth with the 2 °C climate policy target, and the timing and factors of (never-)ending growth. The 814 respondents have a wide range of backgrounds, including growth theory, general economics, environmental economics, ecological economics, environmental social sciences, and natural sciences. The two main aims are: (1) to provide an overview of agreements and disagreements across research fields, and (2) to understand why opinions differ. The survey results indicate substantial disagreement across research fields on almost every posed question. Environmental problems are most frequently mentioned as a very important factor contributing to an end of economic growth. Furthermore, we find that researchers are more skeptical about growth in the context of a concrete problem like the compatibility with the 2 °C climate target than when considering environmental problems more generally. Many respondents suggest ideology, values and worldviews as important reasons for disagreement. This is supported by the statistical analysis, showing that researchers’ political orientation is consistently correlated with views on growth.     

A Mediterranean nocturnal heavy rainfall and tornadic event. Part I: Overview,damage survey and radar analysis

This study presents an analysis of a severe weather case that took place during the early morning of the 2nd of November 2008, when intense convective activity associated with a rapidly evolving low pressure system affected the southern coast of Catalonia (NE Spain). The synoptic framework was dominated by an upper level trough and an associated cold front extending from Gibraltar along the Mediterranean coast of the Iberian Peninsula to SE France, which moved north-eastward. South easterly winds in the north of the Balearic Islands and the coast of Catalonia favoured high values of 0–3 km storm relative helicity which combined with moderate MLCAPE values and high shear favoured the conditions for organized convection. A number of multicell storms and others exhibiting supercell features, as indicated by Doppler radar observations, clustered later in a mesoscale convective system, and moved north-eastwards across Catalonia. They produced ground-level strong damaging wind gusts, an F2 tornado, hail and heavy rainfall. Total lightning activity (intra-cloud and cloud to ground flashes) was also relevant, exhibiting several classical features such as a sudden increased rate before ground level severe damage, as discussed in a companion study. Remarkable surface observations of this event include 24 h precipitation accumulations exceeding 100 mm in four different observatories and 30 minute rainfall amounts up to 40 mm which caused local flash floods. As the convective system evolved northward later that day it also affected SE France causing large hail, ground level damaging wind gusts and heavy rainfall.     

Concentrations and sources of PAHs at three stations in Istanbul,Turkey

The chemical mass balance model was applied to atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in Istanbul, Turkey. A total of 326 airborne samples were collected and analyzed for 16 PAHs and Total Suspended Particles (TSP) in the September 2006–December 2007 period at three monitoring stations: Yildiz, DMO (urban sites) and Kilyos (rural site). The total average PAH concentrations were 100.66 ± 61.26, 84.63 ± 46.66 and 25.12 ± 13.34 ng m^?3 and the TSP concentrations were 101.16 ± 53.22, 152.31 ± 99.12, 49.84 ± 18.58 μg m^?3 for Yildiz, DMO and Kilyos stations respectively. At all the sites, the lighter compounds were the most abundant, notably Nap, AcPy and PA. The average correlation values between TSP and total heavier PAH were greater than 0.5 for Yildiz and DMO stations. The patterns of PAH and TSP concentrations showed spatial and temporal variations. PAH concentrations were evaluated for the PAH contribution from four sources (diesel engines, gasoline engines, natural gas combustion, and coal + wood burning). Vehicle emissions appear to be the major source with contributions of 61.2%, 63.3% and 54.1% for Yildiz, DMO and Kilyos stations respectively. Seasonal and yearly variations had different trends for all sites.     

Attitudes toward hydraulic fracturing: The opposing forces of political conservatism and basic knowledge about fracking

Hydraulic fracturing has become a contentious issue around the globe. In the present study, using a sample of American adults (n = 412), the role of political orientation (conservative vs. liberal) and basic knowledge about fracking on fracking risk perception attitudes, fracking economic attitudes, energy reliance attitudes, trust of energy information sources, and preferred dwelling distance from energy operations was investigated. Basic knowledge about hydraulic fracturing as a possible moderating mechanism was also explored. Correlational and regression results revealed that political ideology and basic fracking knowledge are key predictors of fracking and energy source attitudes, and that the nature of the relation between ideology and fracking risk perceptions, fracking economic attitudes, reliance on natural gas, wind and solar, and distrust of government agencies, are influenced by an individual’s basic knowledge about fracking.     

Promise and reality of market-based environmental policy in China: Empirical analyses of the ecological restoration program on the Qinghai-Tibetan Plateau

Environmental conservation programs in China have increasingly emphasized integration of market-based logic into regulatory programs. But the realization of market logic and the effectiveness of such efforts are widely questioned by scientists and policy analysts. We empirically analyze the design, implementation, and outcomes of the ecological restoration program in the Three-Rivers Headwater Region in China, a large-scale conservation scheme aimed at restoring degraded grasslands and improving local livelihoods. Results indicate that the market mechanisms emphasized in the design of the policy were not realized in practice due to inadequate use of scientific measurements, lack of accountability, and poor monitoring and enforcement. Moreover, because enrollment was not voluntary, as is generally expected in market-based programs, there were negative impacts on herders. A household survey (n = 202) of local herders shows that if conservation incentives were properly designed and implemented, 67% would voluntarily participate in the program. Variance recorded in ecological and socioeconomic conditions points to opportunities to use market-based policy instruments to integrate local information into decision making regarding targeting of land conservation and land retirement. The potential of market-based environmental policies can be expanded through commitments to scientific measurement, voluntary participation, and outcome-based payments.     

Cleaner generation,free-riders,and environmental integrity: clean development mechanism and the power sector

This article provides a first-cut estimate of the potential impacts of the clean development mechanism (CDM) on electricity generation and carbon emissions in the power sector of non-Annex 1 countries. We construct four illustrative CDM regimes that represent a range of approaches under consideration within the climate community. We examine the impact of these CDM regimes on investments in new generation, under illustrative carbon trading prices of US$ 10 and 100/t C. In the cases that are most conducive to CDM activity, roughly 94% of new generation investments remains identical to the without-CDM situation, with only 6% shifting from higher to lower carbon intensity technologies. We estimate that the CDM would bolster renewable energy generation by as little as 15% at US$ 10/t C, or as much as 300% at US$ 100/t C.A striking finding comes from our examination of the potential magnitude of the “free-rider” problem, i.e. crediting of activities that will occur even in the absence of the CDM. The CDM is intended to be globally carbon-neutral — a project reduces emissions in the host country but generates credits that increase emissions in the investor country. However, to the extent that unwarranted credits are awarded to non-additional projects, the CDM would increase global carbon emissions above the without-CDM emissions level. Under two of the CDM regimes considered, cumulative free-riders credits total 250–600 Mt C through the end of the first budget period in 2012. This represents 10–23% of the likely OECD emissions reduction requirement during the first budget period. Since such a magnitude of free-rider credits from non-additional CDM projects could threaten the environmental integrity of the Kyoto protocol, it is imperative that policy makers devise CDM rules that encourage legitimate projects, while effectively screening out non-additional activities.     

Using the mean pressure gradient and NCEP/NCAR reanalysis to estimate the strength of the South Atlantic Anticyclone

A new methodology is proposed to estimate the strength of the South Atlantic Anticyclone (SAA), using the gridded sea level pressure (SLP) of the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis data. The top quartile (1017.3 hPa) of the SLP data was found a reasonable criterion to delimit the SAA area. Consequently, we defined the SAA area as the quadrangle containing 80% of the observations with pressure >1017.3 hPa. In this quadrangle, an area weighted pressure gradient (AWPG) was computed for the whole area and for the north–south and west–east halves. When compared with maximum pressure, the AWPG showed a better correlation with the significant wave height (SWH) and wind speed (WS) derived from altimetry. The mean value of the AWPG was 8 × 10⁻⁴ Pa/m, with representative values of 9.1 × 10⁻⁴ Pa/m and 7.4 × 10⁻⁴ Pa/m for austral winter and summer, respectively. The phase difference between the monthly AWPG in the north and south sub-quadrangles accounts for the evolution of the spatial pattern of the anticyclone throughout a year. This quantitative approach proved to be a useful estimate of the strength of South Atlantic Anticyclone. Further improvements of this approach are discussed.     

Outcome indicator development: Defining education for sustainable development outcomes for the individual level and connecting them to the SDGs

Education for Sustainable Development (ESD) has become a key concept to achieve global sustainable development. ESD aims at enabling people to think and act in a sustainable, future-oriented manner. For this purpose, ESD should not only equip learners with knowledge but is supposed to promote and advance the acquisition of sustainability competencies to address the challenges of the 21st century at a social, environmental, and economic level. Regarding the systematic implementation of ESD and its evidence-based management, an assessment of its outcomes is crucial. So far, however, ESD outcomes have only been partially assessed systematically. We developed a domain-specific ESD outcome indicator test (OIT) which strives to fill this gap. The test is intended to contribute towards the monitoring and further development of ESD in the school system. This article presents the procedure and the central findings of developing a model using an inductive research design. The model comprises the possible outcomes of ESD and thus functions as the basis of the OIT. It considers six thematic action domains for students as well as cognitive, attitudinal, and behavioural outcome components. The six action domains have been defined based on 15 interviews with experts from the arrays of ESD research, practice, and policy and a review of N = 195 sustainability related psychological scales. These were linked to the Sustainable Development Goals (SDGs), so that connectivity between outcomes at the individual level and political respectively societal goals is ensured.     

Pic 2005, a field campaign to investigate low-tropospheric ozone variability in the Pyrenees

The Pic 2005 field campaign took place from 13 June to 7 July 2005 close to the high-altitude permanent atmospheric observatory Pic-du-Midi (PDM), situated at 2875 m asl in the French Pyrenees. The experimental set-up combined in situ ground-based observations at PDM with ozone lidar measurements at two lower sites in close vicinity (600 m asl/28 km away, and 2380 m asl/500 m away). Such an experimental configuration is appropriate to address the question of the vertical layering of the chemical atmosphere in a mountain area and above the plain nearby, and how this influences measurements conducted on a mountain summit under the influence of horizontal transport at regional scale, and vertical transport at local scale. Forecast tools made it possible to plan and carry out 6 one-day Intensive Observation Periods (IOPs), mostly in anticyclonic conditions favoring local thermally induced circulations, with and without local pollution in the lower troposphere.It was thus possible to document i) ozone diurnal variations at PDM; ii) correlation between ozone measurements at PDM and their counterparts at the same altitude in the free troposphere; iii) ozone variability in the vicinity of PDM.The field campaign provided direct experimental evidence that at daytime in the encountered conditions (mostly anticyclonic), PDM failed in a large extent to be representative of the troposphere above the surrounding flat areas at similar altitude. First, ozone daily averages at PDM were found lower than their free-tropospheric counterpart. Thermally induced circulations and convection pumping clean air from the rural boundary layer can account qualitatively for ozone depletion observed at PDM during daytime. However the surface measurements do not support the hypothesis of direct lifting of near-surface air masses up to PDM. Thus, mixing with free-tropospheric air, photochemistry and surface deposition in the valleys appear to be needed ingredients to account quantitatively for the observed variations (in proportions that further studies should determine). Second, ozone variability was found to be much lower at PDM than in the free troposphere—again an indication of atmospheric mixing. In particular at daytime, the PDM observatory did not allow for detection of ozone-rich layers simultaneously visible above the plain. Beyond these first results, the data set presented here paves way to detailed studies of the IOPs.     

Mental models of sea-level change: A mixed methods analysis on the Severn Estuary,UK

Global average sea levels are expected to rise by up to a metre by the end of the century. This long-term rise will combine with shorter-term changes in sea level (e.g. high tides, storm surges) to increase risks of flooding and erosion in vulnerable coastal areas. As communities become increasingly exposed to these risks, understanding their beliefs and responses becomes more important. While studies have explored public responses to climate change, less research has focused on perceptions of the specific risks associated with sea-level change. This paper presents the results of a mental models study that addressed this knowledge gap by exploring expert and public perceptions of sea-level change on the Severn Estuary, a threatened coastal environment in the southwest of the United Kingdom. A model was developed from the literature and expert interviews (N = 11), and compared with public perceptions elicited via interviews (N = 20) and a quantitative survey (N = 359). Whilst we find a high degree of consistency between expert and public understandings, there are important differences that have implications for how sea level risks are interpreted and for what are perceived as appropriate mitigation and adaptation practices. We also find a number of potential barriers to engaging with the issue: individuals express low concern about sea-level change in relation to other matters; they feel detached from the issue, seeing it as something that will happen in future to other people; and many perceive that neither the causes of nor responses to sea-level change are their responsibility. We point to areas upon which future risk communications should therefore concentrate.     

Resilience of traditional knowledge systems: The case of agricultural knowledge in home gardens of the Iberian Peninsula

The resilience of a social–ecological system largely depends on its capacity to learn by absorbing new information to cope with change. But, how resilient are traditional knowledge systems? We explore the resilience of the traditional agricultural knowledge system of home gardeners in the Iberian Peninsula (n = 383). We use multivariate analysis to explore the co-existence of agricultural information derived from two different knowledge systems: (i) knowledge and use of landraces (representative of traditional agricultural knowledge) and (ii) knowledge and use of commercial crop varieties (representative of modern agricultural knowledge). Our analyses show a positive association between both types of knowledge: overall gardeners who are more knowledgeable about commercial crop varieties are also more knowledgeable about landraces. Despite this overall tendency, results from hierarchical cluster analysis showed different groups of traditional and modern knowledge holders. Our results suggest that (a) traditional knowledge is not a frozen and static corpus of knowledge and (b) modern and traditional agricultural knowledge are not necessarily mutually exclusive. Both maintenance of some aspects of the traditional knowledge and incorporation of some aspect of the modern knowledge seem to be core elements of home gardeners’ body of agricultural knowledge which is constantly evolving in response to changing environmental and socioeconomic conditions. Changes in traditional knowledge can be seen as a part of the general self-organizing process of this knowledge system.     

Below-cloud rain scavenging of atmospheric aerosols for aerosol deposition models

Below-cloud aerosol scavenging is generally estimated from field measurements using advanced instruments that measure changes in aerosol distributions with respect to rainfall. In this study, we discuss various scavenging mechanisms and scavenging coefficients from past laboratory and field measurements. Scavenging coefficients derived from field measurements (representing natural aerosols scavenging) are two orders higher than that of theoretical ones for smaller particles (D_p < 2 μm). Measured size-resolved scavenging coefficients can be served as a better option to the default scavenging coefficient (e.g. a constant of 10^?4 s^?1 for all size of aerosols, as used in the CALPUFF model) for representing below-cloud aerosol scavenging. We propose scavenging correction parameter (C_R) as an exponential function of size-resolved scavenging coefficients, winds and width in the downwind of the source–receptor system. For a wind speed of 3 m s^?1, C_R decrease with the width in the downwind for particles of diameters D_p < 0.1 μm but C_R does not vary much for particles in the accumulation mode (0.1 < D_p < 2 μm). For a typical urban aerosol distribution, assuming 3 m s^?1 air-flow in the source–receptor system, 10 km downwind width, 2.84 mm h^?1 of rainfall and using aerosol size dependent scavenging coefficients in the C_R, scavenging of aerosols is found to be 16% in number and 24% in volume of total aerosols. Using the default scavenging coefficient (10^?4 s^?1) in the CALPUFF model, it is found to be 64% in both number and volume of total aerosols.     

Exchange rates,soybean supply response,and deforestation in South America

The advancement of South America's agro-pastoral frontier has been widely linked to losses in biodiversity and tropical forests, with particular impacts on the Brazilian cerrado, the Atlantic Forest, and the Amazon. Here we consider an important, yet largely overlooked, driver of South America's soybean expansion, namely the devaluation of local currencies against the US dollar in the late 1990s and early 2000s. Much interest has emerged in recent years over the environmental implications of soybean production in Brazil, with evidence of both direct incursions into moist tropical forest by soybean producers and of potential indirect effects, via the displacement of existing ranching operations. In this research we utilize historical trends in soybean prices, exchange rates, and cropland dedicated to soybean production in Bolivia, Paraguay, and Brazil to estimate the impact of currency devaluations on area of production. The results suggest that approximately 80,000 km², or 31% of the current extent of soybean production in these countries, emerged as a supply area response to the devaluation of local currencies in the late 1990s. The results also indicate that the more recent depreciation of the dollar and appreciation of the Brazilian real have counteracted a recent rise in global soybean prices, in the process sparing an estimated nearly 90,000 km² from new cropland, 40,000 km² of this in the Amazon alone. Amidst an increasingly neoliberal economic environment, where barriers to trade are jettisoned in favor of the free flow of commodities, relative currency values will occupy an important role in the future sourcing of both agricultural expansion and environmental degradation.     

Past and future carbon sequestration benefits of China’s grain for green program

Carbon sequestration through ecological restoration programs is an increasingly important option to reduce the rise of atmospheric carbon dioxide concentration. China’s Grain for Green Program (GGP) is likely the largest centrally organized land-use change program in human history and yet its carbon sequestration benefit has yet to be systematically assessed. Here we used seven empirical/statistical equations of forest biomass carbon sequestration and five soil carbon change models to estimate the total and decadal carbon sequestration potentials of the GGP during 1999–2050, including changes in four carbon pools: aboveground biomass, roots, forest floor and soil organic carbon. The results showed that the total carbon stock in the GGP-affected areas was 682 Tg C in 2010 and the accumulative carbon sink estimates induced by the GGP would be 1697, 2635, 3438 and 4115 Tg C for 2020, 2030, 2040 and 2050, respectively. Overall, the carbon sequestration capacity of the GGP can offset about 3%–5% of China’s annual carbon emissions (calculated using 2010 emissions) and about 1% of the global carbon emissions. Afforestation by the GGP contributed about 25% of biomass carbon sinks in global carbon sequestration in 2000–2010. The results suggest that large-scale ecological restoration programs such as afforestation and reforestation could help to enhance global carbon sinks, which may shed new light on the carbon sequestration benefits of such programs in China and also in other regions.     

The origin of sub-surface source waters define the sea–air flux of methane in the Mauritanian Upwelling,NW Africa

Concentrations and flux densities of methane were determined during a Lagrangian study of an advective filament in the permanent upwelling region off western Mauritania. Newly upwelled waters were dominated by the presence of North Atlantic Central Water and surface CH₄ concentrations of 2.2 ± 0.3 nmol L⁻¹ were largely in equilibrium with atmospheric values, with surface saturations of 101.7 ± 14%. As the upwelling filament aged and was advected offshore, CH₄ enriched South Atlantic Central Water from intermediate depths of 100–350 m was entrained into the surface mixed layer of the filament following intense mixing associated with the shelf break. Surface saturations increased to 198.9 ± 15% and flux densities increased from a mean value over the shelf of 2.0 ± 1.1 μmol m⁻² d⁻¹ to a maximum of 22.6 μmol m⁻² d⁻¹. Annual CH₄ emissions for this persistent filament were estimated at 0.77 ± 0.64 Gg which equates to a maximum of 0.35% of the global oceanic budget. This raises the known outgassing intensity of this area and highlights the importance of advecting filaments from upwelling waters as efficient vehicles for air-sea exchange.     

Multi-gas emission envelopes to meet greenhouse gas concentration targets: Costs versus certainty of limiting temperature increase

This paper presents a set of technically feasible multi-gas emission pathways (envelopes) for stabilising greenhouse gas concentration at 450, 550 and 650 ppm CO₂-equivalent and their trade-offs between direct abatement costs and probabilities to meet temperature targets. There are different pathways within the envelope. Delayed response pathways initially follow the upper boundary of the emission envelope and reduce more by the end of the century. In contrast, early action pathways first follow the lower boundary and then the upper boundary. The latter require an early peak in the global emissions but keeps the option open for shifting to lower concentration targets in the future. Costs evaluations depend on the discount rate. Early action profiles have high costs early on, but learning-by-doing and smoother reduction rates over time lead to in most cases to lower costs across the century (net present value (NPV)). To achieve the 450 ppm CO₂-equivalent, the global emissions need to peak before 2020. The NPV of costs increase from 0.2% of cumulative gross domestic product to 1.0% as the shift is made from 650 to 450 ppm (discount rate 5%). However, the chances of limiting global mean warming to 2 °C above pre-industrial levels are very small for peaking and stabilisation at 650 ppm (1–23%) and 550 ppm (1–48%), but increase for a peaking at 510 ppm with subsequent stabilisation 450 ppm to 14–67%.