• Energy Research
• Restricted close
• Embargo close
• DE close

Conservation agriculture through no-till based on cropping systems with high biomass-C input, is a strategy to restoring the carbon (C) lost from natural capital by conversion to agricultural land. We hypothesize that cropping systems based on quantity, diversity and frequency of biomass-C input above soil C dynamic equilibrium level can recover the natural capital. The objectives of this study were to: i) assess the C-budget of land use change for two contrasting climatic environments, ii) estimate the C turnover time of the natural capital through no-till cropping systems, and iii) determine the C pathway since soil under native vegetation to no-till cropping systems. In a subtropical and tropical environment, three types of land use were used: a) undisturbed soil under native vegetation as the reference of pristine level; b) degraded soil through continuous tillage; and c) soil under continuous no-till cropping system with high biomass-C input. At the subtropical environment, the soil under continuous tillage caused loss of 25.4 Mg C ha-1 in the 0-40 cm layer over 29 years. Of this, 17 Mg C ha-1 was transferred into the 40-100 cm layers, resulting in the net negative C balance for 0-100 cm layer of 8.4 Mg C ha-1 with an environmental cost of USD 1968 ha-1. The 0.59 Mg C ha-1 yr-1 sequestration rate by no-till cropping system promote the C turnover time (soil and vegetation) of 77 years. For tropical environment, the soil C losses reached 27.0 Mg C ha-1 in the 0-100 cm layer over 8 years, with the environmental cost of USD 6155 ha-1, and the natural capital turnover time through C sequestration rate of 2.15 Mg C ha-1 yr-1 was 49 years. The results indicated that the particulate organic C and mineral associate organic C fractions are the indicators of losses and restoration of C and leading C pathway to recover natural capital through no-till cropping systems.

In recent years, the energy demand has been continuously increasing. At the same time, fossil fuels are being progressively replaced by renewables. However, this shift from fossil fuels such as coal to renewable fuels like wood creates new challenges, as many industrial plants continue to rely on legacy fuels. Unlike coal, the elements present in renewable resources can vary greatly. The differences are influenced by a variety of factors. For example, waste wood can be contaminated by different additives (paints, fire retardants, and others). To understand under which boundary conditions (e.g., temperature, gasification atmosphere) the respective elements are bound in the ash/slag or released into the gas phase, experiments with a molecular beam mass spectrometer (MBMS) with an upstream electrically heated flow reactor were conducted. Pieces of clean wood were impregnated with various heavy metals and examined under several boundary conditions (temperature and gasification atmosphere). Furthermore, impregnated cellulose partly mixed with single ash components served as model fuel for detailed investigations. Additionally, thermochemical equilibrium calculations were carried out. The results of the experiments show that the release of some heavy metals (Cd, Pb, Sb, Sn, Zn) is very strong already at low temperatures, while for others (Cr, Cu) no release can be detected even at high temperatures. The corresponding thermodynamic equilibrium calculations comply with these findings. Since the process management and preparation of the fuels can be adjusted accordingly, these results form an important basis for planning gasification processes using waste wood as fuel.

A sub-seabed release of carbon dioxide (CO2) was conducted to assess the potential impacts of leakage from sub-seabed geological CO2 Capture and Storage CCS) on benthic macrofauna. CO2 gas was released 12 m below the seabed for 37 days, causing significant disruption to sediment carbonate chemistry. Regular macrofauna samples were collected from within the area of active CO2 leakage (Zone 1) and in three additional reference areas, 25 m, 75 m and 450 m from the centre of the leakage (Zones 2, 3 and 4 respectively). Macrofaunal community structure changed significantly in all zones during the study period. However, only the changes in Zone 1 were driven by the CO2 leakage with the changes in reference zones appearing to reflect natural seasonal succession and stochastic weather events. The impacts in Zone 1 occurred rapidly (within a few days), increased in severity through the duration of the leak, and continued to worsen after the leak had stopped. Considerable macrofaunal recovery was seen 18 days after the CO2 gas injection had stopped. In summary, small short-term CCS leakage events are likely to cause highly localised impacts on macrofaunal communities and there is the potential for rapid recovery to occur, depending on the characteristics of the communities and habitats impacted.

Infrared solar spectra recorded at the International Scientific Station of the Jungfraujoch (3580 m altitude), Switzerland, in 1950–1951 and from 1984 to 1992 have been analyzed to determine vertical column abundances of nitrous oxide (N2O) above the station. The best fit to the relatively dense set of measurements made between 1984 and 1992 indicates a mean exponential rate of increase equal to 0.36±0.06% yr−1 (1 σ) and a seasonal modulation of 7.2% peak to peak, the minimum occurring at the end of the winter and the maximum in early September. The column abundances for April of the years 1951, 1984, and 1992 were found equal to 3.49×1018, 3.76×1018, and 3.87×1018 molecules cm−2, respectively; they translate into N2O concentrations at the altitude of the Jungfraujoch equal to 275, 296, and 305 parts per billion by volume. These results indicate that the exponential rate of increase for 1951–1984 was equal to 0.23±0.04% yr−1 (1σ), thus substantially lower than for the 1984–1992 time interval and that the so‐called preindustrial levels of N2O pertained until 1951 with most of the increase in atmospheric N2O occurring thereafter.

AbstractGiven the accelerating rate of biodiversity loss, the need to prioritize marine areas for protection represents a major conservation challenge. The three‐dimensionality of marine life and ecosystems is an inherent element of complexity for setting spatial conservation plans. Yet, the confidence of any recommendation largely depends on shifting climate, which triggers a global redistribution of biodiversity, suggesting the inclusion of time as a fourth dimension. Here, we developed a depth‐specific prioritization analysis to inform the design of protected areas, further including metrics of climate‐driven changes in the ocean. Climate change was captured in this analysis by considering the projected future distribution of >2000 benthic and pelagic species inhabiting the Mediterranean Sea, combined with climatic stability and heterogeneity metrics of the seascape. We identified important areas based on both biological and climatic criteria, where conservation focus should be given in priority when designing a three‐dimensional, climate‐smart protected area network. We detected spatially concise, conservation priority areas, distributed around the basin, that protected marine areas almost equally across all depth zones. Our approach highlights the importance of deep sea zones as priority areas to meet conservation targets for future marine biodiversity, while suggesting that spatial prioritization schemes, that focus on a static two‐dimensional distribution of biodiversity data, might fail to englobe both the vertical properties of species distributions and the fine and larger‐scale impacts associated with climate change.