Organic shales are exposed to treatment fluids during and after hydraulic fracturing operations. The fluid–shale interaction influences the petrophysical alteration of the fractured shale and the fate of the fracturing fluid. We systematically measured the spontaneous water and oil intake of five shale samples collected from the cores of two wells drilled in the Horn River basin. The samples represent three shale formations with different mineralogy and petrophysical properties. We characterize the samples by measuring the porosity, conducting X-ray diffraction, and interpreting the well logging data and scanning electron microscopy images. The water intake is higher than the oil intake for all samples. The excess water intake and the physical alteration degree correlate with the shale mineralogy and petrophysical properties. The ratio between the water and oil intake is much higher than the ratio between the water and oil capillary pressures, even for the non-swelling shales. The comparative study indicates that the water intake of organic shales is controlled by both adsorption and capillarity.

Land use is central to addressing sustainability issues, including biodiversity conservation, climate change, food security, poverty alleviation, and sustainable energy. In this paper, we synthesize knowledge accumulated in land system science, the integrated study of terrestrial social-ecological systems, into 10 hard truths that have strong, general, empirical support. These facts help to explain the challenges of achieving sustainability in land use and thus also point toward solutions. The 10 facts are as follows: 1) Meanings and values of land are socially constructed and contested; 2) land systems exhibit complex behaviors with abrupt, hard-to-predict changes; 3) irreversible changes and path dependence are common features of land systems; 4) some land uses have a small footprint but very large impacts; 5) drivers and impacts of land-use change are globally interconnected and spill over to distant locations; 6) humanity lives on a used planet where all land provides benefits to societies; 7) land-use change usually entails trade-offs between different benefits—"win–wins" are thus rare; 8) land tenure and land-use claims are often unclear, overlapping, and contested; 9) the benefits and burdens from land are unequally distributed; and 10) land users have multiple, sometimes conflicting, ideas of what social and environmental justice entails. The facts have implications for governance, but do not provide fixed answers. Instead they constitute a set of core principles which can guide scientists, policy makers, and practitioners toward meeting sustainability challenges in land use.

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Abstract. The source and sinks of carbon dioxide (CO 2 ) and methane (CH 4 ) due to anthropogenic and natural biospheric activities were estimated for the South Asian region (Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka). Flux estimates were based on top-down methods that use inversions of atmospheric data, and bottom-up methods that use field observations, satellite data, and terrestrial ecosystem models. Based on atmospheric CO 2 inversions, the net biospheric CO 2 flux in South Asia (equivalent to the Net Biome Productivity, NBP) was a sink, estimated at −104 ± 150 Tg C yr −1 during [2007][2008]. Based on the bottom-up approach, the net biospheric CO 2 flux is estimated to be −191 ± 193 Tg C yr −1 during the period of 2000-2009. This last net flux results from the following flux components: (1) the Net Ecosystem Productivity, NEP (net primary production minus heterotrophic respiration) of −220 ± 186 Tg C yr −1 (2) the annual net carbon flux from land-use change of −14 ± 50 Tg C yr −1 , which resulted from a sink of −16 Tg C yr −1 due to the establishment of tree plantations and wood harvest, and a source of 2 Tg C yr −1 due to the expansion of croplands; (3) the riverine export flux from terrestrial ecosystems to the coastal oceans of +42.9 Tg C yr −1 ; and (4) the net CO 2 emission due to biomass burning of +44.1 ± 13.7 Tg C yr −1 . Including the emissions from the combustion of fossil fuels of 444 Tg C yr −1 for the 2000s, we estimate a net CO 2 landatmosphere flux of 297 Tg C yr −1 . In addition to CO 2 , a fraction of the sequestered carbon in terrestrial ecosystems is released to the atmosphere as CH 4 . Based on bottom-up and top-down estimates, and chemistry-transport modeling, we estimate that 37 ± 3.7 Tg C-CH 4 yr −1 were released to atmosphere from South Asia during the 2000s. Taking all CO 2 and CH 4 fluxes together, our best estimate of the net land-atmosphere CO 2 -equivalent flux is a net source of 334 Tg C yr −1 for the South Asian region during the 2000s. If CH 4 emissions are weighted by radiative forcing of molecular CH 4 , the total CO 2 -equivalent flux increases to 1148 Tg C yr −1 suggesting there is great potential of reducing CH 4 emissions for stabilizing greenhouse gases concentrations.

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The source and sinks of carbon dioxide (CO₂) and methane (CH₄) due to anthropogenic and natural biospheric activities were estimated for the South Asia region (Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka). Flux estimates were based on top-down methods that use inversions of atmospheric data, and bottom-up methods that use field observations, satellite data, and terrestrial ecosystem models. Based on atmospheric CO₂ inversions, the net biospheric CO₂ flux in South Asia (equivalent to the Net Biome Productivity, NBP) was a sink, estimated at −104 ± 150 Tg C yr^−1 during 2007–2008. Based on the bottom-up approach, the net biospheric CO₂ flux is estimated to be −191 ± 193 Tg C yr^−1 during the period of 2000–2009. This last net flux results from the following flux components: (1) the Net Ecosystem Productivity, NEP (net primary production minus heterotrophic respiration) of −220 ± 186 Tg C yr^−1 (2) the annual net carbon flux from land-use change of −14 ± 50 Tg C yr^−1, which resulted from a sink of −16 Tg C yr^−1 due to the establishment of tree plantations and wood harvest, and a source of 2 Tg C yr^−1 due to the expansion of croplands; (3) the riverine export flux from terrestrial ecosystems to the coastal oceans of +42.9 Tg C yr^−1; and (4) the net CO₂ emission due to biomass burning of +44.1 ± 13.7 Tg C yr^−1. Including the emissions from the combustion of fossil fuels of 444 Tg C yr^−1 for the decades of 2000s, we estimate a net CO₂ land-to-atmosphere flux of 297 Tg C yr^−1. In addition to CO₂, a fraction of the sequestered carbon in terrestrial ecosystems is released to the atmosphere as CH₄. Based on bottom-up and top-down estimates, and chemistry-transport modeling, we estimate that 37 ± 3.7 Tg C-CH₄ yr^−1 were released to atmosphere from South Asia during the 2000s. Taking all CO₂ and CH₄ fluxes together, our best estimate of the net land-to-atmosphere CO₂-equivalent flux is a net source of 334 Tg C yr^−1 for the South Asia region during the 2000s. If CH₄ emissions are weighted by radiative forcing of molecular CH₄, the total CO₂-equivalent flux increases to 1148 Tg C yr^−1 suggesting there is great potential of reducing CH₄ emissions for stabilizing greenhouse g...