Plant trees for the planet: the potential of forests for climate change mitigation and the major drivers of national forest area

Forests are one of the most cost-effective ways to sequester carbon today. Here, I estimate the world’s land share under forests required to prevent dangerous climate change. For this, I combine newest longitudinal data of FLUXNET on forests’ net ecosystem exchange of carbon (NEE) from 78 forest sites (N?=?607) with countries’ mean temperature and forest area. This straightforward approach indicates that the world’s forests sequester 8.3 GtCO₂year^?1. For the 2 °C climate target, the current forest land share has to be doubled to 60.0% to sequester an additional 7.8 GtCO₂year^?1, which demands less red meat consumption. This afforestation/reforestation (AR) challenge is achievable, as the estimated global biophysical potential of AR is 8.0 GtCO₂year^?1 safeguarding food supply for 10 billion people. Climate-responsible countries have the highest AR potential. For effective climate policies, knowledge on the major drivers of forest area is crucial. Enhancing information here, I analyze forest land share data of 98 countries from 1990 to 2015 applying causal inference (N?=?2494). The results highlight that population growth, industrialization, and increasing temperature reduce forest land share, while more protected forest and economic growth generally increase it. In all, this study confirms the potential of AR for climate change mitigation with a straightforward approach based on the direct measurement of NEE. This might provide a more valid picture given the shortcomings of indirect carbon stock-based inventories. The analysis identifies future regional hotspots for the AR potential and informs the need for fast and forceful action to prevent dangerous climate change.

     

Genese des mitteleuropäischen Buntsandsteins

The continental Buntsandstein red beds represent the parastratigraphically subdivided germanotype facies of the Lower Triassic in Middle Europe. Fluvial deposits are widespread in proximal and medial parts of the sedimentation area. Additionally, aeolian dune sands, alluvial-fan deposits, mud-flow sediments, palaeosols, lacustrine, deltaic, tidal, lagoonal, brackish, marine and evaporitic deposits are present. Numerous isolated occurrences and several concentrations of faunal and floral elements in the generally poorly fossiliferous sequence reflect a diversified and partially rich biosphere of the Buntsandstein. Evolution and zoning testify the control of tectonics on depositional history. The depositional history leads from the end of the saline Zechstein period via predominantly silty-clayey and oolitic shallow-water sediments to a mainly fluvial series which is characterized by the intercalation of aeolian dune sands in its upper part, before by another fluvial sequence in the marginal areas and precipitation of thick halite layers in the basin centre the marine terminal stage is reached which passes into the carbonate Muschelkalk succession.     

Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)

Fluorochemicals (FCs) are oxidatively recalcitrant, environmentally persistent, and resistant to most conventional treatment technologies. FCs have unique physiochemical properties derived from fluorine which is the most electronegative element. Perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) have been detected globally in the hydrosphere, atmosphere and biosphere. Reducing treatment technologies such as reverses osmosis, nano-filtration and activated carbon can remove FCs from water. However, incineration of the concentrated waste is required for complete FC destruction. Recently, a number of alternative technologies for FC decomposition have been reported. The FC degradation technologies span a wide range of chemical processes including direct photolysis, photocatalytic oxidation, photochemical oxidation, photochemical reduction, thermally-induced reduction, and sonochemical pyrolysis. This paper reviews these FC degradation technologies in terms of kinetics, mechanism, energetic cost, and applicability. The optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration, background organic and metal concentration, and available degradation time.