Contributor Nature Sustainability
Two of the United Nations’ Sustainable Development Goals (SDGs) are to “end poverty” (Goal 1) and to “strive to achieve a land-degradation neutral world” (Goal 15.3), which requires that any land degradation is fully offset by restoration of degraded land. A fundamental question is whether these two SDGs are compatible. Ending global poverty while at the same time balancing land degradation with restoration suggests that there may be potential tradeoffs in attaining these two SDGs. Accurately assessing these tradeoffs will require, in turn, a clear understanding of the relationship between land degradation and poverty. Despite decades of research, it is not obvious that such a consensus view exists in the literature.
Future long-term space travel and cis-lunar research platforms such as the Deep Space Gateway require a reliable life support system and - similarly to our demands on Earth - a renewable energy source. The production of so-called ‘solar fuels’, i.e. fuels such as hydrogen or long-chain hydrocarbons generated only from sunlight, water and carbon dioxide is currently investigated for terrestrial applications. These solar fuels are promising candidates for meeting the global quest for alternative energy sources. Currently, the most efficient systems comprise the ones operating according to the natural photosynthetic process: semiconductors are employed as light absorbers which transfer electrons upon photoexcitation to integrated electrocatalysts, catalyzing the respective half-cell reaction of water-splitting (photoanode) or fuel production (photocathode). Although, these systems are interesting as well for space applications from the point of oxygen and fuel generation, solar fuel production in microgravity environment has not been realized and investigated yet.