Catálogo de publicaciones - revistas

<jats:p>Ensure open markets for clean technologies and products</jats:p>

<jats:p>Human activities have caused global temperatures to increase by 1.25°C, and the current emissions trajectory suggests that we will exceed 1.5°C in less than 10 years. Though the growth rate of global carbon dioxide emissions has slowed and many countries have strengthened their emissions targets, current midcentury net zero goals are insufficient to limit global warming to 1.5°C above preindustrial temperatures. The primary barriers to the achievement of a 1.5°C-compatible pathway are not geophysical but rather reflect inertia in our political and technological systems. Both political and corporate leadership are needed to overcome this inertia, supported by increased societal recognition of the need for system-level and individual lifestyle changes. The available evidence does not yet indicate that the world has seriously committed to achieving the 1.5°C goal.</jats:p>

<jats:p>Although many governments, financial institutions, and corporations are embracing nature-based solutions as part of their sustainability and net-zero carbon strategies, some nations, Indigenous peoples, local community groups, and grassroots organizations have rejected this term. This pushback is fueled by (i) critical uncertainties about when, where, how, and for whom nature-based solutions are effective and (ii) controversies surrounding their misuse in greenwashing, violations of human rights, and threats to biodiversity. To clarify how the scientific community can help address these issues, I provide an overview of recent research on the benefits and limits of nature-based solutions, including how they compare with technological approaches, and highlight critical areas for future research.</jats:p>

<jats:p>Without rapid changes to agriculture and food systems, the goals of the 2015 Paris Agreement on climate change will not be met. Food systems are one of the most important contributors to greenhouse gas (GHG) emissions, but they also need to be adapted to cope with climate change impacts. Although many options exist to reduce GHG emissions in the food system, efforts to develop implementable transformation pathways are hampered by a combination of structural challenges such as fragmented decision-making, vested interests, and power imbalances in the climate policy and food communities, all of which are compounded by a lack of joint vision. New processes and governance arrangements are urgently needed for dealing with potential trade-offs among mitigation options and their food security implications.</jats:p>

<jats:p>Changing the course of Earth’s climate is increasingly urgent, but there is also a concurrent need for proactive stewardship of the adaptive capacity of the rapidly changing biosphere. Adaptation ultimately underpins the resilience of Earth’s complex systems; species, communities, and ecosystems shift and evolve over time. Yet oncoming changes will seriously challenge current natural resource management and conservation efforts. We review forward-looking conservation approaches to enable adaptation and resilience. Key opportunities include expanding beyond preservationist approaches by including those that enable and facilitate ecological change. Conservation should not just focus on climate change losers but also on proactive management of emerging opportunities. Local efforts to conserve biodiversity and generate habitat complexity will also help to maintain a diversity of future options for an unpredictable future.</jats:p>

<jats:p> Highlights from the <jats:italic>Science</jats:italic> family of journals </jats:p>

<jats:p>Editors’ selections from the current scientific literature</jats:p>

<jats:p> Efficient and general methods for the synthesis of amines remain in high demand in the chemical industry. Among the many known processes, catalytic hydrogenation is a cost-effective and industrially proven reaction and currently used to produce a wide array of such compounds. We report a homogeneous nickel catalyst for hydrogenative cross coupling of a range of aromatic, heteroaromatic, and aliphatic nitriles with primary and secondary amines or ammonia. This general hydrogenation protocol is showcased by straightforward and highly selective synthesis of &gt;230 functionalized and structurally diverse amines including pharmaceutically relevant and chiral products, as well as <jats:sup>15</jats:sup> N-isotope labeling applications. </jats:p>

<jats:p>Progenitors of the developing human neocortex reside in the ventricular and outer subventricular zones (VZ and OSVZ, respectively). However, whether cells derived from these niches have similar developmental fates is unknown. By performing fate mapping in primary human tissue, we demonstrate that astrocytes derived from these niches populate anatomically distinct layers. Cortical plate astrocytes emerge from VZ progenitors and proliferate locally, while putative white matter astrocytes are morphologically heterogeneous and emerge from both VZ and OSVZ progenitors. Furthermore, via single-cell sequencing of morphologically defined astrocyte subtypes using Patch-seq, we identify molecular distinctions between VZ-derived cortical plate astrocytes and OSVZ-derived white matter astrocytes that persist into adulthood. Together, our study highlights a complex role for cell lineage in the diversification of human neocortical astrocytes.</jats:p>

<jats:p>Rivers support indispensable ecological functions and human health and infrastructure. Yet limited river sampling hinders our understanding of consequential changes to river systems. Satellite-based estimates of suspended sediment concentration and flux for 414 major rivers reveal widespread global change that is directly attributable to human activity in the past half-century. Sediment trapping by dams in the global hydrologic north has contributed to global sediment flux declines to 49% of pre-dam conditions. Recently, intensive land-use change in the global hydrologic south has increased erosion, with river suspended sediment concentration on average 41 ± 7% greater than in the 1980s. This north-south divergence has rapidly reconfigured global patterns in sediment flux to the oceans, with the dominant sources of suspended sediment shifting from Asia to South America.</jats:p>