Nature Reviews Earth & Environment最新文献

Ice phenology has shifted with anthropogenic warming such that many lakes are experiencing a shorter ice season. However, changes to ice quality — the ratio of black and white ice layers — remain little explored, despite relevance to lake physics, ecological function, human recreation and transportation. In this Review, we outline how ice quality is changing and discuss knock-on ecosystem service impacts. Although direct evidence is sparse, there are suggestions that ice quality is diminishing across the Northern Hemisphere, encompassing declining ice thickness, decreasing black ice and increasing white ice. These changes are projected to continue in the future, scaling with global temperature increases, and driving considerable impacts to related ecosystem services. Rising proportions of white ice will markedly reduce bearing strength, implying more dangerous conditions for transportation (limiting operational use of many winter roads) and recreation (increasing the risk of fatal spring-time drownings). Shifts from black to white ice conditions will further reduce the amount of light reaching the water column, minimizing primary production, and altering community composition to favour motile and mixotrophic species; these changes will affect higher trophic levels, including diminished food quantity for zooplankton and fish, with potential developmental consequences. Reliable and translatable in situ sampling methods to assess and predict spatiotemporal variations in ice quality are urgently needed.

The largest terrestrial coalescent landslide areas of the Earth, spanning hundreds to thousands of square kilometres, occur along the fringes of relatively low-relief sedimentary and volcanic tablelands. However, difficulties in landslide recognition in these areas have led to underestimations of their frequency and likelihood. In this Review, we explore the global distribution, controls and dynamics of landslides occurring along tableland fringes. Landslide fringes are caused by the uninterrupted and extensive presence of weak sub-caprock lithologies below a more competent caprock. Topography, escarpment height and caprock thickness do not affect landslide size but can locally influence the type of displacement. Rotational landslides dominate most landslide fringes and will eventually lead to tableland consumption over million-year timescales. Some tableland rims can generate catastrophic long-runout rock avalanches or earthflows, which might in turn trigger tsunamis, river avulsion or outburst floods. Tablelands can also fail by slow (centimetre per year) landslide movements sufficient to cause damage to infrastructure. These hazards are increasing especially in high-latitude tablelands owing to cryosphere degradation, as observed in Western Greenland. A more detailed global inventory of landslide fringe activity is urgently needed to better quantify these potential hazards.

The genus Homo evolved during the Pleistocene — an epoch of gradual cooling and amplification of glacial cycles. The changing climates influenced early human survival, adaptation and evolution in complex ways. In this Review, we present current knowledge about the effects of past climate changes on the evolutionary trajectory of human species. Humans emerged in dry grassland and shrubland when average climate conditions were warm. As global climate started cooling down, human species needed either to track their preferred habitats or to adapt to new local conditions, each of which is indicated in the archaeological record. Limited dispersal ability and narrow ecological preferences were predominant in early species, whereas cultural innovations and consequently wider ecological niches became commonplace in later species, allowing them to live in colder extratropical climates. Yet, despite their growing ecological versatility, all species but one eventually went extinct. Future research should explore cultural transmission between and within species, and the influence of climate change on human genetic diversification.

Decarbonization is crucial to combat climate change. However, some decarbonization strategies could profoundly impact the nitrogen cycle. In this Review, we explore the nitrogen requirements of five major decarbonization strategies to reveal the complex interconnections between the carbon and nitrogen cycles and identify opportunities to enhance their mutually sustainable management. Some decarbonization strategies require substantial new nitrogen production, potentially leading to increased nutrient pollution and exacerbation of eutrophication in aquatic systems. For example, the strategy of substituting 44% of fossil fuels used in marine shipping with ammonia-based fuels could reduce CO₂ emissions by up to 0.38 Gt CO₂-eq yr⁻¹ but would require a corresponding increase in new nitrogen synthesis of 212 Tg N yr⁻¹. Similarly, using biofuels to achieve 0.7 ± 0.3 Gt CO₂-eq yr⁻¹ mitigation would require new nitrogen inputs to croplands of 21–42 Tg N yr⁻¹. To avoid increasing nitrogen losses and exacerbating eutrophication, decarbonization efforts should be designed to provide carbon–nitrogen co-benefits. Reducing the use of carbon-intensive synthetic nitrogen fertilizer is one example that can simultaneously reduce both nitrogen inputs by 14 Tg N yr⁻¹ and CO₂ emissions by 0.04 (0.03–0.06) Gt CO₂-eq yr⁻¹. Future research should guide decarbonization efforts to mitigate eutrophication and enhance nitrogen use efficiency in agriculture, food and energy systems.