Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy

Strong and rapid greenhouse gas (GHG) emission reductions, far beyond those currently committed to, are required to meet the goals of the Paris Agreement. This allows no sector to maintain business as usual practices, while application of the precautionary principle requires avoiding a reliance on negative emission technologies. Animal to plant-sourced protein shifts offer substantial potential for GHG emission reductions. Unabated, the livestock sector could take between 37% and 49% of the GHG budget allowable under the 2°C and 1.5°C targets, respectively, by 2030. Inaction in the livestock sector would require substantial GHG reductions, far beyond what are planned or realistic, from other sectors. This outlook article outlines why animal to plant-sourced protein shifts should be taken up by the Conference of the Parties (COP), and how they could feature as part of countries’ mitigation commitments under their updated Nationally Determined Contributions (NDCs) to be adopted from 2020 onwards. The proposed framework includes an acknowledgment of ‘peak livestock’, followed by targets for large and rapid reductions in livestock numbers based on a combined ‘worst first’ and ‘best available food’ approach. Adequate support, including climate finance, is needed to facilitate countries in implementing animal to plant-sourced protein shifts.

Key policy insights

• Given the livestock sector’s significant contribution to global GHG emissions and methane dominance, animal to plant protein shifts make a necessary contribution to meeting the Paris temperature goals and reducing warming in the short term, while providing a suite of co-benefits.

• Without action, the livestock sector could take between 37% and 49% of the GHG budget allowable under the 2°C and 1.5°C targets, respectively, by 2030.

• Failure to implement animal to plant protein shifts increases the risk of exceeding temperate goals; requires additional GHG reductions from other sectors; and increases reliance on negative emissions technologies.

• COP 24 is an opportunity to bring animal to plant protein shifts to the climate mitigation table.

• Revised NDCs from 2020 should include animal to plant protein shifts, starting with a declaration of ‘peak livestock’, followed by a ‘worst first’ replacement approach, guided by ‘best available food’.

     

Confronting the nitrogen challenge: Options for governance and target setting

The release of excessive anthropogenic nitrogen contributes to global climate change, biodiversity loss, and the degradation of ecosystem services. Despite being an urgent global problem, the excess nitrogen is not governed globally. This paper considers possible governance options for dealing with excessive nitrogen through target setting, which is an approach commonly adopted to address global environmental problems. The articulation of the nitrogen problem and the numerous international institutions dealing with it, provide evidence of a nitrogen regime characterised by limited coordination and targets covering sources and impacts only partially. This calls for improving the nitrogen governance in the direction of more integrated approaches at the global scale. In this vein, the paper investigates two opposite governance options – here labelled as ‘holistic’ and ‘origin-based’ – and evaluates them for their capability to define solutions and targets for human-induced nitrogen. From the analysis, it emerges that origin-based solutions can be preferable to holistic solutions as they can be more specific and potentially have greater immediate results. Independent from which governance arrangement is chosen, what matters most is the speed at which an arrangement can deploy solutions to combat (fast-growing) nitrogen pollution.     

Plio-Pleistocene sedimentation in coastal grabens,north-east Rhodes,Greece

The stratigraphy of marine Plio-Pleistocene sediments from northeast Rhodes (Dodecanese islands, Greece) is revised in the light of facies mapping and the recognition of three major transgression–regression cycles. Before late Pliocene submergence, metamorphosed Mesozoic limestones formed a high-relief karstic landscape. During subsequent transgressions, subsiding basins with spectacular cliffed and bioeroded margins were infilled by a mosaic of carbonate-dominated sediments, sourced by high rates of carbonate productivity on narrow shelves rimming the basins and their drowning islands. Periods of relative sea-level fall superimposed a complex series of ‘fossil’ coastal geomorphological features such as cliffs, abrasion platforms, surf caves, notches, boulder beaches and palaeokarsts. These created the rugged present day topography of the island's northeast coast. Three main lithostratigraphic units, the Kritika, Rhodes and Lindos Acropolis Formations, are defined. The Rhodes and Lindos Acropolis Formations are subdivided into mappable facies groups rather than members, as the lithofacies are strongly diachronous. The Kritika and Rhodes Formations were each subaerially exposed and partly eroded before re-transgression. Although there is a general pattern of lithological succession, details vary across the study area and some facies groups are restricted in development, indicating differences in tectonic behaviour and palaeo-geomorphology between neighbouring basins. A preliminary process-response model is presented for the sedimentation history of the Rhodes and Lindos Acropolis Formations, using sedimentological, palaeontological, palaeoecological and ichnological data.     

三峡库首区重点断裂围限区蓄水的加卸载效应

通过对蓄水前后三峡库首区构造应力场进行三维数值模拟发现,相对于蓄水前,蓄水至135 m水位时,官渡口断裂-马鹿池断裂-牛口断裂围限区、秭归地理中心和九湾溪断裂带,出现了4个主应力下降区和共轭的主应力增长区,形成了差应力场;175 m水位与135 m水位相比,局部差应力场呈现逆向变化,即形成了加载效应与卸载效应的交替过程。这一过程,可能是水库诱发地震的诱震(或触震)因素。     

风水复合侵蚀研究述评

风水复合侵蚀或风水交互作用是干旱、半干旱地区常见的侵蚀过程。这种风力与流水对同一侵蚀对象 (区域) 的共同作用或交替作用塑造了风蚀水蚀交错区特有的侵蚀地貌景观。作为一个相互联系、影响的复杂系统,风水复合侵蚀具有明显的时空分布特征,其侵蚀过程可以划分为古代过程与现代过程。由于以往的风蚀和水蚀研究相互独立,风水复合侵蚀的研究起步较晚。在研究中存在着尺度转化与研究方法不成熟等问题。对风水复合侵蚀的机理与防治以及土壤复合可蚀性的研究都将成为今后研究中的重点与难点。     

国产磁通门磁力仪稳定性分析

国产磁通门磁力仪(GM-3磁通门磁力仪)在全国各地磁台站推广应用,两年来,该仪器在武汉地震台工作比较稳定。本文对该仪器的基线值进行了多层线性回归分析。结果表明仪器性能比较稳定。     

黄河三角洲潮滩剖面特征

利用验潮、潮滩水准测量、沉积物分析和遥感资料,分析了黄河三角洲不同岸段潮滩的特征。水准测量表明,侵蚀潮滩剖面形态为下凹,而淤积潮滩则上凸,由高潮线至低潮线,潮滩沉积物均变粗,这种变粗趋势在北部侵蚀岸段和河口侧缘明显,在河口南侧稳定海岸则不明显。潮滩沉积物含水量为12.2%~32.2%,平均为21%,海滩表层沉积物不排水剪切强度在0.1~0.35 kg/cm2之间。受局限岸滩的平面形态和剖面形态受到周围大坝地形影响,具有和砂质海滩类似的形态,显示波浪对该潮滩的作用强烈,根据剖面测量结果与遥感图像,发现河口北侧有一个小的冲积扇。     

渤海湾表层沉积硅藻组合

分析了渤海湾潮间带4条长度为2~3 km的测线的14个站位的表层沉积硅藻,结合前人在浅海区(低潮线以下至水深约30 m处)15个站位的表层沉积硅藻资料,发现并统计了分属于21属的46种硅藻。应用对应分析方法,将渤海湾潮间带及浅海区表层沉积硅藻初步划分为3个组合。其中,组合Ⅰ为条纹—柱状小环藻-圆筛藻组合,分布在以泥质为主的潮间带区;组合Ⅱ为双眉藻-曲壳藻组合,分布在砂质为主的潮间带区;组合Ⅲ为条纹—柱状小环藻-菱形藻-圆筛藻-具槽直链藻组合,分布在浅海区。从潮间带向浅海区,随水深的增加,呈现出条纹—柱状小环藻数量减少、具槽直链藻数量增加的趋势。     

越南岸外上升流区48万年来高分辨率的生源组分记录及其古海洋学意义

南海西部越南岸外MD05-2901孔沉积物分析显示,该孔覆盖氧同位素1-12期,底界年龄约为48万年。生源组分记录显示表层古生产力冰期高、间冰期低,体现间冰期海平面下降、陆源物质输入增强的影响。生产力在末次冰期达到最高,体现末次盛冰期海陆差异增强,东北风发育对生产力提高的促进作用。碳酸钙含量变化呈现冰期早期含量低、冰消期和间冰期含量高的趋势。其冰消期的高值在MIS1/2、MIS3/4和MIS5/6分界处,与浮游有孔虫碳同位素低值对应,揭示该地区的碳酸钙沉积旋回是“稀释旋回”。同时碳酸钙含量变化领先于同一地区浮游有孔虫氧同位素的变化,证明低纬海区碳酸钙泵作用对大气二氧化碳浓度和温度有影响。滤波分析结果显示碳同位素存在23 ka的岁差周期和偏心率长周期,生源组分的含量变化显示出典型的岁差周期,体现南海季风环流的轨道响应,证明低纬热带过程是调节气候变化的重要因素。     

南海深海盆表层沉积物氮的地球化学特征与生态学功能

研究了南海深海盆区域(南沙海槽西南部)表层沉积物中氮的形态、分布及其在生物地球化学循环中的功能.研究表明,表层沉积物中不同形态氮的含量不同.其中,氧化还原转化态的氮(SOEF-N)含量最高,平均为68.3μg/g,占总氮(TN)的7.08%;弱酸转化态氮(WAEF-N)含量最小,仅占总氮(TN)的1.09%.离子交换态(IEF-N),WAEF-N,S OEF-N及TN的地球化学分布特征存在一定相似性:均由海槽东西两侧向中央递增,并在槽底呈高含量分布;SAEF-N(强碱转化态)分布则与该趋势相反.IEF-N,SAEF-N和SOEF-N的分布主要受沉积物中有机碳含量(OC)控制;而WAEF-N则与碳酸盐(CaCO₃)存在显著的负相关关系;TN与OC不具有显著意义的相关,间接说明二者来源的不同.同时,各形态氮的分布还与沉积物粒度类型密切联系.此外,研究区域内由沉积物提供的氮源很大程度上补偿了浮游植物对水体中营养盐的消耗,对维持该海域的初级生产力水平起到一定作用.其中,IEF-N和SOEF-N的释放对浮游植物生长及初级生产力的贡献较为显著.