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The geochemical and mineralogical investigations conducted on a core retrieved from a paleolake in Faiyum Depression, Egypt, reveal a variation in two precipitation patterns; these are the Ethiopian African Monsoon (EAM) at the Nile Headwaters and the Mediterranean winter rains. The heavy mineral assemblage, and the geochemical characteristics, exhibit significant shifts in clastic input to the paleolake. These variations suggest shifting in the sources of sediment, with an East African origin during the African Humid Period (AHP) and in the Late Holocene, and a White Nile source during the Late Pleistocene and Middle Holocene. Geochemical data is additionally utilized in the determination of variations in the properties of the paleo-water (paleo-salinity and paleo-productivity). The paleo-water of Faiyum Lake exhibited characteristics of a substantial freshwater body during the Early to Mid-Holocene. During the subsequent period, there was a sudden drop in the lake level, accompanied by a subsequent rise in salinity due to hydrological modifications. [ABSTRACT FROM AUTHOR]

China has been committed to achieving carbon neutrality by 2060. China’s pledge of carbon neutrality will play an essential role in galvanising global climate action, which has been largely deferred by the Covid-19 pandemic. China’s carbon neutrality could reduce global warming by approximately 0.2–0.3 °C and save around 1.8 million people from premature death due to air pollution. Along with domestic benefits, China’s pledge of carbon neutrality is a “game-changer” for global climate action and can inspire other large carbon emitters to contribute actively to mitigate carbon emissions, particularly countries along the Belt and Road Initiative (BRI) routes. In order to achieve carbon neutrality by 2060, it is necessary to decarbonise all sectors in China, including energy, industry, transportation, construction, and agriculture. However, this transition will be very challenging, because major technological breakthroughs and large-scale investments are required. Strong policies and implementation plans are essential, including sustainable demand, decarbonizing electricity, electrification, fuel switching, and negative emissions. In particular, if China can peak carbon emissions earlier, it can lower the costs of the carbon neutral transition and make it easier to do so over a longer time horizon. China’s pledge of carbon neutrality by 2060 and recent pledges at the 26th UN Climate Change Conference of the Parties (COP26) are significant contributions and critical steps for global climate action. However, countries worldwide need to achieve carbon neutrality to keep the global temperature from growing beyond the level that will cause catastrophic damages globally. [ABSTRACT FROM AUTHOR]

The degree to which climate variability and anthropogenic stressors have impacted the rich array of boreal lakes in northern Saskatchewan and Alberta was explored in a dataset of 42 lakes from previous paleolimnological investigations of this region. This dataset was used to evaluate the extent of change in diatom assemblages over the past ~ 60 to 70 years in relation to lake and watershed characteristics. Similarity analysis was used to define the degree of change in diatom composition in lake sediment cores from each lake with a focus on post ca. 1945 changes to establish a common time frame to compare across all lakes. This time frame incorporates pre- and post-development of the Athabasca Oil Sands Region and additionally integrates pre- and post-periods of distinct changes in temperature and precipitation. Beta regression analysis was used to identify potential links between diatom assemblage change and lake physical–chemical and landscape characteristics (limno and landscape models, respectively). Similarity analysis indicated nearly 80% of the lakes showed only a very low degree of change (0–25%) since ca. 1945. Lakes with larger percent change in similarity (> 25%) showed increases in planktonic diatoms, although the specific taxa that changed varied from oligotrophic Discostella spp. to meso-eutrophic taxa, such as Asterionella formosa and Stephanodiscus minutulus. Lake volume and percent peat in the catchment were the most important limno and landscape explanatory variables, respectively, albeit the models had low predictive power. The lakes with large diatom compositional change were dispersed across the region, located in various geological and ecological zones and varying degrees of human disturbance. The interplay of climate and morphometric features of lakes is likely an influential driver of these changes, with larger heat-storage capacity in higher-volume lakes that potentially increases the sensitivity to warming. The small surface areas and shallow morphometry of most lakes, a heterogeneous hydrological and geological landscape, and frequent dominance of diatom assemblages by benthic generalists may explain the minimal responses of diatom assemblages over the past ~ 70 years to anthropogenic influences and climate. [ABSTRACT FROM AUTHOR]

We studied the sedimentology, benthic foraminifera, molluscs, and δO and δC of Ammonia tepida tests in two late Holocene sediment cores from Lake Qarun (Egypt). The cores, QARU2 (upper section, 8.2 m) and QARU4 (1.4 m), span approximately the past 500 years of sedimentation. Benthic foraminifera first appeared in the upper part of QARU2 at 314 cm depth, ca. AD 1550. This depth marks the beginning of colonization of the lake by foraminifera and indicates a change in lake water salinity, as foraminifera cannot tolerate fresh water. Initially, three species of benthic foraminifera colonized the lake, Ammonia tepida, Cribroelphidium excavatum and Cribrononion incertum. Relative abundance of these species fluctuated throughout cores QARU2 and QARU4 and highest overall faunal diversity occurred at the beginning of the twentieth century. High relative abundances of C. incertum and deformed tests are attributed to periods of greater lakewater salinity. Peaks in both δO and δC indicate times of higher evaporation and reduced fresh water inflow. Inferred salinity was high around AD 1700 and after AD 1990. Rapid response of climate proxy variables indicates the high sensitivity of Lake Qarun to environmental changes over the past several 100 years. Increases in lakewater Mg concentration during past evaporative events, associated with less fresh water inflow, probably provided conditions suitable for C. incertum to build its white or transparent tests. Gradual decrease of C. incertum, until its disappearance at 100 cm depth ca. AD 1890, indicates a more persistent trend in lake water chemistry. Higher concentrations of dissolved sulphates were the likely cause of this species disappearance. Recent, twentieth-century sediments were deposited under optimal salinity (37‰) for benthic fauna, but further environmental changes are indicated by the decrease or disappearance of several benthic foraminifera and mollusc species. Intermittent hypoxia in the lake's bottom waters, caused by cultural eutrophication, may account for these most recent changes. [ABSTRACT FROM AUTHOR]

A convenient, portable, hand-operated surface-sediment sampler for use in shallow water is described. Collection of replicable, undisturbed surface sediment samples from shallow-water locations is made simple. The sampler is highly portable for use at remote sites and can be operated by one person. It is especially useful for sampling in the 0.3–1.3 m water depth range where other samplers are often unsuccessful. This sampler consists of a PVC tube (about 33-cm length, 7.1-cm diameter) attached to a 1-m-long supporting rod. A lever system is used to close off the PVC core tube. In the open position, the core tube is inserted into the sediment to an optimal depth (typically 1-cm) so that a 1-cm disc of surface sediment is enclosed. This disc is then isolated by operating the lever and tube closure plate. The sampler and sediment sample (with an intact epipelon biofilm) are removed carefully so that most of the enclosed water drains away and the sample is retained intact. [ABSTRACT FROM AUTHOR]

Lake Qarun is a closed saline lake in the northern part of EI-Fayoum Depression (Middle Egypt) at the margin of the Great Western Desert. It is almost entirely sustained by inflow from the Nile River and, during the 20th century, lake water salinity has increased strongly. Physico-chemical characteristics and phytoplankton periodicity in the lake were monitored during 2001. All the water quality variables measured showed considerable seasonal variation, and quantitative and qualitative differences in phytoplankton communities were recorded. The maximum crop density was in August, whereas lowest values occurred in December. Highest crop densities coincided with a high abundance of Bacillariophyceae. The Bacillariophyceae were most diverse with 23 species, then Chlorophyceae with 16, Cyanophyceae with 8, and Chrysphyceae and Dinophyceae with one species each. Despite being a saline inland lake, the open-water phytoplankton communities were composed of some marine! brackish forms but mainly of freshwater communities tolerant to high salinity. The identified phytoplankton species indicate a tendency towards eutrophy but total crop densities were relatively low compared with eutrophic lakes elsewhere. Light limitation by suspended solids as well as hydrological related factors are believed responsible for the relatively low phytoplankton abundance. The lake appears to be ecologically unstable and careful limnological monitoring is recommended. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the protest of residents of China on the relocation of factories from cities to rural areas due to shifting of pollution.

A letter to the editor is presented on the topic of the 2022 Winter Olympics in Beijing, China, and how it will impact water scarcity in the region.

The article calls for stricter regulation and tighter monitoring of the fracking industry in China to reduce seismic activity and environmental pollution in line with the minor earthquakes induced by wastewater injection by Chinese oil and gas industries.

The article discusses the highlights of a workshop about sediments found in Lake Baikal held during the 7th International Palaeolimnology Symposium in Heiligkreuztal, Germany on August 29, 1997. The workshop was headed by Rick Batterbee, which started with an introduction to Lake Baikal by Roger Flower. According to Batterbee, the lake offers potential for introducing connections between climate and endemic diatom plankton abundances.

The article offers information that groundwater resources are deteriorating in China due to shale-gas extraction and mentions that China has prioritized 13 provinces for shale-gas exploitation to satisfy growing energy demands and reduce carbon emissions.

A letter to the editor in response to an article on China's efforts to tackle environmental pollution, published in a previous issue is presented.