Search

Climate change is the most important environmental problem facing humanity in this century. And it has become the great axis of public policies and private actions in developed societies. The effects of altering the planetary energy balance due to anthropogenic greenhouse gas emissions are already becoming evident in some regions of the planet. Among them, the evidence is already significant in the areas with a Mediterranean climate. This paper collects, as a review paper, the evidence and trends that are being recorded in two areas with a Mediterranean climate (the Spanish Mediterranean coast and the central sector of Chile) to assess the effect of the global warming process. The impact that the current climate change is having on the main elements of the climate and on specific environmental processes in both of these geographical spaces has been analysed. The study seeks to update, through an evaluative summary, the state of the issue of climate change in Mediterranean areas, indicating its future impact on elements of the natural environment and on the functioning of the societies that exist in these regions. [ABSTRACT FROM AUTHOR]

The regional impact of climate change on heating and cooling demand is important to consider when designing optimal long-term energy policies. Several studies have addressed this issue, but either at a very aggregated level or without optimizing the whole energy system. The aims of this paper are to fill this gap in a generic way and to assess the impact of climate change on heating and cooling energy demands for residential and commercial sectors at the regional and nodal levels in the context of Chile's energy transition. We propose a methodology based on high resolution climate simulations for the Representative Concentration Pathways (RCP) RCP 2.6 and RCP 8.5 scenarios. First, a statistical analysis is performed to estimate the long-term trends of so-called heating and cooling degree-days and their impact on final regional energy demands. Then, demand pathways in the energy transition are assessed using a multi-sectoral energy planning model. Numerical experiments using data from Chile show an overall positive economic impact of climate change (limited to heating and cooling demands) for the energy system, with a significant decrease in heating demand compared to a limited increase in cooling requirements. For the RCP 8.5 scenario, cost reductions reach 2.1% of the total discounted system cost on the 2020-2050 period mainly due to a significant decrease of gas consumption for heating. This research highlights the importance for policymakers to consider climate change in efficient energy policies. [Display omitted] • Climate change impact on heating/cooling is assessed for Chile's energy transition. • Significant heating demand decrease and low cooling demand increase are observed. • A global positive economic impact for the energy system is estimated. • For the RCP 8.5 scenario, cost reductions reach 2.1% of the total discounted system cost. [ABSTRACT FROM AUTHOR]

Cetacean strandings (CS) have been reported in increasing numbers in coastal areas worldwide. Although the causes of these strandings are unknown, a number of anthropogenic and environmental factors have been suggested. This paper aims to characterize CS patterns and describe their fine-scale spatiotemporal dynamics. We analysed spatial and spatiotemporal CS patterns in Chile from January 1968 to January 2020. We identified a total of 389 CS events affecting eight cetacean families, 21 genera, and 35 species, which represent more than 85% of the reported species richness for the country. Most CS events (94.1%) were single (i.e., ≤two individuals). There were also 18 mass stranding (three to 24 individuals, 4.1%) and nine unusually large mass stranding events (>25 individuals, 2%). Purely spatial tests showed CS events appearing in random occurrence along the Chilean coast. Local tests for spatio-temporal clusters, however, identified a greater number of hotspots reported in the southernmost part of the country, namely, Chilean Patagonia. Specifically, significant spatio-temporal clusters were identified and defined as containing three or more individuals within a two-month period as a focal coastal event (<1 km radius). It is a cause of concern that CS events in Chile have been increasing consistently over the last decades, and although we were not able to identify their causes, we are able to highlight the importance of changes in climate conditions and of an increase in monitoring activities as primary drivers for such patterns, particularly important in Chilean Patagonia. [ABSTRACT FROM AUTHOR]

• FuturES framework optimises electricity scenarios with high renewables penetration. • Reservoir and concentrating solar power modelled based on storage value. • Feasible scenarios created with 81–100% renewables by 2050. • Long-term energy storage helps to achieve low electricity costs. Although electricity supply is still dominated by fossil fuels, it is expected that renewable sources will have a much larger contribution in the future due to the need to mitigate climate change. Therefore, this paper presents a new framework for developing Future Electricity Scenarios (FuturES) with high penetration of renewables. A multi-period linear programming model has been created for power-system expansion planning. This has been coupled with an economic dispatch model, PowerGAMA, to evaluate the technical and economic feasibility of the developed scenarios while matching supply and demand. Application of FuturES is demonstrated through the case of Chile which has ambitious plans to supply electricity using only renewable sources. Four cost-optimal scenarios have been developed for the year 2050 using FuturES: two Business as usual (BAU) and two Renewable electricity (RE) scenarios. The BAU scenarios are unconstrained in terms of the technology type and can include all 11 options considered. The RE scenarios aim to have only renewables in the mix, including storage. The results show that both BAU scenarios have a levelised cost of electricity (LCOE) lower than, or equal to, today's costs ($72.7–77.3 vs $77.6/MWh) and include 81–90% of renewables. The RE scenarios are slightly more expensive than today's costs ($81–87/MWh). The cumulative investment for the BAU scenarios is $123-$145 bn, compared to $147-$157 bn for the RE. The annual investment across the scenarios is estimated at $4.0 ± 0.4 bn. Both RE scenarios show sufficient flexibility in matching supply and demand, despite solar photovoltaics and wind power contributing around half of the total supply. Therefore, the FuturES framework is a powerful tool for aiding the design of cost-efficient power systems with high penetration of renewables. [ABSTRACT FROM AUTHOR]

The time at which climate change signal can be clearly distinguished from noise is known as time of emergence (ToE) and is typically detected by a general circulation model (GCM) signal-to-noise ratio exceeding a certain threshold. ToE is commonly estimated at large scales from GCMs, although management decisions and adaptation strategies are implemented locally. This paper proposes a methodology to estimate ToE for both precipitation and temperature at local scales (i.e., river basin). The methodology considers local climatic conditions and unbiased GCM projections to estimate ToE by using the statistical power to find when the climate significantly differs from the historical one. The method suggests that ToE for temperature already occurred in three Chilean basins (Limarí, Maipo, and Maule). However, in terms of precipitation, an earlier ToE is clearly identified for the Maule basin, indicating that risk assessment and adaptation measures should be implemented first in this basin. [ABSTRACT FROM AUTHOR]

Simple Summary: Atlantic salmon (Salmo salar) has become a commodity worldwide. The culture of Atlantic salmon is by far the most well-developed branch of marine finfish aquaculture, with this species ranking among the top ten most highly produced in global aquaculture. While Atlantic salmon has been commonly farmed in sea cages located in colder waters (e.g., in Norway, Chile and Tasmania), these regions can experience the negative impacts of heat waves that push seawater temperature above values tolerated by this species. These climate-change-driven shifts in water temperature can be associated with mass mortality events and urgent actions are needed to cope with a changing ocean. This paper reviews the thermal limits of adult Atlantic salmon and lists the negative effects driven by heat stress. We highlight how biotechnology and the genetic diversity of wild populations may help producers to tackle this challenge. Selective breeding programs and other more advanced biotechnological solutions (e.g., gene editing) may play a key role in this quest to produce new strains of Atlantic salmon that more readily tolerate higher water temperatures, without compromising productivity and profitability. Atlantic salmon (Salmo salar) cage farming has traditionally been located at higher latitudes where cold seawater temperatures favor this practice. However, these regions can be impacted by ocean warming and heat waves that push seawater temperature beyond the thermo-tolerance limits of this species. As more mass mortality events are reported every year due to abnormal sea temperatures, the Atlantic salmon cage aquaculture industry acknowledges the need to adapt to a changing ocean. This paper reviews adult Atlantic salmon thermal tolerance limits, as well as the deleterious eco-physiological consequences of heat stress, with emphasis on how it negatively affects sea cage aquaculture production cycles. Biotechnological solutions targeting the phenotypic plasticity of Atlantic salmon and its genetic diversity, particularly that of its southernmost populations at the limit of its natural zoogeographic distribution, are discussed. Some of these solutions include selective breeding programs, which may play a key role in this quest for a more thermo-tolerant strain of Atlantic salmon that may help the cage aquaculture industry to adapt to climate uncertainties more rapidly, without compromising profitability. Omics technologies and precision breeding, along with cryopreservation breakthroughs, are also part of the available toolbox that includes other solutions that can allow cage farmers to continue to produce Atlantic salmon in the warmer waters of the oceans of tomorrow. [ABSTRACT FROM AUTHOR]

Agriculture could be one of the most vulnerable economic sectors to the impacts of climate change in the coming decades, with impacts threatening agricultural production in general and food security in particular. Within this context, climate change will impose a challenge to policy makers, especially in those countries that based their development on primary sectors. In this paper we present a non-linear agricultural supply model for the analysis of the economic impacts of changes in crop yields due to climate change. The model accounts for uncertainty through the use of Monte Carlo simulations about crop yields. According to our results, climate change impacts on the Chilean agricultural sector are widespread, with considerable distributional consequences across regions, and with fruits producers being worst-off than crops producers. In general, the results reported here are consistent with those reported by previous studies showing large economic impacts on the northern zone. However, our model does not simulate remarkable economic consequences at the country level as previous studies did. [ABSTRACT FROM AUTHOR]

Broad-scale richness gradients are closely associated with temperature and water availability. However, historical and evolutionary processes have also contributed to shape current diversity patterns. In this paper we focus on the potential influences of Pleistocene glaciation and phylogenetic niche conservatism (the tendency for traits to be maintained during diversification) on the tree diversity gradient in Chile, and we quantify its primary climatic correlates. Tree species richness is greatest at mid latitudes, particularly in the Andes and Coastal ranges, and decreases abruptly to the south and north. Regression tree analysis identified annual precipitation and annual temperature as the primary probable drivers of this gradient. Ice cover during the Last Glacial Maximum was also identified as an 'important' variable, but the contemporary and historical predictors are strongly collinear. Geographically weighted regression indicated that the relationships between richness and environmental variables vary regionally: the relationship between tree richness and precipitation is stronger in north-central Chile, whereas tree richness and temperature are most strongly associated in south-central Chile. By assigning each species the age of the family to which it belongs and averaging all species in each geographical unit, we also found that species from the oldest families are distributed mainly in mid to high latitudes and species from younger families are distributed mainly at lower latitudes. This pattern is closely associated with annual precipitation. Thus, the ecological component of tree richness follows contemporary climatic gradients of both energy and water, but the aridification of the Atacama Desert was an important driver over evolutionary time. The influence of recent Pleistocene glaciation remains unresolved but it cannot be discounted. [ABSTRACT FROM AUTHOR]

The snowpack in the central Andes (30°–37°S) is the primary source for streamflow in central Chile and central-western Argentina, but few published studies are available on snowpack variability in the region. This paper develops the first regional snowpack series (1951–2005) from Chilean and Argentinean snow course records. This series shows a strong regional signal, marked interannual variability, and a positive, though nonsignificant, linear trend. Correlations with local precipitation and temperature records reveal a marked association with conditions in central Chile. High snow accumulation is generally concurrent with El Niño events in the tropical Pacific, but only 5 of the 10 driest years coincided with La Niña events. Evaluation of 500-hPa geopotential height anomaly maps during extreme snow years highlights the crucial significance of tropospheric conditions in the subtropical and southeast Pacific in modulating snowfall. Correlations with gridded SST and SLP data and multiple regressions with large-scale climatic indices corroborate a Pacific ENSO-related influence largely concentrated during the austral winter months. This hampers the predictability of snowpack before the onset of the cold season. Annual and warm-season river discharges on both sides of the cordillera are significantly correlated with the regional snowpack record and show positive linear trends over the 1951–2004 common period, probably related to a greater frequency of above-average snowpacks during recent decades. Future demand and competition for water resources in these highly populated regions will require detailed information about temporal and spatial variations in snow accumulation over the Andes. The results indicate that the relationships between snowpack and atmospheric circulation patterns prior to the winter season are complex, and more detailed analyses are necessary to improve prediction of winter snowfall totals. [ABSTRACT FROM AUTHOR]

The appropriate design of land-use and rural employment policies depends upon the anticipated performance of the farm sector in the context of expected climate changes, especially with respect to land allocations to potential activities. Concerns over the possible net benefits of land-use changes are particularly acute in lower- and middle-income countries, where agriculture tends to be important in employment, income generation and foreign-exchange earnings. This paper presents an analysis of the expected impacts on land use in Chile of projected climate-change scenarios in 2040 and 2070. We developed a farmland allocation model with associated labor employment at the municipal level driven by expected relative net incomes per hectare, constructed from local average per-hectare yields, regional average output prices and per-hectare production cost estimates. The sensitivities of cropland allocations to relative net-income changes were estimated using historical land allocations at the municipal level derived from the last two Chilean Agricultural Censuses. The results show that the impacts of climate changes will be mitigated by land-use adaptation, the main export-earning crops tending to move south; in aggregate, agricultural employment will decrease in all the climate-change scenarios; forestry and agriculture would likely suffer a loss in net-income generation under severe climate-change scenarios. [ABSTRACT FROM AUTHOR]

United Nations' members came together in 2015 and agreed on seventeen sustainable development goals which include hundred and sixty-nine targets related to sustainable development into the overall economic, environmental and social contexts of countries to be achieved by 2030. In order to achieve these goals, more effort may be required than the current policies and strategies. This is particularly true for the energy sector as energy is the key enabler for all development activities. Therefore, there is a need to analyse the required effort and energy to implement these goals based on countries' specific context. The objective of this paper is to assess the indicators of energy-related sustainable development goals and calculate the additional energy requirement to achieve each goal by 2030 for Chile. The key findings of the research indicate that Chile will meet fourteen energy-related sustainable development targets by 2030 under the business as usual scenario. However, Target 2.1, Target 5.b, Target 12.3, Target 13.1, and Target 17.6 require extra energy to meet sustainable development goals in Chile by 2030. Approximately 16 million GJ additional energy is required in order to meet energy-related sustainable development goals in Chile than the business as usual scenario by 2030. This research output can provide insights to researchers trying to assess the achievement of sustainable development goals in other developing countries. [ABSTRACT FROM AUTHOR]

Reconstructing the evolution of the glacial landscape of the semi-arid Andes (32°–34° S) during phases of Holocene deglaciation is key to understand the responses of the cryosphere during warmer periods such as the current one. Despite having geomorphological records with good degrees of preservation, few studies have addressed the changes of the Andes during the glacial-paraglacial transition. In this paper, we investigate and compare geomorphological mappings of four glacial sub-basins of the central Andes of Chile: Juncal Norte (32° S, glacier terminus at ~ 3000 m asl.), Loma Larga (33° S, terminus at ~ 3000 m asl.), Nieves Negras (33° S, terminus at ~ 3000 m asl.), and Universidad (34° S, terminus at ~ 2500 m asl.). The ablation zones of Loma Larga and Nieves Negras glaciers have a mantle of debris, which suggests a process of ablation in situ rather than retreat of the glacier tongue. Both glaciers have a morphology of internal collapse in their debris-covered section. On the other hand, Juncal Norte and Universidad glaciers both have lateral moraines with ice cores, where the differential ablation has triggered backwasting and downwasting processes. The presence of ice-cored lateral moraines indicates greater activity of processes in the lateral sections. The Universidad glacier is characterized by two branches feeding the glacier tongue which shows a prominent medial moraine.For the first time in this part of the Andes, we used 36Cl terrestrial cosmogenic nuclides (TCN) for dating deglaciation geomorphology. We complement our 36Cl data with 14C ages that suggest that glaciers advanced before ~2500 and then before ~850/1000 years BP.The combination of the geomorphology and the geochronology in the different proglacial areas allows the analysis of the deglaciation history and related processes. Identifying how ablation occurs in semi-arid mountain environments is important to assess the behaviour of ice under changing climatic conditions and its preservation under a cover of debris. One of the characteristics and challenges of the deglaciation in the semi-arid Andes is the high production of debris in the ablation zones. [ABSTRACT FROM AUTHOR]

The Pampa del Tamarugal (PdT; ~19º30'S-21º30'S) is an endorheic basin located today at the core of the Atacama Desert (northern Chile), the most arid desert on earth. Water, a fundamental resource for survival of humans, animals and plants, is a scarce resource in the PdT landscape given that precipitation fall upslope over the Andes and the Altiplano and perennial springs infiltrate in the foothills before reaching this basin. However, discontinue human occupations in the since 13ka and the presence extinct fauna dated 18-14ka southernmost part of the PdT, revealed the presence of water in the past under a highly environmental variability. It is widely known that two pluvial phases occurred in the Atacama Desert (CAPE I-II) and the Altiplano (Tauca and Coipasa phases) during the Late Pleistocene characterized by significant increases of rainfall amount and the consequent environmental changes. However, palaeoecological evidence that allowed to understand the environmental scenarios that supported human populations and extinct fauna in the PdT since and/or during the Late Pleistocene is scarce and fragmentary. Thus, this paper presents new palaeoecological evidences from the PdT in order to shed light to the environmental dynamics and landscape characteristics.Between the Guatacondo and Tambillos ravines, growing evidence shows different features of past landscapes and human activities. Thus, plant macro-remains as leaf litter packs, trunks in horizontal position, in situ bases of trunks, plant stem imprints as well as different sedimentary deposits revealed the presence of paleosprings, paleowetlands and small shallow lacustrine basins during the Late Pleistocene. In Quebrada Maní, for example, large paleowetlands developed until 11ka. Instead, the preserved vegetal macro-remains showed a peculiar spatial pattern of vegetation during that period where Prosopis trunks are more frequent in lowlands (~850 m asl) of PdT while the macro-remains, mainly of Escallonia, are abundant near to the foothill (~1150 masl). Later on, during the early and mid-Holocene, an abrupt decrease in rainfall in the Central Andes generated hiperarid conditions in PdT and consequently, no evidence of human populations was found. Sedimentological observations and OSL dates suggest the development of arid landscapes in the Guatacondo ravine (21ºS) by this time, dating the incision of the ravine sometime between 6.6-1.3ka.After that, a new humid pulse during the Late Holocene (2.5-1ka), associated with new human occupations in PdT characterized by the development of villages and wide field-crops occurred. This period of intensive cultural development and "re-use" of the PdT ended around 1-0.7ka, following a trend to aridization recorded in the rodent middens pollen record. After that the villages of PdT were abandoned and population moved to villages located at higher altitude or associated with water oases active until the present. Around 100-150 yr BP, a brief humid pulse in the PdT occurred synchronously with the reoccupation of the field-crops but probably just seasonally.Acknowledgments: FONDECYT# 1181829; CONICYT/PIA ANILLO SOC1405. [ABSTRACT FROM AUTHOR]