Abstract: In the context of updating the 2015 Nationally Determined Contribution (NDC), the government of Chile has updated its estimates of compliance costs for a series of mitigation actions with an emphasis on the energy sector as the main source of its greenhouse gas emissions. Using the information developed in this process, we assess the impact on compliance costs of increasing the flexibility for sources by introducing different emissions trading schemes. For this we develop a detailed optimization model that represents the operational and investment decisions that could be taken by the energy generation, industrial and mining sectors if an Emissions Trading System (ETS) was implemented. An ETS with two cap and trade options is analysed together with an offset mechanism for sources not included in the ETS. Also, two policy goals are considered: a stringent 76% sectoral reduction goal in 2050 similar to Chile's current strict NDC, and a more lax 46% goal similar to Chile's initial 2015 NDC proposal. The results show that (i) cost reductions from increased flexibility for Chile's current strict NDC are significant, and that offsets can play an important role; (ii) the stringency of the reduction goal affects the magnitude of the cost savings related to flexibility and, surprisingly, total abatement costs are negative (i.e. there are benefits) for the 46% reduction goal. In this latter case, the most significant cost reductions result from compelling firms to comply with their allowances in each sector, not increased flexibility. These results highlight the policy relevance of case by case analysis using a modelling approach similar to the one we develop here. Key policy insights ETS implementation can help Chile meet its mitigation commitment for 2050. The compliance costs can vary significantly depending on the flexibility implemented in the emissions trading schemes. Optimization models can help decision-makers define the attributes of an ETS, such as the sectors that should participate, the cap, and the percentage of offsets. The proposed methodology also highlights and quantifies the offsets that can be acquired from sectors that are not part of an ETS, such as forestry, agriculture, and the waste sector. The possibility to acquire of offsets could reduce significantly the cost for industries that participate of an ETS.

Abstract: Climate change and solar geoengineering have different implications for drought. Climate change can “speed up” the hydrological cycle, but it causesgreater evapotranspiration than the historical climate because of higher temperatures. Solar geoengineering (stratospheric aerosol injection), on the other hand, tends to “slow down” the hydrological cycle while reducing potential evapotranspiration. There are two common definitions of drought that take this into account; rainfall-only (SPI) and potential-evapotranspiration (SPEI). In different regions of Africa, this can result in different versions of droughts for each scenario, with drier rainfall (SPI) droughts under geoengineering and drier potential-evapotranspiration (SPEI) droughts under climate change. However, the societal implications of these different types of drought are not clear. We present a systematic review of all papers comparing the relationship between real-world outcomes (streamflow, vegetation, and agricultural yields) with these two definitions of drought in Africa. We also correlate the two drought definitions (SPI and SPEI) with historical vegetation conditions across the continent. We find that potential-evapotranspiration-droughts (SPEI) tend to be more closely related with vegetation conditions, while rainfall-droughts (SPI) tend to be more closely related with streamflows across Africa. In many regions, adaptation plans are likely to be affected differently by these two drought types. In parts of East Africa and coastal West Africa, geoengineering could exacerbate both types of drought, which has implications for current investments in water infrastructure. The reverse is true in parts of Southern Africa. In the Sahel, sectors more sensitive to rainfall-drought (SPI), such as reservoir management, could see reduced water availability under solar geoengineering, while sectors more sensitive to potential-evapotranspiration-drought (SPEI), such as rainfed agriculture, could see increased water availability under solar geoengineering. Given that the implications of climate change and solar geoengineering futures are different in different regions and also for different sectors, we recommend that deliberations on solar geoengineering include the widest possible representation of stakeholders.

Abstract: Ectotherms constitute the vast majority of terrestrial biodiversity and are especially likely to be vulnerable to climate warming because their basic physiological functions such as locomotion, growth, and reproduction are strongly influenced by environmental temperature. An integrated view about the effects of global warming will be reached not just establishing how the increase in mean temperature impacts the natural populations but also establishing the effects of the increase in temperature variance. One of the molecular responses that are activated in a cell under a temperature stress is the heat shock protein response (HSP). Some studies that have detected consistent differences among thermal treatments and ontogenetic stages in HSP70 expression have assumed that these differences had a genetic basis and consequently expression would be heritable. We tested for changes in quantitative genetic parameters of HSP70 expression in a half-sib design where individuals of the beetle Tenebrio molitor were maintained in constant and varying thermal environments. We estimated heritability of HSP70 expression using a linear mixed modelling approach in different ontogenetic stages. Expression levels of HSP70 were consistently higher in the variable environment and heritability estimates were low to moderate. The results imply that within each ontogenetic stage additive genetic variance was higher in the variable environment and in adults compared with constant environment and larvae stage, respectively. We found that almost all the genetic correlations across ontogenetic stages and environment were positive. These suggest that directional selection for higher levels of expression in one environment will result in higher expression levels of HSP70 on the other environment for the same ontogenetic stage. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract: Climate change has intensified in recent decades, leading to increasingly severe droughts. This trend will continue due to the emissions and increasing concentration of greenhouse gas (GHG). One of the main direct climate change consequences is the modification and alteration of the dynamics and function of forest ecosystems, having effects ranging from physiological alterations in plants to definitive changes in their geographical distribution. Mediterranean ecosystems are particularly threatened, where the sclerophyllous forest of central Chile that is considered a biodiversity hotspot, is no exception. Despite that sclerophyllous species present drought adaptation mechanisms, there is no certainty of the climatic minimum thresholds in which it develops, or when climate changes will exceed these thresholds, causing definitive changes in its distribution. To evaluate these changes on the Andean Mediterranean Sclerophyllous Forest vegetation belt of Quillaja saponaria and Lithraea caustica, the forest was divided into six quadrants with similar climates. In each quadrant, a critical threshold of a simplified water balance (SWB) was defined where the forest has historically developed. The SWB is considered to be a limiting factor in the forest development. Then, the Time of Emergence (ToE) of the forest is estimated, as the time when climate change projections exceed the critical thresholds, by using CMIP6 General Circulation Models (GCM), under SSP2-4.5 (moderate) and SSP5-8.5 (pessimistic) scenarios. Results indicate that the forest would begin to be displaced between 2060 and 2080 under the SSP5-8.5 scenario, particularly in the Talagante, Isla de Maipo, Paine, and Don & SIM;ihue area, while no distribution changes are presented under SSP2-4.5 scenario.

Abstract: Purpose of Review: Review our current understanding of how precipitation is related to its thermodynamic environment, i.e., the water vapor and temperature in the surroundings, and implications for changes in extremes in a warmer climate. Recent Findings: Multiple research threads have i) sought empirical relationships that govern onset of strong convective precipitation, or that might identify how precipitation extremes scale with changes in temperature; ii) examined how such extremes change with water vapor in global and regional climate models under warming scenarios; iii) identified fundamental processes that set the characteristic shapes of precipitation distributions. While water vapor increases tend to be governed by the Clausius-Clapeyron relationship to temperature, precipitation extreme changes are more complex and can increase more rapidly, particularly in the tropics. Progress may be aided by bringing separate research threads together and by casting theory in terms of a full explanation of the precipitation probability distribution.

Abstract: The demography and individual performance of species at their range edges provide important insight into how climate warming is impacting species distributions. The boreal limpet Patella vulgata and the Lusitanian limpet P. depressa have overlapping geographic ranges and local distributions in Britain. We measured individual performance at the 2 leading edges of P. depressa distribution (North Wales and South/South-east England) and in non-range edge populations in South-west England. Individuals of P. depressa towards both leading edges were expected to have reduced growth rates and higher mortality rates when compared with non-range edge populations. Conversely, P. vulgata was expected to have equivalent performance across regions, coinciding with the centre of its range. Tagged individuals did not show betweenspecies differences in growth and mortality over a 12 mo period. Nonetheless, individual growth rates and population mortality rates of both Patella species were higher towards the range edge of P. depressa in South/South-east England, when compared with populations at its poleward edge and those in South-west England. Further analysis showed that growth and mortality rates were higher in denser populations for both P. depressa and P. vulgata, with equivalent site-specific performance patterns for both species in all regions. Thus, performance patterns of P. depressa reflected local factors in the same way as P. vulgata, overriding patterns of declining performance expected towards species borders. Comparisons between key congeneric species and their unexpected patterns of performance across their ranges provide insights into processes setting species boundaries and thereby their responses to climate change.

Abstract: Sustainable food production and consumption are key to face the current climate and environmental crisis, hence innovation to produce food with lower impacts are taking more attention. Controlled environment agriculture, also known as vertical farming, is seen as one innovative approach to reduce impacts of producing food while also improv-ing food security. Aeroponic is one of such innovations, which environmental impacts have not been well understood yet. Therefore, this study assesses the environmental impacts of aeroponic farm container system in the UK, including a full set of 19 indicators. The results show that energy requirements drive all the impacts, with climate change estimated at 1.52 kg CO2eq. per 1 kg of microgreens (pea shoots) using 2021 UK grid. Renewable powered systems improve almost all the impacts, with climate change reduced by up to 80 %, making this system competitive with con-ventional agricultural systems. This study proves that aeroponic farm container could offer lower impact food than equivalent imported to the UK, and that also could improve food security in terms of availability, stability, and access to food. Affordability issues need to be assessed in future work.

Abstract: 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.