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An understanding of the trend in cooling and heating degree-days acts as a driving force for building energy demand under climate change conditions. However, little is known about the spatiotemporal trend patterns in cooling and heating degree-days in recent times and their possible causes in Bangladesh. Therefore, we explored the trend and variability of cooling degree-days (CDD) and heating degree-days (HDD) and their possible reasons for variation for the study period 1980–2017 based on daily temperatures datasets from 27 sites in Bangladesh. The results show that the highest annual mean CDD and HDD were identified in the southwestern and central climatic regions of Bangladesh. The CDD trend has significantly increased in Bangladesh, and the HDD trend has increased but non-significance. The outcomes of detrended fluctuation analysis (DFA) and R/S analysis exhibit that CDD and HDD will continue their contemporary trend direction in the future. Land–Ocean Temperature Index (LOTI) had a significant positive influence on CDD; however, there was no significant correlation between HDD and atmospheric circulation indices. The importance analysis from the random forest (RF) model showed that the LOTI is the highest contributing variable for CDD and East Asian Summer Monsoon Index (EASMI) is the largest influential variable for HDD affecting climate variability in Bangladesh. ECMWF ERA5 reanalysis datasets depict that higher summer geopotential height, an anticyclonic center, enhanced relative humidity, declined total and high cloud covers, decreasing surface solar radiation, and high skin temperature fluxes might have influenced on CDD and HDD variations in Bangladesh.

The rapidly warming temperatures in high-latitude and alpine regions have the potential to alter the phenology of Arctic and alpine plants, affecting processes ranging from food webs to ecosystem trace gas fluxes. The International Tundra Experiment (ITEX) was initiated in 1990 to evaluate the effects of expected rapid changes in temperature on tundra plant phenology, growth and community changes using experimental warming. Here, we used the ITEX control data to test the phenological responses to background temperature variation across sites spanning latitudinal and moisture gradients. The dataset overall did not show an advance in phenology; instead, temperature variability during the years sampled and an absence of warming at some sites resulted in mixed responses. Phenological transitions of high Arctic plants clearly occurred at lower heat sum thresholds than those of low Arctic and alpine plants. However, sensitivity to temperature change was similar among plants from the different climate zones. Plants of different communities and growth forms differed for some phenological responses. Heat sums associated with flowering and greening appear to have increased over time. These results point to a complex suite of changes in plant communities and ecosystem function in high latitudes and elevations as the climate warms.

Climate change is expected to influence cooling and heating energy demand of residential buildings and affect overall thermal comfort. Towards this end, the heating (HDD) and cooling (CDD) degree-days along with HDD + CDD were computed from an ensemble of seven high-resolution bias-corrected simulations attained from EURO-CORDEX under two Representative Concentration Pathways (RCP4.5 and RCP8.5). These three indicators were analyzed for 1971–2000 (from E-OBS) and 2011–2040, and 2041–2070, under both RCPs. Results predict a decrease in HDDs most significant under RCP8.5. Conversely, it is projected an increase of CDD values for both scenarios. The decrease in HDDs is projected to be higher than the increase in CDDs hinting to an increase in the energy demand to cool internal environments in Portugal. Statistically significant linear CDD trends were only found for 2041–2070 under RCP4.5. Towards 2070, higher(lower) CDD (HDD and HDD + CDD) anomaly amplitudes are depicted, mainly under RCP8.5. Within the five NUTS II regions projections revealed for 2041–2070 a decrease in heating requirements for Algarve and Lisbon Area higher in Faro, Lisboa and Setúbal whereas for North and Center regions results predicts an increase in cooling energy demand mainly in Bragança, Vila Real, Braga, Viana do Castelo, Porto and Guarda, higher under RCP8.5.

An understanding of mechanisms that underlie the steady increase in crop yields over recent decades is important for promotion of future sustainable yield gains and maintenance of future food security. In this study, we coupled observational maize yield and climate variables based on crop development data from 1981 to 2009 to construct an empirical model that can resolve the separate and combined effects of climate and agricultural practices related to crop timing on maize yield in Northeast China (NEC), the largest spring maize-producing region of China. Climate warming contributed to approximately 15.6% of the trend for increasing yield over the 29 year period. The beneficial effects of climate warming on yield were due to increases in accumulation of temperatures between 10 °C and 30 °C (growing degree days, GDD), which positively contributed to 29.7% of yield and offset the −14.1% yield reduction caused by a trend involving increasing accumulation of temperatures above 30 °C (or extreme degree days, EDD). Adaptive improvements in crop timing practices (e.g. shifts in planting date and selection of later-maturity cultivars) further optimized the impacts of GDD and EDD during the entire growing season by exploiting more GDD during the reproductive phase and fewer EDD during the vegetative phase, thereby contributing to a yield gain of 25.4% over the period from 1981 to 2009. Taken together, climate warming and crop timing practices contributed to 39.4% of the maize yield increase since 1981. Yield losses due to climate warming were detected at only one site located in the southern part of the NEC region, where yield losses must be offset by positive effects of crop timing changes. The trends in maize yields presented here may provide guidance for effective adaptation options for maize production under conditions of continued climate warming.

The temperature-based indicators heating and cooling degree days, are frequently utilized to quantitatively link indoor energy demand and outdoor thermal conditions, especially in the context of climate change. We present a comprehensive study of the heating and cooling degree-days and the degree-days categories for the near past (1976–2005), and the AR5 RCP4.5 and RCP8.5 scenario-driven future (2066–2095) over Southeast Europe based on an elaborated methodology and performed using a 19 combinations of driving global and regional climate models from EURO-CORDEX with horizontal resolution of 0.11°. Alongside the explicit focus of the degree-days categories and the finer grid resolution, the study benefits substantially from the consideration of the monthly, rather than annual, time scale, which allows the assessment of the intra-annual variations of all analyzed parameters. We provide evidences that the EURO-CORDEX ensemble is capable of simulating the spatiotemporal patterns of the degree-days and degree-day categories for the near past period. Generally, we demonstrate also a steady growth in cooling and a decrease in heating degree-days, where the change of the former is larger in relative terms. Additionally, we show an overall shift toward warmer degree-day categories as well as prolongation of the cooling season and shortening of the heating season. As a whole, the magnitude of the projected long-term changes is significantly stronger for the ’pessimistic’ scenario RCP8.5 than the ’realistic’ scenario RCP4.5. These outcomes are consistent with the well-documented general temperature trend in the gradually warming climate of Southeast Europe. The patterns of the projected long-term changes, however, exhibit essential heterogeneity, both in time and space, as well as among the analyzed parameters. This finding is manifested, in particular, in the coexistence of opposite tendencies for some degree-day categories over neighboring parts of the domain and non-negligible month-to-month variations. Most importantly, the present study unequivocally affirms the significance of the anticipated long-term changes of the considered parameters over Southeast Europe in the RCP scenario-driven future with all subsequent and far-reaching effects on the heating, cooling, and ventilation industry.

In this study, we first found that the few and sparse meteorological stations used in earlier comprehensive studies of building climate zoning in a complicated terrain area like Chongqing, China, may lead to the inapplicability of building energy efficiency standards in some areas. To address this issue, the study used daily data from 1908 extremely dense surface meteorological stations from 2011 to 2020 in Chongqing, China. In order to conduct fine zoning of building climate in Chongqing, China, GB50176-2016 and ASHRAE standard 169-2021 were employed, respectively. The findings indicated that by using the ASHRAE standard, the entire Chongqing region was classified into five climate zones. The Chongqing region was categorized into three different climate zones using China GB50176-2016: cold zone (CZ), hot summer and cold winter zone (HSCWZ), and mild zone (MZ). Not to be overlooked is the MZ (China’s GB50176-2016)/mixed-humid zone (ASHRAE standard), which is primarily situated at higher elevations in the southeast and northeast of Chongqing. In comparison to the HSCWZ/warm-humid zone, these zones have drastically different building energy efficiency regulations and approaches. According to preliminary projections, improved building climate zoning will to some extent increase building energy efficiency and reduce emissions in Chongqing. Finally, this study case can be replicated in different regions with complicated terrain.

Climate change is significantly impacting our agricultural crops and their cultivation areas, which are expected to change considerably by the end of the century. Temperature conditions decisively influence the safe suitability of grapes in a given location. To address these changes, we analysed the temporal changes of four temperature indicators: Average Growing Season Temperature (AGST), Growing Degree Days (GDD or Winkler index (GDD-WI), Huglin index (HI), and Biologically Effective Degree Days (BEDD) across 22 Hungarian wine regions from 1971 to 2100. The analysis was based on data from 14 climate models under RCP 4.5 and RCP 8.5 scenarios. To investigate the future suitability of wine grapes, we introduced the dynamic suitability function, which allowed us to analyse the suitability of the average temperature during the growing season for 21 wine grape varieties from 2031 to 2100 in decadal increments. Additionally, a temperature impact function was introduced to characterise the suitability of 21 wine grape varieties with values ranging from 0 to 1, based on the average temperature during the growing season. The results confirmed that the frequency of temperature indices used in grape cultivation will shift distinctly towards warmer climate classes in the future. The increasingly warmer climate presents certain advantages but also has growing cultivation risks. In the most optimistic scenario, the average temperature during the growing season may decrease by 0.8°C over the next seven decades. However, in the most pessimistic model, the change expected by the end of the century exceeds a 4.0°C increase. For wine grape varieties with lower heat requirements, suitability under the pessimistic RCP 8.5 emission scenario is projected to decrease by 29% by the end of the century. Conversely, under the optimistic scenarios, the decline in suitability values is only between 3-4%. For grape varieties with higher heat requirements, a 10% decrease in suitability is expected under the RCP 8.5 scenario. In contrast, the RCP 4.5 scenario suggests that suitability could improve by 1-2% by the end of the century. These findings contribute to a better understanding of the impacts and consequences of climate change and offer insights on how to prepare for these challenges in the viticulture sector.

Cooling Degree Days (CDD) is a convenient technique obtained by summing the cumulative air temperature differences that show how much deviation from the temperature is required for human comfort in a summer season. It is a basic and relatively simple measure for predicting the cooling energy requirements of the buildings. Accurate estimation of the seasonal trend of the CDD values is a crucial policy tool in determining the energy request for cooling the buildings and is critical to better energy management by decision-makers in the country. In this regard, planners or users need to develop appropriate and precise methods that allow them to forecast their future values based on their CDD historical time series data. For this reason, in this study, Seasonal Autoregressive Integrated Moving Average (SARIMA) model is utilized to forecast the CDD values in some regions with high cooling demand in Türkiye. To accomplish this, monthly CDD data from January 1991 to December 2022 are obtained from the provinces of Adana, Adyaman, Antalya, Siirt, and Şanlurfa. First, the CDD values are modeled using the SARIMA time series approach, and then the models are employed to predict the future trends of the CDD values from 2022 to 2031. Obtained results show that with the continuation of global warming at the current rate, CDD values in all selected provinces will increase slightly by 2031, which will cause a change in building energy consumption policies.

In 2023, residential and commercial sectors together consumed approximately 27.6% of total United States (U.S.) energy, equivalent to about 20.6 quadrillion Btu. Factoring in the electrical system energy losses, the residential sector represented approximately 19.7% of total U.S. energy consumption during that time. There were approximately 144 million housing units in the United States in 2023, which is increasing yearly. In this study, information on energy usage in the United States residential sector has been analyzed and then represented as energy intensities to establish benchmark data and to compare energy consumption of varying sizes and locations. First, public sources were identified and data from these previously published sources were aggregated to determine the energy use of the residential sector within the US. Next, as part of this study, the energy data for seven houses/apartments from five different United States climate zones were collected firsthand. That data were analyzed, and the energy intensity of each home was calculated and then compared with the energy intensities of the other homes in the same states using Residential Energy Consumption Survey (RECS) data. The energy intensity for each facility was calculated based on the actual energy bills. Finally, the study evaluated the carbon footprint associated with residential energy consumption in all 50 states to reinforce the importance of sustainable development initiatives.

A wide variety of organisms use the regular seasonal changes in photoperiod as a cue to align their life cycles with favorable conditions. Yet the phenological consequences of photoperiodism for organisms exposed to new climates are often overlooked. We present a conceptual approach and phenology model that maps voltinism (generations per year) and the degree of phenological mismatch that can arise when organisms with a short-day diapause response are introduced to new regions or are otherwise exposed to new climates. Our degree-day-based model combines continent-wide spatialized daily climate data, calculated date-specific and latitude-specific day lengths, and experimentally determined developmental responses to both photoperiod and temperature. Using the case of the knotweed psyllid Aphalara itadori, a new biological control agent being introduced from Japan to North America and Europe to control an invasive weed, we show how incorporating a short-day diapause response will result in geographic patterns of attempted voltinism that are strikingly different from the potential number of generations based on degreedays alone. The difference between the attempted and potential generations represents a quantitative measure of phenological mismatch between diapause timing and the end of the growing season. We conclude that insects moved from lower to higher latitudes (or to cooler climates) will tend to diapause too late, potentially resulting in high mortality from inclement weather, and those moved from higher to lower latitude (to warmer climates) may be prone to diapausing too early, therefore not fully exploiting the growing season and/or suffering from insufficient reserves for the longer duration in diapause. Mapped output reveals a central region with good phenology match that shifts north or south depending on the geographic source of the insect and its corresponding critical photoperiod for diapause. These results have direct relevance for efforts to establish populations of classical biocontrol agents. More generally, our approach and model could be applied to a wide variety of photoperiod- and temperature-sensitive organisms that are exposed to changes in climate, including resident and invasive agricultural pests and species of conservation concern.