Killer Heat in the United States: Climate Choices and the Future of Dangerously Hot Days

This UCS analysis provides a detailed view of how extreme heat events caused by dangerous combinations of temperature and humidity are likely to become more frequent and widespread in the United States over this century. It also describes the implications for everyday life in different regions of the country.We have analyzed where and how often in the contiguous United States the heat index—also known as the National Weather Service (NWS) "feels like" temperature—is expected to top 90°F, 100°F, or 105°F during future warm seasons (April through October). While there is no one standard definition of "extreme heat," in this report we refer to any individual days with conditions that exceed these thresholds as extreme heat days. We also analyzed the spread and frequency of heat conditions so extreme that the NWS formula cannot accurately calculate a corresponding heat index. The "feels like" temperatures in these cases are literally off the charts.We have conducted this analysis for three global climate scenarios associated with different levels of global heattrapping emissions and future warming. These scenarios reflect different levels of action to reduce global emissions, from effectively no action to rapid action. Even the scenario of rapid action to reduce emissions does not spare our communities a future of substantially increased extreme heat. For the greatest odds of securing a safe climate future for ourselves and the ecosystems we all depend on, we would need to take even more aggressive action, in the US and globally, than outlined in any of the scenarios used here. Our challenge is great, but the threat of not meeting it is far greater

Ecological connectivity in the three-dimensional urban green volume using waveform airborne lidar

This is the final version. Available on open access from Nature Research via the DOI in this record.The movements of organisms and the resultant flows of ecosystem services are strongly shaped by landscape connectivity. Studies of urban ecosystems have relied on two-dimensional (2D) measures of greenspace structure to calculate connectivity. It is now possible to explore three-dimensional (3D) connectivity in urban vegetation using waveform lidar technology that measures the full 3D structure of the canopy. Making use of this technology, here we evaluate urban greenspace 3D connectivity, taking into account the full vertical stratification of the vegetation. Using three towns in southern England, UK, all with varying greenspace structures, we describe and compare the structural and functional connectivity using both traditional 2D greenspace models and waveform lidar-generated vegetation strata (namely, grass, shrubs and trees). Measures of connectivity derived from 3D greenspace are lower than those derived from 2D models, as the latter assumes that all vertical vegetation strata are connected, which is rarely true. Fragmented landscapes that have more complex 3D vegetation showed greater functional connectivity and we found highest 2D to 3D functional connectivity biases for short dispersal capacities of organisms (6 m to 16 m). These findings are particularly pertinent in urban systems where the distribution of greenspace is critical for delivery of ecosystem services.This work was funded under the NERC Biodiversity and Ecosystem Services Sustainability (BESS) thematic programme for the ‘Fragments Functions and Flows in Urban Ecosystems’ project (Reference: NE/J015237/1; http://bess-urban.group.shef.ac.uk/). The waveform ALS data were acquired by the NERC Airborne Research and Survey Facility (ARSF) and the team from the ARSF Data Analysis Node at Plymouth Marine Laboratory is acknowledged for undertaking initial ALS processing

Energy saving potential of fragmented green spaces due to their temperature regulating ecosystem services in the summer

Urban green spaces help to moderate the urban heat island (UHI) effects, and can provide important temperature regulating ecosystem services and opportunities for savings in cooling energy. However, because explicit market values for these benefits are still lacking, they are rarely incorporated into urban planning actions. Green spaces can generate a three-dimensional (3D) cool island that may reduce the cooling energy requirements within and around urban areas, but such 3D cooling effect has not been considered in previous studies quantifying energy savings from green spaces. This study presents a new and simple approach to quantify potential energy savings due to the temperature regulating ecosystem services of small-scale fragmented green spaces using the 3D simulation of the summer-day outdoor thermal environment in Nanjing, China. Field survey data and the microclimate model ENVI-met were applied to examine the outdoor 3D thermal environmental patterns at Gulou Campus of Nanjing University under two different scenarios: “with” and “without” green spaces. Modeling results were applied to quantify potential cooling energy savings based on the effect of green spaces on the outdoor urban environment and to calculate the cumulative temperature reduction due to green spaces using a regression model. The results show that, in the horizontal direction, the simulated distribution of wind speed and mean air temperature at 1.5 m height were closely related to the spatial distribution of the underlying surface types. Removal of green spaces increased mean air temperature by 0.5 °C (33.1 °C vs. 33.6 °C). In the vertical direction, removal of green spaces had little effect on the near-surface wind field; however, above the surface, the turbulence perpendicular to the main wind direction significantly increased. Quantification of the cooling benefits of green spaces in relation to the mean height of buildings on Gulou Campus yielded 5.2 W/m2 cooling energy, saving totally 1.3 × 104 kW h during a single daytime hot summer period. This case study corroborates the importance of green space for cooling and informs city planners and decision-makers on how microclimate is impacted by the loss of green spaces. These findings will facilitate preservation, planning, and design of green spaces to increase urban environmental benefits and to improve the microclimate of urban areas at neighborhood, city, and regional scales

#coloniavirus, cambio climático y colonialismo: la construcción colonial de la precariedad en Puerto Rico

En tiempos del COVID-19, en Puerto Rico convergen más de cien años de coloniaje, los embates del cambio climático y la pandemia global. La hegemonía constitucional, fiscal y política de los Estados Unidos sobre Puerto Rico ha dejado al territorio desprovisto de mecanismos mediante los cuales gestionar recursos para enfrentar tanto los impactos del Huracán María como del coronavirus. En esta alocución, exploro, desde una perspectiva de la geografía crítica, la construcción social y colonial de la vulnerabilidad de la población ante los nuevos retos

Longitudinal Electric Generating Units Database (1995-2016)

A data repository of Electrical Generating Units (EGUs) in the continental United States. The data include location, capacity, generation, environmental controls, and CO2, SO2, and NOx emissions data from 1995-2016. This dataset was developed under contract by Synapse Energy Economics (Cambridge, MA, USA) for the Union of Concerned Scientists. The data are available in the original Excel spreadsheet format provided by Synapse, and also in the ESRI file geodatabase format for use in a Geographic Information System (GIS). Please use the following citation instead of the citation generated by OSF: Synapse Energy Economics (2017). Longitudinal electric generating units database (1995-2016). https://osf.io/¬b8zae/. DOI 10.17605/OSF.IO/B8ZAE

RGGI and Environmental Justice longitudinal analysis

This repository contains the data and R scripts used in an analysis of power plants and environmental justice in states participating in the Regional Greenhouse Gases Initiative (RGGI