the effects of urban heat on human health can be significant and are likely to worsen as a result of climate change. if supported by further studies, the research results have clear policy implications, highlighting an adaptive mechanism via which humans can ameliorate the impact of climate change on urban populations.

cities are particularly vulnerable to climate change because they are warmer than rural areas. asphalt roads, tar roofs and other artificial surfaces absorb heat from the sun, creating a heat-island effect that can raise temperatures by an average 2-5 degrees fahrenheit (about 1-3 degrees celsius). white roofs reflect some of that heat back into space and thus cool temperatures–much as wearing a white shirt on a sunny day causes one to feel cooler than wearing a dark shirt.

researchers used a new computer model, designed to assess the impacts of a changing climate on urban populations and to explore options for countering rising temperatures. while the model did not capture individual cities, it did show the white roof effect in large metropolitan regions. the new york area, for example, would cool by almost 2 degrees fahrenheit on summer afternoons.

the model simulates the amount of solar radiation that urban surfaces absorb or reflect, capturing such factors as the influence of roofs, walls, streets and green spaces on local temperatures. the researchers then analyzed the interactions of global climate change and urban areas.

grinnell’s ninety-year-old maps, photographs and field notes provided a basis for locating his original survey sites along a transect that passed from the san joaquin valley through yosemite to mono lake, and covered an elevation range from near sea level to more than 10,000 feet. within the park, moritz’s team returned to sites from the valley floor to the mountain crest and collected animals in many of the same locations as grinnell. moritz’s team relied on live-animal traps; whereas grinnell’s original survey used lethal traps to collect animals. mathematical checks showed that the different collection techniques were not a problem in successfully comparing the two sets of data.

moritz’s team used the new survey results and grinnell’s original data to compare the ranges of 28 species of mammals. on average, the mammals had moved their ranges upward about 500 meters at the same time that the temperature in the area increased 3 degrees celsius. the species that were originally found at lower elevations tended to expand their ranges to higher elevations. species originally at higher elevations tended to contract their ranges as their minimum elevations shifted even higher. this suggests that species are already trying to adapt to a warmer climate. it also suggests that species that have historically lived at higher elevations may not have anywhere to go in the future as mountain tops experience temperature changes. further warming would lead to the extinction of many species that are adapted to cold, alpine conditions.

the new measurement technique may be useful for the detection of air toxins and also further our understanding of the health effects of atmospheric particles. insights gained could ultimately inform regulatory policy for managing air pollution and addressing its impact on global climate change.

a team of university of vermont researchers developed the technique, called near infrared laser desorption/ionization aerosol mass spectrometry, which can analyze trace levels of individual compounds within particles. the ability to measure oa chemical composition will lead to a better understanding of oa sources, as well as what controls their levels in the atmosphere.

aerosol mass spectrometry is widely used to analyze atmospheric aerosols, but usually cannot directly monitor the chemical composition of oa particles at their typical atmospheric concentrations. the nsf-funded innovation uses a low-energy, infrared laser to gently create ions of the organic compounds, keeping them intact and thereby giving results that are easier to interpret. the technique has demonstrated unprecedented sensitivity in detecting individual chemical compounds. this allows for analysis of the changes in aerosol composition as they occur in the atmosphere.

nsf-funded researchers at the colorado school of mines are investigating the benefits of microgrids that operate at 500 hertz instead of 60 hertz. their efforts in theory and simulation have demonstrated the viability and efficiency of 500-hertz single-phase power systems. experimental results using a test bed built by the researchers have confirmed that the high frequency alternating current (hfac) microgrid is a practical method for integrating renewable energy sources into the power grid.

with advances in power electronics, devices, and controls, the utilization of much higher frequencies in the microgrid will significantly reduce the size, weight, and power loss of the energy conversion system. the paradigm shift from centrally controlled, three-phase 60-hertz systems to hfac single-phase microgrids will dramatically change the way electric distribution systems are operated and will increase their energy efficiency, economy, and resilience. the effort also enables future large-scale integration of renewable energy resources in the u.s. energy portfolio.

mosquito control is a challenge when taking into account global climate changes. computer models have shown researchers that the southwestern u.s. is predicted to have drier conditions, but would not decrease mosquito populations in may and june, which extends the length of the season since mosquitoes rely heavily on water sources that are not controlled by precipitation (i.e. man-made, permanent sources such as irrigation networks). research done in 2007 and 2008 indicates that the mosquito aedes aegypti takes at least six days to develop from egg to adult and culex quinquefasciatus takes a minimum of a week. given that information, scientists recommend intervention early on in the mosquito season in order to control their numbers later.

researchers conclude that mosquito control methods will have to begin earlier and extend later into the year than it has in the past, potentially competing with other seasonal concerns. researchers are also evaluating the institutional arrangements of the agencies and departments that are in charge of controlling and monitoring mosquitoes, and aim to help improve the way state and government programs handle mosquito populations.