carbon dioxide with concomitant production of oxygen. The city of New York determined that the cooling potential per area was highest for street trees, followed by living roofs, light covered surface, and open space planting. From the standpoint of cost effectiveness, light surfaces, light roofs, and curbside planting have lower costs per temperature reduction. A hypothetical "cool communities" program in Los Angeles has projected that urban temperatures could be reduced by approximately after planting ten million trees, reroofing five million homes, and painting one-quarter of the roads at an estimated cost of US$1 billion, giving estimated annual benefits of US$170 million from reduced air-conditioning costs and US$360 million in smog related health savings. Mitigation strategies include: White roofs: Painting rooftops white has become a common strategy to reduce the heat island effect. In cities, there are many dark colored surfaces that absorb the heat of the sun in turn lowering the albedo of the city. White rooftops allow high solar reflectance and high solar emittance, increasing the albedo of the city or area the effect is occurring. Passive daytime radiative cooling: A passive daytime radiative cooling roof application can double the energy savings of a white roof, attributed to high solar reflectance and thermal emittance in the infrared window, with the highest cooling potential in hot and dry cities such as Phoenix and Las Vegas. When installed on roofs in dense urban areas, passive daytime radiative cooling panels can significantly lower outdoor surface temperatures at the pedestrian level. Green roofs: Green roofs are another method of decreasing the urban heat island effect. Green roofery is the practice of having vegetation on a roof; such as having trees or a garden. The plants that are on the roof increase the albedo and decreases the urban heat island effect. This method has been studied and criticized for the fact that green roofs are affected by climatic conditions, green roof variables are hard to measure, and are very complex systems Planting trees in cities: Planting trees around the city can be another way of increasing albedo and decreasing the urban heat island effect. It is recommended to plant deciduous trees because they can provide many benefits such as more shade in the summer and not blocking warmth in winter. Green parking lots: Green parking lots use vegetation and surfaces other than asphalt to limit the urban heat island effect. Mitigation policies, measures and