California needs to cool down to keep energy use from rising and water supplies from dropping. An emerging solution that may gain some traction is to paint the state\u2019s towns and cities white. \u201cCool\u201d roof coatings have the potential to dampen air conditioning demand and California warming, according to work done by the federal Environmental Protection Agency and Lawrence Berkeley National Laboratories. While global warming grabs headlines, most of the actual increase in temperatures in California is caused by the spread of pavement, roofing, and even lawns, according to Bill Patzert, an iconoclastic climatologist at the Jet Propulsion Laboratory in Pasadena. Climatologists fret that temperatures may rise 3 degrees by the end of this century unless greenhouse gas emissions are reduced. Patzert is quick to point out that average temperatures over the past 50 years in California cities have been rising at the rate 1 to 1.2 degrees every ten years since 1950 in major cities. On the coastal plain of Southern California, even in undeveloped areas, the average increase has been 2.3 degrees. Temperatures are rising in the Sierra Nevada too, and as long as the urban heat island spreads across the land Californians should expect the increases to continue. That is, unless, cool roofs and even cool pavement coatings are used. According to the federal EPA, cool roof demonstration projects in California have been able to save building owners between 20 and 70 percent in air conditioning energy use. There are a number of cool roof products on the market, from coatings that can be applied over existing roofs to new single-ply roofing sold in rolls. Reflective tiles are available for those who like the Mediterranean look, and then there are metal roofs which are common in many tropical zones. What they all have in common is that they do a better job of reflecting the sun\u2019s rays, as well as a superior job of emitting the energy they absorb. As a result, tests have found that cool roofs reach temperatures of between 100 and 120 degrees in the summer--compared to conventional roof temperatures as high as 150 to 190 degrees. Thus, white\/reflective surfaces reduce energy use for cooling and associated greenhouse gas emissions. Lighter cool pavements also can help, according to Lawrence Berkeley Labs. Patzert adds that native vegetation is cooler than the lawns that spread with suburbanization.