In the effort to slow the pace of global warming, researchers and policy makers are encouraging the use of lighter colors for rooftops and streets worldwide. Dark, non-reflective surfaces which are common for asphalt and asphalt shingles, absorb heat from the sun and create a "heat-island" effect, plus a greater need for air conditioning. Lighter surfaces would reflect the sun’s rays back to outer space, reducing ground-surface temperatures and overall energy requirements.