US cities are losing 36 million trees a year. One of the reasons this is important is because of pollution that is all over our cities. Many tree-filled areas and taken down and replaced with "Impervious areas," which means that buildings and parking lots will replace them. This is important because if we continue to take down trees, cities will become warmer and more polluted. Cities will also use more energy, many of which are damaging to the environment. Keeping trees up also has many benefits, such as emissions reduction, water quality improvement, and heat reduction. Those are few of the many reasons why US cities losing 36 million trees a year is important.