Greening cities, meaning the addition of new parks, community gardens, street trees along traffic-impacted roads, green roofs, and green walls, are increasingly important to urban climate change adaptation. In the 2010s, hot summers affected many urban centers across the globe. Next to a more effective CO2 mitigation, adaptation to heat waves and hot summer day and night temperatures seems inevitable and necessary for the health of urban residents. This chapter will present illustrative examples of green solutions that can lower heat, reduce local flooding that is a consequence of heavy rainfall, and enhance outdoor quality time for different groups of urban residents. Results from recent studies will be used to show the quantitative effects of designing and planting green in cities. In addition to clear success stories, this chapter will also discuss the barriers to and failures of nature-based solution projects that must be overcome in a successful green urban future.