April 22nd is Earth Day, a celebration of our fragile environment, and of our efforts to preserve it. This Earth Day also marks the signing of the landmark Paris Agreement. This is a United Nations agreement that sets targets for reduced greenhouse gas emissions, aimed at holding the warming of the planet at less than 2 degrees Celsius above its pre-industrial level. It also lays out ways in which finance can be used to guide signatories towards a low emission future. Some 120 countries are expected to sign the Agreement today, including the USA and China, providing hope for the future of our world.