Clean and modern but lasting. Logo should work as a B/W version but should not be B/W.
The charity will focus initially on saving lives and later may expand into green initiatives. Instead of paying x $ to a charity and having no idea what happens with that we want measureable results so your donation is directly correlated to saving a life or significantly improving a life.
Measurable results could include anything that really helps such as:
Lives saved, meals delivered, vaccinations given, wells dug, students educated etc. (although initial focus will be on lives saved or actions that save lives. In the future the goal is to expand more broadly to help quantify the actual benefit the charity brings with any given donation or action that is taken.
Design could incorporate some counter concept. It means you know something about what is being done with a donation, it is not into the void; you have a direct measurable result.