My choice of challenges that hinder current social and economic development is the lack of action when it comes to climate change. Different countries have unequal opportunities to work towards this goal and have different starting points.
The developed countries have all the resources and possibilities to make a change, but a comfortable life and lack of motivation to give up a high living standard and consumption habits is standing in the way.
In undeveloped countries I see that education will play the biggest part in solving this problem. In many undeveloped countries there is a lack of information on for example how poor waste management harms people and their local ecosystems. I these countries the motivation to do better is less about the altruistic idea of saving the planet, and more about securing a safe and healthy environment and making sure that their kids have a livelihood in the future.