Points to note for the lesson:
Brainstorming: Method of generating ideas, with the objective of gaining quantity of ideas. Usually 'thinking out of the box' ideas occur after 30 ideas.
Brainwriting: Brainstorming, but recording the ideas down for follow-up later.
Please check this link about Global Challenges for Humanity and here to learn about Mega problems of the 21st Century.
As a group, discuss and decide on one of the mega-problems that you would like to tackle. Research more on the problem and its sub-problems. You will share with your group what you had found in the next lesson.