Read the following excerpt from a speech given by a prominent climate activist:
'As we stand at the edge of an unprecedented environmental crisis, we must consider not just the world we are leaving behind, but the world we are creating for our children and grandchildren. This is not just an appeal for action; it is a call to unite across generations, to embrace our shared responsibility and to prioritize the health of our planet over short-term economic gain. If we fail to act now, we risk obliterating their future, a future that could be rich with opportunity or shadowed by despair.'
Which of the following best describes the primary purpose of this excerpt, taking into account the intended audience?