CLEAN : The climate activist preaching on New York's subway

An elderly man reflects on the challenges his grandchildren will face due to global warming. He highlights the severe consequences of climate change, such as uncontrollable forest fires and rising greenhouse gas levels, which are leading to alarming extinction rates. He urges people to discuss these issues with others, emphasizing the importance of raising awareness and taking action.

What evidence does the speaker provide to support the claim that global warming is a significant issue?

In what ways does the speaker describe the current state of biodiversity in relation to climate change?