Passage Summary: We have to stop burning fossil fuels to save the planet, but doing so makes a country poorer, and since no one wants to be the only one losing money, we're in trouble unless something changes.

Conclusion: Catastrophic environmental consequences are inevitable unless a specific condition regarding international cooperation is met.

Reasoning: Reducing fossil fuels is necessary but hurts a country's economy, and no single country is willing to take that financial hit by itself.

Analysis: The logic here sets up a 'collective action problem' where the cost is individual but the benefit is global. Since the author states that no nation will bear the cost 'singlehandedly,' the logical completion must involve nations acting together. Look for an answer that suggests a multi-national agreement or a collective effort where many countries agree to the standards simultaneously.