Why do emissions deposited in the stratosphere pose a greater global threat than those released in the troposphere?

Answer

Stratospheric emissions can linger for years, spreading globally and interacting with the ozone layer

Emissions released in the troposphere are washed out relatively quickly, but those dumped into the stratosphere can persist for years, allowing them to spread globally and interact with sensitive atmospheric regions.

Why do emissions deposited in the stratosphere pose a greater global threat than those released in the troposphere?
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