Really poor mandate for saving the planet? (7)

I believe the answer is:

useless

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'really poor' is the definition.
'useless' can be an answer for 'poor' (I've seen this before). I am not sure about the 'really' bit.

I can't explain the rest of the clue.

Can you help me to learn more?

(Other definitions for useless that I've seen before include "Is Sue less impractical?" , "Fruitless" , "Vain - unavailing" , "Incompetent" , "Ineffective" .)

I've seen this clue in The Times.

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