Possible Clues:

• Global warming calculation whose shape is suggested by connecting 14 squares in this puzzle in a closed loop based on the appropriate 23-Across
• What an environmentalist wants to reduce
• Caught baron prepared to pay and publish effect on planet
• Initially brilliant contraption for organising personal effects?
• Transport is good in Paris for walking? It makes the papers, as it's a measure of The Greens!
• //www.crosswordgiant.com/crossword-clue/1252911/
• One's sole contribution to global warming?
• Environmental measure taken from miners' track, maybe?
• Botanic Prof torn suffering damage to environment?
• It's an issue for The Greens in 19 down and most of 22 across