Complex sentence: As part of its objective to promote sustainable tourism, Walkers Tours launched a carbon neutral fleet in 2012, ensuring that their entire fleet of 600 vehicles are offset utilizing carbon credits from the Carbon Neutral Company in the United Kingdom.
Split into simpler sentences: As part of its objective to promote sustainable tourism, Walkers Tours launched a carbon neutral fleet in 2012. It insured that the carbon footprint of their entire fleet of 600 vehicles are offset by utilizing carbon credits from the Carbon Neutral Company in the United Kingdom.