Carnival UK cruise brands cut its fuel usage by 5% last year and trimmed CO2 emissions by more than 10%.
The company has also made efforts to save water and increase recycling.
Details of the cruise operators’ environmental performance were outlined in the first annual sustainability report published by the parent company of P&O Cruises, Cunard Line and Ocean Village
The study showed a 5% fall in fuel consumption and a resulting reduction in CO2 emissions of about 11% in 2009.
The amount of water consumed on board the ships fell by almost 3%. About 76% of water consumed on Carnival UK ships is produced on board through reverse osmosis, evaporation and the use of waste heat from power plants and boilers.
There was a trebling of the amount of waste recycled. This included office paper, every tonne of which recycled saved 17 trees and 32,000 litres of water, reduced air pollutants by 27kg and conserved enough electricity to heat the average home for six months, according to the report.
Since a programme to recycle used cooking oil from the ships into biodiesel began in 2008, enough has been generated to fuel a family car to travel more than a million miles, the study shows.
Money raised from the sale of this fuel has been donated to marine environmental preservation projects across Hampshire, the Isle of Wight and Kent.
David Dingle, Carnival UK chief executive, said: “As an industry, we recognise the need to balance out the actions required to sustain an ever-increasing economic benefit for the communities affected by our operations with that of fulfilling wider social and environmental needs.
“As a company, we recognise the need to set the agenda for building an industry that is sustainable economically, socially and environmentally.”
Publishing an annual sustainability report is intended to give transparency to the company’s efforts in these areas.
Carnival UK was one of the original partners of Tourism 2023 which was launched in 2008 by the sustainable development charity Forum for the Future founded by conservationist Jonathon Porrit to help the UK travel and tourism industry plan for a sustainable future.
The company has also been registering its carbon emissions and activities designed to reduce those and other emissions to the Carbon Disclosure Project since 2004.
It is working through Ocean Conservation and the Tourism Alliance to develop a sustainability tool to be used with providers of marine excursions to the cruise industry.