Carnival Corporation has released its 2015 sustainability report detailing the progress made in 2015 against its 2020 sustainability performance goals.

The report's details show the company is on track to meet its goals in the next four years, said Carnival, with sustainability efforts highlighted across its 10 cruise line brands.

The report was prepared in accordance with the Global Reporting Initiative (GRI) G4 "core" level, and a full copy can be downloaded from Carnival Corporation's site.

Highlights include:

•    Reduced the company's carbon intensity rate by 2.8 percent resulting in a 23.4 percent overall carbon dioxide emission reduction relative to the 2005 baseline

•    Equipped 41 percent of fleet with exhaust gas cleaning technology to reduce sulfur compounds and particulate matter from engine exhaust

•    Improved the company's carbon footprint with order of world's first liquefied natural gas (LNG) powered cruise ships, as well as the first cruise ship to be powered by an LNG hybrid barge

•    On track to meet the 10 percentage point increase in fleet-wide capacity coverage of advanced waste water purification systems (AWWPS)

"We know it is increasingly important to have sustainable and transparent operations, so we work hard every day to run our company in a sustainable way, and to share those practices broadly, so that our guests can feel confident that they are making a responsible decision when they book a vacation with us," said Bill Burke, chief maritime officer for Carnival Corporation. "We are committed to providing a safe and comfortable voyage for our guests and crew members as our cruise line brands create great vacations, while at the same time maintaining our deep commitment to protecting the oceans, seas and destinations we visit."

Other future moves include:

•    Actively undertaking shipbuilding research and development for new abatement technologies and equipment to improve energy efficiency including: air lubrication systems using air bubbles to reduce friction between the ship's hull and the water; exhaust gas cleaning systems (EGCS); and alternative fuels like the industry-first use of LNG as the world's cleanest burning fossil fuel

•    Working with suppliers on expanding its sourcing of cage free eggs to 100 percent by 2025

•    Expanding tour operator sustainable practices