The combined total of metric tonnes of CO2 produced by each cruise brand constitutes Carnival Corporation’s carbon footprint, which is reported each year to the international nonprofit organization CDP (Carbon Disclosure Project). For 2015 Carnival has been identified as a leader for the quality of climate change-related information that it has disclosed, with a score of 99 out of 100; Carnival has been awarded a position on the FTSE 350 and the S&P 500 Climate Disclosure Leadership Index (CDLI). Top scores indicate a high level of transparency, hence Carnival’s prominence in the forthcoming Global Climate Change Report. In 2014, Carnival Corporation met its goal to reduce the intensity of carbon dioxide emissions by 20 percent - one year ahead of schedule. Recently the company announced that its four next-generation cruise ships will be the first in the industry to be powered at sea by Liquefied Natural Gas (LNG), one of the world's cleanest burning fossil fuels, an innovation that will lead to a further reduction in both nitrogen oxide (NOx) emissions (of up to 85%) and PM (particulate matter), with PM in the exhaust gas being almost entirely eliminated (a 95%-100% reduction). Also, Carnival has invested in a project for the production of ECO Exhaust Gas Cleaning (ECO-EGCTM) technology, a cutting-edge filtering system designed to remove major pollutants from the exhaust gases irrespective of the ship’s operating condition – at sea, during maneuvering and in port.

According to Carnival Corporation’s calculation of each brand’s upstream and downstream indirect emissions, the portion attributable to Costa Cruises amounts to 6970 metric tonnes of CO2.