Nairobi, Dec 7: Beijing Capital International Airport, China's largest with 94.39 million passengers passing through last year, is making steady progress towards greening its operations, but can do more to minimise its environmental impact, a new UN research said on Wednesday. According to the Assessment Report on Beijing Capital Airport, use of gasoline and diesel by airport vehicles declined 45 per cent and 49 per cent, respectively, between 2010 and 2016, while overall carbon dioxide emissions were cut by almost 16 per cent between 2014 and 2016. This is despite the airport adding roughly 10 million annual passengers since 2010, a growth rate that is comparable to the increase in Beijing's Gross Domestic Product. "Beijing Capital International Airport has shown strong commitment towards sustainability, balancing growth in air, cargo and passenger traffic with enhanced environmental performance," Steven Stone, Chief of Resources and Markets Branch of the Economy Division of the UN Environment said in a statement. "With focused actions in the right places -- including electric vehicles, renewables and better transport links among them -- the airport can continue its leadership in environmental stewardship." Of the airport's 4,000 vehicles, more than 60 per cent are special purpose. The airport aims to switch at least 10 per cent of these and 20 per cent of the general purpose vehicles to electric-powered alternatives by 2020. The airport is also increasing water use efficiency to help cope with the chronic water shortage facing Beijing. The airport's per capita water consumption declined from 23.75 litres in 2012 to 21.24 litres in 2015, a reduction of 10.6 per cent. The airport has contributed up to 9.7 per cent of Beijing's economic output and employed up to six per cent of the city's working population directly and indirectly, making it a cornerstone of the city's growth and jobs. "However, this growth brings pressure on natural resources and the environment, which Beijing Capital will have to manage carefully," says the report, produced in collaboration with the UN Environment-Tongji Institute of Environment for Sustainable Development. The report was released on the last day of the third UN Environment Assembly in Nairobi, which brought together over 4,000 heads of state, ministers, business leaders, UN officials and civil society representatives to tackle the global menace of pollution. In response, the airport is switching from isolated issues of energy consumption, greenhouse gas emissions and noise reduction towards the systemic consideration of its overall operation. Performance in terms of indoor air quality and wastewater treatment is fully up to national standards, while the efforts to encourage recycling among passengers are innovative. "As the only airport operator partner with the UN Environment globally, we are very proud of this cooperation with the world-leading organisation within the UN system in the field of environment," said Zhang Wei, the Vice President of the Beijing Capital International Airport Co. Ltd. According to the report, further milestones could be achieved by ensuring that a greater share of electricity was sourced from renewable energy, waste volume was reduced and energy was recovered from incineration. The share of recyclable waste that is separated should be increased from the current level of 20 per cent to the national target of 35 per cent for 2016-2020.