BEIJING, June 2 (Xinhua) -- UN Secretary-General Antonio Guterres warned on Tuesday that the world has experienced its 11 hottest years on record, calling on countries to accelerate cuts in greenhouse gas emissions and step up efforts to tackle global warming.

He made the remarks in a video message delivered ahead of World Environment Day, observed annually on June 5, at an event hosted by the United Nations Environment Programme (UNEP) China Office in Beijing.

Climate change is already taking a heavy toll on ecosystems, biodiversity, public health and economies worldwide, he said, urging faster and more decisive climate action.

Stephen Jackson, the UN resident coordinator in China, said the UN system stands ready to deepen cooperation with China and other partners in advancing renewable energy and biodiversity conservation, and promoting sustainable urban development and green finance.

Wang Qian, officer-in-charge and head of UNEP China Office, said climate change remains one of the most pressing challenges facing humanity and stressed the importance of turning climate awareness into concrete actions.

Established in 1972, World Environment Day has become one of the UN's largest platforms for environmental outreach. This year's observance is centered on climate change and includes a variety of public engagement events aimed at raising awareness of climate concerns and encouraging sustainable living. ■