WELLINGTON (Reuters) - The United Nations urged the world on Thursday to kick the habit of producing carbon dioxide, saying everyone must act to fight climate change.

Smoke flows from the Fertiberia fertilizer factory in an industrial zone of Huelva, southern Spain, June 4, 2008, one day ahead of the UN's World Environment Day. REUTERS/Javier Barbancho

U.N. Secretary-General Ban Ki-Moon said global warming was becoming the era’s defining issue and would hurt rich and poor.

“Our world is in the grip of a dangerous carbon habit,” Ban said in a statement on World Environment Day, which is being marked by events around the globe and hosted by the New Zealand city of Wellington.

“Addiction is a terrible thing. It consumes and controls us, makes us deny important truths and blinds us to the consequences of our actions,” he said in the speech to reinforce this year’s World Environment Day theme of “CO2 Kick the Habit.”

World Environment Day, conceived in 1972, is the United Nations’ principal day to mark global green issues and aims to give a human face to environmental problems and solutions.

New Zealand, which boasts snow-capped mountains, pristine fjords and isolated beaches used as the backdrop for the “Lord of the Rings” film trilogy, has pledged to become carbon-neutral.

“We take pride in our clean, green identity as a nation and we are determined to take action to protect it. We appreciate that protecting the climate means behavior change by each and every one of us,” said New Zealand Prime Minister Helen Clark.

New Zealand staged art and street festivals to spread the message on how people can reduce carbon usage. In Australia, Adelaide Zoo staged a wild breakfast for corporate leaders to focus on how carbon emissions threaten animal habitats.

GLOBAL EVENTS

In Bangladesh’s capital Dhaka, people plan to clean up Gulshan Baridhara Lake that has become badly polluted, and in Kathmandu the Bagmati River Festival will focus on cleaning up the river there.

Many Asian cities, such as Bangalore and Mumbai, plan tree-planting campaigns, while the Indian town of Pune will open a “Temple of Environment” to help spread green awareness.

But in Europe, which claims to be a leader in the climate change battle, Environment Day passed with barely a blip.

Britain urged individuals to take action and the Environment Agency called on people to be prepared for more flooding, to use less water and protect wildlife.

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Global carbon emissions from burning fossil fuels are rising quickly and scientists predict rising seas, melting glaciers and more intense storms, droughts and floods as the planet warms.

A summit of G8 nations in Japan next month is due to formalize a goal agreed a year ago that global carbon emissions should be reduced by 50 percent below 1990 levels by 2050.

But some nations want a reduction of 80 percent of carbon emissions by 2050 to try to stabilize CO2 concentrations in the air to limit global warming.

Australian Prime Minister Kevin Rudd said climate change was already a reality: “We have been experiencing the worst drought in living memory and our inland rivers are running dry.

“We are committed to reducing greenhouse gas emissions by 60 per cent on 2000 levels by 2050. We will implement emissions trading as the primary mechanism for achieving this target,” he said in a statement.

The U.N. Environment Program said greening the world’s economy would cost as little as a few tenths of global GDP annually over 30 years and would be a driving force for innovation, new businesses and employment.