TROMSOE, Norway - The world marked Environment Day on Tuesday with cheerful events like tree-planting and solar cooking in the heat of Asia, but also gloomier talk in the not-so-frozen north of melting polar caps.

The United Nations chose Tromsoe in Norway to host the day this year to highlight the dangers of melting snow and ice.

On a sunny summer day in the Arctic Circle -- after what locals said was another worryingly warm winter -- scientists issued new warnings but also said political momentum to limit emissions of heat-trapping gases was building, a hopeful sign.

"The message of today is to accept the signs of climate change and come up with a plan to solve the problems," Rajendra Pachauri, chairman of the U.N.'s weighty Intergovernmental Panel on Climate Change, told Reuters.

It won't get dark in Tromsoe for weeks, but in Greece people were urged to turn off all lights at 10 p.m. (1900 GMT) for 10 minutes to show a commitment to protect the environment.

Ordinary people's concerns about climate change have soared in the last half year, along with their expectation that their governments act, according to an Oxford University survey of global online consumers for U.N. Environment Day.

The world's top polluters, the United States and China, have both signaled new will to cut emissions of carbon dioxide, and this week's G8 meeting of rich countries is expected to tackle the issue, but critics say such steps are too slow.

Preferring "people power," more than 50 Australian protesters held a "picnic rally" against the logging of native forests in the southern state of Victoria.

"To protect us from the impacts of dangerous climate change, this destruction must stop," said campaigner Luke Chamberlain.


Even countries like Australia, far from polar regions or high mountain areas, will feel the effects of melting ice.

A new U.N. report said this would affect hundreds of millions of people by disrupting rivers in Asia, thawing Arctic ice and raising ocean levels.

Glaciers are in retreat, permafrost is warming and snowfalls are becoming unreliable in many regions, according to a "Global Outlook for Ice and Snow" written by more than 70 experts.

Parts of the polar regions are already warming two to three times faster than the global average. The huge Greenland Ice Sheet is melting faster than new ice is being formed. If it all goes, oceans will rise by seven meters (23 feet).

If they rise by just one meter, one-fifth of Vietnamese, for example, would lose their homes, the U.N. said on Tuesday.

In the central Vietnam coast's Danang city, stricken by more frequent typhoons and floods, members of the Youth Union planted trees and picked up rubbish from beaches to mark the day.

China said on Tuesday it had slowed a rising tide of pollution from frenetic industrialization -- but also said this week it would not let climate concerns curb its economic growth.


Elsewhere in Asia, people learned about worm farming and composting, listened to lectures about renewable energy and cutting carbon emissions, and school children took part in plays and painting competitions to mark the day.

Hundreds of Indian policemen swapped guns for spades to plant trees, pledging to turn barren areas of the western state of Gujarat into mango and guava orchards.

"If the cops go green, then the people will follow," said Sujata Solanki Majumdar, a senior police officer.

In central Gujarat, housewife Savita Dabhi cooked a four-course meal for her family and friends on a solar cooker outside her home to promote the benefits of renewable energy.

Back in Norway, the head of the U.N. Environment Program told Reuters Environment Day was "a culmination of public awareness and pressure to do something."

"This is just one day out of 365 -- it's not meant to replace action on the other 364," Achim Steiner said.