Activists from leading environmental NGO Greenpeace urged Wednesday world leaders attending the Copenhagen conference on climate change to strike a binding deal against global warming in a mass protest staged in Rome.

Eight members of the organization climbed the Colosseum, the symbol of Rome, where they spread out a 300-meter long banner saying "Copenhagen: Historic deal necessary, make history now!"

Other 50 volunteers protested by lying down on the ground and forming human words calling for concrete actions to curb gas emissions.

"The Copenhagen conference must issue an ambitious binding agreement aimed at a global sustainable development model," said Giuseppe Onufrio, director of Greenpeace Italy.

"It's the last chance to save the planet," he added.

According to Greenpeace activist Francesco Tedesco, climate change and world peace are two sides of the same coin. "If world nations fail in striking an agreement this will determine the extinction of animal and plant species, mass migrations and disease outbreaks," he said, adding that Copenhagen represents a unique opportunity to secure world peace.

Social unrest is expected in Rome on Saturday for the global protests against climate change, organized for the arrival of several important leaders in Copenhagen including U.S. President Barack Obama who will attend the conference on Friday.

Thousands of protesters will gather in 100 Italian cities, led by the World Wide Fund for Nature (WWF), Greenpeace and leading Italian NGO Legambiente. The culminating event will take place in the center of Rome and local authorities fear unrest and disorder.

Climate change impact is strongly felt in Italy. In the last couple of months the country has been hit by a series of natural calamities linked to global warming.

In October a mudslide caused the death of several people in the southern island of Sicilia. Rising temperatures, together with human neglect, are thus endangering the safety of buildings in many areas.

According to a report issued on Wednesday by Legambiente, 79 percent of Italian cities are at risk of natural calamities such as mudslides and floods where houses have been built along rivers and close to the sea.

The Copenhagen conference on climate change opened on Monday, bringing together world nations in a bid to secure a binding agreement against global warming.