Jenny Jones, Green member of the London Assembly and the party's candidate for Mayor in 2012, said: "What we are seeing is thoughtless destruction, spreading first within London, and now in other cities, with no regard at all for the safety of other people.
"Violence, arson and looting can never be justified. The actions by rioters are endangering people's lives. The priority of the police has to be to protect the public in their own homes and businesses.
"The vast majority of young people have nothing to do with this. But we do need to look at why the perpetrators of this violence are so alienated from society. This is about young people who deeply feel that they do not have a stake in society, some of whom were already engaged in criminal activity.
"Just as we have projects that engage with extremists to draw them back into mainstream society, we need to re-engage with alienated young people in a variety of ways, such as creating employment and training opportunities, advice, youth centres, and community services."
Jones continued: "Caroline Lucas MP will be returning to London, as part of the Parliamentary recall, on Thursday. Parliament's immediate priority must be to find solutions that provide security. In the longer-term, all parties in Parliament should work together to address youth unemployment and the alienation that young people feel today."