Representatives from some of the worlds largest cities are in London to share ideas about how to minimise rubbish, boost recycling and examine the latest technologies for managing waste.
The C40 London Waste Workshop was officially opened by London Mayor Boris Johnson at City Hall on Monday March 22 and is due to last three days.
It is attended by representatives from 30 cities including, New York, Tokyo, Bangkok, Mexico City, San Francisco, Madrid and Stockholm.
Over the three days delegates will hear from representatives from other cities about what they are doing to reduce waste and there will also be the opportunity for them to visit some of the sites in London which are used for recycling and waste management purposes
Opening the workshop, Boris Johnson spoke of the next three days as being a chance for cities to learn from each other, and share ideas about what they can do to improve their recycling rates.
He said: When Governments fail to act together, it is all the more necessary for cities to act together so I am glad to see so many colleagues here from the C40 group, here to learn from each other.
I am looking forward to hearing more in particular from New York. We have twice as many bookshops as New York here in London and a quarter of the number of murders for roughly the same population but the fact is they are better at persuading people who live in flats to recycle.
You have done brilliantly in New York, you install shoots in your upper storey flats, we install windows and there is a great difference between us.
Johnson also spoke of the need to for everyone to see waste as a resource rather than a problem which will, in turn, aid in kick-starting the economy.
He said: My ambition is to banish the word waste from our vocabulary. We are not here to discuss waste, we are here to discuss pre-used materials. We are here to discuss potential fuel. We are talking about resources.
The workshop concludes on Wednesday March 24.