"Of course there have been changes. Before the first Rio summit in 1992 there was no glimmer of environmental issues among politicians. Years later, Al Gore won the Nobel Prize for his environment film. Today nearly all politicians talk about the environment and propose solutions – it's a race for the next Nobel Prize."

Gustavo Davila Rodriguez, Mexico

"Kids should be taught to improve the environment when they're in kindergarten. We need to invest more in environmentally friendly technology instead of planting more trees!"

Ricardo Alfonso Orozco Nogales, Mexico

"In under-developed countries like my home country Mexico, bicycles should be the transport medium of the future. Governments should invest in public transport which does not harm the environment. We also need more investment in preventative awareness raising about the environment."

Jetzabel Ortiz, Mexico

Editor: Helen Whittle