We are 7'2 billion people over the world. Our communities are different, so our needs are more diverse. Nevertheless, in a lot of countries, a phenomenon is happening: population's ageing.

People have got a higher life expectancy in some countries, while their birth rates are lessening. This situation is being taken into account by governments, which are implementing more and more policies about elderly, healthcare and called "active ageing" (leisure, non-marginalization and so on).

However, I think they forget other main question: what about Green Living? We can care our old people, but if we do not think with a sustainable mind, current elderly will not be able to take advantage of their lives.

But this quandary appears too in our case: youth people. With globalization and its rapidity, we are making profit of their benefits, but we have to take care of other consequences: we have not to forget the explotation of landscapes, the reduction of current used energies and their effects in our health.

We are a generation that, in some parts around the world, is smaller than before (in the case of our parents or grandparents). So, if birth rates are decreasing, but production continues growing, which type of living conditions do we want for us and for next generations?

The solution is Green Living. We need to implement real, effective and aware policies by governments, but also actions and projects by civil society. We have to advocate for renewable energies, use of other means of transport to avoid pollution (such as bicycles) or to reduce its expansion (public transport: trains, undergrounds...).

But one of the most important actions to face this changing population structure in some parts of the world is awareness-raising and the change of some values as well as the incorporation of others. Solidarity, respect and specially, sustainability are pragmatic values we need for our future.

We have to advocate for sustainability, but also for their real implementation. Do not forget that we can change the world with helps of civil society (individually and in groups), governments and international organizations.

Think globally (with Millennium Development Goals and next Sustainable Development Goals), and act locally!