Today, a month and two days after Spring Equinox, is the Earth Day. A few days ago we celebrated the Earth Hour and now we dedicate an entire day to environmental protection. It was first celebrated in 1970 and now it's organized by the Earth Day Network and takes place in more than 192 countries each year. Over the years milions of people all over the world take action to make the Earth greener and safer and today everybody can act to contribute the Earth Day.

But what is the sense? Will something really change? Will climate change end today? Of course not but what we do today should be repeated every day of our lives. All these daily actions will make the difference. In the past years the word has been spread and a new green generation is ready to face and solve the problems made in the past years.

Earth Day this year is dedicated to green cities. Today, more than half of the world’s population lives in cities. As the urban population grows and the effects of climate change worsen, our cities have to evolve. According to the Earth Day Network we have to improve three aspects of our cities:

Energy. Most of the world currently relies on outdated electric generation structures that are extremely inefficient and dirty. Renewable energy is the energy of this century.

Green Buildings. Buildings account for nearly one third of all global greenhouse gas emissions. Through simple efficiency and design improvements to buildings we can reduce those emissions drastically.

Transportation. The fastest growing source of greenhouse gas emissions worldwide. We need to improve standards, increase public transportation options, invest in alternative transportation, and improve city walkability and bikeability.

But what you can do today not to feel guilty and to help the environment? If you want to join this global movement there are two ways:

Online activism. Lend your voice, spread the word from your computer.

Local campaigns. More than 192 countries (almost all in the world) are celebrating Earth Day. Join the nearest campaign to you.

One of the causes that brought to the first Earth Day was an oil spill in California and today we're still fighting against the same dirty and polluting kind of energy source. It sounds repetitive but change is necessary and change depends from the number of people involved, so let everybody know that today is the Earth Day.

For more details on green cities and global campaigns go to earthday.org