Monday, April 25 was Arbor Day, the Day of the Tree, in Germany. It's an annual celebration of the role of trees in the country's ecosystems and economy. As part of Arbor Day, the German development minister, Gerd Müller, announced in Munich his ministry's support for an ambitious goal promoted by a German non-government organization (NGO) called Plant-for-the-Planet.

"No forest, no life, no oxygen to breathe," Minister Müller said. "Germany's development ministry puts the conservation of forests and of climate stability high up on its policy agenda. Plant-for-the-Planet's engagement is remarkable, and so we're going to expand our collaboration with the group."

Müller said that it was necessary for many more people in the world to grab a spade and "plant the future."

From tiny acorns, mighty oaks do grow

From the beginning, Plant-for-the-Planet's motto has been "stop talking, start planting" - calling on people to take direct action, rather than leave the future of the climate for politicians to discuss inconclusively at inconsequential meetings.

When Plant-for-the-Planet was founded in 2007, its founder was nine years old. Inspired by Kenya's tree-planting Green Belt Movement founded by Wangari Maathai, Felix Finkbeiner had prepared a presentation for his elementary school class in the village of Pähl, in upper Bavaria, which ended with a proposal that children in each of the world's countries could plant a million trees.

One thing led to another, and Plant-for-the-Planet became a global children's movement. Nine years later, fourteen billion trees had already been planted, and the global tree-planting goal had been raised to 1,000 billion (one trillion). According to a Yale University study, there are about 3,000 billion trees growing on the planet today, and there's room for another 1,000 billion.

In December 2011, Planet-for-the-Planet shifted gears and graduated into the big leagues. In the context of the UN Climate Conference in Durban, South Africa, the United Nations Environment Programme transferred responsibility for the "UN Billion Tree Campaign" to Plant-for-the-Planet. That entailed giving responsibility for nurturing the 12 billion trees already planted under the aegis of the Billion Tree Campaign to the youth-led NGO.

Exhortation sometimes works

Felix Finkbeiner, now an 18 year old university student in London enrolled in an international relations program, continues to be a leading spokesperson for Plant-for-the-Planet. He is calling on every citizen to personally plant or sponsor the planting of a thousand trees, every millionaire a million trees, and every billionaire or great corporation a billion trees.

The planting of seedlings, and their nurturance to free-to-grow stage, costs as little as one euro in many developing countries in the global south.

"Global reforestation is also an economic development program, because it generates income for many millions of people in countries that are currently poor, and so reforestation helps address the causes of migration - namely the poverty and climate crises," Finkbeiner said in Munich.

He noted that trees are not only much cheaper to plant and maintain in the global south - they also grow as much as four times faster than in Europe. That means trees in the world's warm countries are more efficient CO2 storage machines.

Collaborative empowerment

The German development ministry is already involved in more than 200 afforestation projects around the world. Even deserts can be afforested, if water can be supplied. Wherever it makes sense to do so, the ministry wants to engage children in its tree-planting efforts by collaborating with Plant-for-the-Planet.

The ministry's hope is that young people in developing countries will feel empowered to help protect their local environments by becoming active in the framework of the Plant-for-the-Planet's afforestation campaign. Plant-for-the-Planet organizes one-day "academies" at which children teach other children about climate risks, and enable them to take first steps to do their part for climate stability and ecosystem restoration by planting some seedlings.

Among Plant-for-the-Planet's current projects is an afforestation program in Campeche, southern Mexico, that employs 78 forest workers.

Reforestation is only one side of the story, of course. Deforestation is the other. Around 10 million hectares of forests are permanently destroyed each year, mostly in tropical countries, leading to the extinction of an estimated 50,000 species of plants, animals and insects annually. Tropical forests are far more biodiverse than temperate forests.

Planting trees is helpful, but new tree plantations are very different from wild primary forests. Preventing the destruction of remaining primary forests is crucial to conservation of species and ecosystems. Yet their destruction continues apace, with the last of Indonesia's jungles getting burned down at a ferocious pace to make room for cash-generating palm-oil plantations, and climate change increasing the frequency of drought and megafires in forests around the world, from South Africa to Australia to Russia to western North America.