Last month, Nobel laureate and environmentalist Wangari Maathai called for a global initiative to plant one billion trees to help fight off global warming and climate changes. Ms. Maathai, the first female African to win the Nobel Peace Prize, says “Anyone can dig a hole; anyone can put a tree in that hole and water it. And everyone can make sure that the tree they plant survives.” While I support Ms. Maathai’s idea, I believe there are a few flaws in her logic.
I, by no means, am a global environmentalist or an arborist or any other kind of –ist that deals with global climates. I do know that there are many people in the world who do not have access to excess water to sustain a tree, let alone live in an environment where trees can survive naturally. As the map below shows, there are many dry zones (gray color on map) across the globe where water just doesn’t naturally fall and collect. Even if we were just to plant trees along the very edges of these zones, it would take a lot of water in zones where water is already scarce in order to keep these trees alive. And with water being more valuable than money in some of these areas, it is unlikely that the individual will sacrifice the water they need to survive to keep a tree alive.
With that said, I do support her call for everyone to plant a tree (as long as they are able to do so practically). For everyone living in humid zones (green color on map), there should be relatively little water investment in keeping a tree alive. For those in the US, Europe, Canada, and China, we should be able to afford to buy a regionally native tree on our own and plant it. Corporate and private contributions can provide trees for those in Africa and other parts of the world where people are financially strapped, allowing the locals to put in the time and sweat investment in planting and carrying for the trees. These new trees can go a long way towards sustaining the local environmental conditions by trapping and retaining rain water by reducing the evaporation loss caused by overheating the unprotected ground.
For those living in the moderate zones (yellow color on map), there will be a little more effort involved. This region should get enough average rainfall during the year to keep an adult tree alive, but a lot of attention needs to be paid during the trees early years, especially if there is below-average rainfall. Typically, most trees over five years old are sufficiently rooted in the ground with access to enough ground water to care for it self. Younger trees might not tap that water, so periodic watering will be needed to ensure its survival. In theory, the more trees planted in the yellow zone can actually affect the local environment causing the green zone to spread into the yellow zone. Unfortunately the orange and red colored zones will require a lot of effort and resources that most individuals would not be able to (or desire to) sustain tree plantings adequately, requiring the need for environmental and commercial organizations to become involved.
So if you have the time, the resources, and the location that you can plant a tree to save the planet (or at least improve the appearance of your surroundings), then I hope you take Ms. Maathai up on her challenge and give back to the planet. Remember to use a regionally native tree as well as one that will grow tall to provide enough shade on the ground. Native trees have a greater chance of surviving unattended in your region than one brought in from somewhere else in the world. Best of luck with your landscaping challenge, and I hope your green thumbs are ready for the task.