Let’s Plant More Trees

In my Earth Day post I talked about the importance of planting trees to absorb CO₂ , the principle greenhouse gas contributing to global warming.  In my What Matters Most post, the analysis from the book Drawdown was used to examine the significance of planting more trees relative to many other actions to address global warming.  Turns out forest related initiatives are very important and over the next 30 years could remove 150 Gigatons of CO₂ .

Earlier this month a new study was released which received considerable press coverage (Associated Press, NY Times, LA Times, among others) which also addressed the potential significance of planting more trees.  The study, led by ecologist, Jean-Francois Bastin, from the Swiss Federal Institute of Technology in Zurich (Zurich Study) details how many new trees the planet realistically could support.  The conclusion:  the earth could support 900 million additional hectares of tree cover – an area approximately the size of Brazil.  And planting this volume of new trees, once mature, would reduce the amount of carbon in the atmosphere by over 200 gigatons – that’s approximately 2/3 of the carbon levels that can be traced to human actions.  This level of reduction is a considerably higher level than estimated previously in the Drawdown analysis. The result would be a carbon level comparable to what the earth was like 100 years ago.

The Zurich Study, using over 70,000 satellite photos, also analyzed the locations of available land (excluding land currently used for agriculture and urban areas) and incorporated climate, temperature, and soil conditions of the various locations as well as the desirable tree densities.   Over half of the land identified is located within six countries:  Russia, the United States, Canada, Australia, Brazil and China. 

Now at first glance, I thought this news was extraordinary – a potential global warming “fix” that could be done at relatively low costs and would likely be less controversial as compared to other “fixes”.  THEN I STARTED READING MORE.

Since the Zurich Study’s release, many scientists not involved with the study have added to the dialogue (several referenced in an article by the Sierra Club) regarding the study’s conclusions.  The critics did not dispute that 200 gigatons of carbon could be absorbed by trees if you planted them on every space of land available. They disputed the implications.  Contrast the headlines of these two news articles:

• Trillion trees might help save planet 
• Trees Alone Can’t Save Us From Climate Change

Examples of critical comments:

• CO₂ savings are overestimated because part of the emissions absorbed by the additional trees would have been absorbed by the soil or the seas anyway. Rather than two-thirds of the CO₂, the true figure would be closer to one-third.
• Many of the new trees planted would be planted in tree plantations. A recent study found tree plantations release much of the CO₂ they sequester back into the atmosphere every 10 to 20 years when the tree farms are logged – thus the study overestimates CO₂ reductions.
• Growing populations may need some of this available land for expanding cities, or to make room for more agriculture so that food shortages aren’t a problem
• Areas that were traditionally grassland as potential reforestation sites would destroy habitat for species that depend on grasslands, and is also a recipe for failure. Trying to grow forest on grassland habitat has traditionally been unsuccessful.
• Converting land used by grazing animals into forests would disproportionately affect poorer people.
• Increasing tree cover can elevate fire risk, decrease water supplies and cause crop damage by wildlife.
• Planting a tree in an area where it wouldn’t grow naturally can cause problems for the overall ecosystem.

 “Restoring forests is a good thing,” according to Karen Holl of the University of California, Santa Cruz. “It’s a good thing for carbon capture, for conserving species, for water quality. But it’s just not a silver bullet. We can’t plant our way out of the climate crisis. There are certain places, like the Amazon, where we need to do whatever to save existing forests.”

My conclusions:  The Zurich study provides a new level of detail as to the potential of the most trees that could be planted and where they could be planted.  But it is arguable the study calculated the likely maximum carbon reduction benefit.  And it also reminds us that forest restoration is complicated.  It’s certainly an important tool in addressing climate change, but by itself can’t solve the problem – it’s only part of the solution and in order to be effective, it needs to be done right.

Dealing with complex and complicated issues requires good scientific analysis.  Fortunately, the United States has some of the best scientists in the world to do this: the research and development (R&D) arm of the U.S. Department of Agriculture (USDA) Forest Service.  The Forest service works to improve the health and use of the United States‘ forests and grasslands and research has been part of the Forest Service mission since the agency’s inception in 1905.

However, most of these scientists will be leaving their jobs shortly because U.S. Secretary of Agriculture, Sonny Perdue, last month announced the planned relocation of the research agencies – from Washington DC to Kansas City.  Purdue suggested the move would and “increase the probability of attracting highly-qualified staff with training and interests in agriculture.”

But groups such as the Union of Concerned Scientists call it a “blatant attack on science” that will “especially hurt farmers, ranchers and eaters at a particularly vulnerable time.  Evidence suggests that the relocation of these agencies is an attempt to hollow out and dismantle USDA science that helps farmers and protects our food supply.”

The American Federation of Government Employees, the union representing the USDA’s Economic Research Service and the National Institute of Food and Agriculture, said the relocation “has resulted in catastrophic attrition at USDA’s top research agencies.”

The most recent data indicates that only 36% of the scientists had agreed to relocate.

Let’s hope Sonny Purdue is right and with the relocation to Kansas City, the USDA and the U.S. Forestry Service will attract highly qualified scientists who can address complicated issues such as the best way to implement reforestation.  Those new scientists will be needed to replace those highly qualified scientists that resigned or retired because of the move.

But what if we, as individuals, decided to take the “plant a trillion trees” challenge.  Now while John Prine will argue that Some Humans Ain’t Human, there are 7.7 billion people on earth, and if each of us would plant 129 trees, we’d be done.  What kind of tree would you plant?  I suggest doing a little research based on where you live, and then pick one you like.  If you’re lucky, it will be around a long time.  Let’s talk it up and get to planting.  What could be more patriotic?