Quirks & Quarks·Analysis

A trillion trees will not be enough if emissions continue to rise

Bob McDonald's science blog

Bob McDonald's science blog

Saplings are pictured on a table at the Dominion Arboretum in Ottawa on June 5, 2019. (Justin Tang/The Canadian Press)

During his state of the union speech, President Donald Trump announced that the U.S. will join the Trillion Tree Initiative to fight climate change. Of course, during the same speech, he boasted how the U.S. has increased production of oil and natural gas.

You might have heard about the idea of a trillion trees. Several groups, including the World Economic Forum, traditional environmental groups and youth activists have jumped on the bandwagon. The idea is a global campaign to encourage governments, businesses, civic organizations and individuals to join together in a massive climate change focused global reforestation effort.

A study published last summer in the journal Science suggested that the Earth had the potential for reforestation that could absorb more than a third of all the carbon humans have emitted since the industrial revolution. While the study was criticized in the same publication in the fall for significantly overestimating the carbon-sequestering potential of reforestation, there is no doubt that having a trillion extra trees on the planet would be beneficial in many other ways.

Trees provide habitat for animals like insects and birds, encourage forest diversity, prevent erosion, help conserve water, and make for great recreational areas. The shade of a tree canopy can reduce the need for air conditioning in urban areas. 

Tree planting on a clearcut in British Columbia. (Tina Lovgreen/CBC)

Unfortunately, one drawback of the tree planting scheme is that it takes 10 or 20 years for trees to grow and absorb enough carbon to make a difference. Meanwhile, worldwide greenhouse gas emissions continue to grow every year. 

President Trump, of course, also pulled the U.S. out of the UN Paris accord, which is a commitment to reduce emissions. So while announcing the tree planting campaign makes it sound like the president is going green, his actions speak otherwise. He's a strong advocate for growing the U.S. coal industry, his administration has been battling to end Obama-era regulation of vehicle fuel economy standards, and under his leadership the U.S. has seen its greenhouse emissions rise for the first time since 2013.

And as we are seeing in Australia, California and Canada's north, wildfires are bigger than ever thanks to a warmer climate, which means any newly planted forest could be at higher risk of fire in the future, releasing sequestered carbon back into the atmosphere.

A reforestation assistant measures a newly planted tree in a field damaged during illegal gold mining in Madre de Dios, Peru, on March 29, 2019. (Rodrigo Abd/The Associated Press)

Tree planting seems like an easy solution to climate change, but without a reduction in fossil fuel emissions, the effort is a drop in the bucket. As American conservation biologist Thomas Lovejoy, an advocate of tree planting, told The Associated Press this summer, "None of this works without emissions cuts."

In Canada we've made efforts to reduce greenhouse emissions, largely through phasing out coal-fired generating plants. But we are also planning to increase our exports of oil and gas through pipelines.

This conundrum is a demonstration of the long-standing conflict between short-term economic gain and long-term environmental sustainability. It is not an easy conflict to resolve because jobs are at stake. However, new jobs are emerging in the rapidly growing clean energy sector, which is one of the fastest growing sectors in the economy.

The transition away from fossil fuels will not be easy, but it won't be impossible either. If we are going to make the effort to cultivate new green trees in order to reduce greenhouse gases, it makes sense to cultivate green technology at the same time.

Clarifications

  • This story has been edited to add the 'analysis' label, as well as links and attribution to some of the statements it contained. Some wording was adjusted to correspond to those changes.
    Feb 12, 2020 5:28 PM ET

About the Author

Bob McDonald is the host of CBC Radio's award-winning weekly science program, Quirks & Quarks. He is also a science commentator for CBC News Network and CBC-TV's The National. He has received 12 honorary degrees and is an Officer of the Order of Canada.