I recently saw the following meme on Facebook. I’ve debunked various versions of it in the past, But this time I decided to just compile that debunk into an article and will fetch it again later when it is needed.
On it’s face. My first take was this:
This is wrong for a lot of reasons. Not the least of which. The Boreal Forest is not carbon neutral.
YOUNG trees. Freshly planted. Absorb carbon like a sponge. OLD trees. Do not absorb any new carbon and release it all when then die.
According to Natural Resources Canada, The Boreal Forest has begun, and I quote: “already degrading irreversibly, triggering a process of forest decline and re-establishment lasting several decades, while also releasing significant quantities of greenhouse gases”
“Canadian boreal woodlands and forests cover approximately 3.09 × 106 km2, located within a larger boreal zone characterized by cool summers and long cold winters. Warming since the 1850s, increases in annual mean temperature of at least 2 °C between 2000 and 2050 are highly probable. Annual mean temperatures across the Canadian boreal zone could be 4–5 °C warmer than today’s by 2100. All aspects of boreal forest ecosystem function are likely to be affected. Further, several potential “tipping elements” — where exposure to increasing changes in climate may trigger distinct shifts in ecosystem state — can be identified across the Canadian boreal zone. Approximately 40% of the forested area is underlain by permafrost, some of which is already degrading irreversibly, triggering a process of forest decline and re-establishment lasting several decades, while also releasing significant quantities of greenhouse gases that will amplify the future global warming trend.”
I then followed up with a Fact Check from AFP:
An online post argues that Canada’s trees absorb more carbon dioxide than the country emits. The post’s reasoning is flawed because it does not take into account the fact that the carbon stored in trees is released when the trees die. Canadian forests have recently become carbon sources rather than carbon sinks due to high tree mortality.
“Canada cleans 10x CO2 than it produces,” is the conclusion of a math-based meme that several thousand people shared on social networks.
The nonprofit organization Trees for the Future estimates that trees can capture an average of 50 pounds of carbon each year. However, this is only an average, and as this document from the US Department of Energy outlines, the amount of carbon captured by a tree depends on a variety of factors such as tree species, age and size. For this reason, carbon sequestration tends to be measured in terms of carbon absorbed per hectare or per forest, not per tree.
Under the United Nations Framework Convention on Climate Change, more commonly called the Paris Agreement, Canada makes a National Inventory Report. According to the most recent submission from in 2016, Canada’s carbon dioxide emissions for that year were 559 million metric tons.
The figure cited in the meme is from a 2008 US Energy Information Administration study. The 2016 EIA figure for Canada was 633 million metric tons.
The idea promoted by this post, as well as a Canadian columnist, ignores one factor paramount to tree carbon absorption estimation: tree mortality. Trees absorb carbon dioxide over the course of their lives, but most of this carbon is released back into the atmosphere when trees are cut or die of natural causes. Ignoring carbon emissions from trees, Kurtz told AFP, would be like “trying to judge your financial health by looking only at your income but not your expenses.”
Kurz, who has conducted research on greenhouse gas emissions and removals in Canada’s managed forest, said he had heard the claim made in the post before and argued that it is “completely without merit.”
While you’re here, Since we’re talking about trees and CO2. Let’s also take a moment to remind you that even if we planted trees literally everywhere. It would still not be enough. From BusinessInsider
Humans emit roughly 30 to 40 billion tons of the greenhouse gas, carbon dioxide, into the atmosphere each year. If we keep it up, Earth will continue to heat up and ultimately devastate our way of life.
So what can we do about it?
Most scientists agree that we need a way to capture some of that CO2 out of the atmosphere. One idea is to plant lots of trees. Trees use CO2 in order to grow. They also release oxygen, so it’s a win-win.
But studies indicate that we simply can’t grow enough trees to capture the necessary amount of CO2 that would help us meet the goals set by the Paris Agreement.
In truth, we would have to cover the entire contiguous US with trees just to capture 10% of the CO2 we emit annually.
There’s just not enough room on this planet to have the farmland it takes to feed the world plus the space to plant the necessary number of trees.