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I was curious about this and wanted to share some quick calculations on how viable this is: A tree can absorb as much as 48 lbs of CO2 per year [1]. This is pr

I was curious about this and wanted to share some quick calculations on how viable this is: A tree can absorb as much as 48 lbs of CO2 per year [1]. This is pretty vague cause this can vary by tree age and size, but let's use this arbitrary number In 2014 the United States generated 6,870 million metric tonnes of CO2 [2]. 48 lbs is about 0.021 metric tonnes [3]. So... 6,870,000,000 / .021 = 327,142,857,142.85 327 trillion trees!! The population in the US on 2014 was roughly 317 million people [4]. This means for each person we would have to plant 6870 / 317 / .021 = 1,031.99 trees Just north of 1000 trees. That's 1k additional trees that need to be planted just to offset our CO2. Crazy [1] https://projects.ncsu.edu/project/treesofstrength/treefact.htm [2] https://www.epa.gov/climate-indicators/climate-change-indicators-us-greenhouse-gas-emissions [3] https://duckduckgo.com/?q=48+lbs+to+metric+ton [4] https://www.census.gov/popclock/embed.php?component=pop_on_date&date=20140101

ashelmire 8y ago
I thought this was pretty interesting. So I looked up how many trees there are per person: https://www.washingtonpost.com/news/energy-environment/wp/2015/09/02/scientists-discover-that-the-world-contains-dramatically-more-trees-than-previously-thought/?utm_term=.322ec8f37a1a https://www.washingtonpost.com/news/energy-environment/wp/20... The US has 716 per person. Sadly, it looks like China and India are the worst culprits: "Brazil had 301 billion trees (1,494 per person), Canada 318 billion (8,953 per person), and China 139 billion (102 trees per person). Among highly populous countries, India (population, 1.267 billion) had a tree population of only 35 billion, leading to just 28 trees per person." By comparison, the US won't take that long to get to carbon-neutrality. India and China are going to be a burden on the planet for the next century at least. Note that you don't need to plant an additional 1000 trees per person, you just need to have 1000 trees per person to cancel out their emissions.
- marcosdumay 8y ago
  So, if you plant 3 times your current forest sizes into wood harvesting forests, you would capture all of your CO2 emissions into a solid. That's probably not reasonable (but I'm not sure). Even then, if you double your forest area, and cut the wood from there you'll offset some 20% of your emission already. It's not a silver bullet, but it is something.
  - Scarblac 8y ago
    Then add that many trees again each following year.
    - marcosdumay 8y ago
      I assumed the forests were harvested every 4 years. That's average for low quality wood, like what goes into MDF.
      - Scarblac 8y ago
        But the emission compensated was only for 2014.
- gandreani 8y ago
  Yeah I don't think China or India are catching up any time soon. They're extremely arid regions. China even has a program in place to plant trees along the Gobi dessert to stop it's expansion. https://en.wikipedia.org/wiki/Three-North_Shelter_Forest_Program https://en.wikipedia.org/wiki/Three-North_Shelter_Forest_Pro.... That will help with the number (closer to 200 tree/person) since they plan to plant 100 billion trees by 2050 http://www.theplaidzebra.com/china-is-building-a-great-green-wall-of-trees-to-stop-desertification/ http://www.theplaidzebra.com/china-is-building-a-great-green...
  - orwin 8y ago
    It's actually a clever plan. They will destroy ecosystems on the way so its not _perfect_, but it's feasible and will likely work if they fuccessfully find the right kind of tree to start the forest. Greenland is doing it too[1], with a lot of setbacks, but they are starting to recover (albeit slowly) [1]https://www.nytimes.com/interactive/2017/10/20/climate/iceland-trees-reforestation.html https://www.nytimes.com/interactive/2017/10/20/climate/icela...
Someone 8y ago
(Even in the short scale, 327,142,857,142 is ‘only’ 327 billion, not 327 trillion) More importantly, those trees will capture that amount every year. So, once you have them, you only have to replace trees that get lost. Assuming a 10 year lifespan (many will die young), it’s only 100 a year to plant. That’s doable (trees you plant will be tiny) However, 1,000 trees at, say, 10 meters average distance cover about 0.1 square kilometers/25 acres. That way, the USA would support about 100 million people (I think 10 meters distance is a bit conservative, but there also will be areas where trees won’t easily grow) ⇒ Americans will have to (at least) halve their energy use. I think that is doable.

ashelmire 8y ago

I thought this was pretty interesting. So I looked up how many trees there are per person: https://www.washingtonpost.com/news/energy-environment/wp/2015/09/02/scientists-discover-that-the-world-contains-dramatically-more-trees-than-previously-thought/?utm_term=.322ec8f37a1a https://www.washingtonpost.com/news/energy-environment/wp/20... The US has 716 per person. Sadly, it looks like China and India are the worst culprits: "Brazil had 301 billion trees (1,494 per person), Canada 318 billion (8,953 per person), and China 139 billion (102 trees per person). Among highly populous countries, India (population, 1.267 billion) had a tree population of only 35 billion, leading to just 28 trees per person." By comparison, the US won't take that long to get to carbon-neutrality. India and China are going to be a burden on the planet for the next century at least. Note that you don't need to plant an additional 1000 trees per person, you just need to have 1000 trees per person to cancel out their emissions.

marcosdumay 8y ago
So, if you plant 3 times your current forest sizes into wood harvesting forests, you would capture all of your CO2 emissions into a solid. That's probably not reasonable (but I'm not sure). Even then, if you double your forest area, and cut the wood from there you'll offset some 20% of your emission already. It's not a silver bullet, but it is something.
- Scarblac 8y ago
  Then add that many trees again each following year.
  - marcosdumay 8y ago
    I assumed the forests were harvested every 4 years. That's average for low quality wood, like what goes into MDF.
    - Scarblac 8y ago
      But the emission compensated was only for 2014.
gandreani 8y ago
Yeah I don't think China or India are catching up any time soon. They're extremely arid regions. China even has a program in place to plant trees along the Gobi dessert to stop it's expansion. https://en.wikipedia.org/wiki/Three-North_Shelter_Forest_Program https://en.wikipedia.org/wiki/Three-North_Shelter_Forest_Pro.... That will help with the number (closer to 200 tree/person) since they plan to plant 100 billion trees by 2050 http://www.theplaidzebra.com/china-is-building-a-great-green-wall-of-trees-to-stop-desertification/ http://www.theplaidzebra.com/china-is-building-a-great-green...
- orwin 8y ago
  It's actually a clever plan. They will destroy ecosystems on the way so its not _perfect_, but it's feasible and will likely work if they fuccessfully find the right kind of tree to start the forest. Greenland is doing it too[1], with a lot of setbacks, but they are starting to recover (albeit slowly) [1]https://www.nytimes.com/interactive/2017/10/20/climate/iceland-trees-reforestation.html https://www.nytimes.com/interactive/2017/10/20/climate/icela...

Someone 8y ago

(Even in the short scale, 327,142,857,142 is ‘only’ 327 billion, not 327 trillion) More importantly, those trees will capture that amount every year. So, once you have them, you only have to replace trees that get lost. Assuming a 10 year lifespan (many will die young), it’s only 100 a year to plant. That’s doable (trees you plant will be tiny) However, 1,000 trees at, say, 10 meters average distance cover about 0.1 square kilometers/25 acres. That way, the USA would support about 100 million people (I think 10 meters distance is a bit conservative, but there also will be areas where trees won’t easily grow) ⇒ Americans will have to (at least) halve their energy use. I think that is doable.