Comment by internet_points
4 days ago
That first map makes it seem like we had gains pretty much all over the world, but it's not showing net gain, most of the countries of the world had a net tree cover loss. I wish it had a map showing net losses per country too – and it'd be interesting to see it going back in time, many countries had periods of very extensive logging during the 1800's and 1900's.
If you scroll there is indeed a map with net gain in the page I shared. Direct link to the net gain map file here: https://research.wri.org/sites/default/files/gfr/2022-10/36%...
gain yes, but not one showing the losses per country
Happy to be your personal google, gives me an excuse to look at it again.
This dashboard is good for that https://www.globalforestwatch.org/dashboards/global/?categor...
This visualization is also good: https://ourworldindata.org/deforestation
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Forest loss data is available for the study period (2000 - 2020). I've worked with this specific data source quite a bit. While it's known for being the gold standard in global forest loss estimation there are many countries that criticize it for over estimating loss. Going back further than 1985 is difficult/impossible as the estimate is derived from satellite data.
I wonder if declassified cold war spy plane photos might be usable to extend the records farther back in history? The resolution and coverage should be pretty good.
They didn’t take high resolution photos everywhere back then. In the early satellites it used physical film they recovered. And later digital storage and bandwidth was expensive and they dumped any data they didn’t need.
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> most of the countries of the world had a net tree cover loss.
This also doesn't really matter.
Russia, Canada, Brazil, the US, and China are about ~60% of the world's trees.
Their forest areas could grow by only 2-3% and dozens of small countries could lose substantial percentages of their forests, and we'd still end up with a ton more trees and forest area.
What happens when the forests in those places burn down?
Depends on how they burn and what forest we are talking about. A small intensity fire will leave many of the healthy trees alive while burning dead ones, and will turn some of the carbon into charcoal which is sequestered. A larger intensity fire will also kill healthy trees, and turns the carbon into CO2.
Many of the forests in North America need to burn every year in that low intensity fire. Their seeds won't even sprout until after a fire (when all the dead undergrowth has been burned away thus leaving the new sprout with sunlight). However this doesn't apply to all forests in North America, and I know even less about other countries.
Moral of the story: consult a forester who knows the local forest before talking about anything. In many places we have been badly mismanaging forests and there is no nice way out. We probably do need to burn down and start over with large parts of North America because of all the harm decades of "Smokey the bear" have done to our forests.
That depends on how many of them burn. A few? Doesn't matter much. All? Goodbye, and thanks for all the carbon.
What percentage of burning down over what time scale?
Be interesting to go back even further, pre agriculture. The world would be awash with trees.
Not really. In some places yes, but trees need specific conditions to exist: there would be lots of grass land and deserts too.