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Comment by cyberax | Hacker News Reader

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This is opposite to everything I've ever read. A brief "greening" period was expected (and is now nearing its end) as climate change started taking off due specifically to this effect.

Edit: to clarify, I'm saying the greening thing already happened due to increases in CO2 levels (though it's possible this is due to heat and not CO2 itself, I guess?).

Hmmm, separately of plant-types, I wonder if there may be a distinction here between how a surge in individual growth doesn't necessarily translate to a surge in the forest.

Imagine a higher CO2 concentration allows a tree to reach maturity a whole +25% faster, taking 16y instead of 20y. However its happening in an established forest, already bounded by mountains, rivers, etc, where mature trees sustain for another 100y before they finally die off and take 10y to decompose, opening the spot for a replacement.

In that case, the number of simultaneous trees doesn't go up very much, because the main effect is to reduce "downtime". The "duty-cycle" for a tree-sized patch of ground goes from having a mature tree ~77% of the time to ~79%.

Interesting theory. I imagine there would be a stratification of mature and immature trees that would be pretty striking if this is the case. It might not be hard to find out if it's true!

So, it turns out that there are two types of plants: those whose growth is rate-limited by available CO2, and those whose aren't, as the latter evolved a more efficient pathway during a previous era of low CO2 concentrations.

So depending on which kinds of plants, you can both be right.

beat me to that.

We will get a change in the mix of plant life.

The scientific research says that drought resistance is due to the increased vegetation growth.

https://www.sciencedirect.com/science/article/abs/pii/S09819...

www.igb.illinois.edu/article/stronger-drought-resistance-urban-vegetation-due-higher-temperature-co2-and-reduced-o3

So why are the forests growing faster

Climate patterns are changing. My kids will retire with the cheap old farmland we bought that I’m planting black walnuts on.

Upstate NY was ideal maple syrup production territory for years. Now, we’ve changed from USDA Zone 5 to 6, so the region will be more like western Virginia in 20 years.

The TLDR is that they aren't. Global warming made some areas more hospitable to forests (warmer, more precipitation) and increased drought resistance counteracts some of the increased aridity in other ares: https://e360.yale.edu/features/greening-drylands-carbon-diox...

The atmosphere has so far barely changed in temperature compared to natural variations in temperature over time that had smaller and lesser effects than the effect we are seeing.

The abnormally rapid rise in CO2 levels we are seeing is unusual and accords better with the unusualness of rapid global greening. It isn't climate change that is causing it. It is CO2, directly.

If you look at the absorption spectrum of CO2 and historical data, I think it would be more correct to say, that CO2 has caused a noticeable increase in temperature in the past, but now absorption has reached a saturation level. The last 100 years temperature effects might have been dominant, but in the future direct effects of CO2 are absolutely going to dominate.

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