Loudmouth, of course there is a level of man-made CO2 that is acceptable to life continuing... no one is arguing there isn't!

But to say industrialisation is a good thing because CO2 makes plants grow is an oversimplification because CO2 is not the only limiting factor to plant growth.

Nothing grows exponentially and that includes plant growth with respect to CO2: it's the heart of what makes a complex system and you have somehow decided plant growth versus CO2 is a simple relationship!!

Wow- very interesting <rolls eyes>

Wow

Sorry, Embarrassment, I've read my previous post over and over and I can't see any suggestion that industrialisation was necessarily a good thing.

My point was simply (sorry if it's still too complicated) that, since the plant-life of the Earth absorbs a certain level of CO2 naturally, what level of CO2 produced by human economic activity might push that level to a sort of tipping-point, just too much for all that plant-life to absorb ?

Of course, one problem in any such calculation is that, the more CO2 is produced, the more is utilised by plant-life to stimulate more growth, (hence the old-fashioned and politically-abandoned term, 'green-house effect') so any target output level is a sort of moving point.

Obviously, we strictly shouldn't be aiming for that point but for something a bit less, to give the Earth a breather, so to speak.

Equally obviously, since it will take some time for our technologies to develop to that point, fossil fuels which produce the least CO2 should be exploited, gas for instance over oil and coal, oil over coal, and black coal over brown coal.

Ideally, one day, renewable energy infrastructure, solar panels and arrays, and wind towers, will be built using renewable energy only.

Joe

Joe, if you believe that nonsense then Venus must be a very green planet indeed.

"Unless humans slow the destruction of Earth's declining supply of plant life, civilization like it is now may become completely unsustainable."
"Scientists estimate that the Earth contained approximately 1,000 billion tons of carbon in living biomass 2,000 years ago. Since that time, humans have reduced that amount by almost half. It is estimated that just over 10 percent of that biomass was destroyed in just the last century."
""You can think of the Earth like a battery that has been charged very slowly over billions of years," said the study's lead author, John Schramski, an associate professor in UGA's College of Engineering. "The sun's energy is stored in plants and fossil fuels, but humans are draining energy much faster than it can be replenished."
"Studies show that the vast majority of losses come from deforestation, hastened by the advent of large-scale mechanized farming and the need to feed a rapidly growing population. As more biomass is destroyed, the planet has less stored energy, which it needs to maintain Earth's complex food webs and biogeochemical balances."

From; Human Domination of the Biosphere Schramski JR, Gattie DK, Brown JH, as published by University of Georgia. in "Continued destruction of Earth's plant life places humans in jeopardy." ScienceDaily, 14 July 2015. In response to Proceedings of the National Academy of Sciences.

A note from lead author John Schramski "I'm not an ardent environmentalist; my training and my scientific work are rooted in thermodynamics. These laws are absolute and incontrovertible; we have a limited amount of biomass energy available on the planet, and once it's exhausted, there is absolutely nothing to replace it."

Dear Paul,

An excellent argument for conservation by Prof. Schramski, thanks!

What a pity that this important issue is being mired by the AGW nonsense. There is no problem with CO2 in the air - the problem is that carbon levels are significantly lower in the earth's biomass and this carbon is unfairly denied from the more-intelligent species that will succeed the human race.

//My point was simply (sorry if it's still too complicated) that, since the plant-life of the Earth absorbs a certain level of CO2 naturally, what level of CO2 produced by human economic activity might push that level to a sort of tipping-point, just too much for all that plant-life to absorb ?//

Doesn't work like that, Joe. Over the course of their entire existence plants aren't carbon sinks; they're carbon neutral. They're only effective carbon sinks while they're growing. Once they stop they're essentially carbon neutral. And when they die, what do you think happens to all that carbon they absorbed during their lifetime? It goes straight back into the environment, and your plant becomes a carbon source. Without an effective way to sequester the carbon plants absorb when growing, planting more trees isn't much of a solution.

And if we're deforesting faster than we're reforesting, it's even less of a solution.

That being said, there are lots of other good reasons to plant trees. For one thing, they're just nice. Who wants to live in a desert?

//There is no problem with CO2 in the air//

I conducted a seance, yuyutsu. The 1746 Cameroonians who asphyxiated in the Lake Nyos event all think you talk shite, and there's a hell of a lot of coalminers voicing their furious agreement.

There's also it's pesky habit of absorbing IR radiation and heating the place up, with resulting damage that causes to ecosystems. But who cares about them?

Hi Paul & Toni,

Sorry if it's too complicated: I was asking (and of course I'm dimly aware that the whole calculation would be immensely complicated) how much CO2 does the plant life across the Earth absorb each year, is there or is there not an acceptable level of man-made CO2 production within the capacity of the Earth's plant-life to cope with ? What might be the effects of extra atmospheric CO2 on stimulating plant-life ?

OF COURSE, there is a limit [case study: Venus], that's my point: what is it ? Yes, I know it's very complicated. Yes, I know plants absorb CO2 only while they are growing, so clearly, any tree-planting - as at present - would take into account the growing life of trees, with a view to using that timber once the trees are mature, and constant re-planting. Hence, in my view, furniture timber species, etc. should be favoured. Such trees shouldn't be allowed to 'die' and just rot, Toni, how dumb would that be ?

There are all sorts of ways to put carbon back into the soil rather than let trees 'die', or burn them. And after all, the more carbon there is in the soil, the healthier and more rapid plant growth is.

If handled right, carbon is not the enemy, CO2 is not the enemy. So how much is an acceptable level of production, since one way or another, we will always be producing CO2, as life on Earth has done for a billion years.

Any more red herrings or false dilemmas or misrepresentations ? Bring them on :)

Joe