$$F(A\rightarrow B) = \frac{110}{600}\cdot [A]$$

I'm aware that the model is very crude but nevertheless, what's the idea behind? It would mean, that F(X->Y) depends only on X and not on Y. Take for instance F(A->B) and we double carbon in A, the assumption would imply, that biomass increases also by factor two - otherwise the additional carbon cannot be "absorbed" by B. Same for F(A, M). When CO₂ increases in air, temperature of M would rise too, but then less CO₂ would be taken by the warmer water, so the coefficient of transport would change.

Is there a way to justify the assumption in a first approximation?

A forest would, over longer time periods, only be a net carbon sink — and corresponding oxygen source — if its biomass increases and/or if dead organic material is removed from the global cycle of matter, e.g. by forming peat underground.

But, for example, parts of the Amazon rain forest stand basically on a relatively thin layer of humus above infertile quartz sand (here is a popular science article); since the rain forest is millions of years old, there is no significant sequestering of organic matter over time in the Amazon.

Of course I may have overlooked something, and rain forests in Africa or Asia, let alone forests in temperate climates, all in places with very different geologies, may indeed sequester carbon. After all, our fossil fuels once were plants.

Are forests overall significant carbon sinks or should I write a letter to the editor? I suppose that Friedman should at least remove the Amazon basin from the sentence.

I'm trying to understand how CO₂ emissions are calculated in the Land Use category "Forest Land Remaining Forest Land". There are several subcategories, the one with the biggest impact seems to be "Change in Biomass" both above and below ground and I would like to understand this subcategory.

I came to this as a bit skeptical of the large negative values (i.e. forests are absorbing large amounts of CO₂) being quoted in various government reports and I would like to have a rough understanding how this number is calculated.

The clearest reference I have found is from climate-policy-watcher but I would like to understand a bit better.

Is the idea of Equation 2.8 in that linked page, that one should first estimate properties of the existing forest and also the "Biomass Expansion Factor", then one assumes that the existing forest will grow according to this factor? It seems from reading the related section on how to estimate the BCEFS, that it is always positive and related to growth of a tree.

However I find that this leads to the conclusion that every forest just expands naturally, which seems pretty odd. Certainly if I compute the total existing forest cover and multiply it by some positive factor, I will come to the conclusion that the forest is expanding and absorbing carbon, but I'm pretty skeptical that this is accurate. Don't most forest just reach steady state in general? Aren't there many non-anthropogenic factors which limit the growth of a forest, so that one cannot estimate the biomass growth of a forest just from the natural growth of a tree?

Assuming the low end of 3 liters CO2 gas per liter soda we get each milliliter of soda contains 0.003 liter CO2. Ambient air has about 400 ppm CO2 or 0.04%, or about 0.0004 liters CO2 per liter air, so to bring it up to about 1500 ppm I would need to add 0.0011 X 10 or 0.011 liters CO2 to the greenhouse, or about 4ml of carbonated water.

The problem is this whole process is very imprecise, and it would be nice if there was a way to measure the CO2 content within 100 ppm with a range of say 0 - 5000 ppm which doesn't cost hundreds of dollars, since this is a 9th grade science project.

Any ideas?

However, in order to use this comparison to make inferences about CO₂ levels, it seems to me that this would require establishing that everything else is held equal. If this is not established, it seems to me that this would not allow one to use plant pores as proxies for past CO₂ levels and thus climate change. Therefore, my question is, how do researchers attempt to hold all else equal when comparing the pore density of fossilized plants to living plants to establish a causal relation between past CO₂ levels and plant pores density?

Reference:

Mann, M. E. and L. R. Kump (2015). Dire Predictions: Understanding Climate Change 2nd Edition. DK Publishing.

► https://www.icos-cp.eu/science-and-impact/global-carbon-budget/2019 via https://www.icos-cp.eu/science-and-impact/global-carbon-budget

Our World in Data has calculated several additional metrics based on the following metrics:

► Energy consumption data from BP Statistical Review of World Energy: https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html

► Long-term GDP data from Maddison Project Database: https://www.rug.nl/ggdc/historicaldevelopment/maddison/releases/maddison-project-database-2018

► Population data from the UN World Population Prospects and Gapminder: https://www.gapminder.org/ https://population.un.org/wpp/