- Almost all the down flow to land and oceans is the result of photosynthesis, almost all the natural up flow from respiration.
- The down flow is proportional to the amount of CO₂ in the atmosphere.
- The CO₂ concentration is therefore directly related to the greenness of the Earth.
Global greening explains the CO₂ rise
- Since 1750 we observe larger natural fluxes and longer residence time due to greening.
- The increasing CO₂ concentration is in line with the greening of the Earth.
The main driver is global warming
- Higher temperatures lead to more emissions from the soil and ocean and to more greening.
- During warm periods, carbon trapped in soils is released faster than photosynthesis can absorb it.
No CO₂ hockey stick
- The present level of greenness (GPP) is not exceptional.
- It is very unlikely that ice core records give an accurate representation of the absolute CO₂ levels.
The human CO₂ level
Since 1960, the CO₂ concentration in the atmosphere has increased from 310 ppm to 425 ppm in 2024 (425 parts per million, slightly more than 0.04%). During that period, human CO₂ emissions also increased. The present belief is that humans have disrupted the natural balance and are fully responsible for the increase in the atmosphere. The natural CO₂ level is thought to be around 280 ppm. The present high CO₂ concentration would be the dominant cause of the observed global warming and other climate changes.

The green CO₂ level
Over the past decade, an increasing amount of scientific evidence has emerged demonstrating that the belief that humans are to blame, is incorrect. The reality is opposite to what most people think. Almost all the flows to and from the atmosphere are the result of biological processes. From satellite observations we know that the Earth is now much greener than one or two centuries ago, with more photosynthesis and more respiration. With an average residence time
The main driver for these changes is global warming. Higher temperatures lead to more emissions from the soil and ocean and to more greening. CO₂ is produced by degradation of biological matter. During warm periods, carbon trapped in soils is released faster than photosynthesis can absorb it, resulting in increasing concentration and more greening.

The orange arrows pointing to the right seem to be missing almost entirely. There is no need to assume that human CO₂ remains longer in the well-mixed atmosphere than any other CO₂. The do not accumulate. The dominant direction is the other way around: global warming is the main driver for more greening and more CO₂ in the atmosphere. So yes, it is true that the climate is changing, it is indeed getting warmer. But that warming actually causes more CO₂ in the atmosphere. Thus, cause and effect are the exact reverse of what is commonly asserted.
The idea of one single natural CO₂ level is largely based on the results of ice core drillings in Antarctica. They indicate a very stable level at around 280 ppm. The present level of greening is however not exceptional. It is very unlikely that in the past millennia the Gross Primary Productivity was never as high as it is today, ans so also the concentration in the atmosphere. That makes it improbable that these ice core records provide an accurate representation of historical atmospheric concentrations.
On this website
Although the climate and carbon cycle are complex, it is not difficult to see that changes the CO₂ level are largely natural and that the present paradigm is incorrect. Even if we do not fully understand or agree on the impact of human emissions, we still can conclude that that the present level is directly related to the greenness of the Earth.
On this website we will discuss the following subjects.
- The CO₂ level is a natural level, consistent with the actual greenness.
- Global warming is the main driver for increased natural emissions and greening.
- The increased CO₂ concentration can be accurately modelled based on the observed temperature changes.
- The main conclusions of the given explanation of the CO₂ rise.
- Some important misunderstandings:
- The belief that human emissions behave differently than other CO₂ and accumulate in the atmosphere.
- The idea that nature cannot be the cause as it is a net sink of CO₂.
- The CO₂ hockey stick based on ice core records from Antarctica.
- Logical errors with respect to the adjustment time and other issues.
Greenco2level.org aims to make factual information about the CO₂ increase accessible to a wider audience, without compromising the quality. We use scientific sources (peer reviewed), and we try to present it in a reliable and responsible manner with references to underlying publications.
Climate change
The question of why it has become warmer is a completely different one. The answer to that is not simple. Due to the complex and chaotic nature, predicting the climate is at least as difficult as predicting the weather, if it is possible at all. Numerous factors impact weather and climate, frequently varying significantly by region. Even though we know more and more about the climate, it is an illusion to think that we can predict or calculate it. Due to the (by definition) long time scale, any prediction of climate change can only be falsified after many decades, which seriously limits the scientific value.
The notion that the current pace of climate change is unprecedented is anyway incorrect. There have been many periods in the recent past where average temperatures have fluctuated significantly. For example, in the Middle Ages and around the beginning of the Christian era it was at least as warm as it is today, while in the 17th century there was a relatively cold period (the Little Ice Age). The present sea level rise is neither exceptional. For the past 200 years, the increase has been about 1 to 2 mm per year, with little to no acceleration observed. But just 10,000 years ago the average rise was 1.5 cm per year, or 10 times as great (See Wikipedia ).