Archives par mot-clé : Carbon Budget

Why is the CO₂ Concentration Rising?

by F. Schrijver, Apr 15, 2022 in WUWT


The general view in society is that human emissions of CO₂ are the all-determining cause of the increased concentration in the atmosphere. Most scientists and even many climate skeptics do not question this. There is some debate about how long this extra CO₂ will stay in the atmosphere, but that’s about it. That’s remarkable, as several scientists have published extensively on the flaws and inconsistencies of this narrative. By looking at the significant increase in the CO₂-flows from and to land and sea it’s in fact easy to see that the CO₂-rise is largely due to natural causes.

The idea that human CO₂ is the all-determining cause of the increased concentration is based on the assumption that the natural inflows and outflows are always and exactly in equilibrium with each other. Based on this perfect equilibrium thinking, human emissions, even though they are relatively small, cause a perturbation year after year. In the so-called global carbon budget[2] about 10 PgC of CO₂ is added every year, while the absorption flux has only increased by 6 PgC/yr (1 Petagram = 1 Gigaton = 1 billion tons). The concentration therefore continues to rise indefinitely as long as people emit CO₂.

To support this idea it is also assumed that human emissions accumulate in the atmosphere. Where you would expect a single residence time for a reservoir with in- and outflows, the IPCC-models calculate with a small residence time of about 4 years for natural CO₂ and a large one for human CO₂: “The removal of all the human-emitted CO2 from the atmosphere by natural processes will take a few hundred thousand years (high confidence)”.

Several scientists, including Murray Salby[9] and Hermann Harde[3], have published extensively on the flaws and inconsistencies of this narrative. They also showed that it is very illogical to think that a slight increase in the up-flux cannot be compensated by a larger down-flux. It’s like increasing the heat energy flow in a house by 5% and expecting that the temperature will keep on rising forever.

Despite this, belief in the IPCC’s model for the increase in concentration is persistent. In this article we will focus on one of the strangest assumptions: the idea that the in- and outflows are stable and in perfect equilibrium. Although they are about 20 times larger than anthropogenic fluxes and have different drivers for up and down, natural flows are not included in the material balance used in the models.

It is in fact easy to see that the increase in the CO₂ concentration is for the most part the result of natural changes, based on the following unmistakable observations.

  1. Fluxes to and from land and sea have increased significantly since 1750.

  2. The increase in these fluxes is natural, i.e. not due to human emissions.

  3. The growth of the natural fluxes can only take place at a higher concentration in the atmosphere.

CARBON CYCLE

by C. Spencer, June 7, 2021 in WUWT


The increase in 12C in the atmosphere is, in my opinion, weak evidence that the annual increases are driven only by fossil fuel sources. The atmosphere can’t tell ‘anthropogenic’ carbon dioxide from natural carbon dioxide. It seems unlikely that a source that represents only about 4% of the total flux is going to drive the system. The oceans sequester the vast majority of the carbon. One would expect that warming oceans (from whatever forcing) would increase the rate of out-gassing in mid-latitudes, and decrease the rate of extraction at high-latitudes. It seems more reasonable to me that, in a world with warming oceans, there would be a shift in the relative amounts of carbon in the oceans and the atmosphere. That would be the case even in the absence of any anthropogenic carbon.

 

….

….

Twice as much carbon flowing from land to ocean than previously thought

by Institute for Basic Science, March 18, 2021 in WUWT 


Every year 600-900 million tons of carbon flow through rivers to the ocean either as particles or in dissolved form. Researchers have known for a long time that this does not represent the total amount of carbon that gets transported from the land to the ocean. But the remaining contributors mostly from coastal ecosystems, such as carbon-rich mangrove forests, and from groundwater discharge into the ocean have been notoriously difficult to measure.

A new study published in the journal Global Biogeochemical Cycles and spearheaded by Dr. Eun Young Kwon, project leader at the IBS Center for Climate Physics South Korea provides new estimates of this elusive component of the global carbon cycle. The study makes use of the existence of two stable carbon isotopes, 12C and 13C, with the latter being slightly heavier, because it has one more neutron in its nucleus. The concentration ratio between these two carbon isotopes (referred to as ?13C) provides a means to track carbon through the different components of the carbon cycle, including the atmosphere, oceans, river systems and the biosphere. Knowing the typical ?13C value of land biosphere and for coastal vegetation, one can now track how this quantity gets diluted in the oceans. “The carbon isotope values act like an invisible dye that tells us something about the source where it came from and how much got released initially” says Dr. Kwon, lead author of the study.