Attribution of Surplus CO2 in the Atmosphere

Guest essay by Leo Goldstein

While we are watching the 21st episode of the Clowns on Parade series (COP21), we should remind the leading participants of a couple of facts that even a clown apprentice can understand. The US, Western Europe, Canada, and Australia (the only countries in the world that engage in the climate masochism) release less than one-third of the anthropogenic CO₂, an even smaller part of other “greenhouse gases” (a misleading name), and almost no black soot. This fact is not in dispute, but the alarmists usually reply that these countries are “historically responsible” for the most CO₂ emissions.

Well, this claim is incorrect, too, and not only because CO₂ release is beneficial because of its large fertilization effect and small and slow warming effect. When the sinks are properly taken into account, only 33% of the surplus CO₂ in the atmosphere is attributable to the US and other Western countries. The rest is attributable to China and the rest of the world, as shown in Table 1.

Table 1. Surplus CO₂ attribution by country or group of countries, 2012.

This analysis uses data and methodology from the most official IPCC aligned authors, including AR lead authors and heads of the Global Carbon Project. The data is known to be skewed against the US, Western Europe, Canada and Australia. The methodology is from Raupach et al, 2014. Figure 1 shows the evolution of the countries’ contributions to the surplus CO₂ levels over time, since 1880.

Fig. 1. Anthropogenic CO₂ accumulation in atmosphere, calculated using methodology from Raupach et al., 2014. To obtain the surplus CO2 concentration in ppm, divide GtC by 2.13.

This graph shows surprisingly low surplus CO₂ levels from 1880 to 1940. This may be because the IPCC models are wrong. Nevertheless, I performed the same analysis using Halperin, 2015 (H2015), and arrived at the same attribution result (with the differences within 2%). The resulting graph of contributions over time is shown in Figure 2.

Fig. 2. Anthropogenic CO₂ accumulation in atmosphere, calculated using H2015 and Comment #1 to H2015. To obtain the surplus CO₂ concentration in ppm, divide GtC by 2.34.

This looks more reasonable, doesn’t it?

BTW, I updated the best estimate of the surplus atmospheric CO₂ half-life to be 35 years (±5 years), based on my subjective corrections to the official data, made after the H2015 had been published (and announced on WUWT first). H2015 has not been retracted or corrected, because its main result is that surplus CO₂ concentration drops exponentially, rather than the exact half-life in the exponential decay formula. Figure 2 shows the results obtained with the updated estimates (but not the corrected data).

Let me also say a few words about the carbon cycle for those who are not familiar with the topic. Carbon is one of the most prevalent elements in the Earth’s crust. In the atmosphere, almost all carbon exists in the form of carbon dioxide (CO₂). There is a continuous exchange of carbon between the atmosphere and two other pools: ocean and land (biomass and detritus). The industrial revolution (1760-1840) brought about a sharp improvement in human conditions, starting in Europe and spreading to the rest of the world. Decreases in epidemics and child mortality rates caused a population increase from one billion in 1800 to more than seven billion today. By converting forests and other natural ecosystems into agricultural lands (land use change) and burning coal and other fossil fuels, humans started releasing growing amounts of CO₂ into the atmosphere. In accordance with the La Chatelier’s principle and other laws of nature, the increased (over putative equilibrium) concentration of CO₂ in the atmosphere caused its accelerated removal to other pools, which became known as sinks. IPCC went to extraordinary lengths to confuse both scientists and the broader public on this topic. But even using IPCC’s own models, one can conclude that only a small fraction of the extra CO₂, released 100 years ago, is still in the air. The calculations take into account the dynamic nature of the exchange (e.g. if a molecule of CO₂ entered the ocean but another one popped out from the ocean into the atmosphere, the net effect is zero). Figure 3 below shows how little impact old CO₂ release has had on contemporary CO₂ concentrations. For example, only 11% of the CO₂ released in 1900 should be counted toward the atmospheric CO₂ in 2012 (according to H2015 and H2015#1).

Fig. 3. Percentage of annual CO₂ release remaining in the atmosphere. The solid line shows values according to H2015 and Comment #1 to H2015.

The “clowns” referenced at the beginning of this article are only the delegations of the western countries, and those who spend their own money and time on worries over CO₂. Many other national delegations who are visiting COP21 in Paris are simply there to protect their nations from this progressive madness. On the other hand, a majority of NGOs and activists going there are simply profiteers and haters. Ultimately, we want to prevent an international conflict over hot air, foisted upon the world by IPCC, UNFCCC, UNEP, and their likes.

References and Supporting Information are available here.