On Spurious Causality, CO2, and Global Temperature

Abstract

Stips et al. (2016) use information flows (Liang (2008, 2014)) to establish causality from various forcings to global temperature. We show that the formulas being used hinge on a simplifying assumption that is nearly always rejected by the data. We propose the well-known forecast error variance decomposition based on a Vector Autoregression as an adequate measure of information flow, and find that most results in Stips et al. (2016) cannot be corroborated. Then, we discuss which modeling choices (e.g., the choice of CO2 series and assumptions about simultaneous relationships) may help in extracting credible estimates of causal flows and the transient climate response simply by looking at the joint dynamics of two climatic time series.

Revisiting causality using stochastics: 2. Applications

“…[28], the influence of El Niño on climate is accompanied by large changes to the carbon cycle, with the pantropical biosphere releasing much more carbon into the atmosphere during large El Niño occurrences. Noticeably, in a very recent paper, Goulet Coulombe & Göbel [29] seem to confirm the finding by Koutsoyiannis & Kundzewicz [4], yet they deem it an ‘ apparently counterintuitive finding that GMTA [global mean surface temperature anomalies] explains a larger portion of the forecast error variance of CO 2 than vice versa ’. To ‘ resolve ’ it, they ‘ explore a last avenue, that of using annual CO 2 emissions '.…”

Compression complexity with ordinal patterns for robust causal inference in irregularly sampled time series

“…They have also analysed the CH 4 -T relationship and found T to drive CH 4 on the paleoclimate scale. This study has been criticized by Goulet et al 92 . They show that an assumption of ‘linearity’ made by Liang’s information flow is nearly always rejected by the data.…”

Global Temperature and Carbon Dioxide Nexus: Evidence from a Maximum Entropy Approach

“…They called attention to the fact that the larger differences in emission pathways of different atmospheric pollutant emissions. Proposing a forecast error variance decomposition, [7] contradicts [30] findings of causality from various forcings to global temperature. Therefore, and in the presence of multiple and contradicting results, the present article tries to contribute to this stream of research.…”

“…Others ignore global warming and pretend that the problem does not exist at all. As evidenced by Letcher [6], the root cause of our present changing climate is the build-up of greenhouse gases, the most important of these gases being carbon dioxide, mainly caused by the burning of fossil fuels [7].…”

“…Cost reductions and global adoptions of low-emissions technologies are mainly attributed to innovation policies pursued [27]. Nationally determined contributions announced before COP26 indicated that it was likely that warming will exceed 1.5 • C during the 21st century, and recent contributions in the literature also discuss and put these problems at the forefront [2,3,7,8,24,28,29]. In [2] it was concluded that the number of deaths increased significantly with the repetition of extreme weather events.…”