Uncertainty and bias in Liggio et al. (2019) on CO2 emissions from oil sands operations
Bibliographic record
Abstract
In the April 2019 issue, Liggio et al. published an analysis that utilized CO 2 emission estimates obtained from aircraft flight studies carried out in the Athabasca Oil Sands area in northeastern Alberta in 2013 1 . The authors reported significant differences between CO 2 emission estimates from their aircraft flight studies compared to the industry-reported emission estimates with the aircraft flight studies implying a significantly higher level of CO 2 emissions in the region of 17 megatonnes (MT) per year. We suggest that these apparent discrepancies can be explained by the uncertainty and bias associated with the methods and procedures used in the ref. 1 analysis. It is essential that these discrepancies be verified as there are potentially significant financial implications from these emission discrepencies—$1.105 billion per year at a rate of $65/tonne.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.017 | 0.075 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.003 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.017 | 0.014 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".