OZONE DEPLETION Emissions of carbon tetrachloride continue despite global prohibition
Bibliographic record
Abstract
To protect Earth’s ozone layer, most uses of carbon tetrachloride were banned years ago. According to reports filed by countries around the world, emissions of this ozone-depleting substance were virtually nil since 2007. But researchers now estimate that some 39,000 metric tons of the chemical were released each year from 2000 to 2012. “We are not supposed to be seeing this,” says Qing Liang, a NASA atmospheric scientist who led an international team that made the finding (Geophys. Res. Lett. 2014, DOI: 10.1002/2014gl060754). “There are either unidentified industrial leakages, large emissions from contaminated sites, or unknown CCl4 sources.” All countries that are members of the United Nations agreed through the Montreal Protocol on Substances That Deplete the Ozone Layer to phase out uses of CCl4 that lead to emissions, such as in fire extinguishers. Under that treaty, the compound is still legally manufactured, mainly as a feedstock for producing hydrofluorocarbons, ...
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".