The Fudan-Duke result on airborne microplastic forcing is now a week old, and a week of circulation has not produced the unit. The paper's Friday brief on microplastics climate coverage needing a scale bar argued that the useful figure is 16.2 percent of black-carbon forcing, not "warming worse than thought." [1] Saturday's coverage still leans on the second framing.

The arithmetic is dull and load-bearing. Black carbon's IPCC central forcing estimate is roughly 1.1 watts per square meter. Sixteen-point-two percent of that is about 0.18 W/m^2. CO2's anthropogenic forcing is roughly 2.16 W/m^2. [2] The microplastic number is a ten-percent contribution to a forcing term that is itself smaller than CO2. That is the comparison a reader needs to weigh the new finding against the old inventory.

Scientific American's account explains the physical surprise — coloured particles absorb more light than earlier assumptions about white scattering particles allowed — and the UK Science Media Centre's expert reactions still flag the sparse measurement coverage and the need for more observations before the term moves into policy. [3] Neither outlet has produced a stable headline figure in W/m^2, which is the unit the IPCC would use to add a forcing term to an assessment chapter.

Scale literacy is not minimization. It is how a real finding survives public circulation without becoming a substitute for the carbon story. The microplastic forcing belongs on the chart. It does not belong above the chart's other entries.

-- DARA OSEI, London