The United States entered into the Montreal Protocol on Substances that Deplete the Ozone Layer. Scientists discovered that man-made chemicals can destroy the layer of ozone gas in the stratosphere. Stratospheric ozone absorbs ultraviolet radiation; as the ozone layer thins, less radiation is absorbed. Increased human exposure to ultraviolet radiation is linked to a range of ailments, including skin cancer and cataracts. Signatory nations agreed to reduce the use of certain substances, including methyl bromide. The Senate ratified the treaty and Congress incorporated its terms into domestic law through the Clean Air Act Amendments of 1990. The United States has reduced its use of methyl bromide to less than 39% of its 1991 baseline. In 1997, the Parties 'adjusted' the Protocol to require developed-country Parties to cease 'production' and 'consumption' of methyl bromide by 2005. Congress amended the Clean Air Act to require EPA to 'promulgate rules for reductions in, and terminate the production, importation, and consumption of, methyl bromide under a schedule that is in accordance with, but not more stringent than, the phase-out schedule of the Montreal Protocol Treaty. Methyl bromide is a naturally occurring gas produced by oceans, grass and forest fires, and volcanoes. It is also man-made and used as a broad-spectrum pesticide. Methyl bromide has an 'ozone depletion potential' ('ODP') of 0.38-0.60. This puts it in the middle range of substances scheduled for elimination under the Protocol. It is not nearly as destructive as chlorofluorocarbons and most other class I substances, almost all of which were phased out in 2000. The Protocol allows exemptions from the general ban 'to the extent that the Parties decide to permit the level of production or consumption that is necessary to satisfy uses agreed by them to be critical uses.' The Parties set general guidelines for implementing the critical-use exemptions. The United States requested a total exemption of about ten thousand metric tons of methyl bromide for sixteen different uses. The Parties granted the United States critical uses in sixteen categories, amounting to 8,942 metric tons of methyl bromide (7,659 metric tons of new production and consumption, with the remainder (1,283 metric tons) to be made up from existing stocks of methyl bromide). D issued a rule implementing 'critical use' exemptions from the treaty's general ban on production and consumption of methyl bromide. P believes the Final Rule violated the agreed upon amounts in the Protocol. The court dismissed P's petition for judicial review for lack of standing. On rehearing, P offered new information that has led the court to change its view on the standing issue.