• The second option is the industrial use of CO2, either directly or as feedstock for production of various carbon-containing chemicals.

• Scientific evidence linking chlorofluorocarbons (CFCs) and other Ozone Depleting Substances (ODSs) to global ozone depletion led to the initial control of chemicals under the 1987 Montreal Protocol and to Amendments and Adjustments in the 1990s that added additional ODSs, agreed phase-outs, and accelerated those phase-outs.

• Among the multitude of topics they cover are air pollution, biodiversity, trade in endangered species, in dangerous chemicals and in genetically modified organisms (GMOs), waste shipments, desertification, disasters, management of water courses, and public access to environmental information.

• These include forest fires, floods, oil spills and chemical pollution of waterways.

• Fossil fuel combustion, industrial practices, and agricultural practices including the use of chemical fertilizers all increase atmospheric nitrous oxide.

• Whether the remarkable gains of the past 25 years will be repeated is uncertain: problems associated with intensifying production on land already in use (e.g., chemical and biological runoff, waterlogging and salinization of soils, soil erosion and compaction) are becoming increasingly evident.

• Climate models attempt to simulate the behaviour of the climate, in an attempt to understand the key physical, chemical and biological processes which govern climate.

• Moreover, it is only since the industrial revolution - and indeed especially in the last few decades - that the problems of pollution and of changes in the chemical composition of the atmosphere have arisen.

• A greenhouse gas causes direct radiative forcing through absorption and emission of radiation and may cause indirect radiative forcing through chemical interactions that influence other greenhouse gases or particles.