The emission of dust and particles could have covered the entire surface of Earth for several years, possibly a decade, creating a harsh environment for living things. Production of carbon dioxide caused by the destruction of carbonate rocks would have led to a sudden greenhouse effect. For over a decade or longer, sunlight would have been blocked from reaching the surface of Earth by the dust particles in the atmosphere, cooling the surface dramatically. Photosynthesis by plants would also have been interrupted, affecting the entire food chain. A model of the event developed by Lomax et al (2001) suggests that net primary productivity rates may have increased to higher than pre-impact levels over the long term because of the high carbon dioxide concentrations.
