Publications by authors named "Ibraheem Nuaaman"
Jacobson argues that our statement that "many climate models may overestimate warming by BC" has not been demonstrated. Jacobson challenges our results on the basis that we have misinterpreted some model results, omitted optical focusing under high relative humidity conditions and by involatile components, and because our measurements consist of only two locations over short atmospheric time periods. We address each of these arguments, acknowledging important issues and clarifying some misconceptions, and stand by our observations.
View Article and Find Full Text PDFAtmospheric black carbon (BC) warms Earth's climate, and its reduction has been targeted for near-term climate change mitigation. Models that include forcing by BC assume internal mixing with non-BC aerosol components that enhance BC absorption, often by a factor of ~2; such model estimates have yet to be clearly validated through atmospheric observations. Here, direct in situ measurements of BC absorption enhancements (E(abs)) and mixing state are reported for two California regions.
View Article and Find Full Text PDFArticle Synopsis
- A study measured gas and particulate emissions from a large container ship as it switched from high-sulfur to low-sulfur fuel in California's regulated coastal waters.
- The findings showed over a 90% reduction in emissions of sulfur dioxide, particulate matter, and other pollutants, with significant decreases also observed in particulate organic matter and black carbon.
- The results highlight the effectiveness of California's fuel quality regulations and vessel speed reduction programs, demonstrating their potential positive impact on health and climate by significantly lowering harmful emissions.