Checking Dust to Dust’s Assumptions about the Prius and the Hummer: Fact-checking using the GREET life cycle model underlines the deep divide between the Dust to Dust study and all previous scientific work

The Rocky Mountain Institute (RMI) conducted a fact-check of a report by CNW Research/Marketing titled 'Dust to Dust,' which claimed the Toyota Prius has a greater environmental impact than the Hummer H3 SUV. Using the GREET life cycle model developed by Argonne National Laboratories, RMI found that the Prius consistently has a lower environmental impact in terms of greenhouse gas emissions and energy consumption, even when manipulating variables to favor the Hummer.

• RMI's analysis using the GREET model contradicts the 'Dust to Dust' report's claim that the Prius has a greater environmental impact than the Hummer H3. RMI found that the Prius maintains a lower environmental impact even when the model is manipulated to favor the Hummer using some of CNW's controversial assumptions.
• The Prius emits fewer greenhouse gases than the Hummer across all lifecycle stages if assembly energy requirements are equal. This result persists even if the Prius's assembly energy is tripled, or if the entire vehicle cycle—including mining, manufacture, painting, and assembly—is tripled.
• The Hummer's primary environmental impact is driven by its poor fuel economy, which causes it to produce significantly more greenhouse gas emissions during the driving phase than at any other point in its lifecycle.
• Testing CNW's specific lifespan assumptions (207,000 miles for the Hummer and 109,000 miles for the Prius) showed that while per-mile emissions for the two vehicles begin to converge, the Prius still performs better. Furthermore, these assumptions cause total lifetime energy and greenhouse-gas emissions to diverge, making the Hummer appear even worse.

APA

Hauenstein, H., & Schewel, L. (n.d.). Checking Dust to Dust’s Assumptions about the Prius and the Hummer: Fact-checking using the GREET life cycle model underlines the deep divide between the Dust to Dust study and all previous scientific work. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_T07-01_DustToDust.pdf

Chicago

Hauenstein, Heidi, and Laura Schewel. Checking Dust to Dust’s Assumptions about the Prius and the Hummer: Fact-checking using the GREET life cycle model underlines the deep divide between the Dust to Dust study and all previous scientific work. RMI, n.d. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_T07-01_DustToDust.pdf.

Wikipedia

{{cite report |last1=Hauenstein |first1=Heidi |last2=Schewel |first2=Laura |title=Checking Dust to Dust’s Assumptions about the Prius and the Hummer: Fact-checking using the GREET life cycle model underlines the deep divide between the Dust to Dust study and all previous scientific work |publisher=RMI |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_T07-01_DustToDust.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{hauensteinndchecking, author = {Hauenstein, Heidi and Schewel, Laura}, title = {{Checking Dust to Dust’s Assumptions about the Prius and the Hummer: Fact-checking using the GREET life cycle model underlines the deep divide between the Dust to Dust study and all previous scientific work}}, institution = {RMI}, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_T07-01_DustToDust.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }