METR 174: Climate Capstone Project (San Jose State University)

    New Information for Green Roofs: Precipitation Rates for Select U.S. Cities     

Introducing Green Roofs



Green roofs are a great way to be eco-friendly! They support wildlife, provide a cooling effect on temperatures in that location, and control storm water runoff to prevent flooding. So why don't we see green roofs everywhere?





Image from: https://www.youtube.com/watch?v=HdEzPYIkRTM





Unfortunately, even these benefits involve expenses that come with maintaining a green roof. So, if someone is willing to invest a lot of money in this product, it should last as long as possible, right?

Well, one sure-fire way to ensure it does is to make sure plants and soil are suitable for the environment it thrives in. For example: knowledge of precipitation amounts expected in the coming years can help green roof companies guide customers to the best options for their location. If plants and soil are compatible with the weather conditions, they will last longer giving people more incentive to invest!




Results



For my Climate Change Solutions class, I collaborated with LiveRoof Hybrid Green Roofs and collected precipitation data for 8 cities in America:






Figure 1: Multimodel averages of HadGEM2-ES, CNRM-CM5, CCSM4, and CESM1-CAM5. All 4 were dervied from CMIP5 data projections.



Figure 1 is a comparison of RCP 4.5 which represents a scenario of CO2 that eventually declines, and RCP 8.5, a scenario it never stops increasing. Yet, the above data shows small differences between the two cases, which only happens to cities around 2099, and their standard deviations (shown as the grey areas) gets higher for cities with more sporadic precipitation.






Figure 2: Seasonal multi-model averages for each city.



Figure 2 can be used to view seasonal model averages over time. A linear regression (trend line test) was performed as well, but very few of the trends were statistically significant.


Lastly, an ensemble model mean was used, which takes the averages of all model runs rather than the actual models. This was done individual for all 8 cities, but none of the trends were statistically significant. If you are still interested in viewing the results, please click on either image below to enlarge it.



Figures 3 and 4: Ensemble means of model runs for each city.




Conclusions



While there was a lot of trend uncertainty in the results, there is still liable information available to my green roof company of interest. They can use the patterns from each regional city to determine which plants and soil to use. To see the listings of avaiable options offered by LiveRoof Hybrid Green Roofs, click here.

Also, to see what my poster on the subject looks like, feel free to view it at this link:



Link to Poster