Project Carbon and Resource Footprint Tool: The Coolclimate Project


Many U.S. cities are tak­ing steps to grow urban cen­ters in an attempt to reduce green­house gas emis­sions. But a chal­lenge is the sig­nif­i­cant car­bon foot­print of spa­cious sub­ur­ban liv­ing, which in many areas, may be can­celling out these efforts.  The report, appear­ing in the ACS jour­nal Envi­ron­men­tal Sci­ence & Tech­nol­o­gy, found that about half of the country’s house­hold car­bon foot­print come from peo­ple liv­ing in the sub­urbs, essen­tial­ly can­celling out the ben­e­fits of low car­bon foot­print cen­tral cities.


Christo­pher Jones and Daniel Kam­men point out that U.S. house­holds though they only com­prise 4.3 per­cent of the glob­al pop­u­la­tion, are respon­si­ble for about 20 per­cent of annu­al world­wide green­house gas emis­sions, which are dri­ving cli­mate change. In response, many gov­er­nors and may­ors across the coun­try have pledged to reduce their states’ and cities’ emis­sions. But more infor­ma­tion on the size and com­po­si­tion of house­hold car­bon foot­print is need­ed to inform poli­cies to make these reduc­tions hap­pen. A few stud­ies have helped fill in some gaps, but they’re most­ly small in scale and not broad­ly applic­a­ble. Kam­men and Jones set out to paint a big­ger picture.


The authors built an ana­lyt­ic mod­el using nation­al sur­vey data to esti­mate aver­age house­hold car­bon foot­prints for over 30,000 zip codes and 10,000 cities and towns in all fifty U.S. states. Their tech­nique inte­grates a wide range of sec­tors, includ­ing trans­porta­tion, house­hold ener­gy use and con­sump­tion of food, goods and ser­vices. The researchers found a num­ber of sur­pris­ing nuances in their analy­sis. For exam­ple, some stud­ies have shown that more pop­u­la­tion-dense areas have low­er emis­sions. But Jones and Kam­men found that pop­u­la­tion-dense sub­urbs have sig­nif­i­cant­ly high­er car­bon foot­prints on aver­age than low­er den­si­ty sub­urbs, and there is a huge range across cities.


As a result of large spa­tial dif­fer­ences in house­hold car­bon foot­prints they con­clude that “an entire­ly new approach of high­ly tai­lored, com­mu­ni­ty-scale car­bon man­age­ment is urgent­ly need­ed.”  One approach is to devel­op com­mu­ni­ca­tion and esti­ma­tion tools for wide­spread use, which the authors have devel­oped and imple­ment­ed for pub­lic use at http://​cool​cli​mate​.berke​ley​.edu/​m​aps and http://​cool​cli​mate​.berke​ley​.edu/​c​a​r​bon cal­cu­la­tor


The authors acknowl­edge fund­ing from the Cal­i­for­nia Air Resources Board and the Nation­al Sci­ence Foun­da­tion (grants to D. Kam­men). Pro­fes­sor Kam­men found­ed and directs the Renew­able and Appro­pri­ate Ener­gy Lab­o­ra­to­ry where this work was con­duct­ed. Christo­pher Jones is a doc­tor­al stu­dent advised by Pro­fes­sor Kammen.