Pulofesa Ashley Broadbent ndi Matei Georgescu a ASU's School of Geographical Sciences and Urban Planning adagwiritsa ntchito zida zamakono zowonetsera momwe zinthu zitatu zazikuluzikulu zingakhudzire kuwonekera kwa anthu ku kutentha kwakukulu kuyambira kuchiyambi kwa zaka za zana lino mpaka kumapeto kwake.