You do get a slightly different slope in one experiment, the «1 % / yr» experiment, where only CO2 rises, and much more slowly than it has over the last few decades. (hubpages.com)
Different Slopes for Different Folks: Genetic Influences on Growth in Delinquent Peer Association and Delinquency During Adolescence. (cambridge.org)
Sawmill Family Resort in Morris, PA offering 12 different slopes with four trails and four black diamond runs. (genettihotel.com)