Context: The last time I checked my carbon budget , I came in at a fifth of the national average . I rarely fly , even when booked to address faraway audiences about my personal obsession , climate change - a subject I \' ve covered in three books . Whenever the word " nuclear " comes up at my talks , a shudder runs through the room . Because everyone knows that real environmentalists loathe nuclear power .
Question: why did he come in at a fifth of the national average for his carbon budget ?
Option 0: he wants to stop being an environmentalist
Option 1: he believes carbon contains the cure for the environments issues
Option 2: he spends carefully because he knows about carbon 's effects on the environment
Option 3: None of the above choices .
Answer: 2