Weart preface and ch. 1

How do scientists reach reliable conclusions? (p. viii)

• about something as impossibly complicated as climate
• that involves scientists from very different disciplines

• he gathered more global data than anyone had before (as a hobby)
  
• he was a steam engineer and blamed carbon dioxide from burning coal

that the atmosphere keeps in heat with carbon dioxide playing the key role had been shown in the 19th century

• water vapor also holds in heat, which means if the earth gets warmer more heat will be held in, while if it gets cooler more heat will escape--instead of returning to balance any fluctuation is reinforced
• carbon dioxide levels can give that a push
• Svante Arrhenius had argued for carbon dioxide regulation temperature in 1896
• but scientists thought they had disproved it--excess would just be absorbed by the oceans

Scientists at the time tended to see nature as stable

• at the time, scientists believed in the balance of nature and assumed that humans could not possibly upset that
• Very important: scientists no longer believe that nature is inherently stable
• climate was the average of weather and by definition assumed to stay the same
• the interesting question was what caused the ice ages
• one theory that the sunspot cycle causes climate variation didn't test out
• scientists say the world keeps changing, it doesn't stay the same