NATS 1840 Lecture Notes - Kyoto Protocol, Ice Core, Mahabharata
Document Summary
Science, technology and the environment (sc nats 1840a) . Even a natural variation could threaten our ability to sustain ourselves; If changes are unprecedented, then more reason to believe human activities are the cause. The study of past climate is called paleoclimatology. Ice cores: long cylinders of packed ice obtained by drilling vertically down using a hollow drill. Core samples extracted in 4-6m segments one core (vostok) is almost 4km long! As snow builds up, it becomes compressed and turns to solid ice. Each season is seen as a distinct layer in a core. A 2. 5 km long core represents a 400,000 year record of climate on earth it contains numerous proxies. Small gas bubbles are samples of past atmosphere; Ice core records are general regarded as reliable. Co2 has varied in range 200-300 ppm; Temperature has averaged 3 degrees colder than today; There have been three ice ages in past 160,000 years.