Narrator: This is Science Today. One of the biggest challenges for climatologists today is to accurately detect if climate changes are caused naturally or unnaturally. Physicist Michael Wehner of the Lawrence Livermore National Laboratory says scientists have to decipher which is which.
Wehner: What changes in the atmosphere are due to natural variability - natural causes like changes in deep ocean circulation and what changes are due to the fact that there's a lot more carbon dioxide or a lot more sulfur aerosols in the atmosphere.
Narrator: Wehner is working on a atmospheric model through a computer program which simulates properties of the atmosphere.
Wehner: And the question is, can we make statements about how variable the model is compared to the real atmosphere. If the model shows lots of variabilities internally, the implications for predictability are that prediction may be low.
Narrator: So getting these computer models to accurately represent variations between one year and the next is part of the challenge. For Science Today, I'm Larissa Branin.