2012 Trip: Climate Change Lecture

Professor Steve Gaines is the University of California Santa Barbara dean of the Donald Bren School of Environmental Science & Management.  He is also a marine biologist  and AAAS fellow.  He gave an excellent lecture on climate change from an interesting perspective.  (outlined below)

WHY is climate science such a difficult subject to communicate about?

• Why is it difficult to understand?
• Why so much controversy?
• Teaching opportunity?

Many things affect the climate....   (and it's hard to communicate the complexities of all of these to the public)

1. Sun's output 
2. Earth's orbit (mainly eccentricity) 
3. Drifting continents (can affect ocean current patterns and consequently heat distribution)
4. Volcanic eruptions (sulfur compounds have a net cooling effect)
5. Greenhouse gases (CO2, CH4, H2O, N2O, etc.)

Only 1 degree C increase since Industrial Revolution, 2 - 5 degrees by 2100?  (is that so bad?)

• If another 1degree rise, how far would you have to move to maintain life in your favorite climate?  ~200km?  Now, what if it rises by 2 - 5 degrees C?
• One of the most extreme ice age events was only 5 degrees C colder - you see how this can make a big difference.

The time period on a graph matters.  

• Scientists talk climate - most people feel and think weather.    There is a big difference.
• Cherry-picking data is tempting when you have confirmation bias.

How do scientists determine temp/CO2 values over the last 800,000 years? (complex data to interpret for the general public)

• ice cores (oxygen isotope ratios for temp., CO2 levels with isotope signature)
• tree rings
• isotopes in rocks containing plant fossils
• ocean sediments

*Many uncomfortable with any uncertainty on these, but for time periods where it is possible to compare and overlap these proxy data, they do fall in line - no wild anomalies.

Most future projections of events are analyzed using MODELS.  Some people not comfortable with that.

• The graph of six different groups' modelling data for temp. projections are different based on assumptions that are different about variables that will impact temperature.
• Global average temp. since the 2007 IPCC report  has increased faster than the most extreme projections in the report.

Uncertainty in the past and in the future.

• Projections in science almost always involve some uncertainty.  
• Many of us are uncomfortable with uncertainty, especially if personal action is required in the face of it.