The Carbon Bathtub Metaphor

I came across the Carbon Bathtub metaphor on climate change in the December issue of National Geographic Magazine while waiting in a doctor’s office.  As I like analogies and visual representations of big ideas, I found this one a great representation of the complicated dynamics in our atmosphere.  As this representation shows:

It’s simple, really: As long as we pour CO2; into the atmosphere faster than nature drains it out, the planet warms. And that extra carbon takes a long time to drain out of the tub.


In a quick read you can review the above graphic and read a short narrative explaining The Carbon Bathtub in National Geographic Magazine, The Big Idea.

The Carbon Bathtub is a systems dynamics representation of Stocks and Flows.  Accordingly, just stabilizing carbon dioxide is insufficient given the constraint of the rate at which the tub drains. 

For a more in-depth explanation of social implications, see Understanding Public Complacency about Climate Change.  Or for a much lengthier academic version, see Understanding Public Complacency About Climate Change: Adults’ mental models of climate change violate conservation of matter.  Both are written by John D. Sterman and Linda Booth Sweeney.

EV Roadmap 2009 Conference Proceedings

EV Roadmap 2009 Proceedings

In two earlier posts I provided summaries of the recent EV RoadMap conference in Portland Oregon on November 9, 2009; both my own brief synopsis and another summary report written by Trip Hyde.  

Since the recently completed proceedings provides a much more comprehensive report, I’ve included the text below though I’d encourage a review of the EV RoadMap 2009 conference proceedings for additional detail. 

Read more

Zero Emission Tour Rolls Through Portland

As part of Nissan’s Zero Emission tour, the Leaf electric car rolled through Portland and was on display at the Oregon Museum of Science and Industry (OMSI) and finishes up at Washington Square Mall on December 23rd.  Through the magic of modern digital imagery, “virtual test drives” are being offered (no, I didn’t actually get to drive the Leaf near Oregon’s Mt. Hood).

Tour staff are on hand to field questions and answer in much greater detail than the Nissan website.  From firsthand observation I’d say the Leaf has a much different presence than all the images I’ve seen in print and on the web.   

Notwithstanding the electric powertrain technology, I think one of the coolest features of the Leaf EV is the ability to pre-heat or pre-cool your car through messages sent from your cell phone.  Although the fundamental reason is to conserve energy stored in the battery by using grid connected electricity (also known as shore power if you’re a boater) to power the car’s HVAC system thus taking the heating or cooling load off the batteries, this is a great feature for any car.  With this feature a driver has the ability to always get into a “climate comfortable” parked car with a simple command from their phone.

Besides such novel features, an electric car will have a much different user-experience than a gas car.  Change is in the air – I’d definitely recommend checking it out to learn more about electric car technology as we’ll be seeing more electric cars in the future.

Here is the full list of cities and dates to check out the car on tour: Read more

Portland Oregon Works to Develop Best Practices for Electric Vehicle Adoption

 In an earlier post I shared my brief reflection as a participant and facilitator in the recent “EV Roadmap: Preparing Oregon for the Introduction of Electric Vehicles.”   After reading this piece written by Trip Hyde and originally published in Gas 2.0, I felt this was a good summary of the event:

While many are suffering burnout from the overwhelming amount of EV discussion as of late, the conference hosted by Portland State University and Portland General Electric last month was different.

Called “EV Road Map: Preparing Oregon for the Introduction of Electric Vehicles,” the event was one of the first to set the stage for real rollout and testing of citywide electric vehicle adoption.

The conference brought together many of the area’s electric vehicle stakeholders to discuss and begin planning for EVs in the region. These stakeholders included OEMs such as Nissan, Toyota, and smart USA, as well as Portland General Electric, local business associations, the local university, many city and county leaders including the Mayor of Corvallis, OR, charging station providers, and fleet managers.

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Smart Grid Course being offered again at Portland State University

Once again Portland State University will be offering the ground-breaking course “Designing the Smart Grid for Sustainable Communities”  this Winter and Spring terms (2010) through the Executive Leadership Institute.  I was fortunate to have taken this two-term course series on the Smart Grid when it was first offered January – June of 2009 and I found it to be of immense value in learning about sustainability issues and the smart grid.  The Smart Grid has many different meanings and it is rapidly evolving; I found the course an excellent learning experience for future ventures.


This two-term course series examines a set of emerging concepts, technologies, and models of system planning and delivery for electricity that are expected to transform the nation’s century-old, centralized power grid into a climate and alternative-energy-friendly “Smart Grid.” The course series stresses a cross-disciplinary approach, deepening individual areas of expertise in the context of teamwork. Each quarter will build on progress from the previous quarter. It will include lectures, active learning strategies, individual and group projects, class presentations from guest speakers and seminar participants, field trips, and a closing conference. For detailed course information, please visit

Class Dates and Location:

Winter Term (January 12 – March 16, 2010) – Tuesdays, 7:00 pm – 9:40 pm

Spring Term (March 30 – May 8, 2010) – Tuesdays, 7:00 pm – 9:40 pm

This class is available for graduate credit or as non-credit professional development. In either case, you should register for both terms as the second term builds upon the material discussed in the first term.

For more information, visit, or register online.