An excerpt from Robert Frost’s ‘The Road Not Taken’

With just a few months to go before the nations of the world meet in Copenhagen to decide the future of the Earth’s atmosphere, behind the scenes negotiations are taking place at a furious pace.  Each nation has a choice to make, as if standing where Robert Frost once did, at a fork in the road, pondering whether to go right or left.

Compared to the intransigence before and during the Kyoto talks back in 2005, current climate change discussions have taken a central place in diplomacy between nations, with the US finally taking a leadership position.  But when one nation says something like ‘we will not reduce our GHG emissions as they are smaller per capita than in developed countries and our impact on temperature rises or sea level will be very small’ (a paraphrase of the recent argument from India), can other nations seeking more action respond to this nation with a quantitative prediction of the impact of its chosen policy?  Or if another nation says, ‘I will commit to a 50% GHG reduction relative to 2010 by 2050, but will not start reductions before 2025’ can the impact of that delay be calculated?  If it could, it would certainly reduce doubters and build support for necessary actions.

Today, thanks to C-ROADS (Climate-Rapid Overview and Decision Support Simulator), tools have been made available to help generate that support.   The C-ROADS simulator was first presented in Copenhagen by Dr. Elizabeth Sawin in March 2009 at the ‘Climate Change-Global Risks, Challenges, and Decisions Conference’.  The simulation was developed by scientists at Sustainability Institute, Ventana Systems and MIT (authors and organizations listed at the end of this article) with the express purpose of enabling decision makers to evaluate specific emission reduction plans.  Professor William Moomaw at Tufts University, a coauthor of the 2001 IPCC report and a well known climatologist told B-GC that C-ROADs ‘has been peer reviewed, that it fits with all past models and events and, in the end, the model projections are a bit scary.’

The model (available at ClimateInteractive.org) is described by its authors as a ‘dynamic nonlinear simulator’ and includes such factors as the ‘carbon cycle, radiative forcing, global mean surface temperatures and sea level change’.  The model is made useful as a negotiating tool by taking into account the emissions history and policies from up to 15 blocs or regions of the world, of which some examples would be the US, Europe, China, India, Russia and Eastern Europe and Africa.  Those policies are then incorporated into the model as inputs so that the impact on temperature and sea levels can be forecasted.   According to Andrew Jones at the Sustainability Institute (SI), one of the models developers, the U.S. State Department has used C-ROADS to analyze the impact of different countries’ policies as leverage in negotiations with other countries.  Jones is planning on presenting C-ROADS model results specific to Chinese policy analysis during a trip to China this September.

The best way to understand the model’s capabilities and its climate change predictions is to look at specific examples.  The baseline prediction is called ‘Business As Usual’ or BAU.  The BAU is consistent with the national policies and trends in place when the IPCC report was written in 2007.  BAU conditions are similar to the assumptions used in the IPCC A1F1 scenario projections that forecasted an increase in global temperatures of between 2.4 and 6.4 degrees C relative to pre-industrial conditions.

Figure 1: Shows C-ROADS projections for Business As Usual conditions

As shown in Figure 1, with BAU conditions, the current annual rate of emitting 10 billion tons of carbon per year (equivalent to 36.7 Billion tons of carbon dioxide) into our atmosphere, or about 2 ppm/year, rises to over 30 Billion tons of carbon per year by 2100, when carbon dioxide levels in the atmosphere will be increasing by a full 6 ppm each year.  The impact is to bring total atmospheric CO2 from the current 390 ppm to about 900 ppm by 2100.  In total, the simulation predicts an increase of about 4.7 degrees C over pre-industrial levels and a sea level rise of just under 3 ft.  In other words, if the people of the earth don’t change their ways, we will live in a world far warmer than it has been for the last 650,000 years (time period for which data is available) with an atmosphere and oceans far different than anything man has experienced before.

C-ROADS has also completed the calculation for a range of policies to reduce greenhouse gas emissions.  The big finding is that only very dramatic changes in our practices will enable us to avoid a much warmer planet by 2100.  Consider the C-ROADS calculated predictions based on March 2009 proposals for emission reductions.  This includes achievement of Obama’s goals of 80% reduction in greenhouse gas emissions below 1990 levels by 2050 in the US and the achievement of similar goals for Europe.  But without a commitment from China, it leaves BAU conditions for that major GHG producer.  For India it is assumed that BAU rates prevail until 2035 and then per capita emissions are fixed going forward.

Despite these assumed major improvements for much of the developed world predicted 2100 conditions result in only slight improvements relative to BAU.

Figure 2: C-ROADS projections for March 2009 emission reduction proposals.

As you can see in Figure 2 significant reduction in emissions from most of the developed world is not enough to keep the earth’s atmosphere in a zone hospitable for human life.  By the end of the century, net CO2 emissions are still rising about 4 ppm each year, the CO2 level in the atmosphere is 750 ppm, or about 2.7 times higher than pre-industrial levels, the temperature rise is still about 4 degrees C (or 7 degrees Farenheit) and sea level is still higher than pre-industrial levels by 2.6 feet.

Assuming all the nations of the earth agree to drop anthropogenic greenhouse gas emissions to 80% of 1990 levels by 2050 at a 6% reduction rate per year from 2010 as well as a 90% reduction in land use emissions, C-ROADs then projects a temperature rise of just over 2 degrees C and a sea level up by nearly 2 feet.   The 2 degree mark is often taken as a maximum acceptable temperature rise stemming from past IPCC meeting discussions (though that number was likely politically developed and has no scientific basis).

Figure 3: C-ROADS projections based on 80% of 1990 GHG emissions by 2050

Only when C-ROADS assumes policies that take down emissions 95% from 1990 levels by 2020, a more dramatic drop than any world political figure has endorsed, does the temperature rise stay just below 2 degrees C.  These are the projections of C-ROADS, and as difficult to accept as they are, the model likely underestimates temperature increases.  That is because the model has not included the effects of methane release by the melting permafrost, because IPCC did not include it and models have not been sufficiently developed to achieve scientific acceptance.  However, though the phenomena is not sufficiently well understood to model, the effect is real.  Virulent greenhouse gases will be released when the permafrost melts and according to SI’s Andrew Jones, it is a ‘huge issue but a tipping point that cannot be modeled’.

To interactively see the effects – move the slider  below -

All the nations of the earth, indeed all people on the earth, have a decision to make.  Do we stay on our current path, business as usual, or do we put our foot on the brakes and make a hard right towards major greenhouse gas reductions and aforestation?  One thing is clear: Robert Frost had it right.  The response will make all the difference!

(Note:  For a brief overview of Climate Change basics, Read The Climate Change Driver on B-GC)

Authors of the C-ROADS report:  Current Emissions Reductions Proposals in the Lead-up to COP-15 are likely to be insufficient to stabilize atmospheric CO2 levels:  Using C-ROADS – a simple computer simulation of climate change-to support long – term climate policy development, presented at the ‘Climate Change-Global Risks, Challenges and Decisions Conference, University of Copenhagen, March 10, 2009.  The paper is available at ClimateInteractive.org.

Authors:
Elizabeth R. Sawin, Sustainability Institute
Andrew Jones, Sustainability Institute
Tom Fiddaman, Ventana Systems
Lori S. Siegel, Sustainability Institute
Diana Wright, Sustainability Institute
Travis Franck, MIT
Andreas Barkman, European Environment Agency
Tom Cummings, the Hague
Felicitas von Peter, Forum for Active Philanthropy
Jacqueline McGlade, European Environment Agency
Robert W. Correll, The H. John Heinz Center for Science, Economics and the Environment, Washington, DC
John Sterman, MIT

If you enjoyed this article, please consider asking your company to become a Partner of the B-Green Collaborative. Partnerships are a necessary support mechanism for the work we do and an inexpensive but effective marketing medium for the Partner. Thank you for visiting and for your support.