Since the creation of the United Nations Framework Convention on Climate Change (UNFCCC) in 1992, the nations of the world have been working together to create an international treaty to limit greenhouse gas emissions and prevent dangerous human interference with the Earth’s climate. Parties to the UNFCCC are poised to meet again for the 15th Conference of Parties (COP-15) in Copenhagen, Denmark in December 2009

As scientific understanding of the urgency of climate change increases, and as signs of climate change accumulate, scientists, citizens, and governments around the world have articulated goals that range from limiting warming to 1.5°C over pre-industrial temperatures (the Alliance of Small Island States) to 2°C (the G8 nations). Groups ranging from scientists to advocacy groups have called for the long-term goal of reducing atmospheric CO2 concentrations to 350 parts per million.

Within the UNFCCC negotiations, various parties have made proposals for reductions in their future CO2 emissions.

This leads to an obvious question: do the proposals ‘on the table’ add up to enough reduction of emissions to achieve stated goals for greenhouse gas concentration or temperature increase?

It is not a simple matter – for policy makers or concerned citizens – to add up these numerous (and changing) proposals to understand how much global greenhouse gas emissions will be reduced if they are implemented. And, even with a clear understanding of future emissions, the complex dynamics of the Earth’s climate system mean that without some sort of computer simulation modeling, it is not possible to know the long-term impacts on greenhouse gas concentrations and temperature for any suite of emissions reductions proposals.

We’ve created the C-ROADS simulator to address this challenge. C-ROADS adds up emissions reductions (for fossil fuel emissions, other GHG emissions, and land-use emissions) into a single global emissions trajectory. The model then accounts for the cycling of the gases through the biosphere and atmosphere and accounts for their impacts on the Earth’s mean temperature over time.

C-ROADS is used in many contexts – as a tool for teaching and for interactive exercises and as a decision support tool for policy makers (including some UNFCCC negotiators).

Our team also uses C-ROADS as the calculation engine behind the Climate Scoreboard. At regular intervals, we use C-ROADS to calculate the long-term climate impacts if proposals ‘on the table’ were to be fully implemented. We report the results in an embeddable widget we call the Climate Scoreboard. We also share the data behind the Scoreboard in graphics, slide-sets, and data tables.

I've heard about a widget. What's that for and how do I get it?

The Climate Scoreboard widget allows individuals and organizations who are following the progress of the global climate treaty negotiations to add a simple representation of the state of the global deal (C-ROADS projections of temperature increase in 2100) on their own websites. When proposals change and our team updates our analysis, the results shown on the embedded widget will automatically change. You can find it here.

In what form do you share the results?

We share our list of current proposals in a simple table and a spreadsheet that includes more documentation on sources and assumptions.

We post our analysis of the likely impacts of current proposals as graphs and as powerpoint slides. In addition, excel files with the model output are available.

We also share an embeddable widget that reports the temperature increase in 2100 (relative to pre-industrial temperatures) in a simple visual form. This can incorporated into webpages, blogs and other online forms and automatically updates when proposals within the climate negotiations change.

Who else has done similar calculations?

We are encouraged by the work of Climate Analytics out of Potsdam University and Ecofys, which are producing independent calculations similar to the ones we offer in the Climate Scoreboard.

How often are you updating the results?

We are updating the results shown on the Climate Scoreboard widget as soon as we learn of new proposals. The data, slide sets and graphics that we share are more time consuming to update, and so may lag the results shown on the Climate Scoreboard widget. When this is the case we carefully note which proposals are included in the Climate Scoreboard but not yet in the data, slide sets, and graphics.

Do the "1.5°-2.0°C" goals shown on the Climate Scoreboard and in the video refer to temperature increase in 2100?

When organizations like the G8 or the Small Island States describe their goals for limiting temperature increase they are likely describing a stabilization goal, where temperature would never exceed that level. Reporting 2100 temperature is only an approximation of that goal, because in most reduction scenarios, temperature does not stabilize until after 2100. In other words, to be sure to not exceed two degrees of temperature increase policy makers should aim somewhat under the 2° goal in 2100.

For the Climate Scoreboard, how did you determine the extent of the blue "uncertainty range" on the thermometer?

We analyzed the confidence ranges for the different scenarios in the IPCC’s “AR4” report, ranging from B1 to A1FI and calculated the range of temperatures across the suite models relative to the mean temperature change estimate. We estimated that the 90% confidence interval (which AR4 defines “likely” to mean), and show that range as the uncertainty in the Climate Scoreboard.

If there are uncertainty ranges, what is the meaning of the line in the middle of it?

The line in the middle is the “mean” value.

What are the sources for the "5 organizations with studies..." in the video about the Climate Scoreboard?

Worldwatch Institute — Low-Carbon Energy: a Roadmap (2008)

http://www.worldwatch.org/node/5945

http://www.worldwatch.org/programs/energy_climate

International Energy Agency — Energy Technology Perspective 2008 — Blue Scenario

http://www.iea.org/w/bookshop/add.aspx?id=353

Greenpeace International & European Renewable Energy Council — The Global Energy [R]evolution (2008)

http://www.energyblueprint.info/

Earth Policy Institute — Plan B 3.0 (2008)

http://www.earthpolicy.org/Books/PB3/data.htm

McKinsey & Company — Pathways to a Low-Carbon Economy v.2 (2009) — Green World scenario

http://www.mckinsey.com/clientservice/ccsi/pathways_low_carbon_economy.asp

What were the general assumptions of the studies by the "five organizations"?

Proposals for changing CO2 emissions only:

Worldwatch Institute’s Low-Carbon Energy Roadmap aims to cut current CO2 emission from fossil fuels in half by 2050, reducing emissions from 30 billion tons per year in 2007 to 15 billion tons per year in 2050.

The International Energy Agency proposes to cut current global CO2 emissions from fossil fuels to 50% (of 2005 levels) by 2050, reducing levels from 28 to 14 billion tons per year.

Greenpeace/EREC’s proposal aims to reduce global CO2 emissions by 50% from 1990 to 2050, reducing levels from 24 to 11 billion tons per year.

Earth Policy Institute’s proposal aims to cut global net CO2 emissions by 80% of 2006 levels by 2020.

Proposal for changing Co2 equivalent emissions:

McKinsey’s proposal aims to cut net global greenhouse gas emissions by 35% of 1990 levels by 2030.

How do you calculate the results?

We follow news reports, government statements and submissions to the UNFCCC and maintain a list of current proposals which we carefully document to show the sources we have used, and which we frequently update.

C-ROADS allows input emissions reductions targets for 12 countries (US, Japan, Russia, Canada, Australia, South Korea, China, India, Brazil, Mexico, South Africa, Indonesia) and 3 blocs of countries (EU, “other developed” and “other developing”). For the 12 countries with individual controls we adjust that country’s modeled emissions from a reference scenario (based on the IPCCs A1FI scenario, with allocations of emissions between countries based on IEAs World Outlook 2008).

The emissions from EU countries are changed as a bloc.

For those countries within the “other developed” or “other developing” countries that have made a proposal to reduce emissions, we weight the contributions based on that country’s contribution to the emissions of the full bloc, based on 2006 data from the International Energy Agency). In other words, each nation's proposals are properly scaled to their actual share of emissions within their bloc in 2006, the last year for which we have data.

What did you assume about "other" greenhouse gasses such as methane?

We assume that country proposals (e.g., “80% reduction below 1990 levels”) refers to all greenhouse gasses. So we apportion cuts across all the gasses in C-ROADS – CO₂, CH₄, N₂O, the F-gasses, etc. – and ensure that they add up to the appropriate reduction in CO₂e.

Why do you only report greenhouse gas concentrations and temperature?

Climate change obviously produces many more impacts than increases in the concentrations of greenhouse gases and changes in global mean temperature. For now our focus is on sharing these results as accurately, clearly and transparently as we can, in forms that others can use to project impacts on societies, ecosystems, and weather patterns. The ‘open innovation’ philosophy of our work leads our relatively small team to concentrate on what we do best, and work with others who can use our temperature output as input into their own tools that show changes with more spatial or geographical detail.

What makes "confirmed proposals" different from "potential proposals"?

“Confirmed proposals” are submissions from a country regarding its own emissions, national level legislation that has been approved and statements from national level government officials. If a proposal is given as a range, we count the low end of the range in confirmed proposals.

“Potential proposals” include legislation that is currently under consideration in a country, campaign promises of newly elected officials, and conditional proposals (cases where a country proposes a certain action if given financial support or if other countries take specified actions). We have also decided to count statements from think tanks with close ties to governments as potential proposals, if it seems those statements could reflect a ‘trial balloon’. If a proposal is given as a range, we count the upper end of the range in potential proposals.

More judgment is obviously required in determining potential proposals, but we think they are important as a leading indicator of what might be possible at any time.

There are many actions around the world that we DON’T count in confirmed or potential proposals simply because they are not linked to the UNFCCC process. For example, actions that are being taken by businesses to save money or to address climate change, actions of citizens, municipalities or state governments. This is not because we don’t think these actions are important. In fact, such actions represent the way that national governments will be able to fulfill their pledges. We are simply trying to stay focused on the question – how far has the global climate treaty come towards achieving its goals, and how much further does it have to go?

What assumptions and approximations do you make in this analysis?

We believe that any effort like ours, which is trying to simplify a very complicated real world system into a few simple indicators must always make approximations and assumptions. In doing so, we do our best to be aware of and make explicit as many of those assumptions as we can.

Assumptions about proposals:

We rely on proposals in the public record – if significant proposals are kept confidential and out of the public view, they aren’t included in our analysis. We assume the EU countries act as a bloc, and the countries of the ‘other developed’ and ‘other developing’ blocs in our model will maintain a constant share of emissions within their blocs. (See above for more detail.)
We assume that emissions stay constant after 2050, whereas in the real world, additional measures might be taken.
We assume that proposals can (and will) be fully implemented, without delay.
Some countries have made proposals for specific actions (rather than for emissions targets). If we don’t have a good estimate for the impact of those actions on emissions then we don’t include the action in our analysis. On the spreadsheet of current proposals we indicate whenever this is the case.
Not all countries specify whether their proposals refer to CO2 emissions or to all GHG emissions. If not specified, we assume the proposal refers to all greenhouse gas emissions. In addition, a few countries have made proposals specifically about carbon emissions, but in some cases, the structure of the model requires us to assume that they take proportional action on other greenhouse gases.

Assumptions inherent in C-ROADS

The C-ROADS “reference scenario” (often called “business as usual”) is based on the A1FI SRES scenario of the Intergovernmental Panel on Climate Change. That is a global scenario, so we made an additional assumption to allocate emissions to countries based on the IEA’s World Outlook 2008 report.
C-ROADS uses a climate sensitivity of 3 (that is 3°C of temperature increase for a doubling of CO2 concentration.)
There are positive feedback loops in the real climate system that are not modeled in the current version of C-ROADS. Additionally, C-ROADS is based upon and calibrated to the results of models from the IPCC’s Fourth Assessment Report. Recent science suggests that AR4 may underestimate the time-scale and magnitude of climate change. As a result, we believe that the Climate Scoreboard may well be presently a ‘best case’ interpretation of the long-term impacts of proposals on the table in the UNFCCC.
The current version of C-ROADS uses a very simplified representation of deforestation’s contribution to climate change, including a single global parameter for deforestation. For countries such as Brazil, Argentina, and Paraguay, which have made pledges to reduce deforestation, we make the simplifying assumption that the global deforestation rate is proportional to those countries’ share of global forested acres. For more information on C-ROADS, please consult the C-ROADS Reference Guide

What did you assume for emissions after the last commitment target given by a country"

For countries with proposals for emissions reductions, we assumed that emissions would stay flat at the level indicated by the latest proposal date. For example, if the proposal was for emissions to drop 80% of 1990 by 2050, the emissions would fall to that level and stay at that level until 2100. Several other assumptions could be argued for of course. Emissions could begin to rise again after the commitment date, or emissions could continue to fall at the same rate as they were leading up to the target year. We chose the steady emissions scenario because it is lies between the two extremes of these other assumptions. For countries with proposals that represent continued growth in emissions at a slower rate than in the reference scenario we assume that, after the target year emissions will resume the rate of growth indicated by the reference scenario.

What is the Low Emissions Path?

On our graphs and figures we offer a conceptual path for emissions reductions. It is a global 50% reduction in CO2 equivalent emissions by 2050. Because the scenarios we test assume constant emissions after the target year, we decide to apply the same logic to the low emissions pathway. It is important to note, however, that the low emissions pathway does not lead to stabilization of temperature beyond 2100.

How can I learn more about the C-ROADS simulator?

Visit http://www.climateinteractive.org/simulations/C-ROADS/overview.

Where can I learn more about the story of the Scoreboard?

Here.

Where can I see a table of all the proposals you included?

Here.

Where can I see the references for the proposals you included?

Here.

Where can I see results for climate impacts other than temperature?

Here.

Where can I see graphs of behavior of these indicators over time?

Here.

Are you giving this simulation capability to the negotiation parties?

Yes, we have an analyst version of the simulator that we are sharing with parties to the UNFCCC process – C-ROADS-CP for “Common Platform.” You can learn about it here.

Are you giving this simulation capability to educators or others?

Yes, we have a version for education, business, and other use that is free and available to anyone on the internet. You can learn about it here.

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