Assessing the impact of your proposal or plan

The Impact Tab allows all proposal authors to estimate the greenhouse gas (GHG) reductions that would result from the action or collection of actions they propose.

You can reach out to the Climate CoLab Impact Assessment Fellows to support you in ensuring that your estimates are as accurate as possible and that they are consistent with the assumptions made in other proposals across the Climate CoLab platform.

The Impact tab ”” along with the 2015 global, regional, and sector contests ”” is part of a pilot test of a new approach to allow you to integrate individual ideas into larger action plans. If something isn’t working as you expected, or if you have comments or suggested changes, please contact the Climate CoLab team at This will help improve the contests in future years.


Using the Impact Tab

The Impact tab is different depending on the contest.  Click here if you are calculating the impact of a sectoral, regional, or global plan.

On the Impact tab, you can estimate how much your proposal will reduce GHG emissions, in sectors and regions around the world.

(1) To begin, select a sector and region.

Sectors include:     Regions include:
Energy supply
Emissions caused by the generation of all the electricity used by all sectors.  If a proposal suggests ways for a sector (e.g. buildings) to reduce its demand for electricity, the emission reductions will not be calculated under that sector but rather under the Energy supply sector.

Emissions generated from the fossil fuels used for heating commercial and residential buildings. Does not include emissions related to the consumption of electricity.

Emissions generated from fossil fuels used for personal and commercial travel, including, cars, airplanes, freight, and shipping. Does not include emissions related to the consumption of electricity.

Emissions generated from fossil fuels used for manufacturing, textiles, and other industrial activities. Does not include emissions related to the consumption of electricity.

Other sectors 
All emissions from agriculture, forestry and other land use (AFOLU) and waste management. Also includes the biological sequestration of GHG by plants (a "negative" emission). Does not include emissions related to the consumption of electricity.

United States


Developed countries in Europe, as defined by the Organisation for Economic Co”‘operation and Development (OECD)



Other Developed Countries
For a full list of countries in this region, click here.

Other Developing Countries
For a full list of countries in this region, click here.


(2) The business as usual (BAU) emission scenario will appear for that region and sector, for each decade from 2020 to 2050.

(3) Estimate the percentage by which emissions will be reduced relative to the BAU scenario for this region and sector.  Enter the estimates that would be true if the proposal were fully successful and all possible users used it.

For example, if your proposal would eliminate 10% of all the emissions caused by China's transportation sector if it were fully adopted in a given year, you would enter 10 for that year. 

Note that the reductions in different years might be different, if, for instance, the technology being used is improving over time. 

Note that many proposals may change emissions in multiple sectors or regions.  For instance, a proposal to use more electric cars would reduce emissions in the transportation sector, but it would increase emissions in the energy supply sector unless it also included ways of generating electricity with fewer emissions.

Note that these reduction numbers could, in some cases, be negative.  For instance, a proposal to increase the use of electric cars would reduce emissions in the transportation sector, but depending on how the electricity is generated, it might increase emissions from the power sector.  In this case, the “emissions reductions”? in the power sector might be negative (meaning the emissions would increase).

(4) Estimate the percentage of how rapidly your proposal will be adopted. Enter reasonable estimates for the percentage of all possible users who would actually adopt your proposal in different years.

For example, if you predict that 10% of the possible users would adopt your proposal in 2020, and 90% would adopt it by 2030, then you would enter 10 for 2020 and 90 for 2030. 

(5) Click save and your proposal’s greenhouse gas emission reductions will be calculated per decade.  The top table will show a summary of the GHG emissions reductions from 2020 to 2050 for all sectors and regions you submitted.



Business As Usual Scenario

A “business-as-usual”? emissions scenario shows the GHG emissions that would result "if future development trends follow those of the past and no changes in policies will take place" (IPCC 2014).  This offers a frame of reference to proposal authors and others who are looking to understand the climate impacts of an idea or plan.

You calculate your proposal's impact by calculating the reductions that would occur relative to BAU for that region and sector.

For a detailed account of how BAU scenarios were calculated, please click here for the report.



I don’t agree with your models/categories/estimates.  How can I let you know?
Even with unlimited time and resources, it would be impossible to make these estimates completely accurate.  As George Box says, “All models are wrong, but some are useful.”? [2]

This year is our first large-scale pilot test of a method for letting very large numbers of people participate in estimating the emission impacts of lots of different climate-related actions.  Our goal this year is to make estimates that are better than nothing and good enough to be useful.  We hope that, over time, the Climate CoLab community will be able to make these estimates better and better.  But we also hope that the community won’t waste time making them more precise than is needed for making the major decisions our society needs to make.

If you have suggestions for how to improve any aspect of the methods and models used in the Climate CoLab, please email us at

Why these regions?
The United States, Europe, China, and India are the world's highest GHG -emitting regions, and so this pilot study has selected to highlight these four specific regions.  To ensure that ideas are being generated for other countries, and so that global plans also incorporate plans from other countries, the two regions "other developing countries" and "other developed countries" were created. Please note that the Europe contest refers to developed European countries. We use the Organization for Economic Co-operation and Development’s (OECD) definitions of developed and developing countries.  To see specific definitions of these regions, please visit the region's contest resources page, linked in the text above. 

Why these sectors?
Our data sets primarily come from the U.S. Energy Information Administration (EIA).  This resource, as well as many others, highlights these sectors as critical energy consumers, and therefore sources of greenhouse gas emissions: energy supply, buildings, transportation, and industry.  Waste management and land use (including agriculture, forestry and other land use) are categorized under Other.

Where does the "business as usual" data come from?
The main data sources for this work are the 2013 energy consumption projections of the International Energy Outlook of the Energy Information Administration (EIA). The EIA energy data is supplemented by the agricultural data from the FAOSTAT database of the Food and Agriculture Organization of the United Nations. Waste and any other emissions not directly accounted for in the above two databases are scaled based on the historical values of the data bank generated by the United Nations Framework Convention on Climate Change (UNFCCC).  For a detailed account of how BAU scenarios were calculated, please click here for the report.

What calculations and assumptions do the Impact Assessment Fellows use?
To access an overview of their methodology, please click here.

What about proposals that suggest ways we can adapt to the impacts of climate change?
As a first step in this pilot study, the impact analysis focuses on mitigation, or, ways to reduce greenhouse gas emissions.  In the future, we hope to be able to include cost impacts and other non-emission impacts.

I entered a proposal in the Transportation sector contest.  Why can I select a different sector in the Impact tab?
A proposal may have an impact in more than one sector.  We hope authors and Impact Assessment Fellows can estimate a proposal's impact on all the sectors it affects.  Here are two examples:

What does GtCO2e mean?  

GtCO2e stands for gigaton of carbon dioxide equivalent.  Carbon dioxide equivalent is a measure used to compare the emissions from various greenhouse gases based upon their global warming potential.  For example, the global warming potential for methane over 100 years is 21.  This means that emissions of one million metric tons of methane is equivalent to emissions of 21 million metric tons of carbon dioxide.[3]



[2] Box, G. E. P., and Draper, N. R., (1987), Empirical Model Building and Response Surfaces, John Wiley & Sons, New York, NY, p. 424
Organization for Economic Co-Operation and Development's (OECD) Glossary of Statistical Terms