RCP future emissions scenarios

On this page we describe the RCP future emissions scenarios as they have been implemented into GEOS-Chem.

RCP scenarios in GEOS-Chem v10-01 and higher versions

Overview

Christoph Keller wrote:

I have downloaded the files from scratch instead of converting the [existing] bpch-files back to netCDF. Interestingly, the ECCAD homepage has more detailed RCP files than the official RCP site, so I decided to use the ECCAD files.

I only downloaded the totals per species. For each of the four RCP scenarios, it would also be possible to get detailed sectorial information (9 sectors in total). If needed, we can easily download these files and update the HEMCO configuration file accordingly. I only did some cosmetic changes to some of the downloaded files, e.g. to convert units from kg/m2/s to kgC/m2/s. We could do this within HEMCO, but I think its cleaner this way. I also compressed all files.

Data Files

In GEOS-Chem v10-01 and newer versions, the RCP future scenario data files are read with the HEMCO emissions component. We have obtained new RCP data files (in COARDS-compliant netCDF format) for use with HEMCO. These new data files are contained in the HEMCO data directory tree. For detailed instructions on how to download these data files to your disk server, please see our Downloading the HEMCO data directories wiki post.

--Bob Y. 14:21, 27 February 2015 (EST)

Setting the HEMCO configuration file

Christoph Keller wrote:

I added the capability to linearly interpolate between time steps to HEMCO. This is really useful/important for the RCP scenarios where only few years are available. You can use the flag ‘I’ for the time cycle attribute to interpolate between time steps. Note that this will always interpolate linearly between two consecutive time steps. The interpolation frequency is determined by the update frequency provided in the HEMCO configuration file. For instance, the RCP netCDF files contain data for 2005, 2010, 2020, 2030, …, 2100. Using the following time stamps will update the emissions every year by linearly interpolate between the two closest years:

         RCP45_NO  ...   2005-2100/1/1/0  I ...

So if the simulation starts on July 1 2013, the data will be calculated as 0.7 * DATA_2010 + 0.3 * DATA_2020. As soon as the simulation enters 2014, the data is updated to 0.6 * DATA_2010 + 0.4 * DATA_2020. This is the default setting.

Now if you set:

         RCP45_NO  ...  2005-2100/1-12/1/0  I ... 

the data will be updated every month, again linearly interpolating between the two closest years. So in this case, the data for July 1 2013 would be calculated as 0.694 * DATA_2010 + 0.306 * DATA_2020, and as soon as the simulation enters August 2013, the data is updated to 0.693 * DATA_2010 + 0.307 * DATA_2020.

--Bob Y. 14:21, 27 February 2015 (EST)

Previous issues that are now resolved

Fix missing HCOOH factors for RCP in HEMCO_Config.rc

This update was included in v11-02f (approved 17 May 2018).

Sebastian Eastham wrote:

It looks like there’s a missing entry in the HEMCO_Config.rc RCP scenarios. Specifically, HCOOH emissions from all of the RCPs use scaling factors 57 and 58, but neither of those are defined. I’m guessing one of these is 0.25 (based on Chris Holmes’ original document describing the implementation of RCP emissions in GEOS-Chem, which stated that 25% of all acids are assumed to be HCOOH) but I wasn’t sure what the other factor might be.

Christoph Keller wrote:

I'm pretty sure that the two scale factors are 0.25 (fraction of HCOOH / total acids) and 0.779661, which converts the molecular weight of RCP acids (59 g/mol) to HCOOH (46 g/mol). So the two scale factor entries should be:

57 RCP_HCOOHfraction 0.25 - - - xy unitless 1
58 RCP_ACIDStoHCOOH 0.779661 - - - xy unitless 1

--Bob Yantosca (talk) 16:02, 17 May 2018 (UTC)

References

When using or displaying the dataset, the user is requested to indicate the corresponding citation:

1. Detlef P. van Vuuren & James A. Edmonds & Mikiko Kainuma & Keywan Riahi & John Weyant (2011), A special issue on the RCPs, Climatic Change., 109 (Special issue) : 1 - 4
2. RCP3PD Reference: van Vuuren, D., M. den Elzen, P. Lucas, B. Eickhout, B. Strengers, B. van Ruijven, S. Wonink, R. van Houdt (2007), Stabilizing greenhouse gas concentrations at low levels: an assessment of reduction strategies and costs, Climatic Change, 81(2): 119 - 159.
3. RCP4.5 Reference: Clarke, L., J. Edmonds, H. Jacoby, H. Pitcher, J. Reilly, R. Richels, 2007, Scenarios of Greenhouse Gas Emissions and Atmospheric Concentrations (Part A) and Review of Integrated Scenario Development and Application (Part B)., A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research : pp 154
4. RCP 6.0 Reference:: Fujino, J., Nair, R., Kainuma, M., Masui, T., Matsuoka, Y. (2006), Multi-gas Mitigation Analysis on Stabilization Scenarios Using Aim Global Model, Intergovernmental Panel on Climate Change, 132 pp. Multi-Greenhouse Gas Mitigation and Climate Policy issue, Special Issue (3): pp 343-354
5. RCP 8.5 Reference:: Keywan Riahi, Arnulf Grübler, and Nebojsa Nakicenovic, (2007), Scenarios of long-term socio-economic and environmental development under climate stabilization, Technological Forecasting and Social Change, 74(7): 887-935.

--Bob Y. 12:43, 27 February 2015 (EST)