Online Emission Scenarios
When running MAGICC6 via live.magicc.org, you can select a number of emission scenarios. Here, we provide a short description of those, ordered by their (often somewhat cryptic) name.
The RCP scenarios are the newest set of scenarios that are used for intercomparison purposes in the global climate science community. The four RCP scenarios are:
- RCP3-PD (which as well goes by the name RCP2.6): This scenario is a strong mitigation scenario. Global emissions peak before 2020 and roughly reduce to halved global emission levels by 2050. This scenario has the best chance of, for example, staying below 2C global warming. None of the other scenarios has a reasonable chance of doing that. The name "PD" results from Peak & Decline, because the radiative under this scenario is likely to peak and then decline. Substantial net negative CO2 emissions are for example implied after the 2070s.
- RCP45: This is a medium-low pathway. This scenario roughly results in a CO2 concentrations of 550ppm by the end of the century and a forcing of approximately 4.5 W/m2. It is comparable to the former SRES B1 scenario, which was the lowest of the 6 Illustrative SRES Marker scenarios used previously in IPCC (see below).
- RCP60: This scenario can be considered a medium-high pathway. This scenario has initially (in the first two, three decades of the 21st century) rather low emissions, but then increases and stabilizes at around 6 W/m2 by the time of 2150.
- RCP85: This is one of the highest emission scenarios around. It implies CO2 concentrations of approximately 2000 ppm by 2250. The opposite of any mitigation scenario, rather a "burn-coal-as-much-as-you-can" world, and likely not a very pleasant world in terms of the climate impacts.
For more information: See the special issue of Climatic Change: van Vuuren, D., J. Edmonds, M. Kainuma, K. Riahi, A. Thomson, K. Hibbard, G. Hurtt, T. Kram, V. Krey, J.-F. Lamarque, T. Masui, M. Meinshausen, N. Nakicenovic, S. Smith and S. Rose (2011). "The representative concentration pathways: an overview." Climatic Change 109(1): 5-31, DOI:10.1007/s10584-011-0148-z, freely available online
These SRES scenarios were the standard scenarios in climate system science for more than a decade. They are still in use and a vast body of literature anchors their results onto one of these 6 Illustrative Marker scenarios.
To be continued.