Sharing Date30 Sep, 2024
RCP scenarios are projections that forecast how atmospheric concentrations of carbon dioxide and other greenhouse gases will change in the coming century, based on different levels of greenhouse gas emissions. These scenarios have been created considering how various economic, social, energy, and technology policies may shape the future. The RCPs were originally named RCP 2.6, RCP 4.5, RCP 6, and RCP 8.5, with this naming based on the possible range of radiative forcing values in 2100. Radiative forcing expresses the change in energy flow in the atmosphere caused by natural or anthropogenic factors, measured in watts per square meter (W/m²)[3]. An increase in radiative forcing is simply regarded as a negative situation. The naming of the above-mentioned RCP models ranges from the best (i.e., the most stringent scenarios) to the worst (i.e., the least stringent scenarios).
The following details how these scenarios are determined and what variables they are based on:
- RCP 2.6: Represents the most optimistic path, where greenhouse gas emissions are rapidly and comprehensively reduced. It is anticipated that emissions will peak in the near future and then show a sharp decline. By the year 2100, the radiative forcing value is expected to stabilize at approximately 2.6 W/m². Therefore, it is projected that the global temperature increase can be kept below 2°C[4]
- RCP 4.5: This scenario involves a moderate level of emission reduction, where emissions are expected to peak around 2040 and then gradually decrease. The radiative forcing value is expected to stabilize at about 4.5 W/m² by 2100. According to this scenario, the global temperature increase is expected to be between 2°C and 3°C[5]
- RCP 6: In this scenario, which predicts a future where emission reductions are delayed, emissions are expected to peak around 2080 and then begin to decrease. By the year 2100, the radiative forcing value is expected to reach approximately 6 W/m². As a result, the global temperature increase is expected to be between 3°C and 4°C[6]
- RCP 8.5: The most pessimistic scenario reflects a situation where emissions continue to rise uncontrollably. By 2100, the radiative forcing value is expected to increase to approximately 8.5 W/m². Under this scenario, there is a likelihood that the global temperature increase will exceed 4°C[7]
Figure 1 CO2 Concentration in the Atmosphere According to RCP Scenarios
Figure 2 RCPs Overview[8]
- RCP scenarios form the basis of global climate models (GCMs), which are used to examine how climate systems will respond based on atmospheric greenhouse gas concentrations[9]. These models predict possible climate changes, such as temperature increases, sea level rise, and shifts in precipitation patterns. These predictions are crucial in shaping the national climate policies of countries around the world.
- RCP scenarios are important tools used by governments and international organizations when setting greenhouse gas emission reduction targets. Global agreements like the Paris Agreement aim to keep temperature increases below 2°C, considering the projections in RCP scenarios. Many countries use these scenarios to prepare their Nationally Determined Contributions (NDCs) and set their emission reduction goals accordingly.
- Different RCP scenarios are used to estimate the potential impacts of climate change in various sectors. Especially in sensitive sectors such as agriculture, energy, water management, and infrastructure, RCP scenarios provide strategic guidance on the risks that may be encountered in the future and the measures that need to be taken in response to these risks. For example, projections under RCP 4.5 and RCP 8.5 scenarios regarding declines in agricultural productivity and challenges in accessing water resources help develop climate change adaptation strategies in the relevant sectors[10]
- RCP scenarios also play a key role in assessing the economic risks posed by climate change. Investors, especially in long-term projects, must consider the risks of climate change. The potential economic costs under high-emission scenarios such as RCP 8.5 increase the shift toward green energy investments. Green financing and carbon markets present significant opportunities in sectors that develop strategies to reduce climate risks[11]
RCP scenarios serve to assess future risks related to climate change and form the basis of strategies developed to address these risks. The data obtained from scientific projections not only provide a roadmap for policymakers, business leaders, and international organizations globally but also serve as a foundation for strategic decisions taken to achieve sustainability goals. Governments and companies are expected to take these scenarios into account when building a low-carbon economy. Success in combating the effects of climate change will only be possible through strategic actions supported by scientific forecasts.
References:
1) The Intergovernmental Panel on Climate Change (IPCC). (2015). AR5 Synthesis Report. Available at: https://www.ipcc.ch/site/assets/uploads/2018/02/SYR_AR5_FINAL_full.pdf. Last accessed: September 2024.
2) Australian Climate Change Science Program. (2013). Representative Concentration Pathways (RCPs). Available at: https://www.cawcr.gov.au/projects/Climatechange/wp-content/uploads/2016/11/ACCSP_RCP.pdf. Last accessed: September 2024.
3) (2010). Explained: Radiative forcing. Available at: https://news.mit.edu/2010/explained-radforce-0309#:~:text=Thus%20radiative%20forcing%2C%20measured%20in,on%20changing%20the%20planet’s%20climate. Last accessed: September 2024.
4) Climate Watch. (n.d.). RCP 2.6. Available at: https://www.climatewatchdata.org/pathways/scenarios/198. Last accessed: September 2024.
5) Thomson, A. M., Calvin, K. V., Smith, S. J., Kyle, G. P., Volke, A., Patel, P., Delgado-Arias, S., Bond-Lamberty, B., Wise, M. A., Clarke, L. E., & Edmonds, J. A. (2011). RCP 4.5: A pathway for stabilization of radiative forcing by 2100. Climatic Change, 109(1–2), 77–94. Available at: https://doi.org/10.1007/s10584-011-0151-4. Last accessed: September 2024.
6) Climate Watch. (n.d.). RCP 6.0. Available at: https://www.climatewatchdata.org/pathways/scenarios/200. Last accessed: September 2024.
7) Climate Watch. (n.d.). RCP 8.5. Available at: https://www.climatewatchdata.org/pathways/scenarios/199. Last accessed: September 2024.
8) Coast Adapt. (2017). What are the RCPs? Available at: https://coastadapt.com.au/sites/default/files/infographics/15-117-NCCARFINFOGRAPHICS-01-UPLOADED-WEB%2827Feb%29.pdf. Last accessed: September 2024.
9) (n.d.). Concept of Modeling and History of Global Climate Models. Available at: https://www.mgm.gov.tr/iklim/iklim-degisikligi.aspx?s=kuresel. Last accessed: September 2024.
10) Wiebe, K., Lotze-Campen, H., Sands, R., Tabeau, A., van der Mensbrugghe, D., Biewald, A., Bodirsky, B., Islam, S., Kavallari, A., Mason-D’Croz, D., Müller, C., Popp, A., Robertson, R., Robinson, S., van Meijl, H., & Willenbockel, D. (2015). Climate change impacts on agriculture in 2050 under a range of plausible socioeconomic and emissions scenarios. Environmental Research Letters, 10(8), 085010. Available at: https://doi.org/10.1088/1748-9326/10/8/085010. Last accessed: September 2024.
11) (n.d.). Assessing the RCP / SSP Framework for Financial Decision Making. Available at: https://climateimpact.edhec.edu/assessing-rcp-ssp-framework-financial-decision-making. Last accessed: September 2024
