RCP stands for ‘Representative Concentration Pathway”. To understand how our climate may change in future, we need to preduct how we will behave. For example, will we continue to burn fossil fuels at an ever-increaseing rate, or will we shift towards renewable energy? The RCPs try to capture these future trends. They make predictions of how concentrations of greenhouse gases in the atmosphere will change in future as a result of human activities. The four RCPs range from very high (RCP8.5) through to very low (RCP2.6) future concentrations. The numerical values of the RCPs (2.6, 4.5, 6.0 and 8.5) refer to the concentrations in 2100.