Radiative Forcing by Species and Uncertainties

8.5.1 Summary of Radiative Forcing by Species and Uncertainties
Table 8.5 has an overview of the RF agents considered here and each of them is given a confdence level for the change in RF over the Industrial Era to the present day. The confdence level is based on the evidence (robust, medium, and limited) and the agreement (high, medium, and low; see further description in Chapter 1). The confdence level of the forcing agents goes beyond the numerical values available in estimates and is an assessment for a particular forcing agent to have a real value within the estimated range. Some of the RF agents have robust evidence such as WMGHG with well documented increases based on high precision measurements as well as contrails as additional clouds which can be seen by direct observations. However, for some forcing agents the evidence is more limited regarding their existence such as aerosol in?uence on cloud cover. The consistency in the fndings for a particular forcing agent determines the evaluation of the evidence. A combination of different methods, for example, observations and modeling, and thus the understanding of the processes causing the
forcing is important for this evaluation. The agreement is a qualitative judgment of the difference between the various estimates for a particular RF agent. Figure 1.11 shows how the combined evidence and agreement results in fve levels for the confdence level.

Tabellen visar att kunskap saknas inom flera områden:

IPCC sida 694

Hans Iwan Bratt 2017-12-08 Tillgänglig för Alla Ändra text