[{"data":1,"prerenderedAt":87},["ShallowReactive",2],{"blog-\u002Fblog\u002Fwhat-is-historical":3},{"id":4,"title":5,"author":6,"body":7,"date":68,"description":69,"experiment":17,"extension":70,"furtherReading":71,"meta":81,"navigation":82,"path":83,"seo":84,"stem":85,"__hash__":86},"content\u002Fblog\u002Fwhat-is-historical.md","What is the historical experiment?","Charles Turner, ACCESS-NRI",{"type":8,"value":9,"toc":62},"minimark",[10,19,24,32,48,51,55],[11,12,13,14,18],"p",{},"The ",[15,16,17],"strong",{},"historical"," experiment is the model's attempt to reproduce the climate we\nhave actually observed, from the mid-19th century up to the near-present. It is\none of the cornerstone simulations every model contributes to CMIP.",[20,21,23],"h2",{"id":22},"what-it-does","What it does",[11,25,26,27,31],{},"Starting from a stable pre-industrial state, the model is driven forward using\nour best reconstruction of the real-world ",[28,29,30],"em",{},"forcings"," over that period:",[33,34,35,39,42,45],"ul",{},[36,37,38],"li",{},"rising greenhouse gas concentrations,",[36,40,41],{},"volcanic eruptions and changes in solar output,",[36,43,44],{},"aerosols and other pollutants,",[36,46,47],{},"land-use change.",[11,49,50],{},"Everything else — the winds, ocean currents, the timing of El Niño — the model\nworks out for itself.",[20,52,54],{"id":53},"why-we-care","Why we care",[11,56,57,58,61],{},"The historical run is how we check the model against reality. If it can\nreproduce the observed warming, the pattern of temperature change, and events\nlike the cooling after major volcanic eruptions, we gain confidence that its\nprojections of the ",[28,59,60],{},"future"," are worth taking seriously. It is also the baseline\nthat future scenario runs branch off from.",{"title":63,"searchDepth":64,"depth":64,"links":65},"",2,[66,67],{"id":22,"depth":64,"text":23},{"id":53,"depth":64,"text":54},"2026-07-03","The historical run recreates the climate of 1850 to the present using our best estimate of what actually drove it.","md",[72,75,78],{"title":73,"url":74},"WCRP CMIP — the Coupled Model Intercomparison Project","https:\u002F\u002Fwcrp-cmip.org\u002Fcmip7\u002F",{"title":76,"url":77},"Eyring et al. (2016): CMIP6 experimental design and organisation (defines the historical simulation)","https:\u002F\u002Fdoi.org\u002F10.5194\u002Fgmd-9-1937-2016",{"title":79,"url":80},"Carbon Brief: how do climate models work?","https:\u002F\u002Fwww.carbonbrief.org\u002Fqa-how-do-climate-models-work\u002F",{},true,"\u002Fblog\u002Fwhat-is-historical",{"title":5,"description":69},"blog\u002Fwhat-is-historical","59nZOFQUExHhYA3c-NPrmbtKnfN4Tu_HIE3ik-r0XYc",1784888533712]