That is in-correct and actually it is the likes of Ted Cruz that is cherry picking ie using the raw data or in-correctly corrected for a specific 18 year time span because that suits his outlook. Real climate scientists on the other hand use accepted time spans like 10, 15 20 or 30 years plus reply on multiple data sources to give confidence to the warming trend observations. So they use weather balloons and ground stations for instance to give multiple inputs so they can cross check to get a "standard".