evidence: Factually Inaccurate: Necessary adjustments to temperature datasets have, in total, reduced the apparent global warming trend since the late 1800s. Many independent datasets support the accuracy of these adjustments. [...] The most significant adjustments to data relate to changing ship-based instruments and methods used to measure sea surface temperatures around the time of World War II. As the use of thermometers in buckets of water hauled up on deck was replaced by thermometers in ship engine water intake pipes, the measured temperatures changed slightly, necessitating a correction to ensure an "apples-to-apples" comparison. [...] Raw data show more global warming since 1880 than is reported by NOAA [or shown in other datasets]. This is because NOAA "adjusts" temperature data to fairly compare different measurement times, places, and technologies. The cooling effect of adjustments on global temperatures has been shown lots of times, such as with the graph below for 1880—2013 temperatures.