Top Highlights

• the UN’s World Meteorological Organization defines climate as a thirty-year average, although climate researchers will sometimes discuss averages over a period as short as ten years. So
• “Anomalies” measure how much the observed condition—in this case, temperature—at a location deviates from the baseline (average) value at that location. Using values relative to a baseline puts changes in the Arctic on the same footing as changes in the Tropics, allowing us to compare changes in climate between locations as well as over time, and s...
• So trends are often highly dependent on the time span being considered; here we can get almost any trend we want depending upon which interval we choose. Such “cherry picking” of data is unfortunately quite common in the media
• The world’s oceans are both the most important and the most problematic piece of the earth’s climate system. They hold more than 90 percent of the climate’s heat and are its long-term memory.
• Second, although the effect of CO2 at today’s concentration is significant (7.6 percent), doubling it doesn’t change things much (an additional 0.8 percent) due to the “painting a black window” effect we’ve already discussed.