“Weather” describes atmospheric conditions at any location — temperature, humidity, clouds, precipitation, and winds. Every place has its own weather, which depends on the time of day, the season, the latitude, local topography, and the nearness and surface temperature of the ocean. Meteorologists need a good knowledge of weather records, atmospheric physics, geography, oceanography, and solar cycles. Weather is mainly about wind — is it hot or cold, moist or dry, strong or weak? Surface atmospheric pressure gradients control wind strength, direction, and temperature, and are valuable tools for short-term forecasting. Longer-term weather forecasters will find value in studying sunspots and El Niño episodes in the oceans. Few weathermen see any value in measuring or forecasting atmospheric CO2 to help forecast the weather. “Climate” is defined as the thirty-year average of weather at that spot. To determine climate trends thus requires centuries of reliable weather records. This is why geologists feature so prominently in determining past climates by mapping Earth’s crust and collecting deep core samples in ice sheets, ocean and lake sediments, and crustal rocks.