Climatology

Long-term climate, Milankovitch cycles, paleoclimate, and atmospheric circulation

What is climatology?

Climatology is the study of climate — the long-term, average pattern of weather in a region or across the whole planet, typically measured over periods of decades. This distinguishes climatology from meteorology, which focuses on short-term, day-to-day weather.

Weather vs. climate

Weather is what's happening in the atmosphere right now or in the coming days; climate is the long-term statistical pattern behind it, built up from many years of weather observations. A useful way to think about the difference: weather is what you experience on a given day, while climate is what generally determines the range of weather you can expect at a given place and time of year.

What shapes a region's climate

A place's climate is shaped by several major factors: its latitude (which controls how directly sunlight strikes the surface), its elevation (higher places are generally cooler), its distance from the ocean (coastal areas tend to have milder, less extreme temperature swings than inland areas), and the ocean currents and prevailing wind patterns that pass through it (covered in the Oceanography and Meteorology articles). Together, these factors explain why, for example, coastal cities are often milder than inland cities at the same latitude.

Climate over deep time

Earth's climate has changed many times over its long history, driven by natural factors including variations in Earth's orbit, volcanic activity, and shifts in the arrangement of continents (from plate tectonics, covered in the Geology article). Scientists study these past climate shifts using evidence preserved in ice cores, sediment layers, and fossils, building a detailed record of how Earth's climate has varied over hundreds of thousands to millions of years.

Why climatology matters

Climatology supports agriculture (helping farmers understand long-term growing conditions), city and infrastructure planning (designing buildings and systems suited to a region's typical climate), and provides the essential scientific foundation for understanding present-day climate patterns and how they are changing over time.