Earth's atmosphere is a very thin layer of gas compared to the size of our planet. If the Earth were an apple, the atmosphere would be like the skin on the apple.

This thin atmosphere is critical to the survival of Earth's plants and animals. It provides the right gases for our bodies to breathe and also keeps the surface temperature on Earth warm. Without the atmosphere, the whole earth would freeze over.

Not only is this thin layer of gas necessary for our survival, but it is also an exciting and dynamic place. Research on Earth's atmosphere can roughly be broken up into studying the weather and the climate.

Weather

Fast changes that happen in the atmosphere, such as storms, hurricanes, and heat waves are considered weather events. You are probably familiar with the weather, it is reported on the news and in the papers. The weather is what determines what you should wear on a given day or whether you should bring your umbrella.

There are many scientists whose research aims at understanding and predicting the weather. Weather prediction is important for public safety in events like tornadoes and flash floods. It is also important for general planning purposes in your everyday life, such as whether to have a picnic on Saturday or Sunday. Researching and understanding weather is chaotic and hard to predict, especially more than a few days in advance.

In order to predict the weather, atmospheric scientists use a mix of radar, satellite images, and weather balloons that measure pressure, temperature, and humidity. All of this information is then put into a computer model that calculates how the weather will change in the future.

Climate

Not all atmospheric scientists study the weather. Some scientists, like myself, are more concerned with the climate. You can think of the climate as the average of the weather. The climate changes seasonally, but not day-to-day. For example, where I grew up in Iowa, I knew it was going to be cold in January and hot in July, even though the day-to-day weather may vary. Deserts and rainforests have very different climates, even though they may have the same weather on any given day.

A large area of current research is aimed at understanding how the climate is changing due to human effects. Humans have been changing the Earth's surface and atmosphere by cutting down forests, planting fields, and burning wood and other fuel for thousands of years. However, our ability to affect the land and atmosphere increases greatly with the industrial revolution.

The largest agent of climate change is the emission of carbon dioxide (CO2) from burning fossil fuels. CO2 is a greenhouse gas, which means that it absorbs infrared light, thus trapping the sun's energy on Earth. Due to all the excess CO2, the Earth is warming, but not uniformly. For example, the arctic is warming at a much faster rate than the tropics, a process called polar amplification. A major goal of atmospheric science is to understand and predict how humans are changing the climate.

Many scientists studying glaciers, forests, deserts, and the ocean have written papers describing the current and past effects of climate change on the respective ecosystem. In order to predict how the climate will change in the future scientist employ the same computer models that are used to predict the weather.