Earth is a special planet for having an atmosphere that enables life to thrive. Our atmosphere surrounds our planet, which keeps us warm and contains oxygen for us to breathe. The atmosphere has different layers with different qualities and is where our weather happens.

Weather refers to the state of the air and our atmosphere at specific times and places, while climate refers to long-term patterns in weather. When we study climate, we also study how climate is changing.

Climate change, which is the study of how our planet’s climate has been changing over time, has significant effects on Earth’s ecosystems. Scientists have observed changes with the oceans—such as warmer temperatures and rising sea levels—and weather patterns—such as heat waves, hurricanes and more—that can have an effect on people, habitats, animals, plants and all ecosystems on Earth.

For example, these environmental changes have led to increased spread of infectious diseases from extreme weather events, as well as increased air pollution from natural events such as wildfires and dust storms and from human sources such as fossil fuel combustion and the byproducts of air conditioning. Climate change can also have unhealthy consequences on communities by worsening food scarcity and undernutrition in some areas of the world.

In addition to affecting our natural world, changes in air quality that are tied to climate change can affect our health. This occurs from climate-driven changes influencing weather conditions (temperature, precipitation, etc.) and concentrations of ground-level ozone and particulate matter (particles and droplets found in the air).

These levels vary from region to region globally, but in general, worsen air pollution. For example, in the U.S. alone, more than 100 million people live in areas with poor air quality. Additionally, the changing climate is also expected to cause earlier and longer springs and summers, warmer temperatures and higher carbon dioxide concentrations. All these changes will increase our exposure to pollen and other airborne allergens, which in turn may lead to more allergy-related illnesses such as asthma and hay fever.

These changes may also affect our health in additional and different ways. For example, poor air quality can negatively affect the cardiovascular system. One study, called the Multi-Ethnic Study of Atherosclerosis and Air Pollution, showed long-term exposure to particulate matter and ozone was associated with the progression and increased risk of heart disease. Put simply, even short-term changes in air pollution can increase our risk of experiencing unhealthy cardiovascular conditions.

Air pollution also directly activates our immune system, too. A Canadian study showed particulate matter exposure increases the risk of developing autoimmune diseases. Research has also shown that people who are exposed to traffic-related air pollution and ground-level ozone over long periods of time are more likely to develop rheumatoid arthritis. Air pollution exposure can also increase our risk of developing and being negatively affected by cancer by as much as 22%. Even with this environmental deck stacked against us, there are ways to improve our circumstances by reducing overall air pollution. Some examples include environmentally friendly and sustainable approaches, such as walking more, using recycled products and using less water. These small changes collectively can lead to improved environmental outcomes and in turn improve health conditions for us all.