Pine bark beetles are munching pine trees throughout the Rocky Mountains. Trees that have been killed because of pine bark beetles have brown needles in this picture. Less pine trees in this area may have an impact on weather and air quality.
Click on image for full size
Carlye Calvin / UCAR

Can Dying Trees Change Weather and Climate?
News story originally written on September 24, 2008

A team of scientists is exploring how forest trees affect weather, air pollution, and climate change. They are studying the forests of the southern Rocky Mountains that are being devastated by pine beetles to understand how fewer trees will impact the region.

Using instruments on airplanes, instruments on the ground, and computer models, scientists at the National Center for Atmospheric Research (NCAR) will study interactions between forests and the atmosphere in the southern Rockies.

The pine trees in this region's forests are being killed by pine beetles. The beetles, which are the size of a grain of rice, eat the bark of pine trees. In large numbers they have the ability to destroy forests. While pine bark beetles are a natural part of this ecosystem, over the past few years the number of beetles has grown rapidly. They are spreading into areas that used to be beetle-free like high altitude mountains. Scientists believe the beetles are overrunning the area in part because of increased temperatures and drought.

Like all plants, forest trees take in carbon dioxide and release oxygen into the atmosphere through the process of photosynthesis.  But they also send water vapor, other gases, and microscopic particles into the air. These gases and particles may be tiny but they can have a big impact. For example, some of the particles released from healthy trees are good spots for water vapor to condense. This forms water droplets in the sky. And lots of water droplets make a cloud.  Eventually that cloud can become so heavy with water that rain falls.

"Forests help control the atmosphere," says NCAR scientist Alex Guenther.  He continues, "There's a big difference between the impacts of a living forest and a dead forest." Scientists suspect that weather and air quality is changing as forests are destroyed by the beetles.

Climate can be affected too. Trees killed by pine beetles release the heat-trapping greenhouse gas carbon dioxide (CO2), into the air. Combined with the CO2 released into the air from burning fossil fuels, this causes more global warming. Also affecting climate, the dead trees have low albedo so they do not reflect as much of the Sun's heat back into space. The scientists' work suggests that the beetle-killed trees could warm the area about 2-4 degrees Fahrenheit.

Last modified October 15, 2011 by Jennifer Bergman.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Air Pollution

What do smog, acid rain, carbon monoxide, fossil fuel exhausts, and tropospheric ozone have in common? They are all examples of air pollution. Air pollution is not new. As far back as the 13 th century,...more

Biomes and Ecosystems

Biomes are large regions of the world with similar plants, animals, and other living things that are adapted to the climate and other conditions. Explore the links below to learn more about different biomes....more

Carbon Dioxide - CO2

Carbon dioxide (CO2) is a kind of gas. There isn't that much carbon dioxide in Earth's atmosphere, but it is still very important. Carbon dioxide is a greenhouse gas. That means it helps trap heat coming...more


Photosynthesis is the name of the process by which autotrophs (self-feeders) convert water, carbon dioxide, and solar energy into sugars and oxygen. It is a complex chemical process by which plants and...more

Aerosols: Tiny Particulates in the Air

When you look up at the sky, you are looking at more than just air. There are also billions of tiny bits of solid and liquid floating in the atmosphere. Those tiny floating particles are called aerosols...more


Condensation is the process by which water changes its state from a vapor or gas to a liquid. Condensation is responsible for the formation of clouds. Common examples of condensation are: dew forming on...more

How Clouds Form

A cloud is composed of tiny water droplets or ice crystals that are suspended in the air. A series of processes have to happen in order for these water droplets or ice crystals to form into clouds in the...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA