A shower of laminated flakes might slow down mountain pine beetles that are leaving a wake of devastated lodgepole pines. What does that have to do with air quality?

Trees take in carbon dioxide, a greenhouse gas, as a part of photosynthesis. If you lose too many trees, you compromise this so-called carbon sink.

To make things worse, dead and decaying trees also release carbon dioxide into the air. An important piece of the Earth's natural control of a climate-warming gas is threatened because beetle infestations have spread to more than 20 million acres into Canada's forests and many acres in the United States.

As the climate warms, the season for warm-weather ozone expands, especially in a place such as the San Joaquin Valley.

A U.S. Forest Service-funded study, published in the February issue of Forest Ecology and Management, showed aerial showers of laminated flakes containing a substance called verbenone resulted in a three-fold reduction in pine beetle attack rates.

There are three national parks, two national forests and a whole lot of lodgepole pines just east of Fresno in the Sierra Nevada. I've seen plenty of rotting lodgepoles and other types of pines that provide a home and nutrition to bugs and critters for centuries.

But crowded forests, fires and the warming temperatures up there are making conditions pretty fruitful for beetles. These flake showers might limit the damage.