Anyone lucky enough to be airborne over west Houston at 2 p.m. Thursday, April 22, might get a sighting of Briargrove Elementary School’s celebration of Earth Day.

In a feat of organization, all 900 students, each dressed in blue or green T-shirts, will gather on the school’s front playing field to project their message skyward as they form the shape of planet earth.

The school is calling the event “Cool Earth Day event.”

Teachers will be holding signs saying “Briargrove Elementary Earth Day 2010.”

Briargrove Elementary, 6145 San Felipe, is one of many schools and organizations around west Houston to mark the 40th anniversary of the birth of the modern environmental movement on April 22, 1970.

Founded by Gaylord Nelson, then a United States senator from Wisconsin, the first Earth Day attracted 20 million participants across the country. In 1990, Earth Day went global, when 200 million people in 141 countries participated, giving a huge boost to recycling efforts worldwide and paving the way for a world earth summit in 1992.

Elsewhere, Writers in the Schools in partnership with Houston Arboretum and Nature Center is hosting a reading of poems and essays about nature, written by Houston elementary and middle school students. Titled “A Light in the Forest,” the event showcases the work of 32 students from Briarmeadow Charter School, Looscan, Neff, St. George Place and Kujawa elementary schools and deaf elementary students from T. H. Rogers School. The readings start at 7 p.m. Thursday at the nature center, 4501 Woodway Drive.

A prayer service, book reading sessions on how to save the planet, art projects, save the earth pledges and online activities will mark The Regis School of the Sacred Heart’s weeklong celebration of Earth Day.

The boys’ Catholic school, located at 7330 Westview Drive, will kick off a series of activities Monday as part of the school’s Social Awareness Program, whose theme for April is environmental awareness. Students in all grades — preschool through eighth grade — will decorate paper grocery bags with environmental messages, to be distributed to customers at the local Kroger store, a school partner.

The students and their families are encouraged to have discussions about how to reduce waste and consumption of water and electricity.

Meanwhile, the Ecology Club at Westside High School, 14201 Briar Forest, is organizing a light-bulb exchange all week as part of the nonprofit Green Team America’s Project GlOW.

The club is affiliated with Green Team America, a grass-roots organization to unite high school students to spread the word through action and education about climate change.

Club members will give out energy-efficient, compact-fluorescent light bulbs, supplied by Green Team America, to students and staff who bring in regular bulbs to exchange.

A club spokesperson said the project should help lower the amount of coal burned to create electricity, thereby reducing the rate of climate change.