Scientists who observe the Earth from space say data they collect show that climate change is affecting the planet's landscape.
With a goal of sharing that data with the public, a forum titled "Changing Landscapes Observed from Space" will open to the public Nov. 8 at Howard Community College.
"It surprises people to learn about the impact on land use changes," said Jim Irons, a Kings Contrivance resident who is deputy director of the Earth Sciences Division at NASA's Goddard Space Flight Center in Beltsville.
"Some people don't understand or don't want to hear about the impact on the local environment and on our quality of life," he said. "We want to talk about why we're concerned by explaining to the public what we do and why we do it."
The forum will cover changes to the urban, agricultural and forest landscapes and to the Chesapeake Bay watershed; it is the fourth such event since 2011 to focus on an aspect of NASA's climate change studies.
The half-day program will be sponsored by two citizen advocacy groups, Transition Howard County and Howard County Climate Change, along with the science, technology and engineering division of Howard Community College. Registration opens at 8:30 a.m. and the program will run from 9 a.m. to noon.
Irons, who spoke Tuesday at HCC at a land use forum geared toward students, has worked for 38 years at NASA, which launched its first Landsat satellite in 1972.
Landsat is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. Irons is the project scientist for Landsat 8, which was launched in 2013.
Edward Hilsenrath, a Fulton resident and retired NASA atmospheric scientist who is helping organize the event, said many people associate NASA with the journey to Mars, the International Space Station or the Hubble Space Telescope, and don't fully understand the scope of NASA's earth science research, which has a budget of $2.5 billion.
"Few people have an idea of what NASA does in its earth science program," he said.
"For many years, we've endeavored to study Earth as a comprehensive system," Irons said, "and we've built and launched a fleet of 17 satellites to observe Earth from outer space."
The satellites "travel north to south, from the lit side to the dark side of the Earth and back to sunlight," he said. "This brings the entire Earth into view every 16 days."
Sensors collect data for light wavelengths beyond what the naked eye can see, and computers can identify land cover differences by the wavelength of the reflected light, he said.
As computers become more powerful, land cover analysis becomes more detailed, he said.
"I cringe when people refer to these sensors as cameras, but they collect data in the same general way," Irons said. "Every pixel in these images is a scientific measurement of about 30 meters by 30 meters, or the size of the infield at Camden Yards. This provides a high degree of accuracy.
"The data is used to test many hypotheses, and one of the biggest is climate change," he said. "That's controversial to some people but not to us."
Increasing population and climate change "impact our economy, our access to food, our water and air quality, and the Chesapeake Bay," he said.
Using the data collected, maps can drawn that show impervious surfaces — such as roads, parking lots, driveways, sidewalks and rooftops — which prevent absorption of rainwater by the soil and increase stormwater runoff and the pollution associated with it.
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"The so-called rain tax is a misnomer; it's an impervious surface tax," Irons said, referring to Maryland's stormwater remediation fee that took effect in 2013.
"But NASA is not attempting to set policy," he said. "We are providing information [through land imaging] to assist in informed policymaking."
Hilsenrath said bringing this information to the community has been his goal since he retired in 2010.
"An educated society is a healthier society," he said. "We are raising awareness that our environment is not to be taken for granted."
The forum's three speakers and their topics will be: Molly Brown of Goddard Space Flight Center, food security; Peter Claggett of the U.S. Geological Survey, the Chesapeake Bay; and Joseph Sexton, a professor of geological sciences at the University of Maryland, land use change.
There will also be a panel discussion by representatives of the Union of Concerned Scientists, the state Department of Planning, and Sen. Ben Cardin's office. A question-and-answer session will follow.
The forum will be in HCC's Health Sciences Building. To register or for more information, go to howardcc.edu/NASAforum.