The climate-changing greenhouse effect exists and has been directly measured in the United States, a new study reports.
The results were highly credible. They confirmed what scientists had already proven using models and lab experiments. Too much carbon dioxide gas emission is saturating the Earth’s atmosphere resulting to global warming.
“We’re actually measuring the fact that rising carbon dioxide concentrations are leading to the greenhouse effect,” said lead study author Dan Feldman, a scientist at the Lawrence Berkeley National Laboratory in California. “This is clear observational evidence that when we add carbon dioxide to the atmosphere, it will push the system to a warmer place.”
Scientists have been recording the levels of carbon dioxide including other “greenhouse gasses” in Earth’s atmosphere, starting in the late 50s. Lab tests and experiments in physics showed that these gasses absorb some of infrared radiation that the Earth releases into space, causing an increase in the planets temperature.
The researchers measured radiative forcing on the Earth’s surface brought about by carbon dioxide at a couple of continuing atmospheric research sites owned by the Department of Energy. One is found in Oklahoma and the other is located near Barrow, Alaska, above the Arctic Circle.
They used highly powerful spectrometers calibrated by the United States Office of Weights and Measures in tracking infrared radiation raining the Earth’s surface, Feldman said. The greenhouse gasses circulating in the atmosphere is doing a great job in absorbing whatever infrared energy the Earth has, then disperses it in all directions, some of which towards the Earth’s surface. The instruments has the ability to detect the “fingerprint” of carbon dioxide’s infrared signal since the molecule releases and absorbs infrared energy at specific wavelengths.
Between 2000 and 2010, atmospheric concentrations of carbon dioxide increased at the 2 research facilities by 22 parts per million. Parts per million means the number of carbon dioxide in a million of air molecules.
The message is that more gas in the atmosphere means more infrared energy is being bombarded back to the planet’s surface instead of directing it back to space.
“This is another direct piece of evidence that supports that the increase in carbon dioxide is indeed contributing to global warming,” said Dave Turner, an atmospheric physicist at the National Severe Storms Laboratory in Oklahoma, who was not involved in the study. “It’s a roadmap as to how we can do exactly the same thing for other trace gases.”
Any probable interference from clouds, weather, water vapor or problems with instrument efficiency were factored out by the scientists.
.The added radiative forcing was o.2 watts per square meter every ten years. It’s approximately 10 percent of the overall rise attributed to all human activities, according to intergovernmental Panel of climate change.
“I would hope that even people who raise their eyebrows at this whole field can see there is a really robust observation underlying this,” Feldman told Live Science.
The research team is now analyzing the contributions to global warming from other greenhouse gases, such as methane.