New study provides definitive proof that the greenhouse effect is real
Researchers have directly observed an increase in the greenhouse effect at Earth’s surface due to carbon dioxide for the first time. The study was led by scientists from the US Department of Energy’s Lawrence Berkeley National Lab, who analyzed atmospheric carbon dioxide’s increasing capacity to absorb thermal radiation emitted from Earth’s surface during an 11-year period at two separate locations in North America.
The researchers say this upward temperature trend is clearly related to increasing CO2 levels from fossil fuel emissions.
The study was published February 25th online in the journal Nature.
Long-term study provides definitive proof of greenhouse effect
The research results confirm the theoretical predictions of the greenhouse effect due to human activity. The study also backs up that the calculations used in modern climate models are on track in representing the impact of CO2.
The researchers examined atmospheric carbon dioxide’s contribution to radiative forcing at two locations (Oklahoma and the North Slope of Alaska) from 2000 to the end of 2010. Radiative forcing measures how much the planet’s energy balance is modified by atmospheric changes. Of note, positive radiative forcing happens when the Earth absorbs more energy from the sun than it lets off as thermal radiation.
The Berkeley lab scientists found that CO2 was clearly responsible for a major increase in radiative forcing at both locations. The increase was close to 0.2 Watts per square meter per decade. The used to statistical models to show this temperature trend is directly related to the increase in atmospheric CO2 in the intervening 11 years. Most of this CO2 comes from the burning of fossil fuels, according to a separate modeling system that keep track of various CO2 global sources.
Statements from researchers
“We see, for the first time in the field, the amplification of the greenhouse effect because there’s more CO2 in the atmosphere to absorb what the Earth emits in response to incoming solar radiation,” commented Daniel Feldman, of Berkeley Lab’s Earth Sciences Division and the lead author of the paper.
Feldman also noted that “Numerous studies show rising atmospheric CO2 concentrations, but our study provides the critical link between those concentrations and the addition of energy to the system, or the greenhouse effect.”.