U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Observational Determination of Surface Radiative Forcing by Atmospheric CO2
Published: February 25, 2015
Posted: July 22, 2016

Scientists have observed carbon dioxide’s (CO2) greenhouse effect at Earth’s surface for the first time. Although the influence of atmospheric CO2 on the planet’s energy balance is well established, this effect had not been experimentally confirmed outside the laboratory until now. The researchers, led by the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory, measured atmospheric CO2’s increasing capacity to absorb thermal radiation emitted from Earth’s surface over an 11-year period at two locations in North America. They used precise spectroscopic instruments operated by DOE’s Atmospheric Radiation Measurement (ARM) program at the ARM research sites in Oklahoma and Alaska. The instruments measure thermal infrared energy that travels down through the atmosphere to the surface and can detect the unique spectral signature of infrared energy from CO2. Other instruments detect the unique signatures of phenomena that also can emit infrared energy such as clouds or vapor. The combination of measurements enabled the scientists to isolate the signals solely attributed to CO2. They found that CO2 was responsible for a significant uptick in radiative forcing at both locations, about 0.2 Watts/m2. They linked this trend to the 22 ppm increase in atmospheric CO2 between 2000 and 2010. The measurements also enabled the scientists to detect, for the first time, the influence of photosynthesis on the balance of energy at the surface. They found that CO2-attributed radiative forcing dipped in the spring as flourishing photosynthetic activity pulled more of the greenhouse gas from the air. Their results agree with theoretical predictions of the greenhouse effect due to human activity. The research also provides further confirmation that the calculations used in today’s climate models are on track when it comes to representing the impact of CO2.

Reference: Feldman, D. R., W. D. Collins, P. J. Gero, M. S. Torn, E. J. Mlawer, and T. R. Shippert. 2015. “Observational Determination of Surface Radiative Forcing by CO2 from 2000 to 2010,” Nature 519, 339-43. DOI: 10.1038/nature14240. (Reference link)

Contact: Shaima Nasiri, SC-23.1, 301-903-0207
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Atmospheric System Research
  • Research Area: Carbon Cycle, Nutrient Cycling
  • Facility: DOE ARM User Facility

Division: SC-23.1 Climate and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)