Revealing Climate Change: How Science Holds the Key

By Guy Seeley

Revealing Climate Change: How Science Holds the Key

Climate change remains one of the world’s most complex problems, crossing borders and blurring lines of science and politics. Given the strong demand for global energy, what are the chances of understanding and finding solutions to an ever-increasing CO2 concentration in Earth’s atmosphere?

AER, a Verisk Analytics business, has been addressing global environmental challenges for decades through highly relevant scientific research. Since scientifically rigorous results are essential to effective environmental policies, AER provides an impartial and unbiased perspective that policymakers can use in their decision making.

An example of this objective approach can be found in Antarctica. In the mid-1970s, researchers of the British Antarctic Survey had begun to identify unusual seasonal decreases in the ozone layer over Antarctica. Given ozone’s crucial role in protecting life on Earth from dangerous ultraviolet radiation, concern about the “ozone hole” was gaining considerable attention. At about the same time, researchers at AER were using modeling methods developed from research studies of Venus’s atmosphere to apply to the stratosphere on Earth.

Adapting AER’s models

Working with leading National Aeronautics and Space Administration (NASA) and university researchers, AER was able to reconfigure these models to help analyze data from early measurement efforts designed to determine why stratospheric ozone was depleted over Antarctica during the Southern Hemisphere spring. This work, performed primarily under NASA sponsorship, led to strong scientific verification that chemical reactions involving chlorofluorocarbons (CFCs) in the stratosphere can lead directly to the depletion of ozone.

Figure: 1Ozone abundance
Seasonal variation in ozone column abundance calculated using the AER model (curved line) compared with measurements (symbols) as a function of date. Adapted from Tung et al., Nature, 332, 6082, p. 811, 1986.

Because the AER model quantified the impact of CFCs on ozone, it could also be used to simulate proposed CFC replacements and assess their effect on the atmosphere. AER’s research program in photochemistry, atmospheric modeling, and the effects of injecting different gases (pollution, chlorofluorocarbons, etc.) into the atmosphere continued for more than two decades. The research was funded through grants obtained from both NASA and the chemical industry, establishing AER as a trusted agent for presenting fact-based analyses of specific environmental problems.

Using an international process that emphasized science in identifying risks and the solutions for addressing them, development of the international agreement took only about ten years. By 1987, an international treaty was signed: the Montreal Protocol on Substances that Deplete the Ozone Layer. This treaty regulated CFCs and prescribed a scientifically based path for countries to cooperate in transitioning to newer ozone-friendly technologies. As of 2017, ozone-damaging CFC levels have decreased significantly, and the ozone layer is recovering. The Montreal Protocol’s framework is widely regarded as having successfully addressed the CFC problem and remains a leading example of global cooperation on solving environmental problems. AER contributed to this important and successful endeavor.

Today, AER is working on a number of scientific topics to investigate effects of CO2 emissions at global, regional, and local scales. AER scientists are joining a wide variety of leading researchers in studying the impact of emissions of carbon into the atmosphere. AER scientists perform state-of-the-art computer simulations of the transport and dispersion of carbon compounds, following the chemicals from their source to downstream measurement locations. Those computations support the analysis of measurements from global and national tall tower networks, from aircraft missions over Alaska and Canada, and from satellite missions by U.S. and international space agencies. These computer simulations of atmospheric flow are critical to reconciling emissions estimates with atmospheric observations and achieving accurate results on the true amount of emitted carbon.

Gauging the greenhouse effect

Figure: 2 Surface Forcing
Greenhouse effect (“radiative forcing”) caused by carbon dioxide between 2000 and 2010 as measured by AER and coworkers at the Department of Energy’s Southern Great Plains atmospheric observatory in Kansas and Oklahoma. The blue line is a least-squares fit to the measurements. Adapted from Feldman et al., Nature, 519, 7543, p. 339, 2015.

At the regional level, AER is leading an effort funded by NASA’s Carbon Monitoring System to determine the amount of carbon emitted by urban areas. For measurements of carbon at even smaller scales, AER is collaborating with Harris Corporation in developing the GreenLITETM system for measuring carbon emissions over areas as large as a city or as small as a single oil well. In June 2017, this system underwent a field test with a major oil company in Europe, with the prospect of deployment to multiple facilities worldwide.

In addition, AER has contributed to the improved accuracy of global computer models used for calculating the strength of the greenhouse effect. The AER radiation model has been a key component of major national climate models operated by U.S. government agencies such as NASA and the National Oceanic and Atmospheric Administration (NOAA), and its accuracy is directly traceable to the highest-resolution experimental observations as well as improvements in the underlying physics. Using this model, in 2015 AER scientists were the first to show the direct impact of CO2 emissions on the heating of the atmosphere.

Scientists at AER are united by a desire to understand fundamental problems that span scientific disciplines. AER is driven to help enhance an overall understanding of the world. AER’s record of impartial and trustworthy research demonstrates the value and application of rigorous scientific methods to problems as vast as global climate change.

Scott Stephenson

Guy Seeley is president of AER, a Verisk business.