2. Levels of carbon dioxide in the atmosphere are increasing due to human activity
Direct measurements of CO2 in the atmosphere have been available since the 1950s and ice core measurements extend this record back to 800,000 years ago. These records show CO2 has increased by 40 percent since the Industrial Revolution and is higher than at any time in the past 800,000 years. Human activities are responsible for this recent increase, mainly from burning fossil fuels such as petroleum, coal and natural gas to generate energy. Scientists have tracked chemical signatures found in fossil fuels that have measurably changed in the atmosphere and are confident that fossil fuels are responsible for increasing CO2 levels.
3. Recent observed global warming can be attributed to increased CO2 and other greenhouse gases
Thousands of scientists have contributed to compiling and reviewing climate studies, including state-of-the-art models of the Earth's climate system that can successfully reproduce the temperature patterns of the 20th century — but only if increasing greenhouse gases are accounted for.
While the challenges and societal impacts of increasing CO2 seem daunting at first, scientific insights also provide cause for optimism. Plans are available that take advantage of emerging technology and offer plausible means of reducing CO2 emissions and stabilizing the climate, such as "The Conservative Case for Carbon Dividends," authored by leading Republicans. Reducing fossil fuel combustion by shifting to new and innovative technology can yield considerable co-benefits, such as improved air quality. These co-benefits are especially significant in the urbanized Wasatch Front, where large, dense populations are exposed to pollutants co-emitted with CO2 during fossil fuel combustion, such as NOx and particulate matter. In fact, our local air pollution challenge can largely be traced to our use of fossil fuels, whether in our cars, homes or factories. There are significant opportunities to reduce emissions as cities develop and grow, requiring construction of new infrastructure.
The University of Utah has been at the forefront of understanding the linkage between cities and CO2 emissions. The U. operates a long-running network of CO2 measurement sites along the Wasatch Front (real-time data can be viewed at http://air.utah.edu) that is one of the longest running urban networks in the world. In addition, a partnership with the Utah Transit Authority has enabled the U. to make CO2 and air quality measurements on TRAX light rail lines throughout the Salt Lake Valley, yielding unprecedented insight into patterns of CO2 emissions and air quality.
Rejection of decades of research into humans' role in global warming undermines the integrity of the scientific process. To maintain U.S. leadership in scientific innovation, we need to continue inspiring young Utahns to participate in research and development that will lead to the next generation of scientific advances. When science is devalued, young people are discouraged from engaging in the scientific community and we will lose the best and brightest scientific minds right when we need them most. We as scientists will keep striving to improve dialogue about the science of climate change and its many possible solutions so that Utah and the U.S. can continue to lead the world.
John C. Lin and Logan E. Mitchell are, respectively, associate professor and postdoctoral fellow in the department of atmospheric sciences at the University of Utah. Diane E. Pataki is professor of biology at the University of Utah.