Though politicians and scientists have disagreed about whether atmospheric warming can be delayed by reducing short-lived climate forcing (SLCF) agents, an international research team has confirmed that a reduction in carbon dioxide emissions is the only long-term solution. Previously, politicians and industry had been pushing for measures to reduce SLCF emissions as a way to buy time before needing to address CO2 emissions directly.
However, the research team found that under a variety of scenarios, such short term measures had an insignificant effect on the long term rise in temperature. Since the sources of these emissions are intrinsically linked, particularly in the form of fossil fuels, such short term measures should only be seen as a supplement to greater efforts to curb CO2 emissions.
Climate change is one of the greatest challenges of our times. Human activities, like fossil-fuel burning, result in emissions of radiation-modifying substances that have a detectable, either warming or cooling, influence on our climate. Some, like soot (black carbon), are very short lived, whereas others, like carbon dioxide (CO2), are very persistent and remain in the atmosphere for centuries to millennia. Importantly, these substances are often emitted by common sources. As climate policy is looking at options to limit emissions of all these substances, understanding their linkages becomes extremely important. Our study disentangles these linkages and therewith helps to avoid crucial misconceptions: Measures reducing short-lived climate forcers are complementary to CO2 mitigation, but neglecting linkages leads to overestimating their climate benefits.
J. Rogelj, M. Schaeffer, M. Meinshausen, D. T. Shindell, W. Hare, Z. Klimont, G. J. M. Velders, M. Amann, H. J. Schellnhuber, Disentangling the effects of CO2 and short-lived climate forcer mitigation, Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1415631111