CHAMPAIGN, Ill. – Skepticism and uncertainty should not excuse inaction in protecting the environment from human-caused climate change, say scientists in a new essay published in the journal Science on August 12.

Climate change skeptics often question the scientific evidence that risks exist, the magnitude of any risks, and assert that policy changes will be too costly, according to co-author Richard Sparks, a retired professional scientist at the Illinois Natural History Survey (INHS), Prairie Research Institute, University of Illinois.

Skepticism has now shifted away from outright denial to what the authors term “neoskepticism,” defined as agreement that climate change exists, but opposition to mitigation actions.

“As evidence mounts, neoskeptics question the severity of the problem and argue that as long as uncertainty exists, the smartest and most financially shrewd move is to do little or nothing,” Sparks said. “They do not examine the risks and costs of inaction, and fail to consider that the risks of extreme and damaging outcomes are continually increasing. Waiting for harmful effects to be proven beyond all reasonable doubt before taking action has increasing costs to the economy, ecosystem integrity, political stability, and human lives.”

A medical analogy is more appropriate than the courtroom analogy—putting the planet on a diet of reduced fossil fuels and carbon dioxide based on the growing preponderance of evidence compared to proving the harmful effects of climate change beyond all reasonable doubt before any action is taken.

Sparks’ research at the INHS, which included long-term monitoring of plants and animals, shows that climate change is occurring. For example, blue catfish were once considered a southern species in the U.S. and occurred only sporadically in the St. Louis, MO area of the Mississippi River. Recent surveys have shown an abundant, reproducing population in that area. In another example, decades-old garden planting guides compared with contemporary versions show that planting zones have moved northward as the warming trend continues.

Although the social and economic sciences can help with decision-making, the authors do not presume that empirical analysis of risks or better analogies will end the skepticism surrounding climate change because skepticism is often motivated by financial interests tied to the use of fossil fuels.

“From my perspective, animals and plants are responding to climate change,” Sparks said. “Those who want to take action on climate change are labeled alarmists, but animals and plants don’t have an agenda. The consequences are so dire; we must take action.”

---

Media contact: Richard Sparks, 618-786-2811, rsparks@illinois.edu

The Science article is available at http://science.sciencemag.org/content/353/6300/653