While voices warning of imminent, catastrophic, man-made global warming grow louder, their volume is matched by others claiming the warming is not significantly human-induced and/or not significant enough to cause alarm. As in most cases of dispute, this issue has more than two sides. With that in mind, I’d like to summarize the range of views (across a wide spectrum) on climate change.
1. Natural variations are the dominant cause of climate change; and human influence on climate variability is minor.
2. Natural variations impact climate change significantly, but human influence is also significant and stems from a number of important effects including, but beyond, the input of CO2.
3. Though natural variations impact climate change, human influences are of greatest significance and include the input of CO2 and, to a lesser extent, other greenhouse gases. (For a more detailed explanation of these positions, see “Roger A. Pielke Sr.’s Position on Climate Change” at http://wp.me/pBKs3-TO.)
The second view could allow for a less-polarized debate and a more open exchange of ideas for discussion among researchers. The first and third views often minimize several climate-impacting phenomena, including cloud cover, precipitation rates, water vapor behavior, aerosols, land use/land cover change, greenhouse gas abundances, natural-but-dramatic climate change, and long-term ocean temperature/current variations, to name a few. Together, these factors have the potential to modify the feedbacks affecting climate model projections.
Unfortunately, some influential participants in the climate-change controversy have sought progress by sensationalizing the issue and resorting to fear tactics as a means to promote action. However, fear-based approaches are a poor substitute for reasoned strategies. (For more on this topic, see Judith Curry, “USGCRP Drat Strategic Plan,” http://bit.ly/qVwiVi.) Careful testing and methodologies improve chances of success (see 1 Thessalonians 5:21). Despite the current polarization in the climate issue, hope of resolving this issue is not lost, as some have declared. Through careful research that considers all climate-impacting phenomena, progress can be made in understanding the complex systems that safeguard Earth’s climate.