Guest essay by Jim Steele, Director emeritus Sierra Nevada Field Campus, San Francisco State University and author of Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism
Recently advocates of CO2 catastrophic climate change have been trumpeting a new paper in PNAS by Kyle C. Cavanaugh et al :“Poleward expansion of mangroves is a threshold response to decreased frequency of extreme cold events” The authors argue “Our analyses provides evidence for a threshold response, with declining frequency of severe cold winter events allowing for poleward expansion of mangroves. Future warming may result in increases in mangrove cover beyond current latitudinal limits of mangrove forests, thereby altering the structure and function of these important coastal ecosystems.”
The authors, from the Smithsonian Environmental Research Center, use a bewildering array of statistics to suggest mangroves are marching march northward along the coast of Florida only because climate change has resulted in just 1.4 fewer days with temperatures falling below -4C between 1984 and 2006. However the authors admitted “decreases in the frequency of extreme cold events was only significant if an extreme cold event was defined as colder than −4 °C; the relationship disappeared when the temperature threshold was raised a small amount” but they later imply this suggests just how sensitive the mangroves are too what most of us would see as an insignificant change.
Their introduction also suggested that the authors were more interested in proving global warming than investigating all the confounding factors that may have also affected the increase in mangroves along their study site of the Indian River Lagoon. I was immediately suspicious because land use changes due to agriculture and urbanization have severely altered Florida’s hydrology and habitat and for decades disappearing mangroves have been a growing concern amongst conservationists. Nonetheless the authors claimed the spread of new mangroves were “uncorrelated with changes in mean annual temperature, mean annual precipitation, and land use.”
However I knew people who participated in Indian River Lagoon Shoreline Restoration Projects – Volunteer Events a few years back. That’s the very area that the authors claimed the expansion of mangroves could only be explained by climate change. Yet these CO2 advocates ignored well-advertised activities such as the “Florida Department of Environmental Protection’s Shoreline Restoration Project” which is working to identify suitable un-vegetated and disturbed shoreline areas to restore fringing mangrove habitats along the Indian River Lagoon. This is accomplished through planting red mangroves (Rhizophora mangle) and associated species, such as marsh grass (Spartina alterniflora).
In April of 2010 there was a call for volunteers “needed to help with plantings, site maintenance, follow-up monitoring, and plant care at the mangrove nursery located on the grounds of the St. Sebastian River Preserve State Park. Planting events will be scheduled in the spring, and follow-up monitoring, site maintenance, and nursery work days are scheduled year round.”
So I sadly present the authors with my “Cheesy Climate Science Award” created in honor of past researchers who lead the way by hijacking conservation success stories and metamorphosing them into a climate catastrophe campaign as done in the IPCC paper here.
Whether climate change is natural or manmade, we can make a more resilient environment by restoring habitat and watersheds. We must demand more critical thinking, so that such frivolous publications stop misrepresenting honest conservation efforts in order to create a picture of climate doom. Trustworthy environmental stewardship must be guided by better science.
Read previous essays at landscapesandcycles.net