NCASI climate change research

Two new studies add to NCASI’s long history of climate change research. In the first, published in the journal Ecological Modelling, Dr. Craig Loehle develops a method for calculating climate sensitivity, which is the amount that the Earth warms for a doubling of CO2 or equivalent forcings.  

One of the concerns with recent warming trends is that there are known fluctuations in climate that appear to be natural, such as the El Niño/Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) cycles. By subtracting these cycles from the temperature history of the past 150 years, Loehle was able to identify the anthropogenic warming signal and estimate the transient sensitivity (which is what we should see over the next 100 years) at 1.1°C. An upper bound on the equilibrium sensitivity is then 1.9°C. This estimate agrees with multiple empirically based estimates, all of which are about half of what climate models estimate.

In the second paper, published in the journal Energy & Environment, Loehle evaluates the likely response of northern latitude trees to warming. He shows that northern trees can be found growing in botanical gardens in the US Southeast and in Australia, indicating their tolerance of warmer temperatures. Studies in greenhouses and simulation models confirm this effect. This indicates that northern forests are unlikely to suffer even rather substantial warming over coming decades.

For further information on these studies or related issues, contact Dr. Craig Loehle.

  

Contact information 

References 

Loehle, C. 2014. A minimal model for estimating climate sensitivity. Ecological Modelling 276:80-84. http://dx.doi.org/10.1016/j.ecolmodel.2014.01.006 

Loehle, C. 2014. Climate change is unlikely to cause a biodiversity crisis: Evidence from northern latitude tree responses to warming. Energy & Environment 25:147-153. http://dx.doi.org/10.1260/0958-305X.25.1.147