A new paper has implicated a physiologic mechanism in vegetation as a cause for Arctic warming.
The "greenhouse effect" is well-known by now, water vapor that plants emit during photosynthesis serves to lower land surface temperature, similar watering the yard on a hot day, but it can lead to a rise in air temperature.
The new paper finds that the Arctic temperature rises when the moisture released by plants is reduced due to the increase of carbon dioxide (CO2 ) in the atmosphere. The increase in atmospheric CO2 concentration closes the pores (stomata) of plants in high-latitude areas and reduces their transpiration, which they find ultimately accelerates Arctic warming.