One of the major concerns with respect to climate change that we have discussed in class is the positive feedback system that the carbon cycle creates. For example respective to plants: as the temperature increases globally, plants will need to reduce the amount that they open their stomata so as to limit their carbon intake because it is more abundant. The effect this has is a  reduced amount of water released through the stomata, which in turn reduces the amount of water given off and therefore cools the atmosphere less. Recently, however, it was discovered that plants would be able to adapt to the increasing carbon dioxide levels better that thought previously.

According to the New York Times article, “plant respiration contributes six times as much carbon dioxide to the atmosphere as fossil fuel emissions”. While this statistic makes up a significant amount of the CO2 in the atmosphere, plants also use much of it as fuel for photosynthesis.  Another negative feedback element that was touched on in class and addressed in the Columbia article is the process of down-regulation. This outcome is the result of the plants adapting in the abundance of CO2 to operate more efficiently. The result is a larger leaf area on average which results in an increased albedo of the earth, thereby cooling it slightly. Based on these findings and more, the new found consensus is that the carbon cycle may, in fact, be a negative feedback system with regards to global warming as opposed to the positive feedback system as previously accepted.

http://www.nytimes.com/2016/03/16/science/global-warming-climate-change-trees-carbon-dioxide.html?rref=collection%2Fcolumn%2Ftrilobites

http://blogs.ei.columbia.edu/2011/02/12/how-plants-could-impact-global-warming/