The Potential of Carbon Sinks - Part 2

Land Carbon Sinks:

Here I refer to the term Land Carbon Sink in lieu of forests and plants. These forests and plants are a very important part of the carbon cycling process, by means of photosynthesis the land carbon sinks utilise the carbon dioxide in the air and release oxygen. Prominent land carbon sinks are in northern Eurasia and northern Africa. These are natural processes, but the question remains – how have they evolved and to what extent will they continue future climate. What is interesting is that there has been an increase in land carbon sinks in the late 1980’s (figure 4). The following video is a summary of the Buermann et al (2016) paper which queries the increase in land carbon sinks and attributes the rise of them to natural climate variability.

As the video highlights, the prevalence of natural climate variability enhanced and enabled the ability of the growth of land carbon sinks, meaning that the presence of anthropogenic carbon dioxide wasn’t the sole factor in the increase of the sinks. This means that when considering the ability to store the anthropogenic carbon dioxide now and in the future, it could be that the earth may not have the capacity it does today to act as a land carbon sink upon the intervention of climate variability not acting in the favour of land carbon sink expansion.

There are several various factors that need to be considered in contemplating land carbon sinks. Even though all plants utilise carbon dioxide, they do so in different ways, the differentiation stems (pun intended) variations in specific plant or crop type, localised environmental conditions and whether the plant is a C³ or C⁴ species (informing the carbon fertilisation effect (CFE) of the plant - C⁴ plants are better equipped to photosynthesise carbon dioxide than C³ plants. This is as the enzyme rubisco is not saturated in C³ plants whilst it is in C⁴ plants. Lack of saturation of the rubisco enzyme leads to a loss of carbon dioxide from the plant, making the photosynthesis process inefficient) (McGrath and Lobell 2013).

There is a great potential for land and ocean carbon sinks to help mitigate our climate ordeals, yet there are also great risks involved as discussed above.