Forest conservation and restoration may not have as much of an impact in fighting climate change as mainstream science currently dictates. For many years now, scientists have thought that because trees take in carbon dioxide during photosynthesis, planting them would naturally sequester carbon and help fight climate change. But recent research into the matter shows that this understanding may be an oversimplification of how trees interact with the atmosphere.

A 2014 research, for example, found that volatile gases emitted by trees actually contribute to the warming of the planet. When mixed with airborne pollutants from vehicles and industries, these compounds give rise to ozone and methane—powerful greenhouse gases that trap heat in the atmosphere.

On top of this, dark green forest canopies absorb more heat than do fields, the bare ground or snow. This absorption may be more or less exaggerated depending on the species of the tree (and the colour of their leaves). This means that when it comes to planting forests, location and tree species matter. A lot. In the tropics, for example, where trees grow relatively fast and transpire significant amounts of water that eventually form clouds, forests help with cooling. Meanwhile, in temperate areas, where forests grow more slowly and cover up snowfields, the effect can be the exact opposite.

A study found that European forests, more than 85 percent of which are currently managed by humans, had, over the course of two-and-a-half centuries, actually contributed to increased warming instead of decreasing it. The researchers attributed this trend to the replacement of natural lighter-canopied broadleaved forests with plantations of darker-canopied coniferous species that tended to absorb more heat.

In addition to determining that sequestration capacity is, in fact, affected by tree species, this study also demonstrates that carbon sequestration is more efficient in natural forests than in those managed by humans. Scientists have determined that naturally standing forests are six times more effective than agroforests and forty times more efficient than plantations at storing carbon. This is because, among other reasons, harvested trees release massive amounts of stored carbon into the atmosphere. Yet, almost half of the areas pledged by countries for the 2011 global effort to restore 150 million hectares of forests, are monoculture plantations. A move that, while highly symbolic, is unlikely to significantly alter carbon concentration in the atmosphere.

Diversified portfolio required

Planting trees is beneficial for humans and the planet in a number of ways—from biodiversity protection to filtration of air and water. My objective in writing this article is not to bring into question the value of planting trees but to rather answer the question: How far can we expect forests to take us in our fight against climate change, especially when there are no clear global guidelines regarding their management?

Emerging research shows that for mitigation outcomes, forest management has to be context-specific. Unfortunately, we have no clear indication of how billions of dollars’ worth of forest carbon management programmes like Reducing Emissions from Deforestation and Forest Degradation (REDD+) are faring when we take into account these recent findings. Additionally, a recent meta-analysis of various REDD+ projects shows that the carbon outcomes of these schemes have also not been well accounted for. Simply put, we have no clear indication of how far forests have bought us in our fight against climate change.

Scrapping carbon management programmes like REDD+ entirely is not the answer because, when well executed, these programmes have the potential to generate social, biodiversity and climate mitigation benefits. A better strategy would be to become more cognisant of new developments in the field and adopt a continuously adapting management strategy. But this is easier said than done, and it might take years before these programmes start generating the mitigation outcomes we want.

Not putting all our eggs in one (carbon sequestration) basket, and diversifying our climate change mitigation portfolio is crucial. Too much focus on building systems that absorb carbon emissions, experts worry, could distract policymakers from making efforts to actually reduce the emissions in the first place.

In addition to carbon sequestration, current mainstream mitigation strategies focus mostly on adopting renewable energies and sustainable modes of transportation—i.e. technocratic solutions that are more inclined towards reducing the impact of consumption, rather than reducing consumption itself.

The insatiable consumer

Climate change, at its core, is a problem created by excessive consumerism. A 2015 study finds that household consumption is responsible for three-fifths of global emissions today. Not surprisingly, the study also finds that consumerism rises with income and that richer populations show a much higher rate of such behaviour than poorer ones. For example, researchers calculated that the per capita consumption of an average American citizen is ten times that of an average Chinese. It is reported that countries that have the highest rates of per capita consumption—i.e. the United States, Luxembourg, Australia etc.—have 5.5 times more environmental impact than the world average. (It is also worth noting that 80 percent of these impacts occur within the supply chains of the products and go largely unnoticed by an average consumer, effectively meaning that our environmental footprints are often much bigger than we realise.)

While it is impossible to reduce household emissions in their entirety, it can be lowered significantly if richer populations were to change their relationship with the goods that they consume. When people mindlessly indulge in fast food, fast fashion and new electronic fads, they incentivise brands and companies to produce low-grade products and services that often have high environmental impacts.

Markets respond to demand and unless consumers demand environmentally (and socially) conscientious products, this tide will not turn. Even if we were to assume that there was enough political will and funding to plant carbon-sequestering trees in all viable land worldwide, we would be able to sequester less than a third of the 620 (and steadily rising) gigatons of carbon emissions. This is simply not enough to avert the punishing effects of climate change. The only way to sustainably mitigate for climate change is to put a check on our consumption and environmental footprint. Sequestering carbon emissions in trees is, at best, a stopgap measure.

***

What do you think?

Dear reader, we’d like to hear from you. We regularly publish letters to the editor on contemporary issues or direct responses to something the Post has recently published. Please send your letters to [email protected] with "Letter to the Editor" in the subject line. Please include your name, location, and a contact address so one of our editors can reach out to you.