Trees and Climate Change by Marlon Pareja

by: Marlon Pareja, DLSUD

What is climate change?            

 Sunlight is the primary source of energy of the earth.  Most of the light that penetrates and the heat generated by it due also to the dynamic inter-plays of the living and non-living a thing in our planet permeate into outer space.  But due to a lot of anthropogenic (human-made) activities like burning of fossil fuels that generate energy for our industrial, domestic, commercial and transportation needs, we have released lots and lots of “greenhouse gases” (GHG).  These GHG are believed to trap the heat in our atmosphere that prohibits it from being released into outer space (the greenhouse effect). These “trapped’ heat creates a very significant effect in the mean global temperature and global climate.  There are evidences that prove that the increase frequency and intensity of typhoons coming into the Philippines is caused by climate change. More than half of the greenhouse gases we release into atmosphere are carbon dioxide (CO2).  

Can planting trees mitigate the effects of climate change?            

A BIG YES!  Trees remove (sequester) CO2 from the atmosphere during photosynthesis to form carbohydrates that are used by the plant for its growth and development. Trees, therefore, act as a carbon sink (repository)  by removing carbon and storing it as cellulose in their trunk, branches, leaves, roots, flowers and fruits while releasing oxygen (that is essential to our survival) back into the air.            

Trees also reduce the greenhouse effect by shading our homes and office buildings.  This reduces air conditioning needs up to 30% thereby reducing the amount of fossil fuels (and further CO2) burned to produce electricity [1].            

A single mature tree can absorb carbon dioxide at a rate of about 22 kg/year and release enough oxygen back into the atmosphere enough to support 2 human beings [2].  A hectare (ha) of trees can sequester about 6.5 tons of carbon each year which can compensate to the amount of carbon dioxide released by an automobile that has travelled about 14,000 km [3].            

The combination of CO2 removal in the atmosphere, carbon storage in wood and the cooling effect of trees make planting trees one of the cheapest and most effective means of mitigating climate change [4].  

What are the other benefits of planting trees?  

Saves Energy.

                 The United States Forest Service (USFS) estimates that putting well-positioned trees in conventional houses will reduce energy consumption by 20-25% [5]. Trees lower local air temperatures by transpiring water and shading surfaces.  Because they lower air temperatures, shade buildings, they can reduce energy use and cooling costs.  

Increase Traffic Safety.

                  Tall trees give the perception of making a street narrower, slowing down traffic.  A treeless street enhances the perception of street being wide and free of hazard, thereby speeding traffic that can lead to accidents [6].

Protect us from Floods waters.

                   Trees reduce topsoil erosion, prevent harmful land pollutants contained in the soil, slow down water runoff (water that cannot be further absorbed by the soil), and ensure that our groundwater supplies are continually replenished.  For every 5% of tree cover added to a community, storm water runoff is reducing by about 2% [7]. 

Sociological Benefits.

                    Studies have shown that hospital patients with a view of trees out their windows recover much faster and with fewer complaints than similar patients without such privilege [5]. Researchers also found that there are fewer reports of physical violence in homes that had trees outside their buildings [4]. A U.S. Department of Energy study also reported that trees reduce noise pollution by 50% by acting as a buffer and absorbing noise.  What does it take to plant a tree? Over a 50-year lifetime, a tree will generate Php 1.5 million worth of oxygen, about Php 3 million worth of air pollution control, recycles Php 1.8 million worth of water, and controls Php 1.5. Million worth of soil erosion. Imagine if there are 1 million trees planted! And yet it will only take less Php 100 to plant and nurture a tree [8]. So support and join our tree planting activities now, it is worth a lifetime!     

References: [1]  ___________. Benefits of Urban Trees. Michigan State University Extension, Urban Forestry #07269501.

                  [2]  McAliney, M. 1993. Arguments for Land Conservation: Documentation and Information Sources for Land Resource Protection, Trust for Public Land.         

                        Sacramento, CA.

                  [3]  Nowak, D. Benefits of Community Trees.USDA Forest Service General Technical Report.

                  [4]  Prow, T.  ___.  The Power of Trees. Human Environmental Research Laboratory at the University of Illinois, USA.

                  [5]  _________1999.  How Trees Fight Climate Change. American Forest publications.

                  [6]  National Arbor Day Foundation pamphlet #90980005.

                  [7]  Coder, K. 1996.  Identified Benefits of Community Trees and Forests.University of Georgia, Ga., USA.[8]. USDA Forest Service Pamphlet # R1-92-100.