By Yvonne Ndungi

Oceans absorb 60% more heat than previously estimated, Princeton University researchers established. It is a clear sign that the Earth is warming faster than anticipated.  The effects of climate change are more glaring ranging from wildfires, prolonged droughts and intensified storms. Scientists have issued endless warnings of increased global temperature mainly caused by human activities.

Published evidence indicates that the net damage costs of climate change are steadily rising. Climate change has a negative impact on food production thus lowering the supply for an increasing human population. Rising sea levels caused by melting snow are slowly gnawing into habitable coastlines. The climate change phenomenon is initiated by greenhouse gases mainly methane, CFC’s and highest of all, carbon dioxide (CO2). To achieve the earlier target, set by the Intergovernmental Panel on Climate Change (IPCC), of reducing global temperatures by 20C, CO2 emissions must be reduced by 25% of the previous approximation.

Natural climate solutions have been advocated to counter the worrying trend. Dubbed as ‘planet re-greening’ the global community has sought methods such as afforestation, agroforestry and reforestation to increase the world’s forest cover. Trees absorb and store CO2, it is part of an elaborate carbon cycle process that strikes a balance of CO2 in the atmosphere.  Destruction of trees through deforestation inhibits the absorption of carbon gases from the atmosphere. Carbon dioxide hinders heat from being released through the ozone layer causing an increase in global temperatures bringing about global warming. The resultant environmental vagaries such as heat waves, tornados and downpours become common occurrences.

The importance of trees cannot be underestimated, tree planting sequestrates 1.1-1.6 giga tones (GT) of CO2 annually. It was recently postulated that afforestation has the potential of removing 1-3 GT carbon dioxide per year in 2030. In 2016 the total greenhouse gas emissions amounted to 49.3 GT of CO2 in 2016.


The late Nobel Laureate Prof. Wangari Maathai was an advocate for forest conservation through the Green Belt Movement. Pictured here planting trees.
The late Nobel Laureate Prof. Wangari Maathai was an advocate for forest conservation through the Green Belt Movement. Pictured here planting trees.

In the presence of the sun’s energy, trees take up CO2 in a biological process known as photosynthesis, to form the plant biomass. By using the atmospheric carbon, they soak up heat hence leaving a cooling effect. Trees absorb water from the soil releasing it into the atmosphere through evaporation, forming clouds that reflect the sun's hot radiations. More so, plants regulate water supplies by releasing or holding water during droughts and flooding respectively. Trees control soil erosion thereby improving water quality downstream and maintaining soil quality upstream. Plants provide habitats to species that may be in the path to extinction and which represent a loss to natural capital.

On average, trees take 50-100 years to grow large enough to absorb substantial amounts of CO2. In a 20-year lifecycle, trees absorb about 40,000 tons of carbon dioxide per square kilometer. A tree plantation of hundred square kilometer has the potential to absorb 4m tons of CO2 for a period of 20 years. It is equivalent to absorbing carbon emitted by fifty thousand cars in their service life. United Kingdom forestry commission observed that, a half hectare of conifer woodland can store CO2 emitted from a vehicle fuel during one average driver’s time.

Forest regeneration face a host of formidable setbacks. Periodical wild fires, tree mauling pests, disease, high cost of acquiring land compounded with protecting young trees are variables that derail quick spread of tree cover. Emergence of a need for biofuels are creating a gruesome competition with afforestation efforts. Critics of reforestation maintain a solid argument that the process lacks accurate reflection on climate change credits.  On those grounds, validity and accuracy of methods to measure accrued benefits are in doubt. Furthermore, they raise the concern ethics of ‘offsetting’. In their view, trees have a compensatory effect rather than eliminating the carbon sources. Lastly, plantations have reported detrimental social and environmental impacts such as displacements. 

Nevertheless, tree planting initiatives should be encouraged on annual basis across the globe. Small well-coordinated activities that contribute to reclaiming the environment are vital. Everyone should get involved and act to the global goal of making this world a better place for us and generations to come. Let us grow beyond anti-literacy conspiracy that climate change is a scientific hoax and act on logic, evidence, facts and proof.