Trees & Pollution
-Usha Nair
‘The woods are lovely, dark and deep’ Robert Frost
Trees have always been a fascinating subject for poets, authors, painters, and dreamers from time immemorial. To the individual, the grace and beauty of trees have brought a lot of joy, inspiration and peace. Over centuries, trees have provided leaves,
fruits, flowers and wood to men, and have been the home to so many insects, birds and animals. Many tribes worshipped trees. Yet increasing urbanisation and the resultant deforestation have led to growing concerns regarding the debilitating impact on environment
and health. Consequently today, environmentalists, urban town planners, public health officials, and even nations are looking at trees with greater respect and highlighting its major role in reducing air pollution.
Till the 20th century, trees were viewed as providing aesthetic, social and natural benefits. Trees were regarded as the ‘lungs of the planet,’ absorbing carbon dioxide and through a process of photosynthesis, releasing oxygen. The 20th century witnessed
the cumulative / multiple disastrous consequences/ effects of man’s irreverent actions / disrespect to nature. Pollution, today, is a household concern as environmental health problems adversely affect everyone, both in developed and developing countries.
Pollution has spread across the planet and is ubiquitous in form, pervading and penetrating the air we breathe, the water we drink, the food we eat, and demanding now, urgent attention, which we failed to give, hitherto. A century back, oil spills, radioactive
waste, mercury poisoning, agricultural and pharmaceutical generated pollutants, plastics, untreated sewage, lead poisoning, air pollution and emission of greenhouse gases,(Bryan Nelson) never occupied the mind-space as it does today. Compelling statistics
have proven the link between pollution and increased number of deaths and suffering patients all over the world ,thereby bringing forth issues, that had till now been festering on the backburner. Living greener is now a necessity for every household in every
part of the world.
Human activity since the Industrial Revolution, have increased the amount of greenhouse gases in the atmosphere. Fossil fuel burning and changes in land use, particularly deforestation, have contributed to concentration of greenhouse gases in the atmosphere,
causing global warming and climate changes. The greenhouse effect is the process by which absorption and emission of infrared radiation by gases warms the lower atmosphere and surface. Major greenhouse gases are water vapour (70% of the greenhouse effect)
Carbon dioxide (26%), methane (9%), and ozone (7%). The burning of coal, oil and other fossil fuels, pesticide use, household combustion devices, motor vehicles, mining operations, industrial facilities, forest fires and manufacturing chemicals are common
sources of air pollution. Tailpipe emissions of automobiles and trucks is a major public health concern and contains significant pollutants including carbon monoxide(CO),volatile organic compounds(VOC),nitrogen oxides(NOx) and particulate matter(PM). Air pollution
contributes to asthma, emphysema, heart disease and impacts pulmonary, cardiac, vascular, and neurological and other potentially lethal conditions.
Source: PBL Netherlands Environmental Assessment Agency/Wikipedia
Air pollution, both indoors and outdoors, is today a crisis and recognised so. There is widespread awareness of the fact that reduced air pollution contributes to improved health. Trees today are vital to combat air pollution. Trees are Nature’s answer
to reducing air pollution and a deterrent to respiratory problems. Trees and urban forests contribute to cleaner air and are recognised as an integral component of our battle to reduce air pollution. In an article on the Effects of Urban Trees on Air Quality,
David J. Nowak lists several benefits from the planting of trees. Researchers at the Davey Institute found that urban trees and forests are saving lives because of the particulates that they remove from the air. A study in the Journal of Preventative Medicine
found that people experienced more deaths from heart disease and respiratory disease when they lived in areas where trees had disappeared. Forests provide natural filtration and storage systems providing cleaner water. Additionally, trees can hold vast amounts
of water that would otherwise stream down hills and surge along rivers and flood into towns. That’s why trees are such an important part of storm-water management and flood control for many cities. Novak talks of carbon sequestration. Burning fossil fuels
puts heat-trapping carbon dioxide into our atmosphere, changing our climate in dangerous ways. Planting trees can slow down this process. A tree can absorb as much as 48 pounds of carbon dioxide per year, and can sequester one ton of carbon dioxide by the
time it reaches 40 years old. Trees lower ozone concentration. Trees contribute to temperature control. The shade and wind-breaking qualities that trees provide benefit everyone from the individual taking shelter from a hot summer day to entire cities. The
annual mean air temperature of a city with 1 million people or more can be 1–3°C warmer than its surroundings. Planting trees reduces this “heat island effect”. And households with shade trees could spend 12% less on cooling costs in the summer. By protecting
trees, we also save all the other plants and animals they shelter, thus promoting bio-diversity. Several studies have found that access to nature yields results in better cognitive functioning, more self-discipline, and improved mental, emotional and psychological
health.
During the 21st century, global surface temperatures have been found to have risen alarmingly.14 out of the 15 hottest years has been in the 21st century. It is anticipated to rise further. Visible and predictable effects of climate change include, warming
global temperatures, rising sea levels, changing precipitation, expansion of deserts in the sub-tropics. Warming is expected to be greatest at the Arctic/Antarctic with the continuing retreat of glaciers, permafrost and sea ice. Other likely changes include
more frequent extreme weather events including, heat waves, drought, heavy rainfall and snowfall, smog & haze (reducing sunlight to plants to carry out photosynthesis resulting in the production of tropospheric ozone which damage plants), ocean acidification
with concurrent effect on marine ecosystems, species extinction, adverse impacts on biodiversity, threat to man’s food security.
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Today, the right to breathe clean air has galvanised nations to work together, through the Intergovernmental Panel on Climate Change, to mitigate global warming by emission reduction, adapting to and building systems resilient to its effects, and jointly
explore future climate re-engineering. They strive towards a low carbon economy through energy conservation, energy efficiency, renewable energy, nuclear energy, carbon capture and storage, enhancing the capacity of carbon sinks to absorb GHGs from the atmosphere
through reforestation and preventing deforestation. Parties to the UN Framework Convention on Climate Change (UNFCCCC) have adopted a range of policies designed to reduce greenhouse gas emissions, so that future global warming is restricted to below 2.0*C
relative to the pre-industrial level and a global average rise of 1.5*C. It is another matter that achieving this goal in the short term appears to be a distant dream, as nations and people struggle to respond to the demands that this goal entails. The big
question posed in the 2014 ‘Report titled Trends in Global CO2 Emissions’ is “when will global carbon emissions level off and start declining in absolute numbers and at what rate”.
Trees, as is evident, are vital to reduce air pollution. Man now faces the uphill and unenviable task of restoring the balance of Nature. Ultimately, Time will tell whether Man is able to effectively resolve the dilemma of promoting development, and yet
ensuring restoration and reforestation of the deep and lovely woods.
Pic of tree from http://compassionkindness.com/
((Usha Nair is a nature lover who can be contacted at ushaenvironment@gmail.com)