By Dr D Bandyopadhyay
Word Research can be written as ‘Re’- meaning again, and ‘search ‘ meaning explore, probe, hunt through, etc. In other words research is equal to re-examining past findings & look through the past records to find new or erstwhile missing clues to get better / incremental values. As perfect truth lies at infinity, so (re-) search will continue to go on till eternity. Philosophically it is synonymous to saying in Upanishad, “_Charaiveti charaiveti” _ , ‘চরৈবেতি চরৈবেতি’, move forward without stopping for brighter tomorrow.
Now-a-days climate-change due to human activities in modern (industrial) times is the most discussed / debated subject. It is causing a telling effect on planetary balance on entire eco-system comprising of both plant and animal (including human) kingdoms. Increase in atmospheric temperature, erratic rainfall pattern, rapid melting of polar and high attitude glaciers, enhanced intensity & frequency of cyclonic storm formation, rise in mean sea level resulting loss of huge land mass, etc. are slowly but surely pushing us to our peril. Surely mother-nature by its unique way will act in distance future to trap environmental greenhouse gases (GHGs) inside the earth crust in form of carbonates to begin the fresh episode of ice-age. But by that time we all would be extinct within a few centuries, if not decades.
Since the onset of industrial times in the 18th century, human activities have raised atmospheric CO2ppm by 50% – meaning the amount of CO2 is now 150% of its value that was in 1750. This human-induced rise is greater than the natural increase observed at the end of the last ice age 20,000 years ago. About hundred years ago in this era of elevated & so called social development by application of science & technology, GHGs has increased its share in composition of air at Polar Regions also. At present 420 parts per million (ppm) of CO2 was 365ppm in 2002 at equatorial region, whereas CO2 was 265ppm at the beginning of industrial revolution in the year of 1750. Concentration in polar region has reached 400ppm in recent past.(1 ppm = 0.0001%).
As of March 2024, the monthly average concentration of CO2 reached a new record high of 425.22 ppm, marking an increase of 4.7 ppm over March 2023. By the latest measurement, levels had further escalated to 427.48 ppm. This continuous increase in CO2 concentrations is a clear indicator of ongoing global environmental stress, primarily driven by the burning of fossil fuels, which is the principal cause of this rise and also a major contributor to climate change. Other significant human activities that emit CO2 include cement production, deforestation, and biomass burning.
Now, let us turn our attention about distribution pattern of CO2 in the atmosphere on the entire earth surface, poles to equator, northern hemisphere against southern half.
1) On the average, regular air composition, CO2 is the heaviest molecule with gas density (D) = 22, followed by O2 (D=16), N2(D=14), water vapour (D=9), inert gases, etc with H2 being lightest. On the basis of partition due to varying centrifugal force acting on different gas molecules on account of earth’s spinning around its axis, CO2 being heaviest would be largely concentrated on its equatorial belt.
2) Due to Brownian movement all gas molecules would tend to be statistically distributed equally on entire globe.
3) Due to oceanic equilibrium & CO2 evolution in near equatorial, specifically, Pacific region, more of CO2 is likely to be found in northern equatorial region.
4) The equatorial low-pressure belt is also known as ‘Doldrums’, meaning ‘the zone with no winds’. There is often little surface wind in the region as air rises due to the heat of the Sun. In other climate zones, like, temperate zone, trade wind zone, etc, wind plays a major role in pressure equalization & mixing of all components.
5) Due to hot & humid weather, vegetation in rain forest areas of Amazon belt in American continent, Congo in Africa or Indonesia in Asia, etc are more; so consumption / stripping of CO2 from atmosphere is more than pole-region with less /no vegetation. Leaves of plants there are rich in chlorophyll, high moisture content and strong sun ray help plants there to trap CO2 from air to turn it into carbohydrates & other organic compounds for plant’s rapid growth. Conversely, less consumption means availability of CO2 in other regions remains more.
There might be many other mutually opposing factors that are affecting local availability of atmospheric CO2.
Net effect of these factors shows that the concentration of GHGs is more at equatorial belt compared to polar region.
Since 1750 & especially in the last 100 years we have largely denuded equatorial ever-green rain-forests to a large extent for our greed for valuable timbers, clearing of large area for space creation and many other human needs of modern times.
Global community presently under various guidelines and protocol, like Kyoto protocol, Paris agreement, etc are focusing on ways & means of reducing GHGs, especially restricting CO2 coming out during burning of fossil fuels & bio-mass. Modern life cannot move even a day without using energy basket comprising mainly of coal, oil & natural gas. Many countries are focusing to increase share of renewable & bio-fuels. But real change is only possible when we will be able to switch to green hydrogen based energy economy to occupy majority of the space currently held by fossil fuels. Technical challenges to achieve this switch-over are being addressed to slowly, but surely. But time is running out to arrest further degradation. Here comes the need for short term and immediate actions.
Carbon sequestration means sucking out CO2 from atmosphere and dumping it under suitable sub-surface strata below the earth surface. This method is being tried by many agencies, but it is costly & viability of its implementation in large scale is under cloud. But natural way to trap atmospheric CO2 by planting trees & allowing/ facilitating it to grow fast is cheap and sustainable one.
We have already discussed that rain forests around equatorial belt is the best place for rapid & deep, sustainable growth of large plants due to hot & humid climatic condition with more photons from almost vertical sun rays falling on the leaves and a bit higher concentration of CO2 in the air. Leaves here look a bit deep green probably due to adequate presence of catalyst chlorophyll (porphyrin ligand with Magnesium as central metal cation) on them. All these conditions are highly conducive for rapid conversion of atmospheric CO2 into plant’s organic (here with double meanings) food, body, thereby striping equivalent amount of GHG from surrounding air.
As the problem of climate change due to excessive GHG content in air has become acute in nature for survival of almost all the flora & fauna of the entire globe, the situation also demands some attentive & urgent measures at global level. So all international fora having necessary political, economic, social, ecological clout to influence one & all, must join hands for joint action plans to:
1) to arrest any further deforestation, 2) Restoration of natural rain forests by planting of saplings suitable for the those areas, 3) Creating local rural and urban mini-forests in their dedicated regional zones in the belt with latitudes from 23°N to 23°S. From central to southern India falls in this belt, 4) Beyond the tropic of cancer & tropic of Capricorn, and the Arctic or Antarctic Circles at 66°33′ north or south latitude, there lie many grass lands as well as arid lands. These areas are to be covered by specific plants suitable for specific climatic condition of that place. With lesser availability of rain / moisture in air & in ground, in arid region plantation of Jatropha like plants having potential of veg oil bearing fruits would have double benefits. Non-edible Jatropha oil can easily be transformed into bio-diesel by cross-estarification with alcohol, like, methanol. Bio-fuels on burning produce CO2, but a look-back into the genesis of fuels through the prism of carbon cycle, says that bio-oil/gas is from atmospheric CO2, so net production of GHG is zero. This way we can take it somewhat easy for sometime till alternate non-fossil fuels internationally take over the energy economy of this beautiful planet. Plants not only clean the air, also help retain the moisture in the air & of the ground. It plays a big role in soil-conservation.
So the slogan rightly says: Plant trees, Save lives on the earth!
About the author: Dr D Bandyopadhyay, MSc PhD, is a retired General Manager of ONGC