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Phytoplanktons and the Climatic Balance
Apr 1, 2007

At the oceans’ shores, the dominant odor one can feel is that of iodine, a salty smell that arises from bubbles and waves and that is spread over the sea by the wind. Mixed with this salty odor are the gases that are released from phytoplanktons, the microscopic plants in the ocean.

There are many identified species of phytoplanktons. Phytoplanktons live for a day or two under normal conditions, and when they die they sink to the bottom. As a single-celled organism, phytoplankton is not only one of the main components of marine food chain, it is also assigned with an important role in carbon cycle which keeps atmospheric temperature in balance and the level of oxygen under control. Because of their significance, scientists have always showed considerable attention to phytoplanktons.

Photosynthesis in phytoplanktons

All living things need energy and organic building blocks in order to grow and maintain their lives. Plants transform sunlight into chemical energy and inorganic materials to organic materials. This process is called photosynthesis. Other living organisms consume plants to meet their food and energy needs. Like terrestrial plants, phytoplanktons also have chlorophyll pigments to process photosynthesis. This is how fish and other animals in the oceans obtain their food.

Global effects

The larger the world’s phytoplankton population, the more carbon dioxide gets pulled from the atmosphere through photosynthesis. Carbon dioxide is responsible for as much as 50% of the total greenhouse effect. There is a divine wisdom behind existence of phytoplanktons in big populations which help with the adjustment of carbon dioxide level in the atmosphere and thereby the greenhouse effect.

Phytoplanktons have an interactive relationship with their environment. This interactive relationship either increases or decreases the population of phytoplanktons in accordance with environmental changes. Scientists have found that a given population of phytoplankton can double once per day. Large populations of this organism, sustained over long periods of time, could significantly lower atmospheric carbon dioxide levels and, in turn, lower average temperatures. Populations of this marine plant will grow or diminish rapidly in response to changes in its environment. Changes in the trends for a given phytoplankton population-such as its density, spatial distribution, and rate of population growth or diminishment-will alert scientists that environmental conditions are changing there.

Phytoplanktons and sulfur cycle

Dimethylsulfide (DMS) is a sulfuric compound which is synthesized by phytoplanktons. This compound has an important role in softening climate and cloud formation. It has a peculiar odor and although it is frequently perceived as a harmfully polluting chemical, it fulfills a very important task within the bio-geo-chemical cycle on Earth. In order to better recognize climate changes on a global scale and to develop smarter environmental politics, we need to know more about this gas compound.

The production of DMS is dependent upon co-existence of various organisms. Some species of phytoplanktons synthesize the dimethylsulfoniopropionate (DMSP) molecule, from which DMS is broken down. Bacteria and phytoplanktons participate in this break down which assimilates DMSP into DMS or other compounds. Some of the produced DMS vaporizes into the atmosphere from the salty sea water and become tropospheric sulfate gas after oxidization. Consequently, this gas plays a direct role in the global radiation balance by the upward scatter of solar radiation, and an indirect role as cloud condensation nuclei (CCN). Clouds affect the Earth’s radiation balance and thereby greatly influence its temperature and climate. DMS represents 95% of the natural marine flux of sulfur gases to the atmosphere, and scientists estimate that the flux of marine DMS supplies about 50% of the global biogenic source of sulfur to the atmosphere.

In order for the sulfuric cycle in nature to continue, it is necessary that sulfuric compounds are transferred from the ocean to land through the atmosphere. DMS, the source for 95% of natural sulfuric gas coming from the oceans, served as cloud condensation nuclei and helps carry sulfuric compounds move to the land with rain.

DMS emissions that originate from phytoplanktons play a significant role in climate formations. One third of the radiation coming from the sun reflects back into the space from the clouds, ice, and snow. The remaining two thirds is absorbed to some extent by the atmosphere, and to a greater extent by oceans and rocks. This energy is converted to heat some of which is later reflected by land and ocean as ultraviolet rays towards the space warming the atmosphere. If the Earth intakes more energy than it loses, the end result is global warming; the opposite is global cooling.

The size of clouds and water driblets indicate global climate changes. The more cloud condensation nuclei (CCN), the smaller the water droplets and the denser a cloud. This, in turn, influences the cloud’s radioactivity.

DMS containing chemical reactions from poles to tropical waters are important for us to estimate man-based and natural effects on the chemistry of atmosphere and the climate more accurately. It sounds somewhat weird for us that we first destroy the environmental balance God has established before we try to discover what we have done using the natural laws He has enjoined.


  • Norris, K.B., 2003. “Dimethylsulfide emission: Climate control by marine algae?” ASFA: Aquatic Sciences and Fisheries Abstracts, http://www.csa. com/discoveryguides/dimethyl/overview.php