Warming is accumulation of carbon dioxide, methane and other air pollutants collecting in the atmosphere like a thickening blanket, trapping the sun s heat and cuasing the planet to heat up.
The green house effect or increasing world temperature is due to the accumulation of carbon dioxide as a result of combustion of fossil fuel methane is responsible for some of the depletion of the protective ozone layer. Methane arises largely from natural anaerobic ecosystems, rice paddies and ruminant animals.
Effects of Global warming:
i. Rapid melting of glaciers will cause floods in widespread damage to crops and livestock.
ii. Aberrant weather changes resulting in droughts and floods. Nearby two thirds of the kharif crop-paddy, oilseeds and pulses is at risk due to little or no rainfalls.
iii. Forests, farmer and cities will face troubles some new pests and more mosquito borne diseases.
iv. Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.
v. Decreased crop fields and decreased arable land availability with subsequent starvation and malnutrition.
vi. Warm and weather conditions will increases the level of infectious diseases.
vii. The rising sea is expected to increase salinity across India’s coastline.
United Sates of a America having only 4 percent worlds population, produce 25 percent of the carbon dioxide pollution from fossil-fuel burning (the largest share of any country). In fact, the United States emits more cabon dioxide than China, India and Japan combined.
i. Maximum support should research and development efforts that will enable fossil-derived fuels to be replaced by biomass-derived fuels.
ii. In the tropical countries, wetland rice may have to be discouraged in favour of dryland cereal production.
iii. In developing countries the production systems are much less dependent on inputs of fossil fuel.
iv. Emphasis must be given to crops that are most efficient in fixing carbon dioxide into biomass.
v. Non renumerative species (especially pigs, poultry rabbits) should be promoted as meat producers, while meat production from ruminants should have a lower priority.
The consequences of global warming are dangerous. There should be a massive movement towards environmental friendly strategies that minimize production of carbon dioxide and methane.
Phytoremediation is the direct use of living plants for remediation of contaminated soil, sludges, sediments, or ground water through contaminant removal, degradation, or containment of the contaminant(s). Growing and, in some cases, harvesting plants on a contaminated site as a remediation method is an aesthetically pleasing, solar-energy driven, passive technique that can be used to remediate sites with shallow, low to moderate levels of contamination.
Significance of phytoremediation:
Phytoremediation takes advantage of natural plant processes. It requires less equipment and labour than other methods since plants do most of the work. Trees and plants can make a site more attractive as well. The site can be cleaned up without removing polluted soil or pumping polluted ground water. This allows workers to avoid contact with harmful chemicals. Phytoremediation has been successfully tested in many locations.
The time it takes to clean up a site using phytoremediation depends on:
i. Type and number of plants being used
ii. Type and amounts of harmful chemicals present
iii. Size and depth of the polluted area
iv. Type of soil and conditions present
These factors vary from site to site. Plants may have to be replaced if bad weather or animals destroy them. This adds time to the cleanup. Often it takes many years to clean up a site with phytoremediation, tree roots take in water and pollution from the ground polluted soil water enters tree where pollution is cleaned up.
Phytoremediation works best at sites with low to medium amounts of pollutions. Plants remove harmful chemical from the ground when their roots take in water and nutrients from polluted soil, streams, and ground water. Plants can clean up chemicals as deep as their roots can grow. Tree roots grow deeper than smaller plants, so they are used to reach pollution deeper in the ground. Once inside the plant, chemicals can be:
i. Stored in the roots, stems, or leaves.
ii. Changed into less harmful chemicals within the plant.
iii. Changed into gases that are released into the air as the plant transpires (breathes).
Phytoremediation uses one basic concept: the plant takes the pollutant through the roots. The pollutant can be stored in the plant (phytoextraction), volatized by the plant (phytovolatization), metabolized by the plant (phytodegradation), or any combination of the above. Phytoextraction is the uptake and storage of pollutants in the plant’s stem or leaves. Some plants, called hyperaccumulators, draw pollutants through the roots. After the pollutants accumulate in the stem and leaves the plants are harvested. Then plants can be either burned or sold. Even if the plants cannot be used, incineration and disposal of the plants is still cheaper than traditional remediation methods.
In addition to transporting nutrients, certain plants are capable of transporting environmental pollutants such as metals, radionuclides, chlorinated solvents, petroleum hydrocarbons, and ammunition wastes through biological means.
Contaminants and contamination levels:
Phytoremediation is effective in the remediation of all types of soil contaminants; however it is more effective on lower concentration of contaminants.
Types of Vegetation Used:
Some of the plants used in phytoremediation are:
Hybrid Poplar Trees
Yellow or White Water Lillies
Vetiver grass combined with applications of zeolite is being used to remove boron, cadmium and lead from indonesian soils contaminated by sludge from the textile industry.
Fate of contaminants:
Once plants extract environmental contaminants, these contaminants are either broken down by the plant into non-hazardous substances or concentrated within plant tissues.
Concentration of contaminants in plant material gives rise to the possibility of animals and insects consuming the contaminated material thereby introducing contaminants into the food chain.
Pros and Cons of Phytoremediation
Phytoremediation is cost effective.
It is suited to remediation of large areas of soil.
It is environmentally friendly.
Phytoremediation sites are more aesthetically pleasing.
Phytoremediation sites require low maintenance.
It involves no noisy and expensive equipment.
Not as effective for sites with high contaminant concentration.
Phytoremediation is slower than conventional methods.
It does not work through (Seasonally effective).
Risk to wildlife/food chain.
It is the responsible travel to ш conserves the environment and welfare of the local people. Eco growing component of the larger tourism industry.
Benefits of Ecotourism
i. It is an environment friendly and potentially more sustainable alternative to extractive activities. Such as farming, logging and mining.
ii. It offers local people the chance to escape from a cycle of poverty and by sharing their knowledge of the local terrain ecology with visitors.
iii. Business initiated through ecotourism ventures can become self sufficient with in a short span of time and can enhance the long term economic prospects of a community.
i. It is an opportunity to preserve ecosystems and biological diversity.
v. It can create jobs in remote regions.
vi. Protected areas and nature conservation provide many benefits to society including preservation of biodiversity.
Dangers of Ecotourism:
i. Tourism in a region that boast opportunities to view endangered species can cause the extinction of these species.
ii. A primary value of ecotourism is the employment opportunities it provides to local people. Yet many tourism operations are owned and run by corporations, providing no benefit to the locals.
iii. If ecotourism operations fail to live up to conservation ideals can have very serious environmental consequences.
The guiding principles for ecotourism:
i. Tourist activities must not degrade the resources.
ii. Tourism must respect the intrinsic value of natural resources.
iii. Tourist revenue must provide conservation, scientific or cultural benefits to the resources and local community.
Achieving the principle depends in large part upon the scale of the operation. Ecotourism can live up to the promises if it follows the principles, adequately monitor and protects its resources and ensure fair distribution of profits with in the community.