What is global warming?
Global warming refers to abnormal rise in the temperature of earth, creating an imbalance in the climatic conditions. Climatic changes can disrupt the sensitive dynamic balance on earth. Scientific evidences over the years have revealed that the prime cause of global warming is greenhouse effect. In the atmospheric layer encircling the earth, there are few gases which trap infrared radiation and do not allow it to escape. The incident solar radiation firstly penetrates the earth’s surface, from where it is reflected back to earth, owing to the presence of such atmospheric gases. Hence, the encircling layers form a greenhouse over the planet.
To some extent greenhouse effect is a prerequisite for the biosphere since it helps in trapping solar radiation, which is the primary source of energy. Without the greenhouse effect, our earth would become a very cold and uninhabitable place. However, if earth gets heated beyond prescribed limits, the natural cycles and energy pathways will get modified, bringing forward an unbalanced and complicated state before us.
Global warming takes place when greenhouse gases like carbon dioxide and methane accumulate in large quantities and absorb solar radiation. The delicate balance in the biosphere tends to get disrupted by global warming. Interrelationships between flora and fauna also get affected.
Conferences and symposiums are organized annually in many different nations for arranging brainstorming sessions in order to resolve the issue of global warming. At Paris Climate conference in 2015, 195 countries have formally agreed to reduce Carbon emissions by taking adequate steps, in turn to prevent global warming. It is expected that level of atmospheric temperature to below 2⁰C. Such conferences are also held by United Nations organizations at their headquarters in Geneva.
What are greenhouse gases?
Sources of greenhouse effect are Carbon dioxide, methane, Nitrous oxides, water vapor, chlorofluorocarbons etc. These are referred to as greenhouse gases. The index of global warming is measured with reference to Carbon dioxide emissions. The concentration of greenhouse gases has been rising with a sharp pace since the year 1958, owing to the Industrial Revolution. Since that year, carbon dioxide concentration of carbon dioxide has increased from 280 parts per million(ppm) to 400 parts per million(ppm).
Methane is a prominent greenhouse gas which is produced as a consequence of the anaerobic decomposition by microbes. It has a higher heat trapping capacity as compared to carbon dioxide.
Nitrous oxide is mainly released during application of fertilizers in agricultural practices and landscaping. Chlorofluorocarbons, generally present in very low quantities in the atmosphere are released along with gaseous emissions from refrigerators and jet planes.
What causes global warming?
Global warming can take place due to both natural and anthropogenic causes. The natural causes are volcanic aerosols given out during volcanic eruptions and changes in the solar constitution over time. But, mostly global warming is attributed to anthropogenic activities i.e human activities, which shows how human dominance over the natural resources has ultimately led to such a crisis.
Unplanned deforestation: Deforestation creates upset in the environmental balance. Plants act as natural sinks to absorb Carbon dioxide and release Oxygen during photosynthesis. This helps to restrict the atmospheric percentage of Carbon dioxide below safe levels. Plants help as Carbon dioxide absorbers and Oxygen providers, in other words air purifiers. But with the indiscriminate felling of trees to set up industries, the carbon dioxide count in the atmosphere will obviously rise, disrupting the sensitive ecological balance.
Increasing dependence on electrical gadgets: With more urbanization and industrialization, people are getting increasingly dependent on electrical gadgets and devices. Most of the developed nations with higher per capita income population are major users of electricity, which contributes significantly to greenhouse effect.
Fossil fuel emission from automobiles: Conventional vehicles are powered by coal or diesel, making them contributors to carbon dioxide emissions in the atmosphere and hence greenhouse effect. Bike riders and car drivers operate their vehicles at frequently changing speeds, which in turn affects the efficiency of the vehicles, besides adding to pollution. Drivers often do not maintain their vehicles properly, adding to emissions and thermal effects.
Increase in livestock population: Methane, a highly potent greenhouse gas is produced as a consequence of the anaerobic decomposition by bacteria. This process takes place naturally in marshy areas and inside intestines of herbivores. The concentration of methane has increased due to rise in livestock population.
Industrial emissions: The combustion of fossil fuels like coal and petroleum raises the percentage of Carbon dioxide in the atmosphere. Throughout the globe, people are heavily dependent on these fuels to meet their energy needs. It has been observed that fossil fuel combustion produces net carbon dioxide emission equivalent to 2 billion tones. Thermal power plants are the major contributors to air pollution and greenhouse effect. Methane is released during industrial processes like the extraction of natural gas.
Modern agricultural practices: Modern agricultural practices are greatly dependent on the utilization of fertilizers like ammonia, urea and many nitrogenous compounds. These are major sources of Nitrous oxides, adding to greenhouse effect.
Increased landfills: Methane emission is steadily rising due to increased number of landfills, especially in urban areas. Methane is actually produced as a result of decomposition of organic matter by bacteria in the absence of Oxygen.
Advances in airline transportation: These have led to increasing dependence on supersonic jet planes which do pass through the stratospheric layer of the atmosphere and emit chlorofluorocarbons which react with ozone layer in the stratosphere and lower its concentration, leading to penetration of ultraviolet rays.
What are the effects of global warming?
The consequences of global warming can be broadly classified into the following:
Effects on seas and oceans
Escalating temperatures could lead to melting of melting of glaciers and icebergs, leading to an upsurge in the levels of rivers and seas. This in turn will affect aquatic ecosystems and habitats apart from modifying precipitation patterns.
Rise in earth’s ocean temperatures, leading to energizing tropical storms is a major outcome of global warming. The effect of global warming is more pronounced on the ocean systems and balances. The current flow patterns can change as well, resulting in storms, cyclones, typhoons and hurricanes. El Nino and AlNina refer to the abnormal ocean wave currents generated in the Pacific due to abnormal climatic conditions.
A large proportion of absorbed solar energy by the Pacific is given out via trade winds, which blow from east to west in the normal circumstances. The cold waters in the deeper layers are allowed to come to top surfaces creating a temperature gradient known as thermocline. If warming continues, the thermocline spreads out and the chances of moderation are reduced. The coral reefs of the pacific are prone to danger because of El Nino.
Global cooling effect
Even a minor increase in temperature of earth or the protective atmosphere caused due to global warming, might result in partial melting of the ice capped regions at the North and South poles. Polar ice cap melting will in turn lead to rising sea levels, thereafter leading to a global cooling effect.
This consequentially could lead to the submergence of the cities, lying near the coastal belt. Gradually this may lead to emergence of Ice age.
Increase in greenhouse gas emissions traps heat within the troposphere and a reduced concentration of ozone in the stratosphere, in turn reducing the absorbed quantity of sunlight and thereby cooling the stratosphere. Human beings and animals will indeed face a real tough situation owing to changed climatic conditions.
What can be done to stop global warming?
In order to control global warming national governments and agencies need to formulate or adopt an effective strategy which firstly enables to reduce emissions and secondly to advocate application of alternative fuels.
- Selecting energy certified appliances: Consumers must verify whether the equipments they purchase are energy saving devices. They must check for energy star labels on appliances like refrigerators and washing machines. Using LED bulbs which bring down electrical energy consumption by 80% serve as significant energy saving initiatives.
- Vehicular maintenance: Automobile drivers can play their role in prevent global warming significantly by utilizing fuel efficient vehicles and resorting to regular maintenance of vehicles. One more step is the equipping of cleaning devices like catalytic convertors, which controls emissions by chemically converting them into harmless byproducts.
- Mass awareness programs: Governments and private organizations must educate the people about the harmful effects of greenhouse gas emission on the biosphere. Environment friendly initiatives like advertising solar torches, wind mills, biogas plants need to be widely publicized and circulated. Organizations must take initiatives for inspiring citizens to opt for reforestation programmes for stopping global warming.
- Investing in renewable energy based home appliances and vehicles: Companies need to invest in manufacturing energy efficient appliances and renewable energy based devices like solar lanterns, heaters etc. Consumers need to be more informed of renewable energy based appliances and solar rooftop installations that form a key part of green buildings and promote energy efficiency.
Conventional vehicles that run on petrol or diesel produce smoke and gases even if well maintained. Drivers can select and drive green vehicles that are powered by electricity and renewable energy sources eg. E-bikes, e-rickshaws, solar cars etc.
- Renovating modern power plants: Industries must renovate their premises from time to time to check for any least possible scopes of occurrence of emissions. Investors may adopt techniques which bring down fossil fuel emissions. Integrated gasification combined cycle (IGCC) is a method which uses fluidized coal particles, the pyrolysis of which helps to drastically bring down harmful gaseous emissions during coal burning. Bharat Heavy Electricals Limited (BHEL) has implemented IGCC model successfully.
- Prior to selecting a solar energy cell type, one must know its features and limitations like energy conversion efficiency and heat tolerance limit.
- Before opting for a new venture in the renewable sector, companies need to do cost benefit analysis carefully.