what is global warming and how it is caused ... Explain briefly ... plsss.
Answers
.
.
.
I hope it will help u....
.
.
.
here ur answer is:-
.
.
.
global warming means increase in the temperature.....it is caused by some harmful gases like carbon dioxide, carbon monoxide and CFC's
Global warming is the current increase in temperature of the Earth's surface (both land and water) as well as it's atmosphere. Average temperatures around the world have risen by 0.75°C (1.4°F) over the last 100 years about two thirds of this increase has occurred since 1975.1 2 In the past, when the Earth experienced increases in temperature it was the result of natural causes but today it is being caused by the accumulation of greenhouse gases in the atmosphere produced by human activities.3
The natural greenhouse effect maintains the Earth's temperature at a safe level making it possible for humans and many other lifeforms to exist.4 However, since the Industrial Revolution human activities have significantly enhanced the greenhouse effect causing the Earth's average temperature to rise by almost 1°C. This is creating the global warming we see today. To put this increase in perspective it is important to understand that during the last ice age, a period of massive climate change, the average temperature change around the globe was only about 5°C.5 6
Increasing greenhouse gas levels are enhancing the greenhouse effect and causing global warming
A long series of scientific research and international studies has shown, with more than 90% certainty, that this increase in overall temperatures is due to the greenhouse gases produced by humans.7 Activities such as deforestation and the burning of fossil fuels are the main sources of these emissions. These findings are recognized by the national science academies of all the major industrialized countries.8
Global warming is affecting many places around the world. It is accelerating the melting of ice sheets, permafrost and glaciers which is causing average sea levels to rise.9 10 It is also changing precipitation and weather patterns in many different places, making some places dryer, with more intense periods of drought and at the same time making other places wetter, with stronger storms and increased flooding.11 12 These changes have affected both nature as well as human society and will continue to have increasingly worse effects if greenhouse gas emissions continue to grow at the same pace as today.
What causes global warming?
Each day new greenhouse gas emissions further accelerate global warming
The cause of global warming is the increasing quantity of greenhouse gases in the our atmosphere produced by human activities, like the burning of fossil fuels or deforestation. These activities produce large amounts of greenhouse gas emissions which is causing global warming.7 Greenhouse gases trap heat in the Earth's atmosphere to keep the planet warm enough to sustain life, this process is called the greenhouse effect.3 It is a natural process and without these gases, the Earth would be too cold for humans, plants and other creatures to live.
The natural greenhouse effect exists due to the balance of the major types of greenhouse gases. However, when abnormally high levels of these gases accumulate in the air, more heat starts getting trapped and leads to the enhancement of the greenhouse effect. Human-caused emissions have been increasing greenhouse levels which is raising worldwide temperatures and driving global warming.3
Greenhouse gas emissions and the enhanced greenhouse effect
Greenhouse gases are produced both naturally and through human activities. Unfortunately, greenhouse gases generated by human activities are being added to the atmosphere at a much faster rate than any natural process can remove them.
Global levels of greenhouse gases have increased dramatically since the dawn of the Industrial Revolution in the 1750s.7 Only a small group of human activities are causing the concentration of the main greenhouse gases (carbon dioxide, methane, nitrous oxide and fluorinated gases) to rise:
The majority of man-made carbon dioxide emissions is from the burning of fossil fuels such as coal and oil so that humans can power various vehicles, machinery, keep warm and create electricity. Other important sources come from land-use changes (ex: deforestation) and industry (ex: cement production).13
Methane is created by humans during fossil fuel production and use, livestock and rice farming, as well as landfills.14
Nitrous oxide emissions are mainly caused by the use of synthetic fertilizers for agriculture, fossil fuel combustion and livestock manure management.15
Fluorinated gases are used mainly in refrigeration, cooling and manufacturing applications.16
Deforestation
Deforestation has become a massive undertaking by humans and transforming forests into farms has a significant number of impacts as far as greenhouse gas emissions are concerned. For centuries, people have burned and cut down forests to clear land for agriculture. This has a double effect on the atmosphere both emiting carbon dioxide into the atmosphere and simultaneously reducing the number of trees that can remove carbon dioxide from the air.