Global Warming: Dr. Abhinandan Bhardwaj explains the science behind Global Warming

Global Warming

Science Behind Global Warming

Dr. Abhinandan Bhardwaj PhD

Climate change and global warming are interlinked. As explained in Climate change section, Earth has experienced several periods in its history which included both ice ages and warm climates. But what we are seeing right now is largely the human induced global warming. Result of such human induced Global warming can directly be seen on changing patterns of Earth's climate, especially long-term weather patterns, which is a huge cause of concern to the scientists around the world. The warm periods in Earth's history has lead to extinction of several animal and plant species. If uncontrolled, Global warming can have devastating effects on earth and eventually threaten the very existence of humans, unless we do something about it.

What is causing present global warming is not a mystery any more. Carbon dioxide and other air pollution gets collected in the atmosphere like a blanket, which results in trapping the sun's heat and causing the planet to warm up. Among the causes are fossil fuel burning, Cement manufacturing and Coal-burning power plants. Coal burning power plants are one of the the largest source of carbon dioxide pollution as they produce around 2.5 billion tons of Co2 every year in US alone. Automobiles are the second largest source, which create nearly 1.5 billion tons of CO2 annually. If we do not do something to reduce and eventually stop pumping the amount of Co2 and other green house gases, its going to be too late before we could do any thing to save this planet. The Global warming is like a cancer, if you detect it earlier you can certainly do something about it, but if you detect it late, then its already too late and we will have to bear the consequences.

Global Warming and Its impacts Watch Video

Is Earth getting warmer?

Normally the local and regional temperatures fluctuate naturally. But over past 100 years average global temperature has risen at an alarmingly rate in the history. Scientists believe that this trend is dangerous. Experts say that unless we do something about reducing the greenhouse emissions, average temperatures of earth could be 3 to 9 degrees higher by the turn of century.

Is Global Warming Bad?

The earth is naturally warmed by rays (or radiation) from the sun which pass through the earth's atmosphere and are reflected back out to space again.
The atmosphere's made up of layers of gases, some of which are called 'greenhouse gases'. They're mostly natural and make up a kind of thermal blanket over the earth.

This lets some of the rays back out of the atmosphere, keeping the earth at the right temperature for animals, plants and humans to survive (60°F/16°C). But Pumping much more Co2 than it naturally occurs can cause temperatures to rise much more and much faster, which then can lead to disastrous repercussions.

What is Causing Global Warming?

Scientists have concluded that human activities are contributing to global warming by adding large amounts of heat-trapping gases to the atmosphere. Our fossil fuel use is the main source of these gases. Every time we drive a car, use electricity from coal-fired power plants, or heat our homes with oil or natural gas, we release carbon dioxide and other heat-trapping gases into the air. The second most important source of greenhouse gases is deforestation, mainly in the tropics, and other land-use changes.
Since pre-industrial times, the atmospheric concentration of carbon dioxide has increased by 31 percent. Over the same period, atmospheric methane has risen by 151 percent, mostly from agricultural activities like growing rice and raising cattle.

How it happens ?

The atmosphere surrounding the earth is mainly composed of Nitrogen (about seventy eight percent, and Oxygen (twenty one percent) with water vapor and various trace gases making up the rest. There are quite a few trace gases, such as; Argon, Carbon Dioxide, Neon, Helium, Methane, Hydrogen, Nitrous Oxide and Ozone. These gases, are often called green house gases. Because during the day the earth soaks up heat, and these gases act like a greenhouse trapping in the heat. Some of the heat is radiated back out into space, and if weren’t for these gases things would freeze over during the night. The issue of course is the increase in greenhouse gases, which is trapping in more heat, and causing a rise in global temperature.