Understanding Greenhouse Effect and Global warming

Posted on Feb 18 2016 - 6:08pm by In-house Geek

What is the Greenhouse effect? Does it have any effect on global warming? What even is global warming? These are the questions that bugs a lot of people’s mind, especially those interested in climate change and renewable energy. We have got the questions couple of times from our clients too so we think we should publish this article for everyone to read and gain more insight.

What is the Global Warming?

Scientists use the term ‘Global warming’ to describe increase in the earth’s temperature which in turn affects the climate of the Earth.

It’s been long observed that there has been a gradual increase in the temperature of the Earth’s atmosphere and oceans. The average temperature gets warmer and warmer which in turn affect the climate of the planet including the water level of the seas and oceans.

What then is the cause of this global warming? As we shall see, the primary cause is the increasing amount of greenhouse gases in our atmosphere. Greenhouse gases are those gas molecules in the atmosphere that can absorb heat (radiation) in significant quantities and therefore affect the climate by increasing the average temperature of the earth’s atmosphere. Example of these gases is: water vapor, CO2, methane, nitrous oxide (N2O), etc.

Greenhouse gases ideally are found right above the earth’s atmosphere. Any radiation that passes through the earth’s atmosphere must first encounter this soft shield of gases.

As we all know, the SUN is the primary source of light and heat for the earth’s atmosphere and surface. The radiation that comes from the light which includes the light we see is called the Ultra-Violet rays. There are other radiations from the sun which we cannot see.

The Ultra-violet radiation has a high energy level because of their short wavelength. This UV rays pass through the earth’s atmosphere with its high energy and falls on the earth’s surface, the visible part of it is what we call light. About 70% of this Ultraviolet radiation is absorbed by the land and oceans and the other 30% is reflected by earth back into the space.

This absorbed 70% heats up the oceans and land and its further released back to atmosphere as Infrared thermal radiation. The Infra-Red radiation (which is in form of heat), unlike the UV radiations, has a lower energy level because of their high wavelength. This means that they can easily be absorbed in the atmosphere instead of going back to space. This absorption occurs when there are sufficient greenhouse gases in the atmosphere. When the greenhouse gases absorb this thermal Infrared radiation, they in turn get heated up and they warm the earth and its atmosphere.

Global Warming Photo: NASA

Global Warming
Photo: NASA

So assuming we have a high level of greenhouse gas up there in the atmosphere, then the thermal Infra-red radiation that should go back into space will be largely absorbed by the gases and then the average temperature of the earth will significantly increase. This is what we call global warming and its effect is the Climate change.

So once again, the greenhouse gases or gases that contribute to the greenhouse effects are:

  1. Water Molecules (H2O)
  2. Carbon dioxide (CO2)
  3. Methane
  4. Nitrous Oxide
  5. Chlorofluorocarbons (CFCs)

Greenhouse gases are needed by the earth’s atmosphere to maintain the average daily temperature of the day. Their absorbed heat in the day in turn warms up the night.

But due to the increase in human activities over the last century, these gases are now in very large quantity in atmosphere which means they now absorb more heat in the form of Infra-red radiation that is needed to balance the temperature of the earth. The effect of this increase in warmth is outlined in the next subheading.

Effects of Global warming on Earth

The effect of global warming is quite visible everywhere we turn to. According to National Geographic, here are some of the effects of Global warming:

Some impacts from increasing temperatures are already happening.

  • Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice.

  • Researcher Bill Fraser has tracked the decline of the Adélie penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.

  • Sea level rise became faster over the last century.

  • Some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas.

  • Precipitation (rain and snowfall) has increased across the globe, on average.

  • Spruce bark beetles have boomed in Alaska thanks to 20 years of warm summers. The insects have chewed up 4 million acres of spruce trees.

Other effects could happen later this century, if warming continues.

  • Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters) by the end of the century, and continued melting at the poles could add between 4 and 8 inches (10 to 20 centimeters).

  • Hurricanes and other storms are likely to become stronger.

  • Species that depend on one another may become out of sync. For example, plants could bloom earlier than their pollinating insects become active.

  • Floods and droughts will become more common. Rainfall in Ethiopia, where droughts are already common, could decline by 10 percent over the next 50 years.

  • Less fresh water will be available. If the Quelccaya ice cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who rely on it for drinking water and electricity without a source of either.

  • Some diseases will spread, such as malaria carried by mosquitoes.

  • Ecosystems will change—some species will move farther north or become more successful; others won’t be able to move and could become extinct. Wildlife research scientist Martyn Obbard has found that since the mid-1980s, with less ice on which to live and fish for food, polar bears have gotten considerably skinnier.  Polar bear biologist Ian Stirling has found a similar pattern in Hudson Bay.  He fears that if sea ice disappears, the polar bears will as well.

 

I cited this excerpt from National Geographic because the facts are well evidenced and they are from a reliable source.

So the question remains:

How can we stop/control Global warming and Climate change?

This is a hard question to answer because some scientists believes that there’s nothing to be done other than learn to adapt to our new world with a hotter climate. The good news is that majority of the scientists agree that if we humans can control and reduce the level of greenhouse gas emission into the atmosphere, global warming will be controlled significantly.

As we can see, it is really a global problem that requires an International action and treaties. The world and the United Nation in particular have not been silent on this.

Visit the United Nations official Climate Change website to learn of the ongoing development on the issue till date.

What contribution can you make?

Although the needed action for a significant change in reducing the emission of greenhouse gasses is global, we all can contribute our own quota to ensure that the next generation of humans will find the world a habitable place for their kind. We take responsibility for the imbalance in the earth’s ecosystem. Our actions are mainly responsible for it.

Scientists agree that one of the ways we can significantly control the global warming effect is by controlling the amount of carbon we release to the atmosphere. When we burn fossil fuels like coal and petrol, the carbon released reacts with the atmospheric oxygen to produce carbon dioxide in excess, which is a greenhouse gas.

Many countries today are switching to renewable energy a resource which is not dependent on fossil fuels and carbon emission.