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What Causes Changes in Earth's Climate?

Updated on December 17, 2014
LoryRich profile image

Lory, a development economist, did research projects on energy/anti-pollution topics for a national research agency in the Philippines.


Heads-Up For Climate Change

"We need to start by having a conversation about climate change. It would be irresponsible to avoid the issue just because it's uncomfortable to talk about."- Al Franken

"Change" is a part of any life process. It is inevitable for any growth to happen. Anything and everything in the environment changes one way or the other- forms, age, appearances, perspective, behavior, mood, relationships, season, etc. The cycle for any life form has to continue in order for it to thrive. And for that matter, because the earth is very much alive, there is also the so called climate change which is the long-term shift in weather condition. And when climate change (as indicated by global warming) occurs in a rate and ways beyond normal, then, that's the time it should get our attention really really hard and for a very good reason- the survival of the human specie and all that make it thrive . . . our very own survival.

An undue warming of the earth on the average makes an undesirable difference on wind patterns, precipitation (rain, snow, sleet or hail that falls to the ground) and storm events. The warming is not uniform. Other regions become warmer while the other areas colder. "Global warming" is the average of the atmospheric temperatures of all the regions.

In a more understanble terms, the abnormal patterns of heavy rains, floods, wildfires, heatwaves and droughts are the natural disasters commonly associated with climate change phenomenon.

"Climate change is happening, humans are causing it, and I think this is perhaps the most serious environmental issue facing us." - Bill Nye


"Who can dispute or gloss over the devastating effects of the strongest typhoon ever that hit the Philippines recently? Japan's tsunami? Horrendous hurricanes that debilitated certain areas in the US? And the many unusual events in other parts of the globe that could be global warming related? Our climate is fast changing. Are humans unknowingly or recklessly heading toward its own self-extinction? It is a wake up call."

The Causes for Climate Change

Various factors, both natural and human, can cause earth's climate to change. Among the natural causes include:

  • the change in the sun's energy output. The sun is the earth's fundamental source of energy. Thus, it is safe to say that any variability in the solar activity can drive changes on the earth's atmospheric conditions; and
  • concentration of volcanic dust in the atmosphere due to volcanic eruptions

However, the NASA (National Aeronautics and Space Administration) reports that "most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect" -- warming that results when the atmosphere traps heat radiating from Earth toward space".

The Greenhouse Effect

Humans and everything else on earth live under a greenhouse like scenario which is made up of various gases known as greenhouse gases. This layer of greenhouse gases mostly water vapor, and including much smaller amounts of carbon dioxide, methane and nitrous oxide, act as a thermal blanket for the Earth, absorbing heat and warming the surface to a life-supporting average of 59 degrees Fahrenheit (15 degrees Celsius).

When sunlight reaches Earth’s surface, it can either be reflected back into space or absorbed by Earth. Once absorbed, the planet releases some of the energy back into the atmosphere as heat (also called infrared radiation). Greenhouse gases (GHGs) like water vapor (H2O), carbon dioxide (CO2), and methane (CH4) absorb energy, slowing or preventing the loss of heat to space. In this way, GHGs act like a blanket, making Earth warmer than it would otherwise be. This process is commonly known as the “greenhouse effect”.

Thus, the greenhouse effect is a process by which thermal radiation from a planetary surface like the earth's surface is absorbed by atmospheric greenhouse gases and is re-radiated in all directions. Since part of this re-radiation is back towards earth's surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gas.

In other words, here's what's happening- the sun's warmth is trapped in the earth's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the earth's surface.There is an imbalance in the global energy input and output level of exchanges.

Below is a diagram sourced from the NASA website to illustrate the process:


Greenhouse Gases

Naturally occurring gases include: water vapor, carbon dioxide, nitrous oxide and ozone. They are necessary for earth to survive. However, if they occur more than necessary and at a faster rate, the long-term effect can be catastrophic. The Greenhouse Effect can also be more clearly understood from the following video.

Human Activities that Amplify Global Warming

The normal presence of greenhouse gases in the atmosphere, in fact, helps earthly life to thrive and flourish. They allow the earth's average temperature to be at a more hospitable 15°C. However, problems arise when the atmospheric concentration of greenhouse gases increases by human activities, as follows:

1. Burning of fossil fuels (oil, natural gas, coal); solid wastes; and wood and wood products increases the release of carbon dioxide in the atmosphere.

2. Agricultural and industrial activities, and combustion of solid waste and fossil fuels emit nitrous oxide.

3. .Rising production, decomposition of organic wastes in solid waste landfills, and the raising of livestock emit methane.

4. The production and transport of fossil fuels such as coal, oil and natural gas also emit methane.

5, Products of foam production, refrigeration, and air-conditioning called chlorofluorocarbons (CFCs),as well as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) from industrial processes also generate gases in the atmosphere that are not naturally occurring.

6. Deforestation due to land use change and forest loss or denudation due to indiscriminate cutting of trees for personal or commercial purposes. It must be noted that trees help absorb carbon dioxide and forests have the larger absorption capacity many times over scattered greens..

Be part of the solution- To reduce pollution is to help mitigate global warming!

Humans polluting the earth largely causes greater concentration of greenhouse gases thereby causes global warming to rise. Thus, pollution can ultimately cause climate to radically change overtime rendering earth to an unlivable level. Good news is - options for adaptation and mitigation do exist and are doable. If humans causes the problem, then, humans can also be part of the solution.

Read more about how anyone and all the citizens of the world, individually or as a group can contribute to raise environmental awareness and / or how to actively participate in anti-pollution campaigns. Hope this hub can help inform-

Latest news on climate change

Early in March 2014, the world's largest scientific organization, the American Association for the Advancement of Science, published a new fact sheet on global warming.

It said: "Climate change is already happening. More heat waves, greater sea level rise and other changes with consequences for human health, natural ecosystems and agriculture are already occurring in the United States and worldwide. These problems are very likely to become worse over the next 10 to 20 years and beyond."

The Academic Community Reminds Us to Get Real Serious About Climate Change

Your thoughts about climate change is important. Let us know your take regarding the statement below.

"The governments of industrialized countries should take more seriously their responsibility over programs that will mitigate the possible ill effects of climate change."

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    • mechomrex profile image

      MechOmrex 2 years ago from Pakistan

      Nice hub Lory.Keep it up

    • Doc Snow profile image

      Doc Snow 3 years ago from Atlanta metropolitan area, GA, USA

      Good job--nice and succinct!