Cause of Global Warming

Are humankind's activities a cause of global warming or is there more to it than what meets the eye?

At a recent talk at our Observatory the speaker said while referring to Venus’s atmosphere of sulphuric acid and Carbon Dioxide: “And this is the cause of global warming…if we people don’t mend our ways, we will end up like Venus.”

That is a huge blanket statement but at the core it has some truth. There is evidence that the world had a previous “warm period” during the Middle Ages (800 – 1300 AD) which, although not as hot as now, was well…warm! So one wonders if this in not merely a repeat or cycle in the world environment.

The other part comment that our lecture made was related to humans and their ways. This is where most people get defensive that they are one cause of global warming. People, like me who live a simple green life, even get a bit irked by this statement…but the truth is humankind in one way or another does contribute to global warming.

These are said to be the main ways that people are affecting the earth’s temperature:

The increase in greenhouse gases due to human activity – since the industrial revolution of the 1700’s there is more C02 and methane in our atmosphere. Simply put – the factories that produce goods – from foods to cars, from clothing to building materials – spew out tons of pollutants into our air.

Burning coal is another occupation that puts sulphur oxides into the air. Due to this, most coal burning plants in the western world have installed "scrubbers" into their smokestacks. Scrubbers contain limestone which absorbs a large percent of the sulphur oxides. There are many natural sources of sulphur oxides being released daily through biological decay and natural forect fires.

Talking about forest fires - lets look at another contributing cause of global warming which is said to be deforestation.

cause global warming Deforestation is the cutting down of masses of our forests around the globe. Trees are used in furniture, paper production, construction and a host of other things. Rain forests are being cleared for agriculture and local cultural groups use the valuable trees for firewood.

Our rainforests were the God-given balance for C02…trees need it for food production. But with the logging activities of man and the burning of the trees to clear ground we are loosing this natural process. In fact, burning of trees releases stored C02 back into the atmosphere.

If you would like to have a more indepth look at the effect of global warming on rainforest, please do read this partner article: global warming and rainforests

The last thing I would like to mention which is has a common connection as a cause of global warming is ozone depletion. Ozone is found in the stratosphere of our atmosphere, The ozone portion of is found between 20 and 30 km's above the surface of the earth. The ozone layer contains o3 and absorbs the harmful UV rays from the sun. According to popular belief there has been a steady decline in the depth of the ozone layer of our stratosphere since the 1970’s.

When I was a child I remember a big out cry about aerosol cans and how they were creating a hole in the ozone layer. I can’t say I was too concerned about it – I was only 9 years old. But I do remember my mom chucking all our aerosols in the bin and moving to more eco-friendly products.

CFC’s (chlorofluorocarbons) are said to be responsible for ozone depletion. CFC’s are found in refrigerators, fire extinguishes, solvents, spray propellants (here’s were aerosols come in) and foam blowing agents. Due to the Montréal Protocol many countries are banning products with CFC’s.

But are the CFC's really responsible for the hole in the ozone layer? Does this same "hole" contribute to global warming? As this is a large topic, please read further at ozone layer depletion

A quick summary of the commonly accepted cause of global warming –