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  Question 4 Answer A
water vapor
The so-called 'Greenhouse Effect' is caused primarily by:   a) water vapor

You are correct!

Water vapor is 95% of greenhouse gases by volume, and, while somewhat less than 95% by impact, is still the most significant greenhouse gas. The remaining 5% of so-called greenhouse gases include methane (CH4), carbon dioxide (CO2), the vast majority of which comes from nature, and various pollutants.

Water droplets, though microscopic individually, exist in such volumes that they are visible as clouds. Clouds act to both cool and warm the planet as they both reflect incoming sunlight from space and absorb infrared energy (heat) coming from the ground, reradiating it in all directions, including back to the ground. Whether a cloud has a net cooling or warming effect depends on the type and height of the cloud but, in general, clouds have an overall cooling impact on the Earth - this effect is not handled adequately in today’s computerized climate models.

Any greenhouse warming, if it does occur, is limited primarily to increasing nighttime temperatures, which provides beneficial moderation of nighttime low temperatures, but little if any increase in daytime high temperatures.

Did you know...

The world's natural wetlands produce a greater ‘greenhouse gas’ contribution, in the form of methane (CH4, 20 times more effective an IR absorber than CO2), than all human sources combined.


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Produced with the assistance of Dr. Tim Ball & Tom Harris, B. Eng., M. Eng. (Mech.), Executive Director, International Climate Science Coalition.
CSCCC FCPP is a member of Civil Society Coalition on Climate Change.
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© Frontier Centre for Public Policy 2017.