The urban heat effect due to cement is less than that due to asphalt (over the same area.) And it's just an urban heat effect. Concrete is actually a better reflector of shortwave radiation (insolation), at about 40%, than are many other land surfaces. For example, desert sand is about the same (at 40%), while grasslands are about 25% (absorbs more) and deciduous trees are about 15% to 18% (still more absorbant.) A coniferous forest will be from 8% to 15%. Even the tundra averages 20%. And the oceans, which cover 70% of the earth are from 7% to 10%. So I think you can readily see now that cement is NOT A PROBLEM here. Not in terms of global warming, because what matters there is how much MORE insolation is kept on Earth. And cement (concrete mix as it is usually used) actually reflects better than much of the Earth's surface. Overall, Earth's global albedo is about 30%. Cement/concrete is about 40%.
Concrete can, in fact, easily be made to reflect shortwave radiation still better, though. GGBS (ground granulated blast furnace slag) can easily increase shortwave reflectance to 60%, from 40%. But in any case cement's ability to absorb shortwave radiation isn't in any way important regarding global warming. It simply doesn't materially affect the Earth's albedo.
Cement DOES have a significant impact on global warming due to its manufacturing processes, though. From Wiki:
? ? ? ? The cement industry is one of two primary industrial producers of carbon
? ? ? ? dioxide (CO?), creating up to 5% of worldwide man-made emissions of this
? ? ? ? gas, of which 50% is from the chemical process and 40% from burning fuel.
? ? ? ? The carbon dioxide CO? produced for the manufacture of one tonne of
? ? ? ? structural concrete (using ~14% cement) is estimated at 410 kg/m3
? ? ? ? (~180 kg/tonne @ density of 2.3 g/cm3) (reduced to 290 kg/m3 with 30%
? ? ? ? fly ash replacement of cement). The CO? emission from the concrete
? ? ? ? production is directly proportional to the cement content used in the
? ? ? ? concrete mix; 900 kg of CO? are emitted for the fabrication of every ton
? ? ? ? of cement. Cement manufacture contributes greenhouse gases both
? ? ? ? directly through the production of carbon dioxide when calcium carbonate
? ? ? ? is thermally decomposed, producing lime and carbon dioxide, and also
? ? ? ? through the use of energy, particularly from the combustion of fossil fuels.
See link below for the above quote.
I think Jonathon has given a good answer; essentially, it is the production of concrete that contributes to the problem. Once it has set, it makes no significant difference.
Tiarra; I don't know if you are a troll, but certainly, you don't speak for all Muslims.
http://answers.yahoo.com/question/index;...
I just hope that when they are calculating the benefits of wind turbines that are taking into account the amount of concrete required to provide the foundations and the effects of the new roads needed to provide access for building and maintenance purposes.
We Muslims do NOT believe that global warming exists, for many reasons.
First and foremost, there are no mentions in the Quran about melting ice caps, rising CO2 levels, or the greenhouse effect. The Quran is the foremost leader on science. It says that the sun and moon rotate in an orbit, and also about tectonic plates. Therefore, if the Quran doesn't talk about something, I don't believe it.
Also, no one cares about dumb animals like polar bears, monkeys, penguins, or coral reefs. They are brainless beings with no soul so they become Satan's BBQ when they die.
The global warming hoax is perpetuated by the dumb scientists who fail to glorify Allah. They just get a fact (this year's Co2 levels are higher than last years) and jump to conclusions based on it. Scientists do NOT know how to analyze data in the guideline in the Quran.
Conclusion: Use as much cement as you want.
actually the roman empire had an warmer time period than us. super volcanoes change climate so much that the human race would look like a single microbe in comparison. human beings affect nothing to are earth. the global warming and climate change are ways to get taxes, establish agenda 21 and control human population.
The climate is realy changed in these recent years!
Concrete, Cement.
Any concrete or cement related building, roads, structure. The past 200yrs, with the increase production of automobiles and methods using rock based structures for roads and buildings has increased by extraordinary amount. Maps are basically lines with roads all over states and country sides. Houses/Buildings are covered by tiny bits of rock called Shingles. Sometimes Copper/Metal roofs.
All of which Draws heat from the Sun. Our Environment has drastically changed with new technology.
Unlike Ancient Times, our Roads are maintained, Clean from debris and/or trees/plants.
Concrete doesn't require energy to burn, it just heats up and it's there for every hour/day throughout the year. And for years to come.
