Is cement minimization only the best solution to reduce carbon dioxide in the atmosphere?
Cement is among the highest producers of CO2 per unit of material, but it does not follow that minimizing its use is the most effective control for greenhouse gases. Cement is also among the most durable materials. Over its lifetime, many applications may have lower CO2 emissions than alternatives that produce lower CO2 in production but that do not last as long. Greenhouse gas mitigation can rarely be as simple as saying to minimize or eliminate certain things.
Dear Aymen,
To produce 1 ton of Portland is emitted more or less the same amount of CO2. Reduction of using of Portland cement, where and when will be possible, should be a good start in terms of CO2 reduction. I’m working using geopolymer technology and geopolymer concrete is one solution that can substitute ,quite immediately ,Portland cement concrete saving till 80% of CO2. The geopolymer concrete is carbon negative like ordinary concrete so can absorb other CO2 during all its life that will be longer than traditional concrete.
I think there are still political and cultural issues to accept a world more safe, this is for me , the biggest obstacle .
All the best
Alex Reggiani
Cement production worldwide is around 5 billion tonnes per year (estimates vary). At a mean value of 0.78 tonnes of CO2 per tonne of cement global CO2 emissions (from calcination and fossil fuel usage) are around 4 billion tonnes per year. So, reducing this amount will be beneficial (nay essential) but greater reductions will have to be made in other areas.
With respect to the cement industry, how can CO2 reductions be made? The heat for calcination could be provided by hydrogen produced by steam reforming natural gas. The CO2 that would have been released in firing the cement kilns is now captured by the hydrogen producer, which is easier and more economic than capturing at the cement plant. Companies are also looking at utilising CO2 to accelerate the hydration reaction when manufacturing cement-based products. Demand for cement can be reduced by incorporating waste material, such as furnace slag, into the production of concrete. The use of cement can be avoided by building with wood, especially waste wood that would otherwise be burned or sent to landfill emitting CO2 and methane, respectively. Using wood beams instead of steel joists also reduces CO2 from the metals refining sector. The link below discusses the use of cross-laminated timber for multi-storey buildings up to 10 levels.
https://www.sciencedirect.com/science/article/pii/S1877705811012811
As CO2 is removed from the atmosphere during photosynthesis, the wooden building sequesters it and operates as a net emissions reduction technology. If timber usage is to be increased in this way, land has to be put aside for forestation which may be an issue. However, reducing CO2 emissions will raise a host of issues that have to be addressed if we are to avoid the worst effects of global climate change. The industrial, commercial, transportation, and domestic sectors all have to reduce their CO2 emissions not just the cement industry.
Reducing CO2 in the atmosphere is a bad idea. CO2 has little, if any, effect on climate. The atmosphere is still impoverished for CO2. Plants must sort through about 2400 molecules to find the one that they can make into food.
In response to Dan Pangburn's comment "CO2 has little, if any, effect on climate." I am sure we disagree about the causes of current global warming but it is incorrect to say that CO2 has no effect on global climate.
That atmospheric CO2 greatly affects the global temperature has been known for almost 200 years. In the early 1800s, Fourier, a French mathematician, identified that the global temperature was greater than expected and reasoned that the earth’s atmosphere must be retaining some of the solar radiation received. Based on laboratory experiments, he proposed that CO2 and water vapour interfere with the infrared radiating from the earth back into space. This process of trapping heat came to be known as the greenhouse effect: without it the earth's temperature would be below zero. In the later 1800s, Arrhenius, a Swedish chemist and Nobel Laureate, made the first calculations quantifying how the atmosphere’s CO2 content affects the global temperature. From that time, the understanding of the factors influencing global climate has improved and shown how complex the controlling mechanisms are.
John W,
“little if any” allows for more than zero.
I am aware of the early work and fully appreciate the groundbreaking findings (I have Arrhenius’ 1896 paper). Recent findings, using MODTRAN corroborated by satellite TOA measurements, have provided further understanding.
In spite of CO2 being a ghg, multiple compelling evidence listed in Section 2 of http://globalclimatedrivers2.blogspot.com rules it out as a significant contributor to climate change. Explanation of why is in Section 5.
All reporting agencies agree there has been little or no change in average global temperature since about 2002.
CO2 has increased since 2002 by 40% of the increase 1800 to 2002 so if CO2 has any effect on temperature it can’t be very much.
Dan, Thanks for the reply and the link. On a related but separate issue. There is an interesting feature of Antartic ice core temperture data that I would like your views on. Following the last ice age, ending 20,000 years ago, the global temperature rose abruptly for 8,000 years and then levelled off at or close to the 1860 level. Three previous similar temperature recoveries in the last 400,000 years lasted 10,000 years and the peak temperature was 2 to 3C greater than the 1860 level. The steady temperature lasting 12,000 years is unique in the records. What changed 12,000 years ago?
John W,
I have also puzzled over this (unsuccessfully). Why did the rise stop? The default (and probably wrong) answer is the solar output must have changed.
One of the things I did years ago was look at the change in land/ocean area. At the depths of the glaciation, the continental shelves were exposed resulting in about 8%(?) more land area.
A more plausible answer is climate temperature is strongly regulated by water vapor-cloud cover-average cloud altitude. http://lowaltitudeclouds.blogspot.com
Given the progressively reduced rate of temperature decline from the peak temperature in the last three interglacials (Vostok data), and with the trend of the current interglacial being essentially flat, I wonder if the previous glaciation is the last one in this ice age.
Thank you for every one for many information that sharing it .
John M Wheeldon
Dan Pangburn
Sarra Drissi
what about replacing cement concrete with geopolymer concrete, which helps in reduction in manufacturing of cement.
Relevant, interesting article in the Guardian (link below). “Concrete: the most destructive material on Earth” (no question mark)
https://www.theguardian.com/cities/2019/feb/25/concrete-the-most-destructive-material-on-earth
“After water, concrete is the most widely used substance on the planet. But its benefits mask enormous dangers to ecology, to health and to culture itself”
I did not realise when making my last post that the Guardian was running articles on concrete throughout the week.
https://www.theguardian.com/world/2019/feb/27/ply-sky-new-materials-take-beyond-concrete-carbon-dioxide
On Tuesday the lead-in was “Ply in the sky: the new materials to take us beyond concrete” The article talks about wood in construction (plyscapers) and various additives that reduce the amount of cement required, which covers the point raised by Swamy nadh Vandanapu.
“Concrete is everywhere, but it’s bad for the planet, generating large amounts of carbon dioxide. Creative alternatives are in the pipeline.” No mention of what material the pipeline is made.
Thank you for every one for many information that sharing it .
Vandanapu Swamy Nadh
John M Wheeldon
I hope that those interested in this topic will review the week's articles in the Guardian along with responses from the cement industry.
The following are the downsides acccording to the series of articles.
Concrete is responsible for up to 8% of the world’s emissions of carbon dioxide, more than any material after fossil fuels.
• Concrete in cities exacerbates flooding that kills thousands of people every year.
• Its dust can be toxic.
• It uses a tremendous amount of fresh water, roughly 10% of the global supply, often in communities where water for irrigation is in short supply.
• It contributes to the heat island effect, raising temperatures in some already dangerously hot cities.
• It clogs landfills around the world, as much of it simply dumped when we’re finished with it – less than 1% of concrete in Brazil is reused, for example.
• It requires huge amounts of a kind of sand that is short supply, damaging natural environments, and that is mined under often deadly circumstances by “sand mafias”.
• If the concrete industry were a country, it would be the third worst emitter of CO2 after China and the US.
Of course concrete has may benefits and it is to be hoped that progress will be made to limit its environmental impact. Here are some of the industry responses
https://www.theguardian.com/cities/2019/mar/01/were-wholly-disappointed-the-industry-responds-to-guardian-concrete-week
Another article from the Guardian on wood usage in the structure of high-rise buildings. Grow trees to capture CO2, then use the wood for construction, effectively sequestering the CO2. This also avoids CO2 released from the manufacture of concrete and steel. There is no mention of the cladding used for the buildings but presumably these are non-concrete, although their manufacture may release CO2. Nevertheless, appears to be measure to reduce the building industries dependence on concrete and steel and lower their CO2 footprint.
https://www.theguardian.com/cities/2019/jul/22/canadian-cities-take-wooden-skyscrapers-to-new-heights
Average global temperature tracks water vapor, not CO2. The planet atmosphere is still impoverished for CO2. CO2, in spite of being a ghg, does not now, never has, and never will have a significant effect on climate. http://diyclimateanalysis.blogspot.com
Dan Pangburn , It is difficult to see how your comment is relevant for the question on cement and CO2 emission!
Obviously actual science describes that water vapour increase is a result of the increased temperature.
Just to put the cat among the pigeons and to show that I read papers other than the Guardian, this article can be found in the Independent.
https://www.independent.co.uk/environment/climate-change-study-journal-temperature-earth-distance-sun-scientific-reports-paper-a9009811.html
Research published in Scientific Reports, extends the controversial view that climate change is the result of natural solar cycles and the Earth getting closer to the Sun. The authors claim that these phenomena account for the 1C increase in global temperatures over the last century and that over the next 600 years global temperatures will increase a further 3C.
Does this view have any credibility? What is the IPCC position on the effect (if any) of the solar systems barycentre?
It is a scientific forum. The actual paper is here:
Article Oscillations of the baseline of solar magnetic field and sol...
HRA,
Plant growth has increased about 15% from the CO2 increase but the planet is still impoverished for CO2. It is ludicrous to look for ways to reduce it. CO2 does not now, has never had and will never have a significant effect on climate. Humanities addition to the natural warming is from increased water vapor from increased irrigation. The increased WV is self-limiting.
You get credit for knowing the high school physics teaching that vapor pressure depends on temperature and when temperature and vapor pressure get high enough, water boils.
It is unclear whether you are simply unaware that average global water vapor, quantified by Total Precipitable Water (TPW), has been measured by satellite and reported by NASA/RSS since 1988 or are too stubborn to do the math.
This shows how:
“Global temperature increase since 2002 from the UAH trend is about 0.127 K per decade (this automatically includes feedback effect). At 24 °C, (75.2 °F) increase in vapor pressure of liquid water is 6.058% per degree (Figure 1.7). Percent increase in water vapor due to temperature increase = 0.127 * 6.058% = 0.769%. Measured % increase from Total Precipitable Water (TPW) in 28 yr = (29.5-28.25)/28.875 = 0.043 = 4.3%. In 10 yr = 10/28*4.3 = 1.54%. Thus measured increase in WV is about 1.54/.769 = 2+ times that for liquid water temperature increase alone.”
It is from the third paragraph in Section 8 of http://globalclimatedrivers2.blogspot.com
Dan Pangburn , You don't contribute to the subject of the question which is cement and CO2 minimisation. Perhaps you should get a real hoppy and fitting forum: https://www.tfes.org/. The quick debunk:
- Plant growth are generally not limited by CO2 uptake and the increase vegetation detected by satellites are well explained by the N and P fertilisation. You have not produced any evidence that the increase was caused by more CO2.
- The Earth average temperature is much lower than 24 C and the increase in temperature and humidity in arctic and temperate regions are much larger than 0.2 C/decade. No evidence has been produced for humidity increasing more than the temperature increase force.
HRA,
Your lack of knowledge and stubbornness are disturbing. A search using the key words ‘plant growth vs co2’ returned several disclosing the increase in plant growth caused by increased CO2. Here are a couple: https://climate.nasa.gov/news/2436/co2-is-making-earth-greenerfor-now (apparently NASA has yet to dig deeper into the science and discover that CO2 has no significant effect on climate)
https://www.climatecentral.org/news/study-finds-plant-growth-surges-as-co2-levels-rise-16094
Take the blinders off! Did you not grasp the calculations? The evidence is the average global temperature increase trend, the average global water vapor increase trend and the widely available vapor pressure vs temperature for water. The use of global average temperature for this assessment is wrong. The increased water vapor is forced into the atmosphere mostly in the tropics and where crop irrigation has increased. A temperature of 24 °C is appropriate. If you make the mistake of using the average global temperature of about 15 °C the factor drops to about 1.8+ instead of 2+.
I wonder how much longer this growing separation, between what the GCMs predict and what the actual measurements are, will need to continue for you to realize that perhaps a lot of what you think you know is wrong.
Dan Pangburn ,
The diagram you are showing compares the temperatures observed in the mid-troposphere. We live in the surface layer where temperatures have risen much faster.
ABM,
I added the line for 'average of six reported changes'. It is the average of the changes for the indicated time period as reported by
RSS v4.0 UAH v6.0 NOAA GISS HadCRUT4 Hadset3
Four of these are surface or near surface measurements. The slope of this line looks to be about the same as the mid-troposphere. Average global temperature tracks water vapor, not CO2.
Changes made to history to corroborate an agenda is science malpractice.
Of course water vapour tracks global temperature - everybody knows that.
But what are 2000 version, 2017 version and 2019 version? Where can I find their data? Why have you not plotted them starting from the same point? And where is your plot of RSS v4.0?
ABM,
What everybody ‘knows’ is only about half of the story. As stated in my calculations 3 days ago (July 25) “measured increase in WV is about 1.54/.769 = 2+ times that for liquid water temperature increase alone.”
The data used is available on line: UAH v6 data is at http://www.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
And WV data at http://data.remss.com/vapor/monthly_1deg/tpw_v07r01_198801_201906.time_series.txt
As stated in the field of the graph “NASA GISS Global Land Surface Temperature Anomaly”. Note that it is Land only. The graph was made by Tony Heller at realclimatescience. Perhaps you can get links to the historical data from him.
What everybody also ‘knows’ is that CO2 is a ghg but, again, that is only about half of the story. Dig a little deeper into the science and discover why CO2 has little, if any, effect on average global temperature but the rising water vapor has had. It’s available in the recently updated analysis at http://globalclimatedrivers2.blogspot.com
Dan Pangburn, If the calculation is wrong the conclusion might also be erroneous!
I thought followers of this thread might be interested in this recent article on how timber can be used for the construction of high-rise buildings, thereby eliminating CO2 released from steel and concrete manufacture that would otherwise have been used as the construction materials.
https://edition.cnn.com/style/article/wooden-skyscraper-revolution-timber/index.html
An interesting fact from the article is that the construction and operation of buildings accounts for 40% of the world's energy consumption, and approximately one-third of greenhouse gas emissions. A remarkable and totally unexpected number.
NASA/GISS continues to hoodwink the gullible into believing the mistake started by their earlier leader the astronomer Hansen and continued by their current leader the mathematician Schmidt that CO2 has caused the planet to warm. A deeper penetration into the science demonstrates that to be wrong. Gullible people have been falsely indoctrinated to believe that burning fossil fuels causes climate change. CO2 has no significant effect on climate. Water vapor is a powerful greenhouse gas. WV has been increasing faster than possible from feedback and is about 10 times more effective at ground level warming than CO2. The slight warming from CO2 at ground level is countered by increased cooling from more CO2 in the stratosphere. Methods and data sources are provided at https://watervaporandwarming.blogspot.com
John M Wheeldon
The idea that wood can replace concrete could be very important.
The manufacture of concrete creates CO2, so replacing it with wood will result in less anthropogenic carbon dioxide entering the atmosphere. Moreover, the wood contains carbon, so as long as more trees are planted to replace those used in construction, then that carbon dioxide will be sequestered at least for the lifetime of the building.
When ice sheets melt the altitude of their surface decreases. But air temperature rises as altitude decreases, so there is a positive feedback loop such that melting of an ice sheet causes the surface to warm, which leads to more melting and an even lower ice sheet. The only way to stop that is to reduce atmospheric CO2, which could be done by switching to wood as a building material.
Aymen J Alsaad
As Iraq is semi-arid, replacing concrete with wood products for housing projects may not be feasible. What measures to replace concrete would be practical for Middle Eastern countries such as yours?
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Atmosphere