Global Warming: Roads versus trees

[Pulsar]

I'm curious purely from an engineering standpoint. What effect doest black asphault have on heat absorption versus having light gray concrete or green trees? Most buildings have some type of dark colored asphault / rubber shingles as well.

It seems like a first-cut approximation could be made if you knew the amount of the earth covered in asphault / roofs, and then compared the reflectivity / absorptivity of the different mediums. Is there any way to get some approximated numbers?

It may be that the % of land covered by roads is so small that it really makes a negligible difference to temperatures. That's my bet, anyway. I just don't have a quick and dirty way of proving it.

 

[GWestphal]

You mean locally or globally?

Cities average about 10 degrees warmer than the surrounding rural areas. But in terms of global temps, no I don't think it makes a dent, maybe on the order of a thousandth of a degree would be my guess.

 

[SiliconWars]

Yeah I'm pretty sure roads are making an extremely negligible impact.

 

[SecurityTheatre]

I'm curious purely from an engineering standpoint. What effect doest black asphault have on heat absorption versus having light gray concrete or green trees? Most buildings have some type of dark colored asphault / rubber shingles as well.

It seems like a first-cut approximation could be made if you knew the amount of the earth covered in asphault / roofs, and then compared the reflectivity / absorptivity of the different mediums. Is there any way to get some approximated numbers?

It may be that the % of land covered by roads is so small that it really makes a negligible difference to temperatures. That's my bet, anyway. I just don't have a quick and dirty way of proving it.

You can look up the "heat island" effect, which is (as was mentioned) a cause of warmer air in cities.

However, the actual surface area of the earth covered by roads is very very small. I would think that clearing forest for farming would have a much greater effect. Trees are very very good at absorbing greenhouse gasses AND cooling the land surface.

 

[GWestphal]

Less than 2% of land is for urban use and only a fraction of that is asphalt , and land is only about 25% of the total surface area. So yeah, probably less than 0.0005% of the earth is asphalt covered.

 

[mindless1]

It may be that the % of land covered by roads is so small that it really makes a negligible difference to temperatures. That's my bet, anyway. I just don't have a quick and dirty way of proving it.

I have a quick and dirty way of proving it. Not black:

 

[denis280]

Sure its not helping the cause.but i think its to late for fixing right now.all they or we can do is slow it down.

 

[mikeymikec]

I have a quick and dirty way of proving it.

It would help if you didn't use (what definitely looks like) an artist's impression.

London is meant to be one of the greenest cities in the world, yet this is how it looks from a satellite view:

 

[SecurityTheatre]

It would help if you didn't use (what definitely looks like) an artist's impression.

London is meant to be one of the greenest cities in the world, yet this is how it looks from a satellite view:

London is a poor example, being a highly dense city and also one of the largest in the world. Very few places on Earth resemble the core of London or Tokyo or New York.

As was said, the fraction of a city that is covered with pavement, cement or other heat absorbing things is probably 25-50% (except in the highest density urban areas, which are rare), and the truely urban environment occupies under 0.5% of the land area. From a brief read on the topic, if you include suburban agglomerations, you can see up to 3% coverage, but those areas will be far less than 25% asphalt.

So, lets make some assumptions that fall on the high-end of this spectrum. Making the assumption that 0.5% of land is 50% covered and 3% of land is 15% covered, and the remaining land (highways and rural areas) are 0.1% covered, and 29.2% of the world is land, the total coverage of the world (liberally) is:

0.20% covered.

Now, that's not insignificant, but I would argue that having upwards of 6% of the Earth's surface covered by unnatural farming, grazing or other agricultural usage is a bigger issue.

Still, I fully support the idea of green roofs to mitigate a huge portion of this issue AND decrease heating/cooling costs at the same time.

 

[mindless1]

The funny part to me is it's all relative to when we evolved. Imagine if the discussion we were having instead was mankind causing continental plate drift. All planets go through some change. We can choose in vain to try to stop it, or better spend the time adapting.

 

[SecurityTheatre]

The funny part to me is it's all relative to when we evolved. Imagine if the discussion we were having instead was mankind causing continental plate drift. All planets go through some change. We can choose in vain to try to stop it, or better spend the time adapting.

What do you mean it is relative to when we evolved? I think you are masking the claim that changes in the environment have no anthropogenic cause. Am I reading you right?

I should point that the most recent issue of New Scientist has a summary of a scientific paper that postulates that life itself actually contributes substantially to continental drift by drastically affecting weather patterns, soil moisture retention and various other ideas.

They made the claim that a lifeless earth would have settled into a more uniform "shallow ocean world" rather than one that has relatively high tectonic activity, much of which is postulated to be exacerbated by erosion forces.

That might be a topic for another thread, however, but I, personally, believe that industrialization will have a profound impact on the biosphere, climate and even geography of the world on a scale we haven't even begun to see yet.

 

[Sheep221]

It would help if you didn't use (what definitely looks like) an artist's impression.

London is meant to be one of the greenest cities in the world, yet this is how it looks from a satellite view:

London has really bad air quality and green is something that is first seen somewhere in the suburbs, the city center itself has almost no grass or the trees in that matter.

 

[Pulsar]

London has really bad air quality and green is something that is first seen somewhere in the suburbs, the city center itself has almost no grass or the trees in that matter.

That's unfortunate. Hopefully people begin to look at that sort of thing a little differently. A lot of corporations are proving you can do it and actually save money if you plan in advance. For instance, Ford's Rouge factory complex has a green roof, in Detroit of all places!

 

[mindless1]

What do you mean it is relative to when we evolved? I think you are masking the claim that changes in the environment have no anthropogenic cause. Am I reading you right?

It is not masking something to write a sentence you don't understand, rather that could be accounted for by both my lack of willingness to write a long piece for a forum topic, and that you seem to want tunnel vision that discards other relevant global changes and only focusing on the one that our current state of evolution caused us to fixate on - which is relative to when we evolved.

I am instead suggesting it is rather silly to focus on because the amount of change mankind could make, relative to the already minor impact mankind has on environmental change, serves no useful purpose, causing more problems.

I should point that the most recent issue of New Scientist has a summary of a scientific paper that postulates that life itself actually contributes substantially to continental drift by drastically affecting weather patterns, soil moisture retention and various other ideas.

Yeah. Nonsense. Pre-industrial era life did very little to the environment that would effect weather, except for the Indian rain dances which we all know worked effectively. Weather changes and soil moisture retention may have coincided with changes in animal and human populations and activities but soil moisture retention causing plate drift is like suggesting a fly hit the world trade center and knocked it down.

They made the claim that a lifeless earth would have settled into a more uniform "shallow ocean world" rather than one that has relatively high tectonic activity, much of which is postulated to be exacerbated by erosion forces.

What they did there was seek to convince people in a non-scientific way that an idea they had might be true. Am I wrong in thinking that this is what magazines do, generate controversial articles to boost readership? It's a business, with those involved financially gaining from drawing people into the content. If anything, life and especially humans have a tendency to erode and level an area, not the other way around, but again it is to a trivial extent relative to planetary changes occurring regardless of either.

That might be a topic for another thread, however, but I, personally, believe that industrialization will have a profound impact on the biosphere, climate and even geography of the world on a scale we haven't even begun to see yet.

I completely disagree. Industrialization increases the pollution balance in the atmosphere which we need to maintain below a certain threshold for temperature moderation, crop growth, and health of all living species. At the same time the sky is not falling, the impact otherwise is out of our control and would happen either way and in fact had already been happening for millions of years when humans weren't a significant presence on earth.

We are now back at the beginning of my post. We're noticing things around us that have been going on for millions of years and trying to blame human actions relative to this stage in our evolution, things that will keep going on long after we cease to exist as a species. All this data we have is only due to us now collecting data about it. How many years out of millions do we have data on? Not guesses and theories, but data?

There are a lot of quacks out there but the one thing they all have in common is their central theme is we need to drop everything and change to suit them. This is the vanity of man, that when someone isn't content they want the rest of the world to change instead of changing oneself.

 

[SecurityTheatre]

It is not masking something to write a sentence you don't understand, rather that could be accounted for by both my lack of willingness to write a long piece for a forum topic, and that you seem to want tunnel vision that discards other relevant global changes and only focusing on the one that our current state of evolution caused us to fixate on - which is relative to when we evolved.

Your wording was chosen carefully, don't be a dick and claim it wasn't.

I am instead suggesting it is rather silly to focus on because the amount of change mankind could make, relative to the already minor impact mankind has on environmental change, serves no useful purpose, causing more problems.

Have you ever studied feedback systems? Many feedback systems are startling stable, but a little "kick" in one direction that is outside of the capability of the system to respond and the entire system collapses in a sometimes spectacular way. I'm not saying this is the case, but I'm saying it MAY be the case. Being aware of this serves a useful purpose and denying this concept is essentially tossing some dice and hoping you're right.

Good luck with that.

Yeah. Nonsense. Pre-industrial era life did very little to the environment that would effect weather, except for the Indian rain dances which we all know worked effectively. Weather changes and soil moisture retention may have coincided with changes in animal and human populations and activities but soil moisture retention causing plate drift is like suggesting a fly hit the world trade center and knocked it down.

It sounds to me like you are claiming they said "human life". You are aware the difference between "life" and "human life", right?

Did you seriously just claim a lifeless landscape erodes less than one covered with life? Based on what evidence?

What they did there was seek to convince people in a non-scientific way that an idea they had might be true. Am I wrong in thinking that this is what magazines do, generate controversial articles to boost readership?

I believe this was a free-access scientific journal based on terrestrial simulations using best-effort rigorous investigation of real-world data. Do I think the conclusions are 100% correct? Nope. Do I think they are interesting, relevant and potentially accurate? Yep, I do.

We are now back at the beginning of my post. We're noticing things around us that have been going on for millions of years and trying to blame human actions relative to this stage in our evolution, things that will keep going on long after we cease to exist as a species. All this data we have is only due to us now collecting data about it. How many years out of millions do we have data on? Not guesses and theories, but data?

Accurate measures of CO2 in the atmosphere? We have accurate data for about 800,000 years using direct measurement, via bubbles trapped in ice cores. The current atmospheric CO2 levels climbed from "below average" to "higher than ever recorded" in less than 100 years, a rise that previously took 50,000 years or more. Certainly, we don't know exactly what the implications of this change are, but to claim that it's just a trend in the long-term biosphere cycle is asinine.

their central theme is we need to drop everything and change to suit them. This is the vanity of man, that when someone isn't content they want the rest of the world to change instead of changing oneself.

The scientists doing this work do not advocate dropping everything, but making 1-3% annual changes in a gradual fashion. I know of nobody reputable arguing to drop everything, that's YOUR straw man, completely invented.

 

[mindless1]

^ There are no reputable scientists suggesting 1-3% annual change.

We don't seem to be on the same page. I'm suggesting that it does not matter that C02 levels rose, that yes they will be higher than at some points in earth's history and lower than others, but there is no relevance to the minor change we're making, it's a piece of trivia, like the trivial amount of influence life had on continental drift but in that case the argument is even backwards. Leveled continents would come from higher moisture saturation level and be due to vegetation slowing the loss of moisture, not the other way around. Mentioning what some people "postulate" is ridiculous to introduce into a conversation as an argument. That's NOT science, that's backwards selective deduction with an agenda motivating it.

Anyway, since I think it's a ridiculous thing to consider, I'm done spending time on it and am leaving the topic.

 

[SecurityTheatre]

^ There are no reputable scientists suggesting 1-3% annual change.

The Kyoto targets were a reduction of between 0.2% and 1.1% per year depending on country, or 0.1-2.4% adjusting for population growth.

ALMOST EVERY REPUTABLE SCIENTEST agreed with these targets... You are still attacking a straw man, aggressively and absurdly, and making up information in order to do it.

*shrug*

Please continue, it's amusing.

I'm suggesting that it does not matter that C02 levels rose, that yes they will be higher than at some points in earth's history and lower than others, but there is no relevance to the minor change we're making, it's a piece of trivia

According to the best scientific evidence, the CO2 concentration has suddenly, and rapidly increased to approximately 220% of median levels in under 100 years. It has done this approximately 4000% faster than at any other point in the last 800,000 years, as (accurately) measured from ice core samples.

Our definitions of trivial are different, clearly.

Leveled continents would come from higher moisture saturation level and be due to vegetation slowing the loss of moisture, not the other way around.

Yeah, sure, this continent claim is just a wild postulate based on one simulation. It is a bit silly, but you do understand that soil without vegetation erodes and compacts. In very dry areas, it breaks down into sand and blows around. In both cases, it's pretty common that the loss of vegitation in existing landscapes almost immediately results in large-scale erosion. But sure, this is all speculative, and has no relevance for the other topic of CO2 levels and their potential impact.

Mentioning what some people "postulate" is ridiculous to introduce into a conversation as an argument. That's NOT science, that's backwards selective deduction with an agenda motivating it.

Sure, it's an "educated guess" although it is backed by best-effort simulations (unlike most of what you are claiming).

But seriously, what "agenda" is motivating the guy who published simulation results showing continental changes based on the presence of life? You do realize it wasn't published by anyone (or any organization) with any stake in AGW topics, right? Just some random grad student with a fancy simulation model.

Cheers!