Global warming

[questor]

what was the earth's temperature during the age of the dinosaurs?

considerably warmer than now?

[lindagarrette]

what was the earth's temperature during the age of the dinosaurs?

considerably warmer than now?

 

Yes and there are many factors that explain variation in climate. Here's the definitive source.http://www.scotese.com/climate.htm

[questor]

Linda, a quote from your link:

''During the last 2 billion years the Earth's climate has alternated between a frigid "Ice House", like today's world, and a steaming "Hot House", like the world of the dinosaurs.''

this indicates that a lot of global warming is needed before our current generation can claim we are the cause of it. doesn't this indicate to you that massive global temperature fluctuations occur without human presence?

[pgrmdave]

Is there a generally accepted reason why the earth naturally bounces back and forth between hot and cold? Do we know if planets without any life have a similar cycle of climates?

[questor]

i think it has to do with the planets attitude to the sun. just as intriguing is the sometime change of the earth's magnetic polarity.

[InfiniteNow]

Linda, a quote from your link:

''During the last 2 billion years the Earth's climate has alternated between a frigid "Ice House", like today's world, and a steaming "Hot House", like the world of the dinosaurs.''

this indicates that a lot of global warming is needed before our current generation can claim we are the

cause

<

bold & color added by InfiniteNow

>

of it. doesn't this indicate to you that massive global temperature fluctuations occur without human presence?

Not addressing your question, but I don't think this is a pride issue, or that it matters who takes credit for the change. However, anyone who says that our impact is negligible may be overstating their argument some.

[Abi]

Re: albedo...

 

 

Public release date: 23-Jan-2006

Contact: Sheryl Weinstein

[email protected]

973-994-3257

New Jersey Institute of Technology

 

NJIT solar physicists report paradox: Less sunlight, but temps rise

Less sunlight reaching the Earth's surface has not translated into cooler temperatures, according to a team of solar physicists at New Jersey Institute of Technology

 

Less sunlight reaching the Earth's surface has not translated into cooler temperatures, according to a team of solar physicists at New Jersey Institute of Technology (NJIT). The scientists, who monitor the Earth's reflectance by measuring what is known as the moon's earthshine, have observed that the amount of light reflected by Earth -- its albedo -- has increased since 2000. The result has been less sunlight reaching the Earth's surface.

 

"Our findings have significant implications for the study of climate change," said Philip R. Goode, PhD, principal investigator and distinguished professor of physics at NJIT. "The results raise questions about how global temperatures can still rise when the amount of sunlight reaching the surface has decreased." The scientists find that the seemingly paradoxical result is due to an increase in the cloud cover coupled with a peculiar re-arrangement of the clouds, but are unsure why this is happening. This large variability of the clouds and albedo presents a fundamental, unmet challenge to our ability to understand and predict the Earth's climate.

 

Goode is the director of Big Bear Solar Observatory, California, where the observations were carried out. NJIT has owned and operated the observatory since 1997. Goode's findings are reported tomorrow in "Can the Earth's Albedo and Surface Temperatures Increase Together," published tomorrow by Eos (Jan. 24, 2006), the weekly newspaper of geophysics published by the American Geophysical Union. The National Aeronautics and Space Administration funded the research.

 

"Recently analyzed cloud data from the International Satellite Cloud Climatology Project (ISCCP) confirm the trend in reflectance," said Goode. "The data also reveal that from 2000 to now the clouds have changed so that the Earth may continue warming, even with declining sunlight. These large and peculiar variabilities of the clouds, coupled with a resulting increasing albedo, presents a fundamental, unmet challenge for all scientists who wish to understand and predict the Earth's climate." Co-authors with Goode are post-doctoral associates Enric Palle and Pilar Montanes-Rodriguez, who work at the observatory, and Steven E. Koonin, a professor of theoretical physics at California Institute of Technology (Cal Tech).

 

Climate depends on sunlight, less the part of sunlight that is promptly reflected plus how well the Earth holds heat. At any moment, more than half the Earth is swathed in clouds, and they dominate the Earth's reflectance. Both the sunlight reaching Earth and the amount of atmospheric heat trapped are sensitive to clouds, which both cool the Earth (especially low thick clouds) by reflecting the sunlight and warm the Earth by acting as blankets (especially high thin clouds).

 

It has been argued that an increasing albedo during the past five years would be inconsistent with the observed behavior in the global land and sea-surface temperatures because, in principle, an increase in the albedo would seem to imply that the decrease in the sunlight absorbed by the planet would lead to cooler temperatures.

 

The just-released update of the 20-year sequence of ISCCP satellite cloud data shows that during the first 15 years of observations, the percent difference between high lying and low-lying clouds remained steady at 7-8 percent. But in the last five years, for some unknown reason, the difference has almost doubled to 13 percent. The ISCCP data is a careful compilation of cloud observations covering the entire Earth from a range of meteorological satellites.

 

"That increase in the difference signals a relative decrease in the cooling effect of clouds," said Goode. "Thus, the rising reflectance of the Earth has not led to a reversal of global warming from the increase in sunlight being reflected back into space." What has happened is that the low, cooling clouds have decreased during the most recent years, while high, warming clouds have increased even more. Thus, the cloud data also reveal an increase in total cloud amount during 2000-2004. That increase is consistent with the earlier earthshine result of growing reflectance throughout that period.

 

Goode noted that the Earth's reflectance depends primarily on cloud properties. Recent ground-based and satellite studies of the albedo have shown a surprisingly significant inter-annual and decadal variability. From about 1985-2000, the Earth steadily received more sunlight, before the recent reversal of the trend from 2000-2004. "This is not the first time such a situation occurred," Goode said.

 

Ground-based radiometers hint at a similar reversal from the 1960's through the mid-1980's, which some scientists have dubbed global dimming. Thus, it seems there may be a large, unexplained decadal variation in sunlight reaching the Earth, as well as a large effect of clouds re-arranging by altitude.

 

"From these data and results, we caution scientists against concluding that global dimming would mean a cooler Earth, and that clouds need a better treatment in climate models" said Goode.

 

The earthshine studied by Goode and his colleagues can be seen as a ghostly glow associated with the moon's "dark side" -- or the portion of the lunar disk not lit by the Sun. The cloudier the Earth, the brighter the earthshine. "The phenomenon of earthshine was first observed by Leonardo DaVinci," said Goode.

[cwes99_03]

Ah nm, they are saying that the increased albedo is due to increased cloud coverage of the earth. Interesting thought, but I would think that in this age with satellite imagery of the entire planet possible, that better measurements of albedo than earth shine on the moon would be possible.

 

Thanks for the article, but I'd like everyone to keep looking.

[ConsiderThis]

There was a piece on the news some time ago about lightening the color of asphalt and how much difference that made to surrounding temperatures.

 

Any ideas on how I can find some info on this?

 

So far I haven't Googled the right words, I guess.

 

Your fingernails reflect your ... --

Learn some warning signs --

Karen Kline

[ConsiderThis]

Well, I found this:

 

Cool Alternative Paving Materials & Techniques

Prepared by Dr. Lisa Gartland

Back to Cool Strategies | Back to Sacramento Cool Community Program

 

Below is a list of various paving materials and techniques which can be made lighter in color and, therefore, cooler. For the coolest pavement, pick the lightest shade available. It's been shown that light gray and tan colors can reduce pavement surface temperatures by 20 to 40°F. There is also preliminary evidence to suggest that cooler pavements last longer.

 

Codes in parentheses:

 

N - New pavement applications, R - Resurfacing pavement applications

 

A - Asphalt material type, C - Concrete material type, O - Other material type

It's at CleanAirCounts

[Michaelangelica]

How much effect does the massive amounts of road surface have on global warming?

I agree.

What would happen if all road surfaces were white in colour?

Wouldn't this help?

(I am reminded of a game I once had called SimEarth, where you could change earth's reflected heat and watch the results)

 

There must be many things we can do to slow Global Warming

 

Imagine a City like New York with thousands of stories of plants, in every multi-story building.

Imagine every office a veritable jungle.

No plastic plants allowed.(& all potting mixes to contain 20% carbon)

Wouldn't this help?

 

Imagine if everybody in suburbia grew their grass 1" longer what would this do?

 

What if everybody in Suburban gardens used charcoal (Terra preta) as a soil amendment how much CO2 would this sequester?

Wouldn't this help?

[LJP07]

Yeah, I think if these little but effective measures were taken around the world, Global Warming would be slowing down obviously, what's the biggest threat that results in Global Warming to date, that would also be another place to start.

 

I also came across some interesting info regarding Global Warming:

http://www.isen.com/blog/2006/07/evidence-for-global-warming.html

 

I also came across an interesting quote:

 

" Climate change is the most severe problem that we are facing today -- more serious even than the threat of terrorism."

 

We all see the effects of reducing terrorism, if only the same drastic action could be taken today.

[cwes99_03]

Prolu, I recommend reading some of the other global warming threads too to get a balanced viewpoint. I'm not suggesting that we can change anything with this thread.

Instead I was simply looking for some brainstorming on what other things might cause an increase in the temperature of the earth.

 

1) Greenhouse effect

2)decreased albedo of the earth (what causes this, is there any data to support the idea)

3) increased solar activity

4) increased techtonic activity (volcanoes releasing heat, etc.)

 

There is almost nothing we can do about these if you are well informed on the subject. But this can't stop us from trying to minimize our contribution. Thus we talk about increasing the albedo of the earth where we have decreased it, namely on road surfaces, farm ground?, rooftops, major development of natural habitats that naturally reduce earth's temperature, and yes CO2 production.

[Zythryn]

As I understand it, the most CO2 added to our atmosphere by man is through fossil fuel electrical plants. Transportation is a smaller but still significant source of CO2.

 

If we can continue to clean up our power generation (solar, wind, tidal, geothermal, nuclear, etc) and switch out transportation to run on that clean electricity/bio diesel that would be a huge step forward.

 

Some people say we can't do anything and we should simply watch it happen. However, if there is even a possibility that we can do something those two areas seem to be the easiest to switch.

[cwes99_03]

Zyth, could you provide a website to back that up. I don't know if your thoughts are right or not, but it would help me to know if you could find data supporting that claim.

 

Oh, and I like to throw this in to the mix. While I advocate minimizing our effect on global warming, I hate it when I hear people say we should do everything we can to reverse global warming. That is actually the worst thing to do.

 

Say those who proclaim that we are in a global warming crisis are wrong, and three years from now we have temperatures 2 degrees on average below the 100 year average. Then we will have been fighting global warming just to have to fight global cooling and a new ice age.

 

No, that is not the answer. That is why I say the answer is to fight mankinds involvement, and let the natural cycles manage things.

[Zythryn]

Instead I was simply looking for some brainstorming on what other things might cause an increase in the temperature of the earth.

 

Is anyone subscribed to Popular Science? About 6-9 months ago they did a spread on ways to combat global warming. It was very interesting, ranging from science fiction to things we could do today.

One of the suggestions was to build ships in the southern hemisphere (I forget the reasoning) that would use evaporated sea water to create more cloud cover. This cloud cover would reflect more light lowering the temperature.

The ships would be fairly inexpensive but you would need a lot of them.

 

Another was to seed the south atlantic with lots of iron. This would cause a major bloom of algea which would soak up tons of CO2. The problem with this plan is if we miscalculate it would be very difficult to turn off:)

 

There may be disagreement about how much of an effect we can have. However I think we can agree that any amount of effect is good. Even the side effects of a cleaner enviornment would make life more pleasant for many people.

[cwes99_03]

Hey Zyth, check my edit above for why I think that isn't the best idea (besides the disastrous effects of algae growth in the ocean on the rest of marine life).