Global warming or not?

[Sparrow]

I think that's why Stephen Hawking recommends we keep our heads down with regard to aliens.
Our experience of spacefaring civilisations suggests they're likely to be unprincipled and violent.

[kennyc]

Originally Posted by Sparrow

I think that's why Stephen Hawking recommends we keep our heads down with regard to aliens.
Our experience of spacefaring civilisations suggests they're likely to be unprincipled and violent.

[GeoffC]

Of course !


The Hollywood Model ....

[astra]

Originally Posted by Sparrow

I think that's why Stephen Hawking recommends we keep our heads down with regard to aliens.
Our experience of spacefaring civilisations suggests they're likely to be unprincipled and violent.

I agree with him.
So, GeoffC, my answer to your question

and what would we, given our experience, do if they said "no" ....

would be we leave peacefully and go to Venus.

[WT Sharpe]

Originally Posted by Sparrow

I think that's why Stephen Hawking recommends we keep our heads down with regard to aliens.
Our experience of spacefaring civilisations suggests they're likely to be unprincipled and violent.

It's a little late for that. The first radio broadcast was transmitted in 1906.

[Glenndk]

Originally Posted by Icarusbop

...
We also need to consider the possibility that global warming is happening, but not caused my man (non-anthropogenic global warming)..
so, what do you all reckon?

This text is intended primarily for people over e.g. 18 year old. Younger people should just enjoy your youth and not worry too much about global warming or not. Wait till you are grown up.

-

Global warming or not?

I am confident that IPCC has done their best to assess global warming (or not). According to the latest IPCC report:

Climate Change 2007: Synthesis Report ("Full report"):
http://www.ipcc.ch/publications_and_...sis_report.htm
http://www.ipcc.ch/pdf/assessment-re...yr/ar4_syr.pdf
Quote: "...
An Assessment of the Intergovernmental Panel on Climate Change
...
[pdf-page 5, paper page 27]
Where uncertainty is assessed more quantitatively using expert judgement of the correctness of underlying data, models or analyses, then the following scale of confidence levels is used to express the assessed chance of a finding being correct: very high confidence at least 9 out of 10; high confidence about 8 out of 10; medium confidence about 5 out of 10; low confidence about 2 out of 10; and very low confidence less than 1 out of 10.
Where uncertainty in specific outcomes is assessed using expert judgment and statistical analysis of a body of evidence (e.g. observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%; likely >66%; more likely than not > 50%; about as likely as not 33% to 66%; unlikely <33%; very unlikely <10%; extremely unlikely <5%; exceptionally unlikely <1%.
...
[pdf-page 15, paper page 37]
There is very high confidence that the global average net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] W/m2 (Figure 2.4). {WGI 2.3, 6.5, 2.9, SPM}
...
[pdf-page 17, paper page 39]
It is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent (except Antarctica) (Figure 2.5). {WGI 3.2, 9.4, SPM}
...
[pdf-page 18, paper page 40]
Anthropogenic warming over the last three decades has likely had a discernible influence at the global scale on observed changes in many physical and biological systems. {WGII 1.4}
...
[pdf-page 50, paper page 72]
Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. {WGI 3.9, SPM}
...
Anthropogenic warming over the last three decades has likely had a discernible influence at the global scale on observed changes in many physical and biological systems. {WGII 1.4, SPM}
..."

-

I am pretty confident that earths civillizations will take action, when the right tools are at hand.

Today we have powerfull tools to communicate (internet and (mobile) phones!) earthwide within seconds. We have accomplished enormous positive innovations with worldwide impact - even within the last 2-3 decades.

Once one or more energy storage conversion processes - directly or indirectly - from solar energy to e.g. hydrocarbon has been found and proved useable in global scale, I believe we are done. The total conversion efficiency just has to be a little more than biologically photosynthesis (approx. 6.6%).

Of cause we shall try to minimize energy consumption, but that is not enough - but it will buy some more time.

We ought to tax fossil fuel and coal, and use that tax to study ways to use and store solar energy - and maybe fusion energy. We need to be able to store e.g. solar energy for at least half a year - optionally e.g. 10 years.

Please note that wind energy and wave energy are "just" converted solar energy. A sort of "problem" is that fossil fuel and coal are pretty cheap. But once we have found one or more suitable technologies to replace most of the burning of fossil fuel and coal, that technology will be used almost everywhere.

Hydrocarbons (oil, petrol, many synthetic fuels..) are very good energy carriers. When we can make them ourselves efficiently in e.g. deserts or other plant scarce places - e.g. roofs - they will replace burning of fossil fuel and coal.

Solar cells/photovoltaics are getting cheaper and cheaper and can feed an intelligently controlled electrical power grids, and a synthetic fuel power plant can convert the surplus energy to synthetic fuel. The problem here is that the use of the electrical power grid needs to be changed, but the reward is a more stable and self-healing grid.

If we can efficiently extract CO2 out of the atmosphere - for synthetic fuel, the CO2 concentrations might be lowered more quickly than by biologically photosynthesis alone.

-

Some sources:

upei.ca: Photosynthesis:
http://web.archive.org/web/200712162..._synthesis.htm
Quote: "...The overall efficiency is then .286x.43x.8x.67 = .066 or 6.6%..."

Could be less when plants are evaluated over a year:
http://en.wikipedia.org/wiki/Photosynthesis#Efficiency


American Chemical Society (2008, April 11). Expert Foresees 10 More Years Of Research & Development To Make Solar Energy Competitive. ScienceDaily. Retrieved April 24, 2008:
http://www.sciencedaily.com/releases...0407172717.htm
Quote: "... "Solar can potentially provide all the electricity and fuel we need to power the planet," Harry Gray, Ph.D...In his talk at the ACS Presidential Symposium, Gray cited the vast potential of solar energy, noting that more energy from sunlight strikes the Earth in one hour than all of the energy consumed on the planet in one year..."


The area of the black dots' solar power is enough to power the whole world (18TeraWatt) - assuming 8% conversion efficiency:
http://upload.wikimedia.org/wikipedi..._land_area.png
Description:
http://da.wikipedia.org/wiki/Fil:Solar_land_area.png


This paper has, among others, an efficient way of extracting CO2 out of the atmosphere:

Green Freedom (tm) A Concept for Producing Carbon-Neutral Synthetic Fuels and Chemicals (Patent Pending). F. Jeffrey Martin, William L. Kubic, Los Alamos National Laboratory, LA-UR-07-7897:
http://www.lanl.gov/news/newsbulleti...m_Overview.pdf
Quote: "...Making gasoline from air and water sounds exotic, but now practical technology has been developed to implement known chemical pathways for producing fuel from these abundant raw materials...With Green Freedom(tm), this possibility has progressed beyond speculation to a realistic, low-risk concept because it is based on novel process integration and modest extensions of existing technology..."


http://en.wikipedia.org/wiki/Fischer-Tropsch_process

http://en.wikipedia.org/wiki/Artificial_photosynthesis

July 31, 2008, Solar-Power Breakthrough.
Researchers have found a cheap and easy way to store the energy made by solar power.
http://www.technologyreview.com/Energy/21155/
(Actually it is a first step towards synthetic fuel - output is hydrogen)

-

December 7, 2007, sandia.gov: Sandia’s Sunshine to Petrol project seeks fuels from thin air:
http://www.sandia.gov/LabNews/ln12-0...ws12-07-07.pdf

14-February-2006, Fuelcellworks: Sandia Labs Researcher Rich Diver Invents New Way to Make Hydrogen for Fuel:
http://web.archive.org/web/200804161...ppage4553.html
Quote: "...His invention, the Counter Rotating Ring Receiver Reactor Recuperator (CR5, for short), splits water into hydrogen and oxygen, using a simple, two-step thermochemical process...the theme of his PhD dissertation at the University of Minnesota — and of concentrated solar gained from his 15 years working with Stirling engine solar collector systems at Sandia..."

December 5, 2007, Sandia National Laboratories - Sandia’s Sunshine to Petrol project seeks fuel from thin air:
https://share.sandia.gov/news/resour.../sunshine.html
Quote: "...CR5 inventor Rich Diver says the original idea for the device was to break down water into hydrogen and oxygen...Over the past year they have shown proof of concept and are completing a prototype device that will use concentrated solar energy to reenergize carbon dioxide or water, the products of combustion. This will form carbon monoxide, hydrogen, and oxygen, which ultimately could be used to synthesize liquid fuels in an integrated S2P system..."

[Glenndk]

Originally Posted by kennyc

Which is exactly the issue. Unless we can find a way to expand into space/other planets we my die in our own filth just like a virus that consumes everything available to it before dying itself.

You are wrong - we are more intelligent than a virus and microbes (=microorganisms) - we fight them every day and wins most of the time. We just need to focus more on recycling our waste.

Mankind are getting more and more conscious about that we need to live in harmony with the rest of nature. Actually microbes (and vira) has terraformed the earth and made it possible for higher organism to evovle here. We are here on the mercy of microbes! We should thank many of the microbes!

Biota (life) rules this earth - first and foremost microbes - and to some extend humans.

And yes, we should try to terraform and colonize other habitable planets, if they are unhabited in the first place. We should just "dump" some hardy microbes onto the planet and wait for some millions years. These microbes will multiply exponentielly - and transform the whole planet crust to be thorougly criss-crossed with live - like earth.

-

Need sources? - most of them are in english:

http://da.wikipedia.org/wiki/Biota_%...r.2Freferencer

-

Examples:

BBC News, 28 September, 2001: The microbes that 'rule the world':
http://news.bbc.co.uk/1/hi/sci/tech/1569264.stm
Quote: "...The Earth's climate may be dependent upon microbes that eat rock beneath the sea floor, according to new research....The number of the worm-like tracks in the rocks diminishes with depth; at 300 metres (985 feet) below the sea floor, they become much rarer..."


BioMed Central (2010, April 7). First animals to live without oxygen discovered. ScienceDaily. Retrieved April 18, 2010:
http://www.sciencedaily.com/releases...0407094450.htm
Quote: "...Deep under the Mediterranean Sea, small animals have been discovered that live their entire lives without oxygen and surrounded by 'poisonous' sulphides...the open access journal BMC Biology report the existence of multicellular organisms (new members of the group Loricifera), showing that they are alive, metabolically active, and apparently reproducing in spite of a complete absence of oxygen...."The finding by Danovaro et al. offers the tantalizing promise of metazoan life in other anoxic settings, for example in the subsurface ocean beneath hydrothermal vents or subduction zones or in other anoxic basins."..."


Oregon State University (2004, January 1). Bacteria Discoveries Could Resemble Mars, Other Planets. ScienceDaily:
http://www.sciencedaily.com/releases...0101091149.htm
Quote: "...A team of scientists has discovered bacteria in a hole drilled more than 4,000 feet deep in volcanic rock on the island of Hawaii...Finally, they removed DNA from a crushed sample of the rock and found that it had come from novel types of microorganisms..."


17 December, 2003, BBCNews: Oldest evidence of photosynthesis:
http://news.bbc.co.uk/2/hi/science/nature/3321819.stm
Quote: "...Scientists claim to have found the oldest evidence of photosynthesis - the most important chemical reaction on Earth - in 3.7-billion-year-old rocks....If their findings are correct, life was very sophisticated, very early on in Earth history," said Buick...But life may be older and more robust than we thought..."


May 23, 2008, nationalgeographic.com: Hot Life-Forms Found a Mile Under Seafloor:
http://news.nationalgeographic.com/n.../39220343.html
Quote: "...All told, Parkes said, these prokaryotes could amount to 10 to 30 percent of the world's total living matter..."


BBCNews: 27 September, 2000, When slime is not so thick:
http://news.bbc.co.uk/2/hi/science/nature/944790.stm
Quote: "...It means that some of the lowliest creatures in the plant and animal kingdoms, such as slime and amoeba, may not be as primitive as once thought..."


The Amoeba dubia has 200 times the DNA that a human has - that makes you wonder...

-

Nature 436, 390-394 (21 July 2005), Deep sub-seafloor prokaryotes stimulated at interfaces over geological time:
http://www.nature.com/nature/journal...ture03796.html
Quote: "...
The sub-seafloor biosphere is the largest prokaryotic habitat on Earth
...
Recently, subsurface prokaryotes have been found to be ubiquitous on Earth (for example, in sediments, rocks, aquifers, mines, basalts and crustal fluids, oil reservoirs and ice sheets3).
..."

-

Some life endures space - most sources are in english:
http://da.wikipedia.org/wiki/Udenjor...r.2Freferencer

Nov 09, 2005, Space Daily: Lichen Survives In Space:
http://www.spacedaily.com/news/life-05zzzzzzzr.html
Quote: "...suggests that lichens might survive at the surface of Mars..."


8 November 2005, ESA: Lichen survives in space:
http://www.esa.int/esaCP/SEMUJM638FE_index_0.html
Quote: "...two different species (Rhizocarpon geographicum and Xanthoria elegans) were exposed for a total 14.6 days before being returned to Earth...indicate that lichens have the capacity to resist full exposure to the harsh space conditions, especially high levels of UV radiation. Analysis post flight showed a full rate of survival and an unchanged ability for photosynthesis..."


BBC News, 10 July, 2000, Snow microbes found at South Pole
http://news.bbc.co.uk/2/hi/science/nature/827063.stm
Quote: "...able to survive the large doses of ultraviolet radiation, extreme cold and darkness...The microbes have DNA sequences similar to a category of bacteria known as Deinococcus..."

7 January, 2002, BBCNews: Alien life could be like Antarctic bugs:
http://news.bbc.co.uk/2/hi/science/nature/1765792.stm
Quote: "...Beauveria bassiana..."

The Swedish Research Council (2009, November 12). New Explanation For Nature's Hardiest Life Form. ScienceDaily. Retrieved November 15, 2009:
http://www.sciencedaily.com/releases...1111121249.htm
Quote: "...In this form the bacteria can survive for hundreds, perhaps millions, of years in a dormant state and, what's more, endure drought, extreme temperatures, radiation, and toxins that would quickly knock out unprotected bacteria...spores can survive temperatures up to 150 degrees centigrade..."


http://en.wikipedia.org/wiki/Tardigrade
Quote: "...
More than 1,000 species of tardigrades have been described. Tardigrades occur over the entire world, from the high Himalayas (above 6,000 m), to the deep sea (below 4,000 m) and from the polar regions to the equator.
...
Tardigrades are polyextremophiles and are able to survive in extreme environments that would kill almost any other animal. Some can survive temperatures of -273°C (-460 °F), close to absolute zero,[5] temperatures as high as 151 °C (303 °F), 1,000 times more radiation than other animals,[6] and almost a decade without water.[7] In September 2007, tardigrades were taken into low Earth orbit on the FOTON-M3 mission and for 10 days were exposed to the vacuum of space. After they were returned to Earth, it was discovered that many of them survived and laid eggs that hatched normally, making these the only animals known to be able to survive the vacuum of space.[8]
..."

http://en.wikipedia.org/wiki/Brine_shrimp
Quote: "...
Brine shrimp eggs are metabolically inactive and can remain in total stasis for two years while in dry oxygen-free conditions, even at temperatures below freezing. This characteristic is called cryptobiosis meaning "hidden life" (also called diapause). While in cryptobiosis, brine shrimp eggs can survive temperatures of liquid air (−190 °C or −310.0 °F) and a small percentage can survive above boiling temperature (105 °C or 221 °F) for up to two hours.[2]
..."

[kennyc]

Hee-Hee. Not sure why that rattled your cage so much, but the fact is we are killing ourselves due mostly to our overpopulating the planet -- as I said just like a virus that consumes its host and then dies itself. Life consumes itself. You can post all the links you want but the direction is clear and it has nothing to do with intelligence. Odds are we will be replaced by our machines once we get them to the point of being able to replicate themselves and they will have a much better chance of survival in the universe.

[Glenndk]

Originally Posted by kennyc

Hee-Hee. Not sure why that rattled your cage so much, but the fact is we are killing ourselves due mostly to our overpopulating the planet -- as I said just like a virus that consumes its host and then dies itself. Life consumes itself. You can post all the links you want but the direction is clear and it has nothing to do with intelligence. Odds are we will be replaced by our machines once we get them to the point of being able to replicate themselves and they will have a much better chance of survival in the universe.

The world population trend is slowing. China has made an one child policy - and in Europe the trend is negative (less than two children per couple).

[Glenndk]

Originally Posted by kennyc

...
Odds are we will be replaced by our machines once we get them to the point of being able to replicate themselves and they will have a much better chance of survival in the universe.

The machines can not think the way we do. I do not think that this will change in the (near) future.

But we can use machines as tools - also in space as we already do.

[kennyc]

Originally Posted by Glenndk

The world population trend is slowing. China has made an one child policy - and in Europe the trend is negative (less than two children per couple).

I don't think so. I'm talking about the world, not a few countries. I'm not going to argue about this (any more than I'm going to argue about the subject topic - the facts are evident).

Look at the numbers. It's the vast number of humans and what they do that is causing global warming (to get back on topic!)

[astra]

Originally Posted by Glenndk

The world population trend is slowing. China has made an one child policy - and in Europe the trend is negative (less than two children per couple).

You wish...
Chine and India as stand alone countries might be at the top of the list at the moment. However, there are others who breed like rabbits all over the world with no regard to the reality.

[kennyc]

Originally Posted by Glenndk

The machines can not think the way we do. I do not think that this will change in (near) future.

But we can use machines as tools - also in space as we already do.

I can see you just want to start an argument -- I'm not going to play your game, but will say that you certainly have some pre-set ideas about what is and what isn't the place of humanity in the universe which makes me

[Glenndk]

Originally Posted by kennyc

I don't think so. I'm talking about the world, not a few countries. I'm not going to argue about this (any more than I'm going to argue about the subject topic - the facts are evident).

Look at the numbers. It's the vast number of humans and what they do that is causing global warming (to get back on topic!)

The population trend is definitely slowing:

http://en.wikipedia.org/wiki/World_population
Quote: "...
The growth rate peaked at 2.2% in 1963, and declined to 1.10% by 2009. Annual births have reduced to 140 million since their peak at 173 million in the late 1990s, and are expected to remain constant, while deaths number 57 million per year and are expected to increase to 90 million per year by 2050. Current projections show a steady decline in the population growth rate, with the population expected to reach between 8 and 10.5 billion between the year 2040[4][5] and 2050.[2]
..."

[Glenndk]

Originally Posted by astra

You wish...
Chine and India as stand alone countries might be at the top of the list at the moment. However, there are others who breed like rabbits all over the world with no regard to the reality.

I hope most people breed like humans.