Naked Science Forum
Life Sciences => The Environment => Topic started by: Airthumbs on 04/01/2011 14:03:03
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Throughout the history of planet Earth, animals and eco-systems have adapted to climate change. What is so different now? Right now climate change is happening more quickly then ever before, this will make it much harder for ecological systems and humans to adapt.
Over the 4 billion year history of the planet climate has been wildly variable, times when the planet was covered in ice and times when exotic tropical animals have roamed the poles.
During all our recorded history, 6000-8000 years, the climate has been unusually stable. With the dawn of a new age, the industrial revolution, around 1780 when we first started burning fossil fuels, CO2 (Carbon Dioxide), levels were around 280ppm (parts per million), 1960 upto 330ppm, 1990's 360ppm, 380ppm today.
By the middle of the century, 2050, it is forecast that these levels will be 500ppm. The last time the planet came to equilibrium with those levels of greenhouse gasses was 20-40 million years ago with ocean levels were about 200 meters higher then today.
There will always be doubters and sceptics of phenomenon involved with human induced climate change. There are some very powerful economic forces at work that do not want to see things change as this would be to their disadvantage.
There is no doubt that the surface of the earth is getting hotter, the evidence is clearly there. 20 years ago it was difficult to state whether or not this was due to mankind, today there is so much accumulated evidence from so many sources it is very difficult to refute that we are contributing towards this rapid change in climate.
I think it is really time to stop arguing about climate change, and take positive steps to change our dependence on a petroleum based economy. It seems that human kind mostly destroy things, many people will say that's in our nature but, as David Attenborough sais "It is time that we took a moral responsibility to become stewards on the planet that we happened to have developed".
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I have no doubt that within a half century to a century, we will be forced to wean ourselves to a large extent off of liquid petroleum, and within a century, we may naturally also slow down on the consumption of coal... if we can keep up with our ever increasing power consumption needs, and get other alternative energy sources online.
We've had nuclear power for a half a century, yet there are some big problems that remain to be resolved.
The Global Warming Debate, however, is far from resolved.
- What is the actual human contribution to local or global temperature changes?
- Are the estimated temperature changes unprecidented?
- What regions are most impacted by these influences?
- Are the effects positive or negative?
- What are the likely local and global effects of these changes? Crops? Animals? Eco-systems? Sea Levels?
- Are we likely to see "natural" climate changes that will overwhelm the human contributions? In the near future? In the distant future? WHY?
- Is there a "tipping point"?
- Are the temperature effects linear? Are there natural feedback processes that would tend to prevent a runaway warming effect?
One of the problems is that records are sparse, and incomplete over the last century, and may not properly take into account non-CO2 mitigated changes such as urbanization.
The records are much less precise over thousands, hundreds of thousands, or millions of years.
Even the purported climate stability during the Holocene Epoch may be a misnomer.
Here is an estimate of Greenland temperatures over the last 10,000 years, which indicate that we may not be anywhere near a "high". And, since Greenland keeps coming up with the discussions of glaciers, this may indicate that we aren't at a critical point for Greenland either.
http://www.theresilientearth.com/?q=content/little-ice-age-ii-sequel
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.theresilientearth.com%2Ffiles%2Fimages%2Feasterbrook_holocene_temps.png&hash=b98bc3d22e5a2ec83bde4d0b3447b72d)
The photo above ignores the 100,000 or so years out of the previous 114,000 years in which temperatures were significantly more frigid than they are today. And, if we were to return to the average temperature of 20,000 years ago, humanity would suffer tremendously.
Recently I've been looking at sunspots and solar irradiance. There has been an observed correlation of the more sunspots, the more solar irradiance, so it is a good method to understand historical energy from the sun.
http://www.theresilientearth.com/?q=content/little-ice-age-ii-sequel
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.theresilientearth.com%2Ffiles%2Fimages%2Fsunspot_numbers_400yr-500.jpg&hash=ecb33891d0b0abe3ab57054435c7b65a)
This is an interesting composite graph showing a cumulative change from the average number of sunspots from the last 500 years.
http://www.theresilientearth.com/?q=content/atmospheric-solar-heat-amplifier-discovered
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.theresilientearth.com%2Ffiles%2Fimages%2Fsolar_irradiance_departure.png&hash=61e9933bb1de0fed6faca61e75396e37)
A little belated, we are now beginning the Solar Cycle 24. Indications are that it could be one of the weakest solar cycles in a half century. However, time will tell. Some people are predicting that it could be the beginning of a climatic shift.
I'm not predicting that our average temperatures over the next few years will drop by 10°C, but there is a lot we have yet to understand about the controlling influences of our climate.
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Clifford?
"We've had nuclear power for a half a century, yet there are some big problems that remain to be resolved."
Ahh, now what can that be :)
We already have gen 4 reactors, at least on wiki ::)) Check it up, and they all work too, according to the wiki at least. Marvelous really :) NP Clifford. If they don't work I'll make another wiki with gen 5.. All by myself too, and they will be good, ecological and safe, only green energy I promise. and it's quick too. I reckon I can make that wiki in a week, or less.
In the mean time we have some wastes, was that what you meant? Like wastes able to be tracked all the way to that nuclear beginning maybe? Some fifty sixty years ago? Still, as long as they don't bury them where I live, right :) And after me we can make a gen 6 too that eats them, and then burp out even more 'green energy'. I'm sure we can..
And Airthumbs, it's a good idea.
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Ok after having some time to try and soak up the response from cliffordK I have this to say....
I appreciate that taking Ice cores from Greenland is a good way of analysing the gaseous content of the atmosphere for the globe but..... I feel that the measurements for temperature could be very misleading as they are very localised. Is there anyway of correlating what this readings show and what was happening in the Sahara for example? And how do these temperature readings fit in with global averages?
I think that studying the Sun for its effects on the Earth is very important and has been strangely overlooked in the past. I know the Sun has been unusually quiet recently but apparently is beginning to wake up again.
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I think I tried this one before and got shot down in flames. However, if at first you.....
We must have a pretty good idea of the thermal energy that's being put into the Earth from all sources. We also know that the Earth radiates energy into space.
Energy in = energy out - Happiness!
Energy in ≠ energy out - Unhappiness!
Sooooo, how can we measure the energy out bit? I was wondering if we can determine that from really far away by taking the Earth's temperature. If you get far enough away, all the localized variations are integrated into a single value. If we know the temperature, we should be able to determine the energy being radiated.
If this were to actually work, it would seem to provide us with the sort of data we really need.
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Interesting idea Geezer. But to get a reading you need a distribution. In space you can get a thermal reading of Earth, or, of the Sun, but there are no thermal distribution, aka mean temperature in Space. Well, there is one in one way, in the absence of temperature, more or less. We need something 'vibrating' to get that 'mean' temperature. But the problem is tricky Geezer, if we live in a non-linear system then there can be a lot of unthought of 'effects' that will contribute to a tipping into a new climate configuration.
And a major one is the Sun, and it's solar-spots. And looked at that way all we do on Earth is 'noise' disturbing a equilibrium, and with our man-made warming we have to create a lot of noise. And if it so, then even if we could get that 'mean distribution of energy flow' we couldn't still take that as a proof that the 'system' isn't reaching a tipping point. Isn't we overdue for a magnetic flip also according to some ideas?
Earth is overdue in a lot of ways, I think we've had the balance we have now longer than could be expected any which way.
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I don't know if this has anything to do with a tipping point of sorts but; The Earth's magnetic north pole is drifting from northern Canada towards Siberia with a presently accelerating rate, 10 km per year at the beginning of the 20th century, up to 40 km per year in 2003, and has been accelerating since. This I would say indicates that we are currently going through a process of Geo-magnetic reversal, however this could still take thousands of years! The exact position of the magnetic north and south poles are essential for navigation at sea. The marine magnetic compass at sea is mainly used for steering a course. The compass reading must be accurate, especially on long sea passages, because any errors of one or two degrees can make a difference of thousands of nautical miles in reaching your destination, (on long hauls anyway).
It has been suggested that when this so called flip does occur we may loose the protection of our so called magnetic shield. I just hope this does not happen at a solar maximum!! NASA have a pretty good webpage about this; http://www.nasa.gov/vision/earth/lookingatearth/29dec_magneticfield.html
How this would effect the climate of the earth in anyway, is open to debate.
Geezer, I think your idea on taking a mean reading of the global surface temperature is a good one. I like the equation you provided in your post above.... as Yor_on said though, it may not provide us with enough information on these so called tipping points. I wonder if the Voyager probes could be turned round to look back at the earth and take those kind of readings?
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Maybe I'm missing something here, but if we can determine whether or not the system is in thermal equilibrium, does that not address the question of global warming once and for all? After all, it's not called Global Warming for nothing. It's actually impossible to determine if the Earth is warming unless you use a method that integrates all the effects. The Earth is no different from any other thermodynamic system.
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Maybe I'm missing something here, but if we can determine whether or not the system is in thermal equilibrium, does that not address the question of global warming once and for all? After all, it's not called Global Warming for nothing. It's actually impossible to determine if the Earth is warming unless you use a method that integrates all the effects. The Earth is no different from any other thermodynamic system.
Maybe you could get into your spaceship and fly far away enough to take some of those readings? Or we could just send NASA an e-mail and ask them to do it with Voyager. Having said that in my experience they just ignore you anyway.
If you do decide to go on a jolly can you take me too?
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Voyager is now beyond Pluto... From that distance, Earth will look like a speck of sand.
There are satellites orbiting the earth now that are designed to look at the Temperature of earth via infrared (IR) emissions. Hopefully they could do a full spectographic analysis, including IR emissions as well as reflected light.
If not, then we need to put a more capable satellite (or a few of them) in orbit near the distance of the moon.
And, to answer the question, we really will need to validate the models and have some high resolution imaging.
What are the actual emissions on cloudy days?
What is the effect of SMOG?
Can we eliminate the Urban Effect? The Urban Effect is also warming, but it is of a different nature.
Some reports indicate that snow confounds the measurements... why?
What are the actual emissions from blue oceans vs ice caps? From the ocean on the fringes of the North Pole Ice Cap?
Daytime Emissions?
Nighttime Emissions?
What else?
Flaring Natural Gas in Nigeria and Africa?
Burning Rain Forests in Brazil?
Smog over China?
I have to think that most of the data already exists. It may already be in the models.
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I found this link quite informative on current climatic modelling systems; http://www.gcrio.org/CONSEQUENCES/fall95/mod.html
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I appreciate that taking Ice cores from Greenland is a good way of analysing the gaseous content of the atmosphere for the globe but..... I feel that the measurements for temperature could be very misleading as they are very localised. Is there anyway of correlating what this readings show and what was happening in the Sahara for example? And how do these temperature readings fit in with global averages?
Certainly Greenland and Antarctica are different. And, may not represent other eco-systems.
There are a lot of notes about 18O, which can be tested in a variety of models.
With the Milankovitch cycles...
Eccentricity coupled with Precession...
Will tend to give at times:
North: Winter closest to sun, short, warm winter, long, cool summer.
South: Winter farthest from sun, long, cool winter, short hot summer.
(or visa-versa).
Looking at the CO2/Temperature overlays... somewhat of an artificial scale... but the rising CO2 and temperature in Antarctica seems to go at similar times, but the falling temperatures seem to pre-date the falling CO2 levels by several thousand years. In some cases, responses in the North and South also seemed to be somewhat delayed, or perhaps not as severe for certain events.
I have also been curious about the correspondence to more global events.
We may be seeing more severe temperature swings in Russia, Greenland, and Canada now than in the rest of the globe, so perhaps a 5 degree shift in Russia would correspond to a ½ degree shift elsewhere.
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I found this link quite informative on current climatic modelling systems; http://www.gcrio.org/CONSEQUENCES/fall95/mod.html
Excellent Link, although over a decade old. But, still some of the same issues we're dealing with today.
Very Probable:
(3) Higher surface temperatures will cause an increase in the average precipitation over the globe. This comes about because temperature affects the rate at which surface water is evaporated (to return to the ground in the form of rainfall and snow). While the connections between temperature and precipitation rates are well understood, the distribution of changes in precipitation over the Earth is less certain.
[...]
Probable:
(8) Continental dryness will increase at middle latitudes in summer in the Northern Hemisphere. The basis for this prediction is the fact, cited earlier, that higher temperatures lead to much higher rates of evaporation: in net effect, the increase in evaporation will on a regional basis exceed the accompanying increase in rainfall. The amount of drying is qualified, however, by several factors that are not well represented in models. These include the movement of evaporated moisture from place to place through atmospheric circulation; the effects of changes in ground cover due to the response of vegetation to increased carbon dioxide; the role of aerosols; and interactions between the land surface and the atmosphere, including the storage of wintertime precipitation in soils.
(9) Rain and snow at high latitudes will increase as the amount of moisture in the atmosphere is increased. The freshwater that is added there by precipitation could alter the deepwater circulation of the oceans, which is driven in part by differences in the salt content of different parts of the ocean and which in turn affects climate. Additional precipitation could also affect the size of the polar ice caps, and hence perturb sea-level.
Uncertain:
(12) Changes in climate variability will occur. However, the exact nature of changes in climate variability due to greenhouse warming is as yet not well defined. All models predict a possible reduction in wintertime variability in warmer climates; it is also commonly predicted that thunderstorm activity should increase as a result of the increased moisture content of the atmosphere. The frequency of El Niñ o events could change as a result of a global warming, as could the frequency of atmospheric "blocking" events that set up persistent weather patterns that last weeks to months at a time.
(13) Changes in the climate of regional-scale areas (from the size of large metropolitan regions to the scale of states or small countries) are likely to be quite different from the global average. We have only a very limited capability to estimate changes expected in the climate of any specific region. The spatial resolution of climate models is, as yet, too coarse to incorporate effects such as regional land characteristics, surface contours, and local hydrologic conditions, even though these factors are known to be important. Regional changes in climate can differ from global changes, but the nature of the probable differences is uncertain.
[...]
(16) Interactions between climate and vegetation may modify the magnitude of predicted greenhouse warming, but whether these effects will amplify or diminish climate change is as yet uncertain. The limited assessments that have been made suggest possible feedbacks due to climate-induced changes in vegetation, such as the replacement of high-latitude tundra by vegetation more characteristic of temperate latitudes, or the displacement of forests by grassland. Other climate impacts can result from the direct effects of enhanced carbon dioxide on plant growth, from impacts of tropical deforestation, and from the effects of plant productivity on atmospheric chemistry.
This is one of the major problems that I see.
Some people have proclaimed less water, less snow, less vegetation, etc..
Yet, that will probably be true at some local areas, but not necessarily true on a global scale.
Especially when coupled to intense industrial agriculture which tends to spread more water over the surface of the planet for longer periods of time.
I'd imagine that the northerly climates would benefit significantly.
While "warm", the equatorial regions would likely still get significant amounts of rainfall.
What that would do to the Sahara is another question.
What is our responsibility to maintain the "Status Quo" beyond what Nature has done in the past?
Very Probable:
(6) Global warming will cause sea level to rise. This is expected as a consequence of three temperature-related changes: the physical expansion of sea water as the ocean temperature increases, the partial melting of mountain glaciers, and changes in the extent and thickness of the Antarctic and Arctic ice sheets.
Antarctic could possibly respond with more snow (as mentioned above), and what seems to be happening.
Arctic... They need to be careful not to include the polar sea ice as causing a rise in sea levels. The same would be for Antarctic sea ice, or sea ice elsewhere. This is likely the reason why the sea level response has been very mild if any so far.
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I found this site very informative about the subject. http://climate.nasa.gov/
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I found this site very informative about the subject. http://climate.nasa.gov/
I bumped into this a couple of days ago.
http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts
http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/download-the-report
Unfortunately, for a 200 page document, it is hardly more than an executive summary, and only presents conclusions, and not the process at arriving at the conclusion.
Lots of good pictures as well as good references though. Obviously USA-Centric
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So is it time to ignore the sceptics? [;D]
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So is it time to ignore the sceptics? [;D]
Absolutely not. [xx(]
We MAY have some big changes in front of us.
And... the US Government propaganda report above presents some pretty pictures of very healthy little white bears (which apparently aren't as pleasant when one gets close), along with predictions of them being extinct in the wild in 75 yrs. Hmmm...
Can I send you this photo to put next to the government propaganda photo? This guy looks "happy" to have found some new hunting grounds [:)]
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.cbc.ca%2Fgfx%2Fimages%2Fnews%2Fphotos%2F2010%2F08%2F30%2Fpolar-shamattawa2.jpg&hash=3d98cdcd7a5ea47535362f3a4391667e)
CBC News: Monday, August 30, 2010
Of course, the great herds of Buffalo are all but extinct in the wild NOW, and nobody is willing to make the big decisions required to reconstruct the former plains eco-systems.
We are making big changes on the planet. Some of the consequences we understand and can predict. Some we don't, or can't predict. Some we can predict, and don't want to believe. You can decide where Anthropogenic Global Warming fits.
Obviously we can't just sit back and wait forever for better data.
However, this current decade will provide us with some unique opportunities to challenge the Anthropogenic Global Warming theories. My predictions are that there will be no significant positive changes in the global temperatures from now until 2018. In fact, there could be a negative temperature reaction. Coupling that with the most recent decade, that will put us at no major changes from about 1998 (or about 2003) to 2018, or a 2 decade period.
If, however, this current decade brings a significant upward shift in temperatures, verified with both land reports and satellite imagery, then we can conclude that the sun alone isn't responsible for the global warming, and put that debate to rest... at which point focus could return to human causes.
If, there is no significant increase in temperatures this decade, that doesn't mean the globe won't be primed for a huge jump in the future, and we'll have to see what the next couple of decades bring.
While we really need to wait for data between 1 and 3 decades in the future...
That doesn't mean that we shouldn't incentivize conservation now, as well as dealing with critical issues such as population growth, natural habitat decline for many species, and global resource waste and depletion, and other extremely challenging issues.
Population Growth should be considered critical. Many of the Developing Countries have HUGE population growth problems.
http://en.wikipedia.org/wiki/List_of_countries_by_population_growth_rate
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F9%2F98%2FPopulation_growth_rate_world_2005-2010_UN.PNG%2F800px-Population_growth_rate_world_2005-2010_UN.PNG&hash=0692c6a233924b4332cabce218d4cbbd)
However, the USA and most of Europe should not be excluded from this... (except eastern Europe that may be getting a reprieve via emigration... which really doesn't count).
In many senses, growth equates to continuing natural habitat destruction (as well as more global warming potential).
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I think I tried this one before and got shot down in flames. However, if at first you.....
We must have a pretty good idea of the thermal energy that's being put into the Earth from all sources. We also know that the Earth radiates energy into space.
Energy in = energy out - Happiness!
Energy in ≠ energy out - Unhappiness!
Sooooo, how can we measure the energy out bit? I was wondering if we can determine that from really far away by taking the Earth's temperature. If you get far enough away, all the localized variations are integrated into a single value. If we know the temperature, we should be able to determine the energy being radiated.
If this were to actually work, it would seem to provide us with the sort of data we really need.
Well...
It looks like NASA has that...
Or should have it
Or could have it.
Well, anyway here is a cool page. It shows Earth's net radiation for 2007.
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=CERES_NETFLUX_M#
From that page, there are links to data pages for other years.
And, other pages to the Total Solar Irradiance.
So, one should be able to calculate the energy input, the output, and the net.
It is probably a more complicated equation though.
Trees, for example, absorb solar energy and produce chemical energy.
At equilibrium, that should also be released back into the biosphere. But, not all of the chemical/biologic energy would immediately be released.
And, now we're also consuming a lot of fossil fuel energy, and even a little nuclear energy which never would have entered into the solar equation.
Instruments need calibrated, and still drift some.
If you're off in your calculations by a fraction of a percent. The error could build up quickly. There seems to be substantial variability in the solar energy. at least at a fine resolution.