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Positives and negatives of global warming

The skeptic argument...

"Two thousand years of published human histories say that warm periods were good for people. It was the harsh, unstable Dark Ages and Little Ice Age that brought bigger storms, untimely frost, widespread famine and plagues of disease." (source: Sid Avery)

What the science says...

The best way to put this in perspective is to compare all the positives of global warming to the negatives (note - some of the positives are tongue in cheek):

Positives

Negatives

Agriculture

Agriculture

Health

Health

Arctic Melt

Arctic Melt

Environment

Environment

Glacier Melt

Glacier Melt

Economical

Economical

Miscellaneous weird stuff

Miscellaneous weird stuff

Printable Version

Further reading

National Geographic have an informative article listing the various positives and negatives of global warming for Greenland.

Comments 1 to 21:

  1. This NY Times article apparently refers to the following document:
    “Estimating Future Costs for Alaska Public Infrastructure At Risk from Climate Change”
    [ Response: Many thanks, I've updated the link (under Economical) - always good to go direct to the source! ]
  2. Malaria spread? It already reaches the Arctic circle how much more could it spread?

    I know tongue in cheek but some of these things are mutually exclusive.
  3. Philippe Chantreau at 10:09 AM on 27 December, 2007
    Malaria is one among others. Italy recently had a brush with Chikungunya (more fun to pronounce, if not to experience).

    Dengue fever is also to be considered

    Furthermore, "skeptics" take as fact the idea of "CO2 fertilization" popularized heavily by the propaganda site called CO2Science. However, that fact may not be nearly as much good news as they imagine.
    http://www.ars.usda.gov/is/AR/archive/nov02/plant1102.htm
    http://www.pnas.org/cgi/content/abstract/97/24/13430
    http://www.sciencemag.org/cgi/content/full/312/5782/1918

    Those positives and negatives are still pretty much open to speculation, I remain quite skeptical of the "CO2 fertilization" idea in light of the open air experiments conducted so far.
  4. This is totally wrong. Higher CO2 levels as a result of industrial-CO2-release will cause BUMPER CROPS EVERYWHERE.

    On top of that if there is industrial-CO2-warming, an idea for which there is no evidence, but if it transpires it will certainly be a less harsh phenomenon than warming as a result of a brighter sun. The dire predictions are totally baseless. If you dig you will never find any justification for them whatsoever.
  5. "Those positives and negatives are still pretty much open to speculation, I remain quite skeptical of the "CO2 fertilization" idea in light of the open air experiments conducted so far."

    1. Every last open air experiment so far has CONFIRMED the fertilization effect.

    2. Open air experiments may appear to be "streetwise" but they are very much likely to UNDERESTIMATE the CO2-fertilisation effect.

    Open air experiments sound to me like an appalling waste of money. You either control a factor in an experiment or you do not. Piping CO2 into the area isn't going to have the same effect as having the CO2 homogenised in the air. Since the plant is accessing the CO2 at the molecular level and not at the level of little eddies and wisps of unhomogenised CO2. What looks at first like the streetwise simulation on second thoughts appears to be hopelessly unrealistic. And it appears to underestimate the massive and universal benefit of extra CO2.

    But nonetheless these experiments CONFIRM this universal benefit. They underestimate the benefit but still they confirm the benefit.
  6. Philippe Chantreau at 16:09 PM on 29 December, 2007
    What makes you think that the limits on Rubisco Activase will not manifest themselves? How could it be good to shift the ratio of ATP/ADP toward ADP?

    Since CO2 level is already quite a bit higher, those bumper crops should already start to show up. Examples?

    Universal benefit? How is it universal?
  7. Philippe Chantreau at 16:23 PM on 29 December, 2007
    And if you dig, you find stuff about methane hydrates and the P/T extinction, so it is a stretch to say there is no justification whatsoever of dire predictions. I'd say that it would be as much of an exaggeration than to predict bumper crops on the basis of the existing CO2 fertilization alone.
  8. Wondering Aloud at 06:52 AM on 8 January, 2008
    In other words Malaria should be removed from the list. Maybe there are other diseases but Malaria which already exists in the Arctic is not one of the bugs that is likely to increase its range due to climate change so its inclusion here is simply wrong. Other diseases would also have to be evaluated case by case and there are many if not more illnesses associated with low temperatures.

    I haven't had time to research many of these claims but the few I have researched on the negative side are very doubtful, like polar bears being threatened, which is directly contradicted by the available data. This is an old salesman trick of inflating the number of arguments on your side and minimizing the number on your opponents side. It doesn't impress me and it does the AGW argument more harm than good.
  9. Wondering Aloud at 05:00 AM on 10 June, 2008
    http://www.financialpost.com/story.html?id=569586
  10. Mostly pure speculation; extrapolation without including negative feedbacks is useless and as WA. says, harmful to the argument.
    ? expanding desert areas? Look at the existing deserts and tell me how they formed and grew BEFORE any AGW effects. Oh, and right now Egypt has drilled over 100 wells into the Sahara bedrock and (so far) found sufficient fresh water for the next 500 years. Thank you satellite radar imaging which showed the underlying ancient river courses and lakes.
    The same technology shows similar ancient water deposits in Darfur ( the war there is directly attributable to scarcity of water) and the government there has been offered the expertise to explore it...which could end that conflict and turn the country into an oasis.
    My Point? All the doom and gloom projections NEVER NEVER can account for paradigm shifts caused by technology. ( NY was predicted to end up knee deep in horse **** in the 1800's because of exponential increases in the use of horses....it never happened, instead, the automobile did).
    My point?
  11. What about global warming reduces heating fuel consumption?

    Philippe:
    We should hold very lightly info that doesn't have empirical data tacked onto it....eg: Co2 fertilisation ( or lack of it)
    Jasper Ridge have been conducting controlled experiments on plants for the past 3 yrs and their data shows 1/3rd increase in biomass if CO2 alone is increased, and up to 85% increase if water/minerals/ temp are optimised WITHOUT extra CO2.
  12. From the Ministry of Ag, Ontario:

    "The benefits of carbon dioxide supplementation on plant growth and production within the greenhouse environment have been well understood for many years...

    For the majority of greenhouse crops, net photosynthesis increases as CO2 levels increase from 340–1,000 ppm (parts per million). Most crops show that for any given level of photosynthetically active radiation (PAR), increasing the CO2 level to 1,000 ppm will increase the photosynthesis by about 50% over ambient CO2 levels. For some crops the economics may not warrant supplementing to 1,000 ppm CO2 at low light levels. For others such as tulips, and Easter lilies, no response has been observed."

    http://www.omafra.gov.on.ca/english/crops/facts/00-077.htm

    Commercial growers all over the world have invested millions of $ into CO2 enhancement of greenhouses: Given that they are businessmen, if there was no appreciable crop increase they wouldn't be doing it- No?
    Now I would call a 50% increase in crop mass substantial, maybe not BUMPER, but clearly enough to warrant the cash investment.
    So there is plenty of empirical, current, evidence that raising levels of CO2 causes plants to grow bigger and faster. It isn't an issue, it's a fact.
    Just as clear is that concentrations up to 1000ppm the Rubisco Activase limit does not manifest.
  13. Can Carbon Dioxide Be A Good Thing?
    Physicist Explains Benefits Of Carbon Dioxide
    June 1, 2007 — A physicist from Colorado State University and his colleagues from the North American Carbon Program (NACP) have discerned and confirmed the unforeseen advantages of rising carbon dioxide levels. Through the processes of photosynthesis and respiration, scientists have been able to elucidate why plants are growing more rapidly than they are dying. The NACP is employing methods, such as the use of cell phone and aircraft towers to monitor and retrieve carbon data for their continuing study.
  14. Well John after much reading I think this is a thread where you are likely wrong.

    I have read a lot of claims that CO2 increasing yields is a myth, however in controlled experiments it really tends to have a large positive effect. Some have even claimed that it doesn't work in the "Real World".. A good argument sometimes but one that doesn't work very well here. If CO2 increases yields under controlled conditions but this is not seen in the real world that would in fact strongly suggest that our readings of CO2 increasing were incorrect not that CO2 doesn't help. That would be an interesting thing to investigate.
  15. Lets look at this from a logical perspective.

    Warmer means more like the world that we evolved in during the PETM (when prosimians first appear) in Asia.

    Colder means more like the world that came close to driving us to extinction (glacial maximum) in Africa.

    We are from a tropical paradise, no polar ice caps and green pole to pole. Which do we wan't for our offspring? Warm and abundant or cold and starvation?
  16. #14....Most of the examples of increased CO2 giving increased plant growth have come from environments where the CO2 level is artificially held at around 1000ppm. In the real world the levels have risen from around 260ppm (1000AD) through 290ppm (1900AD) to 380ppm
    (2005), in other words the increase over the period we have started taking interest in what's going on is at best 100ppm. Roughly, doubling the level gives a 50% increase in growth, so adding a third (real world) isn't going to show up much at the small scale level.
    Globally, however, the increase may be significant, although probably unquantifiable
  17. A good book on this topic:

    http://www.amazon.com/Six-Degrees-Future-Hotter-Planet/dp/142620213X

    This book has hundreds of references to objective peer-reviewed studies on the effects of global warming, at each degree C in global temperature rise. Essentially, costs immediately exceed benefits. With each degree of warming, the cost-benefit gap expands greatly.
  18. Millions of years ago, climate conditions were such that plant life grew rapidly on a global scale. CO2 and WV levels were high enough to sustain this growth and during this period much of the FF's we now burn were laid down. Plant life sequestered CO2 and locked it up as FF, thereby reducing the CO2 levels, although at times, 'natural' events such as vulcanic erutions/forest fires would have temporarily offset this sequestration.
    The end result is that CO2 levels hit (possibly) an all time low of around 200ppm and stayed there. As this level is close to the minimum C3 plants can tolerate, further growth and investment of new habitat were resticted. At this time, only C3 plants existed (fossil records of C4 plants indicate their emergence around 8mya) and C3 plants, in order to prosper, require CO2 levels higher than 200ppm. If the levels fall below this figure, then growth effectively halts as does sequestration.
    One can argue that the emergence of C4 plants was 'caused' by persistent low levels of CO2 - an adaptation of metabolic process to environmental pressures - and since they are more efficient in their use of CO2,(they had to be) they began to colonise and modify habitats where C3 plants could no longer compete effectively.
    C4 plants are grasses, and include the cereals. The rise of civilisation was made possible only because of these plants and man's ability to husband them, so we actually owe our existence to low levels of atmospheric CO2.
    Current concern is directed at enhanced CO2 levels through burning FF's, and the (modelled) effects this may have on climate, and the consequent impact on man's habitat.
    The current level of around 380ppm, whilst nearly double that during the period C3 plants were dominant, is still towards the lower level of tolerance for them.
    It can therefore be argued that further increases of CO2 will be beneficial to this class of plants and not detrimental to C4's until levels exceed 1000ppm; in other words, our CO2 emissions are helping C3 plants, and quite possibly helping (in some small way) to offset the losses incurred by de-forestation.

    Yes, they may be disadvantages to mankind and his preferred lifestyle/habitat from CO2 enhancement, but there are benefits to the biosphere at large.
  19. High Carbon Dioxide Boosts Plant Respiration, Potentially Affecting Climate And Crops
    ScienceDaily (Feb. 10, 2009)
    "The leaves of soybeans grown at the elevated carbon dioxide (CO2) levels predicted for the year 2050 respire more than those grown under current atmospheric conditions, researchers report, a finding that will help fine-tune climate models and could point to increased crop yields as CO2 levels rise."
  20. "This book has hundreds of references to objective peer-reviewed studies on the effects of global warming, at each degree C in global temperature rise. Essentially, costs immediately exceed benefits. With each degree of warming, the cost-benefit gap expands greatly."

    How much colder should the earth be to idealize the benificial ascpect for man. Of course I am most intested as to what "peer reviewed" studies have concluded. Another thing I am most intersested in is what "peer revied studies" have concluded thet the DOW jones should be at by the year 2025.

    Dont you alarmists have any sense of humility as to what you think you know.

    For the record "peer review" is simply a call for rudimentary error checking - it is not thesis confirming and it is by no means systematic, thorough, or even unbiased. It has its place but it is neither an essential nor required component of sound science. Theory confirmation is derived by outcome - not opinions of self proclaimed "experts"
  21. Some of your pros and cons listed above and not correct.

    The longer geological record contradicts statements made by the IPCC and other climatologists, because the IPCC and other climatologists don't usually bother to consult the longer geological record, and the usual argument from climatologists is that 'geologists are not climate scientists', which is false; climate is a subset of geology (earth science), not the other way around, (with both ultimately a subset of astronomy).

    The longer geological record has much to say about the lists you have given above, for eg:

    -Increased desertification corresponds to globally cool periods, NOT warm periods, in the geological past, (which is the opposite of what the IPPC projects). This genrally means that African and the US, and some Asian crop yields will increase with warming, not decrease. Globally, there is more rainfall.

    Africa, for example, began to become drier with the onset of glacial periods several million years ago, with larger areas of savannah and reduced rainforest cover, (which may well have led to the evolution of the savannah-ape line-that's us).
    -Warm periods do not correspond with increased extinction in the geological record, rather, biodiversity increases (which is the opposite of what the IPCC projects)
    -Coral reefs thrive during sea level rise, whilst sea level falls produce extinction.
    -Coral reefs thrive during warmer periods, and oceans do not become acidic from greatly increased C02; there were many periods of thriving corals and other marine life in the geological record when C02 was much higher than today.
    -Polar bear populations have survived the many warm interglacials in the last several hundred thousand years, warmer periods do NOT promote their extinction. The bigger threats to polar bears are ecotourists, bureaucrats, and hunters.
    -The Tibetan plateau began to rise around 30-40 million years ago; changes in short -term climate are paradoxical and not thought to greatly affect water supply/runoff in this region as much as longer period changes in elevation; as during globally warmer periods snow (and rain) precipitation increases along with seasonal meltwaters-particularly on the Chinese (cooler) side, whilst in cooler periods ice and snow cover increases but overall precipitation and seasonal meltwater generally decreases.

    Other points:
    -Crop yields at all latitudes increase with increased C02, (already an estimated 15% since about 1850), the same goes for tropical rainforests,(the Carboniferous period had high vegetation levels and high C02-much higher than at present)
    -Both Europe and USA have thrived in warmer periods, both ecologically (in the past) and economically during human occupation eg reduced energy consumption for heating, increased rainfall, less droughts, less deserts (USA).
    -Lakes do no "vanish" on a global scale during globally warmer periods; if anything it is generally the opposite (point 1 above-lower desertification occurs during warmer periods).

    I could dig up alot of other longer geological record indices, but again, what surprises me is the complete ignorance amongst many who promote various global warming scenarios/projections on what the actual record of the earth itself has to say on these matters.

    A similar thing occurs with creation scientists, and in various discussions and debates within biology about evolution; the longer geological record is usually ignored (other than the usual-'the fossil record is incomplete'), when it was the geological record that formed the general foundation about thinking about evolution in the first place, and has alot to say about it.

    Another related topic is the long history of debates around catastrophism and uniformitariaism-which also have much to say about current issues/debate concerning global warming-but that is for another day and another thread.

    In general, there needs to be more input/integration from the actual geological record on various climate change scenarios/issues, which directly contradict some of the (surmised/projected) points in your list above.

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