February 27, 2014 at 1:56 pm #5215
Actually, we do produce enough food to feed the entire globe.
The problem is distribution, and this is where the high prices occur. Rising fuel prices are the largest component of the rising food prices. Raising taxes or substituting higher prices fuel will only exacerbate this increase. Since the increases in atmospheric CO2, temperature, and rainfall have all helped to increase agricultural yields over the past several decades (other factors have come into play also), projected increases this century will only further help crop production.
The great Sahel drought of the 1970s and 80s occurred during a time of cooling, possibly brought about by aerosol use:
February 27, 2014 at 3:34 pm #5217
[quote=5215]Since the increases in atmospheric CO2, temperature, and rainfall have all helped to increase agricultural yields over the past several decades.[/quote]
Apparently plants do not uniformly grow better with elevated CO2 levels (-> increased rate of climate change), see for instance http://climatestate.com/2013/09/23/plant-productivity-reduction-with-climate-change/ and http://www.skepticalscience.com/co2-plant-food.htm
February 27, 2014 at 5:31 pm #5219
Recent research has shown that the CO2 fertilization is significant:
Greenhouse typically operate at 1000 ppm atmospheric CO2 levels, in order to stimulate growth. This has been known for quite some time. Yes, there are a few plants that have evolved to grow in the lower atmospheric levels of today. However, most plants are CO2-deprived, and highly levels would stimulate growth.
I have found SKS not to be the best source of information. This may have more to do with Dana’s biases than anything else. We have disagreed on more than one occasion.
February 27, 2014 at 5:58 pm #5223
Yes, this might be true for some plant species and current observations, but this doesn’t necessarily contributes to food crops and projections into the future.
Watch Richard Alley explain how increased temperature (which come with elevated CO2 levels) have non-linear effects in crop yields (watch at around 15 mins in) http://climatestate.com/2013/07/06/state-of-the-climate-system-2013-by-richard-alley/
Then you have to factor in
Nature Stunner: As Climate Change Speeds Up, The Number Of Extremely Hot Days Is Soaring http://thinkprogress.org/climate/2014/02/26/3332101/climate-change-extremes/
February 27, 2014 at 6:19 pm #5229
Sorry, did not get any audio with the link. One of the best parameters we have to make future projections is past observations (although as they say in the investing world, “past performance does not guarantee future success”). Scientifically, unless we have a valid reason why past trends will not continue, this is the best indicator. Of course, this will only apply so long as carbon dioxide is the limiting factor to growth. This is most evident at higher elevations where CO2 levels are lowest, which Mann demonstarted in his work. Like most parameters, the increases at lower levels will have more profound effects than at higher levels. Below 200 ppm CO2, most plant growth ceases. The first increases above that level have the greatest effect. Incremental increases have progressively smaller influences (i.e. non-linear). Increases are known to occur up to at least 1000 ppm, with varying results depending on temperature, water supply, and other nutrients. Indeed, while a point will be reached whereby no more increases can be obtained, no level has been found that leads to detrimental effects.
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