Unprecedented heat will trigger global food crisis

[GliderGuider]

A Science article, reported in the Globe and Mail, referenced in LBN: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=102&topic_id=3681024&mesg_id=3681024

The real threat from global warming isn't rising seas levels, it's falling food supplies.

[Citizen Number 9]

1. Doesn't the government have huge warehouses of cheese somewhere?

Bacon?

[Citizen Number 9]

2. I don't think the deniers are going to be too swayed by this.

They have a hard enough time accepting the basic research, much less the theories about "Wild Weather" due to MMGW.

[Bigmack]

3. I think the trigger was pulled

a while ago, and the food crisis is in the process of unfolding...... Ms Bigmack

[Howzit]

4. I thought greenhouses were used to elevate temperature so that more food could be grown?

Don't they inject CO2 into greenhouses to stimulate growth even faster?

I can see a water shortage causing a food shortage, but don't higher average temperatures mean a longer growing season?



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

[GliderGuider]

5. Greenhouses

Greenhouses are used either to provide earlier warmth to promote early germination in cold climates, or to provide controlled temperatures year-round. Greenhouses= operations are not an appropriate analogy for the unfortunately-named "greenhouse effect".

There will be two agriculturally significant effects of climate change. The first will be increased variability in local temperatures, which will cause an increase in heat waves, early freezes, droughts and flooding episodes. The second effect will be an average upward shift of the temperature curve, which will result in mid-summer temperatures more often exceeding the tolerance limits of plants, causing withering and reduced yields.

Contrary to the popular right-wing talking point, research has shown that excess CO2 does not provide an overall benefit to plant growth for a variety of reasons. Here are a couple of examples:

Higher Carbon Dioxide, Lack Of Nitrogen Limit Plant Growth

ScienceDaily (Apr. 13, 2006) — Earth's plant life will not be able to "store" excess carbon from rising atmospheric carbon dioxide levels as well as scientists once thought because plants likely cannot get enough nutrients, such as nitrogen, when there are higher levels of carbon dioxide, according to scientists publishing in this week's issue of the journal Nature.

That, in turn, is likely to dampen the ability of plants to offset increases in atmospheric carbon dioxide.

"We found that atmospheric carbon dioxide levels may rise even faster than anticipated, because ecosystems likely will not store as much carbon as had been predicted," said Peter Reich of the University of Minnesota, lead author of the study, which was conducted at the National Science Foundation (NSF)'s Cedar Creek Long-Term Ecological Research (LTER) site in Minn.

"As a result, soils will be unable to sustain plant growth over time ," said plant ecologist David Ellsworth of the University of Michigan.

Estimating the role of terrestrial ecosystems as current and future sinks--or storage places--for excess carbon dioxide hinges on an ability to understand the complex interaction between atmospheric carbon dioxide and nitrogen in soils, the scientists believe.

The six-year study, the longest of its kind, sheds light on the relationship between carbon dioxide emissions and plant productivity. In the experiment, scientists grew 16 different grassland plants in 296 field plots. The plots were exposed to both ambient and elevated carbon dioxide levels, and varying levels of nitrogen.

High carbon dioxide levels can retard plant growth, study reveals

Stanford Report, December 5, 2002
BY MARK SHWARTZ

The prevailing view among scientists is that global climate change may prove beneficial to many farmers and foresters -- at least in the short term. The logic is straightforward: Plants need atmospheric carbon dioxide to produce food, and by emitting more carbon dioxide into the air, our cars and factories create new sources of plant nutrition that will cause some crops and trees to grow bigger and faster.

But an unprecedented three-year experiment conducted at Stanford University is raising questions about that long-held assumption. Writing in the journal Science, researchers concluded that elevated atmospheric carbon dioxide actually reduces plant growth when combined with other likely consequences of climate change -- namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.

The results of the study may prompt researchers and policymakers to rethink one of the standard arguments against taking action to prevent global warming: that natural ecosystems will minimize the problem of fossil fuel emissions by transferring large amounts of carbon in the atmosphere to plants and soils.