After watching Ken Burns’ documentary on the Dust Bowl recently broadcast on PBS, the Phactor was intending to write a blog about how easy it would be for those conditions to return, and that the additional problem of global warming will make it all the harder to forestall, but as this link demonstrates, someone did a great job on this already. The drought conditions of this past summer need only persist for a hand full of years for dust bowl problems to return. Another big problem is that farmers still fail to realize how much soil is being lost by wind erosion annually, a problem easily reduced in scale by cover crops, no-till farming, and the elimination of fall plowing. Ignoring this potential problem is especially worrisome because so many of our politicians just don’t like to listen to science and prefer living in their own world of make believe. You’d think those OK and TX politicians would be clamoring for action, but the actual farm bill being framed will eliminate incentives for conservation, that being a no-no, ironically, for conservatives. At any rate, if you have not seen this terrific documentary, do not miss the chance. Sorry, it doesn’t seem to be available on line; if this is wrong, a correction would be appreciated. HT to Agricultural Biodiversity for being on the spot as usual. And just found even more discussion and resources if you are so interested.
2 comments:
Bend
said...
You need to be careful when invoking climate change on this issue as its link to droughts is controversial, to say the least. Don't take me wrong, global warming is a problem, but there's little evidence that it is driving droughts-particularly droughts in the mid and south west USA. See, for example: http://www.agu.org/pubs/crossref/2006/2006GL025711.shtml
The 2012 ipcc report itself states, "There is not enough evidence at present to suggest high confidence in observed trends in dryness due to lack of direct observations, some geographical inconsistencies in the trends, and some dependencies of inferred trends on the index choice." pdf here: http://www.ipcc-wg2.gov/SREX/images/uploads/SREX-All_FINAL.pdf
A recent paper in nature concludes "...based on the underlying physical principles that take into account changes in available energy, humidity and wind speed, [calculations] suggest that there has been little change in drought over the past 60 years."
This isn't to say that there won't be increased droughts due to climate change. It's just to say that the evidence of such a link isn't there at all.
As global warming changes climate patterns, however, it is possible that some areas would experience more rainfall while others would experience less. But with statistical scrutiny no such change can yet be attributed to anything other than natural precipitation variability.
2 comments:
You need to be careful when invoking climate change on this issue as its link to droughts is controversial, to say the least. Don't take me wrong, global warming is a problem, but there's little evidence that it is driving droughts-particularly droughts in the mid and south west USA. See, for example:
http://www.agu.org/pubs/crossref/2006/2006GL025711.shtml
The 2012 ipcc report itself states, "There is not enough evidence at present to suggest high confidence in observed trends in dryness due to lack of direct observations, some geographical inconsistencies in the trends, and some dependencies of inferred trends on the index choice."
pdf here:
http://www.ipcc-wg2.gov/SREX/images/uploads/SREX-All_FINAL.pdf
A recent paper in nature concludes "...based on the underlying physical principles that take into account changes in available energy, humidity and wind speed, [calculations] suggest that there has been little change in drought over the past 60 years."
http://www.nature.com/nature/journal/v491/n7424/full/nature11575.html
This isn't to say that there won't be increased droughts due to climate change. It's just to say that the evidence of such a link isn't there at all.
As global warming changes climate patterns, however, it is possible that some areas would experience more rainfall while others would experience less. But with statistical scrutiny no such change can yet be attributed to anything other than natural precipitation variability.
online here: http://video.pbs.org/program/dust-bowl/
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