From Wiley-Blackwell
Is rainfall a greater threat to China’s agriculture than warming?
Impact of climate change on China explored in new plant science virtual issue
New research into the impact of climate change on Chinese cereal crops has found rainfall has a greater impact than rising temperature. The research, published in the Journal of the Science of Food and Agriculture found that while maize is sensitive to warming increases in temperature from 1980 onwards correlated with both higher and lower yields of rice and wheat.
The study was carried by Dr. Tianyi Zhang, from the Institute of Atmospheric Physics, and Dr. Yao Huang, from the Institute of Botany, both at the Chinese Academy of Sciences. The paper is part of a special collection of free articles on the links between climate change, agriculture and the function of plants.
“China has experienced significant climate change over the last century”, said Zhang. “The annual mean air temperature increased by 1.1 °C from 1951 to 2001, rainfall in Western China increased by up to 15% per decade and decreased in the North.”
“Projections from climate models predict that mean temperature could rise by 2.3-3.3 °C by 2050 while rainfall could increase by 5-7%,” said Huang. “This could have a major impact on China’s agriculture which accounts for 7% of the world’s arable land but feeds about 22% of the global population.”
The authors turned to China’s provincial agricultural statistics and compared the data to climate information from the China Meteorological Administration. They focused their analysis on China’s main cereal crops, rice, which is grown throughout China, as well as wheat and maize, which are mainly grown in the North.
The results show a significant warming trend in China from 1980 to 2008 and that maize is particularly sensitive to warming. However, they also found that rising temperature collated with both higher and lower wheat and rice yields, refuting the thoughts that warming often results in a decline in harvests.
“Of the three cereal crops, further analysis suggested that reduction in yields with higher temperature is accompanied by lower rainfall, which mainly occurred in northern parts of China,” said Zhang. “This suggests it was potentially droughts, relative to warming, that more affected harvest yields in the current climate.”
“It is often claimed that the rising temperature causes a decrease in the yields of Chinese cereal crops, yet our results show that warming had no significant harmful effect on cereal yields especially for rice and wheat at a national scale from 1980 to 2008,” concluded Zhang and Huang. “However, warming may still plays an indirect role, like the exacerbated drought conditions caused by the rising temperatures.”
This special collection of free articles is featured on the new Life Science pages on wileychina.com, which are being launched from March 2012 to create a Life Sciences Centre for the Chinese research community. New pages will be launched each month and in March the focus is on Climate Change and Plant Science.
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Every farmer knows that plants need both rain and appropriate warmth to germinate and grow to maturity. The authors of the article point out that warming “exacerbates” drought conditions, with potentially devastating consequences for the hundreds of millions who depend on this food for their survival.The Chinese are already buying land in Africa to replace the crops which are being lost in their own country.
Another food crisis is looming as a result of the rapid glacial melt (7% decline per year now) in the Himalayas, which threatens the available in stream flows of all major rivers in Asia and SE Asia. Flooding is wiping out crops in Bangladesh, for example, thereby threatening the livelihoods of millions, and the Indus River has recently flooded displacing millions more and threatening food supplies in Pakistan.
Warming (climate change) is having devastating impacts everywhere, but especially in areas where billions of the world’s populations live, and where much of global commerce is conducted.
REPLY: “Another food crisis is looming as a result of the rapid glacial melt (7% decline per year now) in the Himalayas”
Hugh, are you brain damaged? The Himalyan Glaciers 2035 scare has been exposed as an error, and even the IPCC admits it now. By your figures, it is even worse!
at 7% per year, they’ll be gone in about 14 years (7%x14= 98%) or in the year 2026. You are even wronger than wrong.
-Anthony
There is no terrestrial place on Earth where it is too hot to grow plants. Too dry, too cold, absolutely. But not too hot. (Except for fresh, still cooling lava flows — there, happy now nitpickers?)
The most productive agricultural regions are also the warmest. Fancy that.
Maize is originally a tropical plant. Varieties have been developed that will grow farther north, but the tropics are home. Ditto staples such as rice, wheat, manioc, taro, edible beans, yams, cassava, sorghum, amaranth, millet, and even potatoes (though at high altitudes).
Why is this? Because, dear friends, plants evolved in much warmer times. The last ~1.8 million years have been the COLDEST on Planet Earth in the last quarter of a billion years. Plant genera are much older than 1.8 million years.
The Goreans claim global warming will damage agriculture. Nope. Just the opposite.
I’ve said it before and I’ll say it again
WARMER IS BETTER
“Projections from climate models predict …”
Oh my gosh, next they’ll be telling us that children in England won’t know what snow is… :-))
I guess we all know how accurate climate models are.
Philip Bradley said @ur momisugly April 5, 2012 at 2:35 am
It’s the same in cooler places like Tasmania, too. There are two reasons rainfall generates more growth than irrigation.
Rain carries ammonia created by lightning into the soil. Rain also contains dissolved CO2. Once in the soil, this produces free hydrogen ions that can then displace cationic nutrients, such as calcium and magnesium from the clay particles and humus.
Robert Brown said @ur momisugly April 5, 2012 at 7:56 am
Not so, Robert, though it’s not entirely starightforward:
http://onlinelibrary.wiley.com/doi/10.1111/j.1439-037X.1989.tb00757.x/abstract
I live in Colorado. I could have told you this based on my front yard, or even hops plants in the back. Though Denver isn’t too hot, the sun is powerful and radiation is way up there compared to other places. Grass lives if it rains, and does not if there is a drought.
What China look at Britain
Millions of householders across southern and eastern England are being hit by a hosepipe ban as drought grips parts of the country.
East Anglia saw just 426mm of rain during 2011, which is a third less than the annual average for the region.
http://news.sky.com/home/uk-news/article/16203130
http://news.sky.com/home/uk-news/article/16202949
http://news.sky.com/home/uk-news/article/16202714
http://news.sky.com/home/video/uk-news/video/16203034
Philip Bradley says:
April 5, 2012 at 2:35 am
Anyone who has a garden in a warm to hot climate as I do, knows that plants grow after it rains. They really grow when it is hot after rain.
_____________________________
Understatement. I just went from 6″ high abrussi rye to rye that is so high I can not see my 13 hand ponies not even their heads. And it happened in about a week. Darn stuff bolted faster than I have ever seen before ~ CO2 + warmth + rain
All this stuff was studies in the 1800’s and earlier. http://www.k12.hi.us/~ckuroda/history_of_hydroponics.html
Death Valley has recorded one of the worlds hottest temps, and yet it has a golf course with green grass.
Today it appears that many disciplines are taught without understanding the importance of observation. With some it is as if observation is unreliable.
Not to worry, the Chinese are so advanced they already adapted to rainfall changes before computer models projected the crisis.
The predominant food grain in China has always been rice, which requires more water than other grains (wheat, corn [maize]). However, the average per-capita rice consumption has been declining since 1995. According to this reference ( An analysis of Food Grain Consumption in Urban Jiangsu Province of China ), annual per-capita rice consumption went from 71.3 kg in 1995 to 56.2 kg in 2000 and 50.2 kg in 2007. That’s a reverse hockey stick with a whopping 21% reduction in just 5 years from 1995 to 2000, and an overall 30% reduction in 12 years.
Are the Chinese in Jiangsu Province starving? No. The Chinese are eating more meat and poultry and planting other grains as livestock feed.
So if the climate dries out, China will just grow less rice and use grains needing less water to feed livestock for food. On the other hand if rainfall increases (which is not inconsistent with Climate Change Theory), China will just raise more ducks and geese in vast artificial ponds. So they’re fine either way: drier climate means more chicken and pork; wetter climate means more waterfowl, fish and rice.
Problem solved by adaption, and they started doing it back before 2000.
[A certain amount of sarcasm here, but the reference is real]