Climate: Risks loom for China: study

Sep 01, 2010
A Chinese farmer tends to crops on the outskirts of Beijing in June 2010. Climate change could reduce key harvests in China by a fifth if the gloomiest scenarios prove true, according to a study on Wednesday.

Climate change could reduce key harvests in China by a fifth if the gloomiest scenarios prove true, according to a study on Wednesday.

Publishing in the journal Nature, a team of Chinese scientists say China's climate "has clearly warmed" over the past half century, gaining 1.2 degrees Celsius (2.2 degrees Fahrenheit) since 1960.

The hotspots were northeastern with a of 0.36 C (0.65 F) per decade, and Inner Mongolia, with a warming of 0.4 C (0.7 F) per decade.

Nationally, heatwaves have become more common, the number of cold days has fallen sharply and glaciers that are vital river feeders are in retreat, they say.

The last century was the warmest period since 1600 and the country's seven warmest years have all occurred in the past decade.

Climate extremes included which hit the country in the 1960s, the late 1970s, early 1980s, the 1990s and in northeastern China in the last decade.

In 1998, floods inundated 21 million hectares (52.5 million acres) of land, destroyed five million homes in the Yangtze basin and inflicted 20 billion dollars in damage.

Floods this year affected 230 million people, of whom more than 15 million had to be evacuated from their homes, and left more than 4,200 people dead or missing, according to a toll issued on Tuesday.

The paper, lead-authored by Peking University environmental scientist Shilong Piao, warns of problems for China's racing economy in coming decades if bites hard.

Accurate prediction, though, is hard, it says.

"China experienced explosive economic growth in recent decades, but with only seven percent of the world's arable land available to feed 20 percent of the world's population, China's economy may be vulnerable to climate change itself," it warns.

The biggest problem could be , amplified by a growing and increasingly wealthy population.

Water is abundant in southern China but sparse in the country's north, and overall China's per capita water availability is only 25 percent of the world average.

"Many regions lie in transitional zones where water resources, and hence agricultural production, could be affected positively or negatively by changes in climate," the study says.

In the most favourable scenario, grain yields by mid-century could remain stable or benefit from the rise in carbon dioxide levels.

But in the worst scenario, there could be declines of four to 14 percent for rice, between two and 20 percent for wheat and between zero and 23 percent for corn in cases where these crops are rainfed rather than irrigated.

The comparison is the yields of these crops between 1996 and 2000. Any future improvements in agro-technology in coming decades are not factored in.

"The range of model results is large, implying large uncertainties," cautions the paper.

The many unknowns are reflected by the wide range in predicting warming for China as a whole -- from 1 C to 5 C (1.8-9.0 F) by 2100, depending on worldwide emissions of greenhouse gases.

Computer simulations for climate impacts have advanced substantially for modelling what will happen worldwide, but lag when it comes to predicting regional effects, especially on rainfall, the paper says.

"To reach a more definitive conclusion, future work must... develop a better understanding of the managed and unmanaged responses to crops to changes in climate, diseases, pests and atmospheric constituents."

Explore further: Dead floppy drive: Kenya recycles global e-waste

add to favorites email to friend print save as pdf

Related Stories

China to surpass U.S. emissions levels

Nov 07, 2006

The International Energy Agency says China will surpass the United States in carbon dioxide emissions by 2009, about a decade ahead of previous predictions.

Study: Shrinking glaciers to spark food shortages

Jun 10, 2010

(AP) -- Nearly 60 million people living around the Himalayas will suffer food shortages in the coming decades as glaciers shrink and the water sources for crops dry up, a study said Thursday.

Recommended for you

Dead floppy drive: Kenya recycles global e-waste

Aug 22, 2014

In an industrial area outside Kenya's capital city, workers in hard hats and white masks take shiny new power drills to computer parts. This assembly line is not assembling, though. It is dismantling some ...

New paper calls for more carbon capture and storage research

Aug 22, 2014

Federal efforts to reduce greenhouse gas emissions must involve increased investment in research and development of carbon capture and storage technologies, according to a new paper published by the University of Wyoming's ...

Coal gas boom in China holds climate change risks

Aug 22, 2014

Deep in the hilly grasslands of remote Inner Mongolia, twin smoke stacks rise more than 200 feet into the sky, their steam and sulfur billowing over herds of sheep and cattle. Both day and night, the rumble ...

User comments : 0