News blog

Temperature increases damage rice yields

Rising global temperatures are slashing rice production in many parts of Asia, including India and the Philippines, scientists have found. (BBC, AP)

Over 0.5 billion of the world’s poorest people depend on rice as their staple food. But as temperatures have warmed over the past 25 years, growth rates of rice yields have fallen by 10-20% in Asia, which produces the lion’s share of the world’s rice.

A study published in the Proceedings for the National Academy of Science (PNAS) yesterday, says farmers can expect the drop in yields to persist in the future as the climate continues to warm.


“We found that as the daily minimum temperature increases, or as nights get hotter, rice yields drop,” said Jarrod Welch, lead author of the report and graduate student of economics at the University of California, San Diego.

The study also found that yields increase with higher daytime temperatures, but says that these gains will be lost by faster rising night time temperatures.

The study is the first to assess the impact of both daily maximum and minimum temperatures on irrigated rice production in the field. It looked at data from 277 rice farms in six countries.

“Our study is unique because it uses data collected in farmers’ fields, under real-world conditions,” said Welch. “This is an important addition to what we already know from controlled experiments.”

The researchers say that the mechanism responsible for the yield losses has “not been conclusively identified”. But they suggest that the energy which could be put into yield is lost as a result of increased respiration due to the heat.

Comments

  1. Report this comment

    Mike Edwards said:

    This blog entry misreports the scientific paper:

    “Rising global temperatures are slashing rice production in many parts of Asia, including India and the Philippines, scientists have found.”

    This statement is nowhere supported in the paper.

    “But as temperatures have warmed over the past 25 years, rice yields have fallen by 10-20% in Asia, which produces the lion’s share of the world’s rice.”

    This statement is not supported by the paper. It is also completely false. Rice yields have actually RISEN over the past 25 years in almost every Asian country.

    There is important science here – you do the science no justice by misreporting it in this way.

  2. Report this comment

    Bindu Sukumaran said:

    I hail from a place famous for paddy fields. I doubt whether its just the temperature rice alone which is contributing to the decreased yield. Paddy fields are being cleared to pave way for the construction of buildings as urbanisaion is happening and younger generation is no longer interested in getting their hand dirty. White collar jobs are sought after and developing countries are trying to mimic the developed world seeing often the hustle and bustle of city life projected by media. Land for staple food production should be maintained in par with urbanisation. May concrete jungles grow but same time the raw materials for survival and the attitude of young generation be deep rooted in the ground.

  3. Report this comment

    Mutuelle santé said:

    It seems that the harvest will lower due to the temperature rise. Rice scarcity mean the rise price behind.

  4. Report this comment

    litesong said:

    Mike Edwards wrote:

    Rice yields have actually RISEN over the past 25 years in almost every Asian country.

    =====

    litesong wrote:

    Sure, science & genetic advancements have raised crop yields. But, Mike Edwards’ argument can’t trade on that advantage. Temperatures ARE hurting crop yields.

Comments are closed.