‘Sunburnt and discoloured’: Japan steps up efforts to mitigate global warming impact on food security and quality

Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF) recently released the 2023 Global Warming Impacy Survey Report covering the impacts of high temperatures and other issues arising from climate change to agri-food supply chains, with particular focus on rice, fruits, vegetables and dairy.

“Several key agri-food products were found to have been impacted by global warming due to rising temperatures – for example this affected about 50% of rice crops nationwide all throughout Japan,”​ MAFF highlighted in the report.

“We also found that about 30% of apples and 20% of grapes in Japan ended up with poor or delayed colouration due to the temperature change, and worse yet about 30% of Unshu mandarins ended up sunburnt and lost.​

“Some 40% of tomatoes and 40% of strawberries ended up flowering and fruiting poorly, affecting yield, and even milk supply has been affected – the high temperatures have affected the dairy cows, so about 10% of all milk was affected whether from a yield or composition aspect.”​

These numbers are significant in any scenario, but particularly so for Japan which has long been suffering from low food self-sufficiency rates​ and is looking to hit a 75% production target by 2030, as well as hoping to use rice flour as a means of solving its wheat flour shortage issues​ brought on by the Russia-Ukraine war.

In hopes of combatting these impacts and getting back on track with its agri-food production, MAFF has announced that a number of initiatives in the various food categories are being implemented specifically to counter the impacts of global warming.

“In rice, we are both using water and scheduling management as well as the introduction of high temperature-resistant rice varieties – at present about 180,000 hectares of this has been planted, making up about 14.7% of the supply,”​ it said.

“To deal with the discolouration in fruits we are introducing new varieties that are resistant to the impacts of temperature as well, and for the sunburnt mandarins we are using shading materials and calcium agents as well as thinning out fruit from the surface that has been sunburnt.​

“Other initiatives for impacts of high temperatures include the use of fine mist air conditioning and circulating fans to regulate temperature as well as ventilation especially when it comes to the dairy cows.”​

Japan’s average annual temperature in 2023 was recorded as the highest ever seen since 1964 in several regions.

New food focus​

Whilst working to save existing agri-food products in order to preserve current food supply chains depending on these, MAFF is also looking outside of the box in order to ensure not all of its eggs are placed in one basket.

“We believe that there is a need to develop new food products in Japan in response to global warming, and one of the major items we are looking at is sweet potatoes,”​ it said,

“This is ongoing in Hokkaido where cultivation area has increased to 100 hectares as of 2023; and in Akita where various adapted varieties are being cultivated in response to increasing production needs.”​

Sweet potatoes are known to be more susceptible to cold than to heat - they can develop ‘chill injury’ that can manifest as poor quality product conditions such as pitting, discolouration, uneven ripening, off flavour and more but generally grow well in heat.

These are also tubers that grow underground similar to regular potatoes, but require warmer soil than the latter.