An article in New Scientist, “Matcha is under threat from climate change – can genomics save it?” claims that climate change is causing green tea to suffer low yields and to taste worse. [some emphasis, links added]
This is false for multiple reasons.
While hot weather can [produce bitter-tasting tea leaves], Japan hasn’t seen significantly higher temperatures, and yields are actually improving over time.
New Scientist claims that warming weather in Japan is “reducing yields and impacting the plant’s distinct umami flavour,” but that tea growers can use genetic selection to grow more heat-tolerant plants, though it takes some time.
Temperature can indeed cause some plants like tea to produce more bitter-flavored compounds; it seems suspect that temperatures have changed enough in Japan to impact tea leaves permanently or in a widespread way.
New Scientist reports that during the spring growing season, daytime temperatures are usually around 20 to 25°C, while spring temperatures in the region where matcha tea is grown have risen “by roughly 0.6 to 1°C over the past 100 years.”
Logically, that means the new range might be more like 20.6 or 21°C to 26°C, a change so minimal that it would be unlikely to impact the plants all that much, especially since they experience much larger [daily temperature swings].
And that change has occurred gradually over a hundred years, not instantaneously.
Current matcha tea, made with ground-up green tea leaves, must not taste all that bad given the last decade alone (with allegedly the highest-ever temperatures) has seen the drink explode in popularity worldwide.
Tatler Asia reported last year that “matcha production has increased from 1,471 tons to 4,176 tons between 2010 and 2023, or around a 185 percent increase. In other words, the global demand for tea powder has increased by almost threefold over 13 years. The ministry also stated that more than half of the matcha produced in Japan was now exported internationally—including Hong Kong.”
One issue that is not addressed in the article is where those temperatures are recorded. We are given a region, but the temperature stations are not evenly spaced.
They are often located near urban centers that suffer from the urban heat island (UHI) effect, as discussed numerous times at Climate Realism, and greatly boost nighttime lows.
The New Scientist asserts that yields are suffering due to climate change. By contrast, data from the United Nations Food and Agriculture Organization (UN FAO) show that [yields fluctuate] from year to year, as with any agricultural product; the overall trend in tea harvests shows an increase, not a decrease.
The most recent record for Japanese tea yields was in 2018; the second-highest in 2024. (See figure below)
This data is for tea in general, but all types of tea come from the same plant. Green tea, from which matcha is made, is harvested when the leaves are still fresh and green, whereas black tea is harvested much later.
Selective tea breeding takes time, and New Scientist admits it has been going on for as long as commercial tea growing has existed. Growers have always carefully selected their plants for tolerance to a wide variety of conditions and for certain traits. Genomic selection can accomplish this much faster.
Another option would be to plant or harvest tea earlier, when temperatures are more in line with what producers want.
By the way, although New Scientist treats Japan as the sole source of matcha, it is not. China is a major grower and exporter of matcha, exceeding Japan in exports for the first time in history in 2025.
One report says that China is likely to produce 70 percent of the world’s matcha in 2026. The same report forecasts a 50 percent growth in matcha production from 2025 to 2026 to meet fast-growing global demand.
The latest data from the U.N. Food and Agriculture Organization show that green tea production (matcha being ground-up, shade-grown green tea) in China increased by more than 142 percent between 2010 and 2023. (see the figure below)
So modest warming has not seemed to have hampered matcha production in either Japan or China.
False news stories are published almost daily that try to scare people into taking action on climate change by claiming some luxury product they enjoy is disappearing because of it.
What’s true of those stories is also true of this one from New Scientist; there are plenty of reasons to be skeptical of claims that matcha is being threatened by climate change.
Yes, temperature can and does impact the taste of tea, but warming has not been extreme in Japan, and modern agricultural technology offers a workaround. Yields and production of green tea and tea in general have increased amid modest warming, with no evidence of a warming-induced production slowdown.
Read more at Climate Realism
