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Effects will become more obvious as Japan’s climate changes


Residents of Japan’s big cities, and of Tokyo in particular, are well aware of the heat-island effect — especially now with the onset of summer.

The effect occurs because concrete and asphalt retain radiant energy, making the whole city a vast absorber and then emitter of convected heat, which creates powerful thermals that trigger sudden “guerrilla storms” — and renders the nights barely more agreeable than the stifling, claggy days. And if you think summers have been getting worse — you’re right.

Figures from the Japan Meteorological Agency (JMA) show that annual average air temperatures nationwide rose by a rate equivalent to 1.15°C per century between 1898 and 2010. This is considerably higher than the global average temperature rise of 0.74°C over the last century (according to the Intergovernmental Panel on Climate Change’s “Climate Change 2007: Synthesis Report Summary for Policymakers”).

Not only have temperatures been rising in Japan, but they’ve been rising faster here than they have elsewhere — with some of that difference accounted for by the heat-island effect found in cities and dense urban areas.

I’ve just been looking at the first comprehensive report into the impacts of climate change in Japan. A few points jump out: Plants are flowering earlier each spring and, counterintuitively, insects are appearing later — perhaps because their pupal stages need a certain period of chilling in order to develop, so with winters getting warmer they take longer to develop. In addition, species’ ranges — the physical areas they inhabit — are expanding northward by between 18 km and 140 km per decade.

That report’s lead author is Yuko Ogawa-Onishi, who works at my old research base, the National Institute for Environmental Studies in Tsukuba, Ibaraki Prefecture, and at the University of Oxford. Ogawa-Onishi, with colleague Pam Berry at Oxford, reviewed as many publications as they could about observed and projected impacts of climate change in Japan, using both local and international publications.

By reviewing JMA weather-station data, the pair found evidence that the heat-island effect also occurs in relatively small cities. However, they point out that urban and industrial areas of Japan cover only 5 percent of the land area, while mountains, forests and agricultural regions account for more than 80 percent — so heating due to urbanization can only have a limited effect.

As for future conditions in Japan, they found some predictions suggest that, by 2100, temperatures are likely to increase by 2°C to 3°C (relative to a baseline average temperature between 1981 and 2000) — with summers getting wetter, and other seasons drier.

That’s bad, but a more pessimistic prediction — and by that I mean a mathematical model, not something someone has read in their tea leaves — has Japan’s mean temperature increasing by a whopping 4.8°C by 2100, with a 10 percent increase in rainfall.

Ogawa-Onishi and Berry’s report appears in the journal Biological Conservation (DOI: 10.1016/j.biocon.2012.06.024) — but what do its findings mean for iconic Japanese natural phenomena?

For cherry blossom, we’re looking at flowers coming 2.2 days earlier per decade. The first cicadas will sing 2.5 to 4.3 days later per decade. The Great Mormon swallowtail butterfly (Papilio memnon, okay so it’s not really iconic, but I like it) will move 130 km north per decade. Likewise, Sika deer (of Nara photo-op fame) will move northward.

“Plants and animals can adapt to climate change, but there is a limit,” says Ogawa-Onishi. “In southern Japan, we have already witnessed cherry trees not blooming after extremely warm winters, which indicates the limits to their adaptive capacity.”

Most people in Japan are very aware of the changes in natural events, in particular, the flowering of cherry trees.

Similarly, seasonal food is popular with most people in Japan, and they are aware that the availability of seasonal vegetables and certain fish at particular times of the year has changed. Some species can adapt, others can not adapt as well, says Ogawa-Onishi. Some things important to Japanese culture will certainly change.

But the changes that Ogawa-Onishi and Berry explore aren’t just important for pretty national emblems. Japan is a biological hotspot. With more than 90,000 species of fauna, flora and fungii in an area of 380,000 sq. km, it is a globally important biological region (which was one of the reasons I went to study insects in Japan — there are so many of them, and there are some very cool ones).

However, a major impact will be on the rice harvest, which will suffer a decrease of up to 40 percent in central and southern Japan. So rice imports will increase.

And, although if you travel around Japan you will find a profusion of paddy fields in rural areas, specialist foods everywhere you go, and every town seemingly famous for a certain fruit or fish — some 60 percent of the nation’s food is actually imported — and that proportion is set to rise.

For comparison, the United Kingdom imports about 25 percent of its food, and the United States exports more food than it imports.

In the face of this sort of ominous news, Oxford scientist Berry says there are easy ways to get involved and influence things for the better. She cites both the kind of steps that help reduce (mitigate) our impact, and ones that help adjust to the effect of climate change.

“There are simple mitigation actions that involve the use of less fuel, for example turning down the thermostat in winter or using less air conditioning in summer,” she says. Such advice may sound obvious, but a difference of 1°C can save about a ton of carbon emissions a year.

Meanwhile, switching off electronic devices rather then leaving them on standby can save 15 percent of a household’s energy bill. “Every little helps, and if enough people did these things there could be a real difference,” says Berry.

And there are ways to help species adapt to the effect of climate change. “People can help biodiversity by leaving some wild areas in their garden or planting wildflower mixes,” says Berry.

And she calls for us to make sure there are “permeable” areas in our towns and cities, and to plant trees and generally “greenify” our urban jungles.

Rowan Hooper (@rowhoop on Twitter) is the News Editor of New Scientist magazine. The second volume of Natural Selections columns translated into Japanese is published by Shinchosha at ¥1,500. The title is “Hito wa Ima mo Shinka Shiteru (The Evolving Human).”

  • Michael Radcliffe

    Oh dear. Sadly, many of the people who will read this article think they are concerned about they environment – yet are opposed to nuclear power! The refusal of some people to connect the dots is extraordinary; yet to ignore the ability of nuclear energy to mitigate climate change by producing zero-carbon electricity is an indefensible hyprocrisy. I’m guessing many that are happy to criticise Japan’s nuclear industry will be staying away from articles like this!

    • Spudator

      While nuclear power may mitigate climate change, I’m afraid climate change could well turn out to be the least of our worries. The real problem facing humanity, of which climate change is merely a symptom, is our out-of-control population growth. Already there are probably far too many of us for earth to support, and the number continues to grow and grow. It wouldn’t be so bad if we lived simpler, closer-to-nature lives; but we all want our modern lifestyles and the voracious resource consumption, garbage production and pollution those lifestyles entail. It’s this ever-increasing destruction that we wreak on our planet, as we lust after the latest-model smartphone—or some other useless crap that we think we need but don’t—that will destroy us.

      Predicting the future really is quite simple. Nature is a closed, finite system consisting of various subsystems exhibiting dynamic equilibrium within themselves and amongst themselves. So long as these subsystems remain in equilibrium, they can continue to operate. But if a subsystem loses equilibrium and starts overbalancing, a point must come where, unless the balance is restored, the subsystem comes crashing down because the overall system can no longer hold it up. (Actually, from the point of view of the overall system, such a subsystem crash represents a restoration of equilibrium and is thus quite normal and a part of the system’s tendency to maintain overall balance.)

      Right now, the overbalancing subsystem is us, the human race. Unless we do something about our insane population growth, we’re going to crash and burn. This is inarguable. We have to urgently decide how many people the earth can support, allow the population to come down to that level, and keep it there. Quite simply, we have to stop breeding like rabbits; and I think the only way to do that is to copy the Chinese: all countries need to institute a policy of one child per couple. On top of that, there should be government incentives for people to sign contracts agreeing not to have any children at all. Given that the future looks so grim for our children, I think there must already be a lot of thinking people who wonder about the morality of bringing more kids into the world.

      • Joseph Jaworski

        Spudator, are you a troll, or do you honestly support the position you have just advanced? The ideas put forth by Paul Ehrlich in “The Population Bomb” have been so widely discredited I will not waste time reiterating them here. Instead, I want to focus on the morally repugnant idea that the one-child policy of China is anything short of a gross violation of human rights.

        When we last clashed, Spudator called my hypothetical
        policy of having children forcibly taken from patents who smoke “as horrifying as it’s preposterous.” How is a China-style
        one-child policy (which entails forced abortions) any different? I suspect the difference may lie in the debate over fetus personhood. I am willing to concede this point; let us assume that, right up until the moment of birth, a fetus is indisputably non-human and not deserving of any kind of protection under the law. This does not change the fact that the mother is being forced to undergo an invasive, potentially dangerous surgical
        procedure. We do not allow such a thing in free societies. Furthermore, what would happen under such a one-child policy if a woman manages to give birth at home, away from the eyes of the authorities? Once a family is discovered to have more than one child, what is the proper course of action? Do we jail one or both parents? Do we execute the unauthorized child? Do we take the unauthorized child away?

        Coming back to our last conversation, Spudator mentioned that he has a “high-school aged daughter.” Based on his position, I would assume that Spudator only has one child, and I would further assume that he is teaching his daughter that she should only have one child as well. Spudator, if you truly believe in the position you have just advanced, and are willing to subject strangers to a China-style, one-child policy, are you willing to subject your own daughter to the same policy?

    • Adrian Bourne

      Does the nuclear industry pay you? How long before workers can get to the pile at Fukushima? Ten year? People are dead and dying from that disaster, and every one of these plants have that potential. Most of them are past their usable lifetimes.

      The industry twaddle that they are “exceeding expected lifetimes” is pure whitewash to protect shareholders. It’s a dirty and expensive industry that uses fossil fuel to refine, transport and dispose of it’s toxic waste — that we can’t get rid of or store safely for it’s very long half-lifes.

      Hanford, here in Washington, has millions of barrels of radioactive waste from the nuclear industry that are leaking into the ground and are only 5 miles from the Columbia river — a major water way here in the Pacific NW. So, how close do you live to a nuclear waste dump? How safe does that make you feel? Chernobyl is still a deadly place to live 25 years later.

      The safest distance from a nuclear power plant is about 93 million miles away. (that’s the distance to the sun, if you didn’t get that.) Solar, wind, water power, and the will to stand up to the nuclear robber barons is what we need in this climate crisis. I can’t imagine a wind farm “disaster” that could have the far reaching and generational, adverse effects of a nuclear disaster.

      • Michael Radcliffe

        Oh dear. A nuclear opponent who is willing to read about the effects of global warming. I do wonder how you deal with the cognitive dissonance.
        If the Fukushima accident was so terrible, why after two years are there no deaths or injuries? People are dying? What people? Why is it that nobody has informed the WHO or the government?

  • Ellwood

    It’s great to see the impacts of climate change getting coverage in the popular media. Thanks for the well-researched article.