A report released this month by the Intergovernmental Panel on Climate Change (IPCC) indicates that unless global warming is limited to 1.5 degrees Celsius above preindustrial levels, Japan’s summer of extreme weather may become the new normal.
The report’s findings stand out from previous assessments by concluding that the goal of 2 degrees, agreed on in the landmark 2015 Paris Agreement on climate change, is not enough to prevent the worst impacts of climate change.
Based on over 6,000 scientific studies and compiled by an international team of more than 80 climate scientists, the report details what may be in store for Japan: An increased frequency and intensity of extreme weather, sea level rise that threatens cities, and damage to agricultural systems.
“Japan will see more and more heavy rain, and more and more disasters are predicted to come, I’m afraid to say,” Mikiko Kainuma, one of the IPCC report’s lead authors, said in a recent interview with The Japan Times.
Kainuma, who serves as a senior research adviser at the Institute for Global Environmental Studies, also said that days on which temperatures reach 35 degrees or higher will be far more common, with implications for the safety of the country’s aging population and the health of crops.
Of particular concern in the IPCC report is the ability of geographically constrained countries such as Japan to adapt to sea level rise. Seventy-three percent of Japan’s landmass is forested, mountainous and unsuitable for agricultural, industrial or residential use, and the ability of the population to migrate away from inundated coastal areas is limited.
According to the IPCC report, under a 2 degree scenario, more than 50 million people in Japan will be exposed to significant flood risk due to sea level rise. Coastal cities will also be increasingly vulnerable to compound flooding, the term for flooding driven by multiple factors such as storm surge and heavy rain.
Economists at the Union of Concerned Scientists predict that coastal flooding could put almost $1 trillion of Osaka’s assets at risk by the 2070s. Tokyo is similarly threatened, ranked by the Organization for Economic Co-operation and Development among the 10 cities most vulnerable to sea level rise worldwide.
The government has conducted its own analysis of the risks posed by climate change. It predicts that with temperature rises of as little as 1.7 degrees, occurrences of heavy rainfall will increase significantly by the end of this century — and there are growing concerns that the frequent occurrence of flood-related disasters will exceed the capacity of existing infrastructure — according to a 2018 impact assessment report authored by several government ministries, including the Environment Ministry, the Land, Infrastructure, Transport and Tourism Ministry and the Meteorological Agency.
The same report also concludes that agricultural staples are also at risk. The production of crops as diverse as rice, mikan oranges and shiitake mushrooms is expected to be impacted as the country warms. Recently, there have been reports of reduced rice yields in extremely warm years, a worrying trend for a country in which food self-sufficiency, based on the amount of calories consumed, was only 38 percent in 2017.
To avoid these changes, the IPCC report calls for a near 45 percent reduction in global emissions based on 2010 levels by 2030. Following the Paris agreement, Japan pledged a 26 percent cut in its greenhouse gas emissions by 2030 from the 2013 level. While the pledge is significant, experts agree it is not enough to meet a 1.5 degree scenario.
“The Japanese government is not taking a global leadership position on climate change,” said Yuko Nishida, a specialist in climate change at the Tokyo-based Renewable Energy Institute.
Nishida said the hesitation to implement a nationwide cap-and-trade program, long under consideration, is one such example of the current government’s failure to implement what she calls an “ambitious” climate agenda.
However, while the government has been criticized for its lack of mitigation policy, its stance on adaptation is much clearer.
“Mitigation, or measures to control the emissions of greenhouse gases, (is) not enough,” reads its 2018 impact assessment report. “We need to take measures for adaptation, or measures to deal with the impacts that are already here as well as medium-to long-term impacts that are inevitable.”
In 2015, the Cabinet endorsed a broad vision for adaptation, as well as specific measures that range from research in the agricultural sector to the promotion of urban development that incorporates climate risk models.
As of 2017, the government was directly involved in the funding and administration of 355 projects directly aimed at adapting to a warmer future. These projects include ¥4.5 billion spent in 2017 to operate and analyze data from GOSAT, Japan’s greenhouse gas observation satellite, as well as the development of pre-emptive measures and evacuation plans for areas likely to be at risk of heat waves and frequent flooding.
And perhaps the most high-profile example of adaptation is the $2 billion Metropolitan Area Outer Underground Discharge Channel, the world’s largest underground flood water diversion facility, built in Kasukabe, Saitama Prefecture, to protect the Tokyo metropolis from flooding.
Nishida said that when it comes to adaptation strategies, it is necessary to find balance between disaster prevention and disaster preparedness: “We can’t just have hard infrastructure in order to prepare for climate change induced disasters, we need to have soft policies such as disaster preparedness as well.”
Nishida said that Japan has made progress on soft policies such as evacuation plans and early warning systems, a result of the 2011 Great East Japan Earthquake that struck the Tohoku region.
The government took another step forward this year with the passage of a climate change adaptation bill in June. It spells out concrete plans for adaptation across seven sectors, from agriculture to health care. The law also calls for an impact assessment to be released every five years.
But many believe that in the long term, it still makes more financial sense to focus first on mitigation strategies over adaptation.
“Adaptation is not expected to work well without being accompanied by mitigation … and should only be a supplementary policy to deal with remaining climate risks,” Kiyoshi Takahashi, a researcher at the National Institute for Environmental Studies, said in a recent interview with The Japan Times. “We need to prioritize mitigation.”