The formal notification by the United States that it will leave the 2015 Paris climate change agreement — two years after President Donald Trump announced his administration’s intention to do so — comes amid fresh reminders of the serious effects of global warming in the form of more frequent extreme weather conditions accompanied by more devastating damage.

The exit of the world’s second-largest emitter of greenhouse gases marks a setback for the framework accord just before its measures to fight global warming start to kick in next year. Key participants in the Paris accord, including Japan, need to make extra efforts to shore up the agreement by upgrading their commitment to reduce their own emissions of heat-trapping gases. Merely calling the Trump administration’s decision “regrettable” is not enough.

To avert the catastrophic effects of climate change, the Paris agreement sets a target of keeping the rise in global temperature well within 2 degrees Celsius from pre-industrial levels and close to 1.5 degrees. What’s clear is that the voluntary pollution-reduction targets set so far by the participating countries, even if achieved, would be far from sufficient to tame climate change. Therefore, the signatories must keep upgrading and meeting their commitments.

Japan’s efforts in this regard have so far been less than impressive. The government’s target of reducing the nation’s greenhouse gas emissions 26 percent from 2013 levels by 2030 pales in comparison, for example, with the European Union’s goal of a 40 percent cut from 1990 levels. At the U.N. Climate Action Summit in September, Secretary-General Antonio Guterres noted that 77 nations have committed to eliminating their emissions on a net basis by 2050, but Japan — which has maintained its long-term target of cutting emissions by 80 percent by the middle of this century — was not among them.

Even before the efforts under the Paris agreement are implemented, the severe effects of climate change are materializing — to the extent that it’s called the climate crisis these days. Over the past few years, Japan has experienced heat waves and torrential rainfalls unlike any it has seen before, resulting in massive damage. What used to be viewed as extreme weather is taking place more frequently across the globe, and ice in polar regions is reported to be melting at an unprecedented speed.

Rising sea temperatures are making typhoons more powerful and multiplying the damage they cause. Typhoon Hagibis, the most powerful to hit this nation in decades, maintained its devastating force as it landed — ocean temperatures around Japan were 1 to 2 degrees higher than normal for the season — bringing record-breaking rainfall over a broad swath of eastern Japan that demolished river embankments and flooded nearby areas. Experts warn that the frequency of powerful typhoons and torrential rains will only increase if global warming worsens at the current pace.

The Special Report on the Ocean and Cryosphere in a Changing Climate, released in September by the U.N.’s Intergovernmental Panel on Climate Change (IPCC), cautioned that global warming not only enhances the disaster risk from mega-typhoons and high tides but inflicts grave damage on the marine ecosystem. The rise in sea water temperature between 1993 and 2017 was twice as fast as the period from 1969 to 1993, the report said, attributing the change to the effects of man-made warming. In the worst-case scenario regarding emissions levels, the world’s sea levels at the end of this century will be as much as 1.1 meter higher than around the close of the 20th century.

While rising sea levels and ocean temperatures threaten to multiply the damage from natural disasters such as typhoons, the IPCC report warns that marine life worldwide could be reduced by up to 20 percent and the fish stock good for catch by 24 percent by the end of this century, severely affecting the food supply for humans.

Clearly, global warming is no longer a threat in the distant future. In the wake of the heavy damage from typhoons and torrential rains this year, a panel of the Land, Transport, Infrastructure and Tourism Ministry called for adapting the nation’s flood defense system to the impact of climate change. The launch of formal proceedings for the U.S. exit from the Paris agreement should prompt Japan and other major emitters to step up their fight against climate change in ways that prod the U.S. to return to the accord’s framework.