Under its new goal, Japan, one of the worldâs top polluters, would still seek to reduce its current emissions. But it would release 3 percent more greenhouse gases by 2020 compared to levels in 1990. Japanâs previous government had promised before the Fukushima crisis to cut greenhouse emissions by 25 percent from 1990 levels, expecting that it could rely on nuclear power to achieve that goal.  Since the 2011 disaster, Japanâs nuclear power program, which provided about 30 percent of the countryâs electricity, has ground to a halt amid public jitters over safety. The current government is pushing to restart reactors, but it remains unclear when that might happen.  âWeâre down to zero nuclear; anyone doing the math will find that target impossible now,â Nobuteru Ishihara, the environment minister, said in Tokyo after announcing the new target. He said the original goal was âunrealistic in the first place.â  âThe current government seeks economic growth while doing our best to meet emissions targets,â he added.  Japanâs weaker emissions target is a major setback in the fight against global warming and comes as negotiators are working in Warsaw on an international agreement to curb greenhouse gas emissions. It also added to concerns about the difficulty in reducing the atmospheric pollution that many scientists say makes extreme weather events like the devastating typhoon that hit the Philippines last week more severe and more frequent.  Climate negotiations have been moving at a glacial pace since a meeting in Copenhagen in 2009 that ended in acrimony after the United States and rapidly developing countries like China were unable to come to terms on how to allocate responsibility. The Warsaw conference has adopted a narrow goal of creating a road map for replacing the Kyoto Protocol, which technically expired last year, and to address the thorny issues of how poor countries should be compensated for the costs of adapting to climate change.  âThere is regret about the announcement from Japan,â Christiana Figueres, leader of the United Nations Framework Convention on Climate Change, the body overseeing the Warsaw talks, said at a news conference. But she added that Japan had made significant strides in energy efficiency and renewable power and said she was hopeful the new target would prove conservative.  In an apparent bid to deflect criticism of its new target, Japan said it would provide about $16 billion in private and public funds through 2015 to help developing countries curb their greenhouse gas emissions.  While Japanâs surprisingly modest plan was an unwelcome development to climate delegates, it was just one of many indications that negotiators will have a difficult time arranging anything beyond a cosmetic deal in Warsaw. It comes just two days after Australiaâs new conservative government introduced a bill in Parliament to repeal the carbon tax enacted by its Labor predecessor.  Signatories to the United Nations treaty agreed in 2010 to cut greenhouse gas emissions to hold the rise in global temperatures to 3.6 degrees Fahrenheit, or 2 degrees Celsius, above preindustrial levels â the most scientists say the Earth can tolerate before the effects of global warming become vastly more pernicious. Backtracking by Japan and Australia on emissions, as well as efforts by the United States and China that might be described as lukewarm, do not bode well for reaching that target.  More broadly, Japanâs action shows the crucial role that many experts say nuclear power must play if humankind has any chance of reaching its emissions goals. Just two weeks ago, four prominent climate scientists wrote an open letter calling for environmental groups to embrace nuclear power as the only hope to head off catastrophic global warming.  âEnergy demand is going to increase,â Stuart Neil, senior director of external relations and communications for the World Energy Council, an alliance of governments, corporations and energy activists, said Friday by telephone from Warsaw. âWe need to look at that in a sustainable way. But the reality is that weâre looking at a doubling of demand by 2050,â with most growth outside of the developed world.  âEven in the best-case scenario,â he added, âthere will be a doubling of CO2 emissions by 2050.â  In 2011, Japan was the worldâs fifth biggest emitter of carbon dioxide, after China, the United States, India and Russia. Together, these countries, along with the European Union, represent about 70 percent of total global carbon dioxide emissions, according to the Environmental Protection Agency in the United States.  Japan had been a laggard in pursuing renewable energy, choosing instead to rely on its 50 reactors to pare back greenhouse emissions. Before the accident, less than 3 percent of the electricity Japan generated came from renewable energy sources, compared to about 30 percent from nuclear power.  The energy shortfall resulting from the closing of its nuclear plants has left Japan scrambling to fire up old coal- and gas-powered stations, and ramp up its imports of fossil fuels. In the year through March, Japan released the equivalent of 1.2 billion metric tons of carbon dioxide, more than 7 percent higher than the year preceding the nuclear accident and 14 percent higher than levels in 1990.  To kick-start its renewable power program, Japan introduced incentives to diversify its energy sources last year. In the programâs first 12 months, through June, the country added renewable power equal to the output of about four nuclear reactors.  Japanâs new target assumes that no nuclear reactors will come online by 2020 and that the country will make energy savings of about 20 percent by investing in renewable energy sources and energy-efficient technology, Mr. Ishihara said. Compared to 2005 levels, Japan seeks to reduce emissions by 3.8 percent, he said.  Hiroko Tabuchi reported from Tokyo and David Jolly from Paris.
Tokyoâs decision to no longer adhere to its plan could complicate efforts to forge a global climate change pact.