Lima, Peru • With this year on track to become the warmest on record, more than 190 nations began talks Monday on new limits for the greenhouse gases that are causing billions of dollars in damage and making life harder to sustain around the world.
New targets for limiting gas emissions blamed on fossil fuels were announced ahead of this conference by the U.S., the European Union and China, the first Asian nation to make such a pledge. This has injected optimism into negotiations.
But India, Russia, Japan and Australia have yet to commit to new limits. Scientists say much sharper emissions cuts are needed to keep global warming within 2 degrees C (3.6 F) of pre-industrial times, the overall goal of the United Nation talks. Global temperatures have already risen about 0.8 degrees C (1.3 F), and more heat-trapping gases are emitted every year.
Every degree of warming can cause long-lasting impacts, from melting ice caps and rising sea levels to the loss of species.
"Human influence on the climate system is clear," Rajendra Pachauri, who leads the U.N.'s panel of climate-change experts, told delegates at the opening session in Lima.
To have a decent chance of reversing the warming trend before the planet hits the 2-degree mark, the world needs to slash emissions by 40 percent to 70 percent by 2050 and to near-zero by the end of the century, according to the panel's assessments.
Scientists are practically united in warning that there's no way to meet this goal by continuing business as usual. It would require a sustained, permanent, worldwide shift from fossil fuels to renewable energy sources to power homes, vehicles and industries. And even then, the transition might not happen fast enough without a large-scale deployment of new technologies to remove greenhouse gases from the atmosphere.
The biggest challenge for the U.N.-sponsored talks is dividing responsibilities between rich Western countries and emerging economies such as China and India. The poorest and most vulnerable nations also need help to develop their economies without aggravating global warming, and to adapt to climate changes that are already causing more violent weather, prolonged droughts and intense flooding.
Among them is host country Peru, whose glaciers are melting ever-faster, threatening water supplies on the coastal desert where 70 percent of its citizens live and threatening the nation's hydropower and food security.
This Oct. 17, 2014 photo shows a power plant area in Cirebon , West Java. The sprawling power station that hums and coughs along this coast in Indonesia is labeled as a Japanese contribution to the global fight against climate change. The plants promote new coal technology from Japanese companies, which is cleaner than old coal technology but still pollutes far more than solar, wind or natural gas. Villagers nearby also complain that the coal plant is damaging the local environment, and that stocks of fish, shrimp and green mussels have dwindled. (AP Photo/Achmad Ibrahim)
People arrive to the Climate Change Conference in Lima, Peru, Monday, Dec. 1, 2014. Delegates from more than 190 countries will meet in Lima for two weeks to work on drafts for a global climate deal that is supposed to be adopted next year in Paris. (AP Photo/Rodrigo Abd)
Artists perform during the inauguration of Climate Change Conference in Lima, Peru, Monday, Dec. 1, 2014. Delegates from more than 190 countries will meet in Lima for two weeks to work on drafts for a global climate deal that is supposed to be adopted next year in Paris. (AP Photo/Rodrigo Abd)
Marcin Korolec, Minister of the Environment of the Republic of Poland and former president of COP19, right, gives a symbolic mallet to Peru's Minister of the Environment and new President of COP20, Manuel Pulgar-Vidal during the opening ceremony of Climate Change Conference in Lima, Peru, Monday, Dec. 1, 2014. Delegates from more than 190 countries will meet in Lima for the next two weeks to work on drafts for a global climate deal that is supposed to be adopted next year in Paris. (AP Photo/Martin Mejia)