The prevention of an extra individual degree of heat can make a difference between life and death in the coming decades for a lot of people and ecosystems on this hot planet, an international panel of researchers reported on Sunday. But they give little hope that the world will rise to the challenge. Nobel Prize-winning Intergovernmental Panel on Climate Change issued its gloomy report at a meeting in Incheon, South Korea. In the 728-sided document, the UN organization informed how the weather, health and ecosystems of the world would be better if world leaders could in some way limit future human warming to just 0.9 degrees Fahrenheit (half a degree Celsius) from now on now of the globally agreed goal of 1
.8 degrees F (1 degree C). Among other things: – Half as many people would suffer from lack of water. – There would be fewer deaths and diseases from heat, smog and infectious diseases. – Sea should rise almost 4 inches (0.1 meters) less. – Half as many animals with hind legs and plants would lose the majority of their habitats. – There would be significantly less heat waves, drops and droughts. – The West Antarctic can not kick into irreversible melting. "And it can only be enough to save most of the world's coral reefs from dying. "For some people, it's a life or death issue without a doubt," said Cornell University climate researcher Natalie Mahowald, a leading author of the report. Limiting the warming to 0.9 degrees from now means that the world can keep a twilight of the ecosystems we have. Adding an additional 0.9 degrees above it – the looser global goal – means essentially a different and challenging soil for humans and species, says another of the report's main author, Ove Hoegh-Guldberg, Head of Global Change Institute at the University of Queensland, Australia. But meeting the more ambitious goal of somewhat less warming would require immediate draconian cuts in the release of heat-catching gases and dramatic changes in the energy field. While the U.N. panel says technically possible, there was little chance that the necessary adjustments would happen. In 2010, international negotiators agreed to limit heating to 2 degrees C (3.6 degrees F) since pre-industrial times. It is called 2-degree goal. By 2015, when the world's nations agreed on the historic climate agreement in Paris, they set dual targets: 2 degrees C and a more demanding 1.5 degrees C target from pre-industrial times. The 1.5 was on the call of vulnerable countries who called 2 degrees a death sentence. The world has already heated 1 degree C since pre-industrial times, so the number really is about the difference between another half degree C or 0.9 degrees F from now on. "There is no definite way to limit global warming to 1.5 above pre-industrial levels," said the report. More than 90 researchers wrote the report, based on more than 6,000 peer reviews. "Global warming is likely to reach 1.5 degrees C between 2030 and 2052 if it continues to increase at current speed, "said the report. Deep in the report, researchers say that less than 2 percent of 529 of their estimated future scenarios are kept warm below 1.5 goals without the temperature going over and in some way will return in the future. The commitments made in the Paris agreement 2015 are "clearly insufficient to limit heating to 1.5 by any means," said one of the study's writer Joerj Roeglj from Imperial College in London. " I just do not see the opportunity to do one and a half "and even 2 degrees looks unlikely," says Appalachian State University Environmental Researcher Gregg Marland, who is not part of the UN panel, but has tracked global emissions for decades of the US Energy Department. He liked the report to an academic exercise wondering what would happen if a frog had wings. Nevertheless, the authors report that they are still optimistic. Restricting the warming to the lower goal is "not impossible but will require unprecedented changes," said U.N. Panel Manager Hoesung Lee at a press conference where researchers repeatedly refused to spell out how feasible that goal is. They said it is up to the governments to decide whether the unrivaled changes are taking place. "We have a monumental task in front of us, but it's not impossible," said Mahowald earlier. "This is our chance to decide how the world will look." To limit the warming to the lower temperature target, the world needs "rapid and comprehensive" changes in energy systems, land use, urban and industrial design, transport and building use, "the report says. Annual carbon dioxide pollution levels still rising must now decrease by half by 2030 and then be close to zero in 2050. Emissions of other greenhouse gases, such as methane, must also fall. To quickly switch away from fossil fuels like coal, oil and gas to do this can be more expensive than the less ambitious target, but it would clean the air from other pollutants. And it would have the advantage of avoiding more than 100 million premature deaths in this century, "the report said. "Climate-related health, supply, food security, water supply, human security and economic growth risks are expected to increase with global warming," said the report, adding that the world's poor are more likely to suffer the hardest. Princeton University climate researcher Michael Oppenheimer said that extreme weather, especially heat waves, will be more fatal if the lower target passes. Meeting the harder to reach the target "can cause approximately 420 million fewer people to be exposed to extreme heat waves often and about 65 million fewer people are exposed to exceptional heat waves." The deadly heat waves that beat India and Pakistan 2015 will be practical annual events around the world reach the warmer of the two goals, says the report. Coral and other ecosystems are also in danger. The report said that warmer water coral reefs "will largely disappear." The result will determine if "my grandchildren would look beautiful coral reefs, "Princeton Oppenheimer said. For researchers, there is some" wishful thinking "that the report will encourage governments and people to act quickly and strongly, one of the leaders of the panel, says German biologist Hans-Otto Portner." If action is not taken, it will bring the planet to an unprecedented climate future. "___ Follow Seth Borenstein on Twitter: @bo Renbears. His work is here. ___ Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. AP is solely responsible for all content. ___ This story has been corrected as to how expensive stricter emissions will be than a looser target. It's more expensive, but not three to four times more expensive.