Report: Earth nears warming’s worst effects

A landmark report released Sunday from the world’s top climate change group says that “rapid, far-reaching and unprecedented changes in all aspects of society” are required to ward off the worst impacts of global warming. The report, released in South Korea by the United Nations’ Intergovernmental Panel on Climate Change, said the world’s economies must quickly reduce fossil fuel use while at the same time dramatically increasing use of clean, efficient energy. These transitions must start now and be well underway in the next 20 years. The goal is to cap global warming at 1.5 degrees Celsius (2.7 Fahrenheit) above preindustrial levels, which the group said may prove nearly impossible unless swift action is taken. Limiting warming to that level would significantly reduce the risk of climate impacts such as water scarcity, flood and drought, extreme heat, tropical cyclones, biodiversity loss, and sea level rise, the report said. Global warming, aka climate change, is caused by the burning of fossil fuels such as oil, gas and coal that release greenhouse gases like carbon dioxide, which has warmed the planet to levels that cannot be explained by natural causes. This report shows the longer we wait, “the more difficult, the more expensive and the more dangerous it will be,” said Bill Hare, a physicist with the nonprofit group Climate Analytics. World governments requested the report be prepared after the Paris Agreement was adopted in December 2015 to combat climate change. Nations agreed to reduce emissions of greenhouse gases in order to hold the increase in global average temperature to well below 2 degrees Celsius above preindustrial levels and aim to limit the increase to 1.5 degree Celsius. “For some people this is a life-ordeath situation, without a doubt,” said Cornell University climate scientist Natalie Mahowald, a lead author on the report. Halting global warming would mean half as many people on Earth would suffer from lack of water, and there would be fewer deaths and illnesses from heat, smog and infectious diseases, according to the report. Panmao Zhai, co-chair of the IPCC working group, said that “one of the key messages that comes out very strongly from this report is that we are already seeing the consequences of 1 degree Celsius of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice, among other changes. Every country in the world except the United States is a part of the Paris Agreement. “The IPCC report is a sobering reminder that we’re still not on track to achieve the goals outlined in the Paris Agreement,” said Will McGoldrick of the Nature Conservancy. “If we’re serious about keeping global warming well below 2 degrees Celsius and striving for no more than 1.5 degrees, we cannot afford further delay.” More than 90 scientists wrote the 728-page report, based on more than 6,000 peer-reviewed references.

“For some people this is a life-or-death situation, without a doubt.” Natalie Mahowald Cornell University climate scientist and a lead author on the report

JEFF PEISCHL/NOAA-CIRES The Bakken oil and gas field in North Dakota produces methane emissions during fossil fuel extraction. The greenhouse gas contributes to global warming, whose effects scientists say will be dire.