Human influence on global warming is 'unequivocal,' UN report says

A deer walks through thick smoke to avoid a row of cars that were burned during the Dixie fire, which occurred in Greenville, California, on August 6. This massive wildfire, which has burned since mid-July, is the largest in California's history. Image credit: Photo Credit: Josh Edelson/AFP via Getty ImagesIn recent months, record-breaking wildfires, historic floods and baking droughts have been the focus of headlines. A new report from hundreds of climate experts, which confirms that these extreme events are indeed linked to climate change and if humans are at fault, is proof.According to the report, it is "unambiguous" that human activity is causing climate change. It's also affecting Earth's oceans and atmosphere in ways that are "widespread, rapid."The first installment of the Sixth Assessment Report by the United Nations Intergovernmental Panel on Climate Change, the UN body responsible for evaluating climate science, was released in a virtual press conference on Monday (8/9). The report contains more than 14,000 studies by the authors that document climate change, record human influence on global warming, and make predictions about the future if we don't reduce greenhouse gas emissions like carbon dioxide (CO2) that drive climate change.Related: Climate change reality: 10 myths dispelled"The IPCC has accepted the agreement of all the 195 member nations that it is unambiguous that human activity is causing global climate change is the strongest statement that they have ever made," Ko Barrett (IPCC Vice Chair and Senior advisor for Climate at National Oceanic and Atmospheric Administration, NOAA) stated at a briefing held on Aug. 8.This report was produced by the IPCC's Working Group I. It presents the scientific evidence that the Earth's climate is changing. The report also explains how human activity contributes to this change. The IPCC will deliver two additional reports by 2022 from two other working groups. These reports will address climate vulnerability and impacts in communities all over the globe, as well as potential mitigation strategies.This photo was taken July 28th and shows a rescuer walking through a flood zone in Yangzhou, China's eastern Jiangsu Province. It was taken after heavy rains caused by Typhoon Infa had inundated China's eastern coast. Image credit: Photo by STR/AFP via Getty ImagesThe new report was authored by more than 200 scientists. They found that global warming has been driven by human activity. This is primarily due to the increased production of CO2 from fossil fuel burning. Climate change has caused extreme weather events to become more frequent, longer-lasting, and intense for human communities all over the globe. Earth's current warming rate will continue to rise, causing it to heat up by 2.7 degrees Fahrenheit (11.5 degrees Celsius). It will also warm up to 3.6 F (2 C) in 2050. This will increase the severity of extreme weather.The authors stated that surface temperatures would continue to rise until the mid-century, regardless of the future emission scenarios.Changes incrementalAccording to the report, atmospheric heat-trapping carbon dioxide levels are higher than ever in the past 2 million years. The Arctic sea ice has fallen to its lowest level in 1000 years. Glacier retreat has been unprecedented for at least the past 2,000 years. The seas have increased more in the last century than in the previous 3,000 years, at an average rate of 0.15 inches (4 mils per year), and flooding events have doubled in coastal areas since 1960s, Bob Kopp, an IPCC author and director of Rutgers Institute of Earth, Ocean and Atmospheric Sciences, stated at the briefing.Heat waves in the oceans and on land are more frequent than ever, with five times the frequency of the 1950s. The frequency of severe droughts, which used to occur once a decade, has increased by 70%. This number could double if global temperatures rise by 3.6 F, according to Paola Andrea Arias, co-author of the IPCC and an associate professor at University of Antioquia, Medelln, Colombia."The IPCC's agreement with all 195 members that it is unambiguous that human activity causes climate change is the strongest statement they have ever made. Ko Barrett, NOAAAccording to the report, powerful hurricanes are also more likely to form and deposit more rain than they did decades back. Most land areas are also experiencing more intense and frequent precipitation events.The authors stated that "with every additional increase in global warming, extremes continue to grow." Extreme heat waves, which used to occur once a decade, now happen three times per decade. These heat waves could occur four times per decade if the global average temperature rises by 0.9 F (0.5 C). The resulting temperatures would reach nearly 3.6 F (2 C). Scientists reported that record-breaking rainfall events and droughts will increase in frequency, intensity and frequency if Earth continues to heat.Climate change has different impacts on different parts. It is not proportional to global warming. (Image credit: IPCC 2020)There is no turning backBarrett stated at the IPCC briefing that "there's no going back to" the climate that has lasted on Earth for thousands and years. Barrett stated that some of the changes we are seeing now can be slowed down or stopped if global temperatures rise to 2.7 F below pre-Industrial levels. She added that this goal is "impossible to achieve" without significant reductions in the emissions that are currently warming our planet.The report stated that "achieving global net zero CO2 emissions" is necessary for stabilizing the CO2-induced global temperature rise.Kopp said that limiting warming to below 3.6 F would have a dramatic impact on sea level rise. Current warming is causing oceans to rise 7 feet (2m) by the end century. Kopp stated that the irreversible ice loss from Antarctica's glaciers and ice sheet in Greenland is likely to continue for decades. Therefore, oceans will continue rising even though global temperatures drop. However, this process will be prolonged by hundreds of years and possibly millennia.He said, "Even in cases where we're dealing with the most extreme example irreversible change, which is sea level and ice sheets, there's an enormous impact on how fast that happens and how manageable these changes are."According to the report, future scenarios that have low or very low greenhouse gas emissions are the most promising. These could lead to effects that could be visible within the next two decades. Barrett stated that while it is possible to prevent many of the most devastating effects of climate change, it requires "unprecedented transformational change [with] rapid reductions in greenhouse gas emissions to net zero before 2050," Barrett said during the briefing.Barrett stated, "The idea there is still a way forward, I believe, is a point we should give us some hope."Original publication on Live Science