Brand new IPCC report: extreme weather in the age of climate change

    10 Aug 2021

    Today, the UN Intergovernmental Panel on Climate Change presented a thorough report analyzing what is happening to the planet due to human activity and what consequences we can expect from climate change. Experts have based on five scenarios – with the expectation that the world will either stop producing CO2 or emissions will double. 

    What tells to the world the ~3000 pages major scientific report on climate change released by IPCC today? The climate crisis is now here, and we have to face it:

    “The IPCC report is a code red for humanity” – UN Secretary-general Antonio Guterres.

    “The changes we see now are widespread. They’re rapid. They’re intensifying. They’re unprecedented in thousands of years,” – IPCC member Bob Kopp, professor, and director of the Institute of Earth, Ocean, and Atmospheric Sciences at Rutgers University.

    Key points of the report: 

    • In all emission scenarios, global warming will reach 1.5° C or 1.6° C over the next two decades. 

    • Human activities are the leading cause of more frequent and intense heatwaves, melting glaciers, and global warming. 

    • The Gulf Stream will slow down over the course of a century. The complete collapse of the Atlantic Ocean will disrupt regional weather conditions, weaken African and Asian monsoons, and exacerbate droughts in Europe. 

    • Methane emissions are now higher than ever in the last 800,000 years. Methane, which is emitted into the atmosphere from coal mines, agriculture, and the oil and gas industry, impacts global warming that is 84 times higher than CO2 emissions over a 20-year period. 

    • Melting Antarctic ice sheets could cause sea levels to rise by 15 meters by 2500 years. 

    • In many regions, the likelihood of fires will increase.

    (Too) hot summer 2021

    This year, the temperature reached anomalous levels or set new records:

    • In Hungary and Malta: more than + 40 ° С;

    • In France: Paris + 43 ° С;

    • In the USA: Phoenix, Portland, Washington, British Columbia – more than +46 ° С;

    • In Canada: Lytton, east of Vancouver + 49.6° C;

    And this is not an exhaustive list.

    The abnormal heat on the Pacific coast killed more than a billion animals in June.

    The last “unsinkable” ice arch of the Arctic is threatened with extinction. More than 30° C in the Arctic was recorded in May.

    Due to burning, the forests of the Amazon emit more carbon than they can hold. 80% of “forest-free” land is used for livestock needs worldwide.

    Due to the drought, new forest fires are breaking out, and their scale is growing. Forests in Russia were also on fire: in Karelia, the fire area has increased seven times in a week, and in Yakutia, at least 100,000 hectares have already burned.

    The images from Germany this summer were startling and horrifying: houses, shops, and streets in the picturesque cities and villages along the Ahr and other rivers violently washed away by fast-moving floodwaters. Are these severe weather patterns linked to climate change and environmental damage?

    Let’s analyze this, thanks to Gulf News.

    The flooding was caused by a storm that slowed to a crawl over parts of Europe, dumping as much as 6 inches of rain on the region near Cologne and Bonn before finally beginning to let up. There was flooding in Belgium, the Netherlands, and Switzerland, but the worst impacts were in Germany, where the official death toll passed 125 and was sure to climb.

    The storm was a frightening example of an extreme weather event, with some places getting a month’s worth of rain in a day. But in an era of climate change, extreme weather events are becoming more common.

    The question is, how much did climate change affect this specific storm and the resulting floods?

    A complete answer will have to await analyses, almost certain to be undertaken given the magnitude of the disaster, that will seek to learn if climate change made this storm more likely and, if so, by how much.

    But for many scientists, the trend is clear. “The answer is yes – all major weather these days is being affected by the changes in climate,” said Donald J. Wuebbles, a professor of atmospheric sciences at the University of Illinois.

    Already studies have shown an increase in extreme downpours as the world warms. The Intergovernmental Panel on Climate Change, the United Nations-backed group that reports on the science and impacts of global warming, has said that the frequency of these events will increase as temperatures continue to rise.

    Geert Jan van Oldenborgh, a researcher with the Royal Netherlands Meteorological Institute, said that in studies of extreme rain events in the Netherlands, “the observed increase is stronger than we expected.”

    Van Oldenborgh is one of the primary scientists with World Weather Attribution, a loose-knit group that quickly analyzes specific extreme weather events concerning any climate-change impact. He said the group, which just finished a rapid analysis of the heatwave that struck the Pacific Northwest in late June, discussed whether they would study the German floods.

    The world warmed as societies pumped heat-trapping gases into the atmosphere

    One reason for more substantial downpours has to do with fundamental physics: warmer air holds more moisture, making it more likely that a specific storm will produce more precipitation. The world had warmed by a little more than 1° C since the 19th century, when societies began pumping vast amounts of heat-trapping gases into the atmosphere.

    For every 1° C of warming, air can hold 7% more moisture. As a result, said Hayley Fowler, a professor of climate change impacts at Newcastle University in England, “These kinds of storm events will increase in intensity.”

    The day after Britain recorded its hottest August day in 17 years, much of its southern coastline was packed with visitors, many of whom had been forced to abandon foreign holidays because of COVID-19 travel restrictions. Authorities in Bournemouth, home to a golden seven-mile beach, warned at lunchtime that most of the stretch was so busy that “safe social distancing is not possible” and urged people to stay away.

    And although it is still a subject of debate, some studies suggest rapid warming in the Arctic affects the jet stream by reducing the temperature difference between northern and southern parts of the Northern Hemisphere. One effect in summer and fall, Fowler said, is that the high-altitude, globe-circling air current is weakening and slowing down.

    “That means the storms have to move more slowly,” Fowler said. The storm that caused the recent flooding was practically stationary, she noted. The combination of more moisture and a stalled storm system can lead to extra-heavy rains over a given area.

    Kai Kornhuber, a climate scientist with the Earth Institute of Columbia University, said that his and his colleagues’ research, and papers from other scientists, drew similar conclusions about slowing weather systems. “They all point in the same direction – that the summertime mid-latitude circulation, the jet stream, is slowing down and constitutes a more persistent weather pattern” that means extreme events like heatwaves and pounding rains are likely to go on and on.

    ‘Wave resonance’

    Michael E. Mann, a climate scientist at Penn State University, has studied the effects of a different summertime jet stream phenomenon known as “wave resonance” in locking weather systems in place.

    Climate change, he said, is making the stalling weather events more frequent. But he said it was premature to say that the European disaster was caused by wave resonance.

    Jennifer Francis, a senior scientist with the Woodwell Climate Research Center in Massachusetts, said that while dawdling weather systems can have many causes, they generally don’t occur in a vacuum.

    The European storm is “part of this bigger picture of extremes we’ve been seeing all along the Northern Hemisphere this summer,” she said, including the heat in the American West and Pacific Northwest, intense rainfall, and cooler temperatures in the Midwest, and heatwaves in Scandinavia and Siberia.

    “It’s never in isolation when it comes to an odd configuration of the jet stream,” Francis said. “One extreme in one place is always accompanied by extremes of different types.”

    “It is all connected, and it’s all the same story, really,” she added.

    Influence of climate change

    When it comes to floods, however, other factors can come into play and complicate any analysis of the influence of climate change.

    For one thing, local topography has to be taken into account, as that can affect rainfall patterns and how much runoff gets into which rivers.

    Human impacts can complicate an analysis even further. Development near rivers, for instance, often replaces open land, which can absorb rain, with buildings, streets, and parking lots that increase the amount of water that drains into rivers. Infrastructure built to cope with heavy runoff and rising rivers may be under-designed and inadequate.

    And meteorological conditions can sometimes lead to different conclusions.

    A 2016 study by World Weather Attribution of flooding in France and Germany in May of that year found that climate change affected the French flooding, caused by three days of rain. But the situation in Germany was different; a one-day storm caused the flooding. The computer simulations did not find that the likelihood of shorter storms in that area had increased in a changing climate.

    While some development can make flooding worse, other projects can reduce flooding. That appears to have been the case in the Netherlands, which was not as severely affected by the storm.

    After several significant floods on the Meuse River in the 1990s, the Dutch government began ad Room for the River program to reduce flooding, said Nathalie Asselman. She advises the government and other clients on flood risk.

    The work involved lowering and widening river beds, lowering flood plains, and excavating side channels. “These measures aim to lower flood levels,” she said.

    While a dike near the Meuse in the southern Netherlands suffered a breach that caused some flooding until it was repaired, the measures appear to have worked.

    Flood levels on the Meuse were about a foot lower than would have been the case without them, Asselman said. That meant smaller tributaries backed up less where they met the Meuse, producing less flooding.

    “If we wouldn’t have implemented these measures, then the situation would have been worse,” she said. “Both on the main river and the tributaries.”

    Killer heatwaves sweep again. Will nature’s fury be deadlier than COVID-19?

    Large parts of the world are in the grip of a heatwave, taking temperatures to record levels. Read More

    A heatwave is an extended period of hot weather relative to the expected conditions of the area at that time of year, which may be accompanied by high humidity.

    Is global warming just a whim of nature? Fact-checking

    Skeptics still believe that climate warming is a natural process. In the history of the Earth, they say, there were both cold and warm periods, so CO2 emissions have nothing to do with it. What does science say? Let’s check, thankfully to DW.

    For 4.5 billion years of its history, planet Earth has experienced periods of both warming and cooling. It is a fact. Temperatures have been changing for millennia. This process was caused by a change in the orbit in which the Earth revolves around the Sun. When our planet moved away from it, it became colder; when it approached, warming began.

    When, however, at the end of the 20th century, scientists began to study how the temperature on Earth changed over time; they found that since the 1980s, warming began to occur much faster than before.

    Sharp warming in the twentieth century

    In 1998, American scientists from the University of Massachusetts and the University of Arizona’s Dendrochronology Laboratory published a study showing the average annual temperature on Earth over the past 1000 years. To establish the temperature at a time when thermometers did not yet exist, that is, 500 or more years ago, they modeled time series, relying on records in natural storage media – glaciers, annual tree rings, and corals.

    As a result, it turned out that deviations from the norm for many centuries were insignificant, but in the twentieth century, there was an unexpected sharp jump in temperature.

    The authors of the study published in 2013 in the journal Science analyzed the change in temperature on Earth and in an even more ancient period – 11 thousand years ago. They came to the same conclusion: in the past century, our planet has warmed up faster than in any other period since the end of the previous ice age.

    At the same time, according to scientists, in the last 2000 years, the Earth has been relative to the Sun in such an orbit, in which in previous times, a period of its natural cooling began. But, the study says this natural cooling is currently not being felt due to the unprecedented warming caused by greenhouse gas emissions.

    How do CO2 emissions relate to climate change?

    The greenhouse effect is a natural process that, in fact, makes life possible on Earth. It occurs because certain gases in our atmosphere absorb the heat emitted by the Earth and partially return it – something like this happens in a greenhouse.

    Natural greenhouse gases include carbon dioxide (CO2), methane, and nitric oxide (laughing gas). For millennia, nature has optimally regulated the content of these gases in the atmosphere. This changed when humans started burning fossil fuels to generate energy, which led to dramatic increases in CO2 emissions. As a result of this and other activities of humanity, the natural balance in the atmosphere was disrupted: the Earth began to heat up faster and faster.

    According to the State of the Global Climate 2020 report by the United Nations World Meteorological Organization, the average annual temperature last year was 1.2° C higher than in the pre-industrial period, that is, from 1850 to 1900 when humanity did not yet use fossil raw materials in en masse as energy carriers. As the authors of the report point out, human-induced growth in greenhouse gas emissions is “one of the most important causes of climate change.”

    In 2001, the Intergovernmental Panel on Climate Change (IPCC) concluded that atmospheric CO2 concentrations were 280 parts per million (ppm) for millennia in the pre-industrial period. By 1999, according to the IPCC, it had increased to 367 ppm.

    The IPCC group was created in 1988 as a UN body and is attended by representatives from 195 countries who assess the scientific evidence obtained in connection with climate change. The IPCC also believes that the increase in CO2 in the atmosphere is a consequence of human emissions, which are three-quarters of the combustion of fossil fuels, and changes in land use cause the rest.

    In May 2021, the average CO2 concentration in the Earth’s atmosphere was 415 ppm. The last time such a high concentration of carbon dioxide was in the earth’s atmosphere was several million years ago – when there was no modern man yet, and the level of the world’s oceans was, on average, 30 meters higher than now.

    Benjamin Cook, who studies climate at NASA’s Robert Goddard Institute for Space Research, said that when at the end of the last century, scientists began to look for an explanation for global warming, they began to study various factors such as greenhouse gases, solar energy, circulation in the oceans, volcanic activity. “And only the increase in greenhouse gas emissions from the burning of fossil fuels has matched the warming on the Earth,” Cook said in an interview with DW.

    How unanimous are scientists?

    According to Cook, the scientific community today is convinced of man-made climate change and the theory of gravity. “There are some uncertainties and nuances in climate science that can be debated,” he says, “but one thing today is agreed by virtually all scientists: warming is caused by the burning of fossil fuels.”

    An analysis of 11,602 climate change scientific articles published in the first seven months of 2019 showed that 100% of the scientists who wrote them agreed with the anthropogenic nature of global warming. This analysis was carried out by James Lawrence Powell, a renowned American geologist and author of 11 books on climate change.

    Is there no alternative?

    “If there were an alternative theory that explains climate change differently from greenhouse gas emissions, and were proven in the course of scientific research, it would be a real breakthrough, – says Benjamin Cook.–- It would be work worthy of the Nobel Prize.”

    The Intergovernmental Panel on Climate Change is also convinced that global warming is the work of man. Back in 1995, the IPCC said that “the available evidence makes it highly likely that humans have a significant impact on the global climate.”

     “In a scientific approach, conclusions need to collect data, do research, make calculations,” says Helen Jaco de Combe, a researcher at the University of the South Pacific in Fiji, an IPCC member and an adviser to the government of the Marshall Islands. “And all of this tells us that the current climate change is caused by human activity.”

    The planet is dangerously hot; humanity is to blame. The world has signed a climate sentence.

    Scientists worldwide have completed many years of medical examination of the planet and unanimously diagnosed that global warming is in full swing and its indisputable cause – humans.

    “There is no doubt that the atmosphere, ocean, and land have warmed up under the influence of human activity,” said authors of the landmark climate report released on August 9.

    Without a decisive reduction in emissions, the world will not meet the goal set in the Paris Agreement to keep global average temperatures up to 1.5° C from pre-industrial levels until the middle of the century. Humanity will break this ceiling ten years earlier, in 2040, scientists have warned.

    And the next milestone is 2° C warming, which will have catastrophic consequences, will fall by the end of this century if we continue to smoke the sky and cut down forests at the current rate in the next two decades.

    The position of scientists has long been known, and warning reports appear constantly. However, this is special. And not just because it was written by two hundred scientists based on the results of 14,000 scientific papers over the past decade.

    The main thing is that almost all countries of the world have signed their conclusions. What is written in the report is now a consensus of the scientific community and the world community as a whole.

    Now the authorities of the 195 countries that approved the report have no reason to invoke skeptics and postpone emission reductions. And the chance to make increased commitments in this regard will fall in a few months – in early November in Scotland will meet delayed for a year due to the coronavirus world climate summit.

    A report by the IPCC, which won the 2007 Nobel Peace Prize, was published on Monday. This is a group of climate experts at the UN, which since 1990 has conducted six climate surveys on the planet. The current – the sixth – has been prepared for over eightTechnology years.

    The signatures of 195 countries under its conclusions make today’s report the main climate document of the world community and the starting point in international discussions on how to combat global warming.

    The 3949-page report states, among other things, that the last decade has been the hottest in 125,000 years.

    Greenhouse gases emitted into the atmosphere are already enough to increase the average temperature by 1.5° C compared to the 19th century. Still, it has risen by 1.1° C so far, as soot particles from fossil fuel combustion also have a reflectivity.

    The current impact of natural sources of global warming, such as the sun and volcanoes, scientists estimate as close to zero.

    Even if the world cuts emissions immediately and dramatically, some processes are irreversible for centuries to come, if not millennia – this is especially true of temperatures and ocean levels, as well as the area of ​​ice cover.

    In the time since the previous report was released in 2013, scientists have learned to clearly identify the link between extreme weather events such as heat, hurricanes and floods, and climate change.

    Continued global warming threatens even more severe “swings” between drought and floods, cold and heat.

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