As global warming continues to move forward, scientists are paying close attention to some key indicators to measure the degree of change enveloping our planet The latest climate change report of the World Meteorological Organization (WMO) focuses on some of these important signs, detailing a series of shocking new records created in 2021
The new [2021 climate report] issued by the World Meteorological Organization( https://public.wmo.int/en/media/press-release/four-key-climate-change-indicators-break-records-2021 ) 》It continues to fill in important details of the increasingly grim picture following similar shocking publications by the world's top climate scientists this year. Compiled by dozens of experts, the report focuses on the key indicators of climate change, which is continuing, and especially depicts the trend of several indicators entering unknown fields throughout 2021.
Despite the cooling effect of La Nina, the global average temperature in 2021 is about 1.11 ° C higher than the pre industrial level, which proves that we are moving towards the limit of 1.5 ° C stipulated in the Paris agreement to avoid the most disastrous impact of climate change. According to the authors, the past seven years have been the hottest on record, highlighting an overall warming trend. Since the 1980s, each decade has been warmer than the previous decade.
Petteri taalas, Secretary General of the World Meteorological Organization, said: "It's only a matter of time before we see another hottest year in history. Our climate is changing before our eyes. The heat trapped by human induced greenhouse gases will warm the earth for many generations to come. Sea level rise, ocean heat and acidification will last for hundreds of years unless a means of removing carbon from the atmosphere is invented. Some glaciers have reached the point of irreversibility, which will have more than 20 impacts on an already The world where billion people experience water pressure has a long-term impact. "
The startling findings outlined in the report include the global high concentration of greenhouse gases in the atmosphere. At present, the global concentration of carbon dioxide is 413.2ppm, 149% of the pre industrial level. Scientists have previously warned that this accumulation is accelerating at a dangerous rate, increasing at a rate of about 0.9 ppm per year from the low level of 300 ppm in the 1960s, and about 2.4 ppm - 350 ppm per year between 2010 and 2019, which is considered safe by experts. Early data from a monitoring station in Hawaii showed that the concentration actually reached 420.23 ppm in April 2022.
"The report emphasizes that carbon dioxide in the atmosphere has now exceeded 420ppm in 2022," commented Dr. Tom Mortlock, an adjunct researcher at Macquarie University in Australia. "From this perspective, Antarctica's ice core records show that carbon dioxide in the atmosphere fluctuates naturally between 150 and 300 ppm. We may now be 40% higher than the natural level of carbon dioxide in the last million years of earth's history, which has happened in the past 150 years. It is now clear that the recent warming is driven by human generated greenhouse gas emissions. If we want to avoid climate change In the worst case, we must limit the temperature rise to 1.5 ℃ according to the Paris Agreement. "
Although climate change has many impacts on the entire terrestrial environment, most of its impacts can be seen through the response of the ocean, which is illustrated in many aspects in the state of climate report. Between 2013 and 2021, the global average sea level increased by an average of 4.5 mm (0.18 inches) per year, about twice that from 1993 to 2002, due to the increase in the melting rate of the ice sheet, which reached a record level in 2021.
The ocean absorbs about 23% of the carbon dioxide produced by human activities, and when it reacts chemically, it will acidify the sea water. This not only poses a serious threat to the marine environment such as the Great Barrier Reef, where serious coral reef bleaching continues to occur, but also the ocean's ability to absorb these carbon dioxide is declining with the decline of pH value. According to the author, they have now reached an all-time low.
"There is great confidence that the surface pH of the high seas is now the lowest in at least 26000 years and that the current rate of pH change is at least unprecedented since then," they wrote
In addition to these effects, the ocean, like the earth, is also warming. The data depict that the growth of ocean temperature has been particularly strong in the past 20 years and reached a new high in 2021. In 2021, a strong ocean heat wave occurred in most of the oceans. The upper 2000 meters (6500 feet) continued to warm, and this warmth penetrated deeper and deeper.
In addition to these new benchmarks, climate change continues to drive extreme weather events, such as record breaking heat waves in North America and the Mediterranean, severe floods in China and Western Europe, and severe droughts in Africa and Asia. The authors also pointed out that under the accelerated melting of the Greenland ice sheet, the summit station, the highest point of the ice sheet, recorded the first rainfall in history.
University of Griffith, Australia Ian Lowe, Honorary Professor of technology and society, said: "The new WMO report is uncomfortable to read. It records the acceleration of climate change. The past seven years have been the hottest seven years in history. As oceans warm and sea levels rise faster, the world's oceans become more acidified. Unless we take urgent action to reduce the burning of fossil fuels, there will be no chance to save the Great Barrier Reef. With more severe heat waves, floods and wildfires, the world has changed Has been paying a high price for decades of inaction since science became clear. "
The WMO's global climate report is presented as a supplement to the IPCC's sixth assessment report to be completed this year. It will also serve as an official document and negotiating resource for the United Nations Climate Change Conference (cop27) to be held in Egypt later this year.