WMO report to COP26: 2021 is set to join the 7 hottest years on record
No matter what temperatures are like for the rest of this year, 2021 will join the hottest seven years in the record books.
As climate negotiations commence this week in Glasgow during the UN's COP26 meeting, the World Meteorological Organization released a preliminary State of the Climate report for 2021 that is already painting a dire picture for the globe.
Echoing similar findings to what NOAA had included in their latest global climate report, the WMO's State of the Global Climate 2021 provisional report gathers data from numerous agencies and experts around the world to highlight the impacts of climate change on the planet so far this year.
"The provisional WMO State of the Global Climate 2021 report draws from the latest scientific evidence to show how our planet is changing before our eyes. From the ocean depths to mountain tops, from melting glaciers to relentless extreme weather events, ecosystems and communities around the globe are being devastated," United Nations Secretary-General António Guterres said in a press release on Sunday.
According to the report, temperatures thus far in 2021 — from January through September — are sufficient to guarantee that this year is within the top seven hottest years on record.
While the next three months will determine exactly where the year falls on the list, the report states: "It is nevertheless likely that 2021 will be between the 5th and 7th warmest year on record and therefore likely that the most recent seven years, 2015 to 2021, will be the seven warmest years on record."
This graph plots global annual temperatures from 1850 to 2021, compared to what they were in the 50 years prior to the start of the 20th century, revealing how much hotter human activities have made the planet since the start of the Industrial Revolution. Credit: WMO
As shown in the graph above, the past seven years also stand out as a significant new 'plateau' for global temperatures, which began with the record-setting 2015–2016 El Niño. Even the coldest years from the past seven are hotter than anything we've seen in years before.
On a local scale, numerous records for heat have been matched or broken so far this year:
Lytton, B.C. reached 49.6°C on June 29 (a new record high for Canada),
Death Valley, California reached 54.4°C on July 9,
a weather station in Sicily reached 48.8°C on August 11 (a provisional European record),
Kairouan, Tunisia reached a record 50.3°C, and
Montoro, Spain recorded a temperature of 47.4°C on August 14 (a national record for Spain), while on that same day Madrid had its hottest day on record with 42.7°C, just to name a few.
Year-to-date global temperature anomalies, January to September, are plotted on this map, which compares them to the 30 year global average from 1981-2010. Credit: WMO
Along with this, greenhouse gas concentrations rose to new record levels in our atmosphere in 2020, despite any slowdowns due to the COVID-19 pandemic.
Global sea level rise reached a new record high as of September 2021. Due to a combination of the thermal expansion of the ocean waters (as the world's oceans retain more heat), the addition of more water due to melting ice sheets, and the exchange of water with lakes and rivers on land, the world's oceans have risen by over 100 millimetres since the early 1990s.
Since 2013, the rate of sea level rise (now at 4.4 mm/year) has also more than doubled from the rate seen in the 1990s and early 2000s (2.1 mm/yr).
Sea level rise has reached a new record high, and the rate of rise continues to accelerate. Credit: WMO
As of 2020, the average pH of ocean water is now at an all-time low. pH is a scale that ranks how acidic or basic water is. A pH of zero (0) is the most acidic (battery acid or hydrochloric acid), 7 is neutral (pure water), and 14 is the most basic (drain cleaner). Due to chemical processes and biological life in the oceans, seawater is slightly basic with an average pH of 8.11. Since record-keeping began in 1985, though, the pH has been decreasing steadily, and is now at just over 8.05.
According to the report, based on studies of past conditions on Earth, this is the most acidic the oceans have been in the past 26,000 years. Earth's oceans absorb roughly one quarter of the carbon dioxide emitted into the atmosphere. There, the CO2 reacts with seawater to become carbonic acid and as the concentration of carbonic acid has increased, this has lowered the pH of the water. This process is known as ocean acidification.
This graph tracks the yearly average pH of the oceans from 1985 to 2020, revealing the trend of ocean acidification that is occurring as a result of increasing greenhouse gas emissions. The current pH of the oceans is the most acidic they've been in around 26,000 years. Credit: WMO
While these changes in pH appear small, many forms of marine life require the oceans to remain slightly basic. While not all species are affected the same, this impacts corals, shellfish, and phytoplankton. As ocean acidification continues, and the pH of seawater is pushed closer to neutral, the closer we are to seeing fundamental, and likely devastating, changes to the balance of life in the oceans.
As temperatures continue to rise, the world is seeing a dangerous contrast between drought and extreme precipitation.
The city of Zhengzhou, China, received a total of 720 millimetres of rain between July 17–21. Over half of that total fell in just a six hour period, with 201.9 mm of rainfall falling in only one hour. This is typically months worth of rainfall for China, coming down in just a few days time. Over 100,000 people were evacuated from the area, and the Zhengzhou weather bureau called it a "once in one thousand years" event.
Just a few days before, on July 14–15, Western Germany and eastern Belgium received 100 to 150 mm over a wide area, resulting in flooding and landslides that caused over 200 deaths.
In contrast, some regions of South America and Africa experienced extreme drought conditions. Meanwhile, the southwest United States had its driest period on record from January 2020 through August 2021. Due to dry conditions across much of Canada, the report states that wheat and canola crops are forecast to be 30–40 per cent below what they were just last year.
Although global precipitation appears to average out, there are now many regions experiencing extremes of wet and dry weather. Credit: WMO
According to the WMO, this provisional State of the Climate report "is one of the flagship scientific reports which will inform negotiations [at COP26] and which will be showcased at the Science pavilion hosted by WMO, the Intergovernmental Panel on Climate Change and the UK Met Office."
"COP26 must be a turning point for people and planet," Gutierrez said. "Scientists are clear on the facts. Now leaders need to be just as clear in their actions. The door is open; the solutions are there. COP26 must be a turning point. We must act now — with ambition and solidarity — to safeguard our future and save humanity."
Thumbnail image courtesy Wang Ying/Xinhua via Getty Images
