Climate Change

What WMO report says on climate trends: Drivers and impacts

2015-2021 will be the warmest years on record, the World Meteorological Organization report flagged

 
By Jayanta Basu
Published: Monday 01 November 2021
The last seven years are on track to be the warmest on record, according to the provisional WMO report. Photo: iStock

The novel coronavirus disease (COVID-19) pandemic could not deter the world from emitting greenhouse gases. And now, record atmospheric greenhouse gas concentrations in 2021 have propelled the planet into uncharted territory, according to the World Meteorological Organization (WMO).

The last seven years are on track to be the warmest on record, according to the provisional WMO State of the Global Climate 2021 report. The report was based on data for the first nine months of 2021.

Here is a low-down of what the WMO report has laid out:

On greenhouse gases
  • Greenhouse gas concentrations reached new highs in 2020
  • Levels of carbon dioxide (CO2) were 413.2 parts per million (ppm); methane (CH4) 1889 parts per billion (ppb); and nitrous oxide (N2O) 333.2 ppb, respectively — 149, 262 and 123 per cent of pre-industrial (1750) levels
  • The rise continued in 2021

on temperature rise

  • The global mean temperature for 2021 (based on data from January-September) was about 1.09°C above the 1850-1900 average
  • 2015-2021 will be the warmest years on record

On the ocean

  • The upper 2,000-metre of the ocean continued to warm in 2019, reaching a new record high. A preliminary analysis based on seven global data sets suggested that 2020 surpassed the record
  • Ocean warming rates showed a particularly strong increase in the past two decades and are expected to continue to rise in the future
  • The ocean absorbed around 23 per cent of the annual emissions of anthropogenic COto the atmosphere and so, has become more acidic. Open ocean surface pH declined globally over the last 40 years; it is now the lowest it has been in at least 26,000 years
  • As the pH of the ocean decreases, its capacity to absorb COfrom the atmosphere also declines  

On sea level 

  • The mean global mean sea level rise was 2.1 millimeters a year between 1993 and 2002 and 4.4 mm a year between 2013 and 2021, an increase by a factor of two between the periods
  • This was mostly due to an accelerated loss of ice mass from glaciers and ice sheets

On glaciers and ice sheets

  • Mass loss from North American glaciers accelerated over the last two decades, nearly doubling during 2015-2019 compared to 2000-2004
  • An exceptionally warm, dry summer in 2021 in western North America took a brutal toll on the region’s mountain glaciers
  • In Greenland, temperatures and melt-water runoff were well above normal in August 2021 due to a major incursion of warm, humid air in mid-August
  • On August 14, the rain was observed for several hours at Summit Station, the highest point on the Greenland Ice Sheet (3,216 m). Air temperatures remained above freezing for about nine hours. There is no previous report of rainfall at Summit. 

 On extreme weather 

  • Heatwaves affected western North America in June and July. Several places broke station records by 4-6°C and caused hundreds of heat-related deaths 
  • California reached 54.4°C on July 9, equalling a similar 2020 value as the highest recorded in the world since at least the 1930s
  • There were numerous major wildfires

On precipitation

  • Extreme rainfall hit Henan Province of China from 17-21 July. The city of Zhengzhou on July 20 received 201.9 mm of rainfall in one hour (a Chinese national record)
  • Western Europe experienced its most severe flooding on record in mid-July
  • Significant drought affected much of subtropical South America for the second successive year

On attribution to climate change 

  • A study in the Pacific Northwest found that heatwaves are “still rare or very rare in today’s climate, but would have been virtually impossible without climate change.”
  • The heavy rainfall in western Europe “was made more likely by climate change.

On socio-economic and environmental impacts 

  • Conflict, extreme weather events and economic shocks have increased in frequency and intensity in the last 10 years. The compounded effects of these perils, further exacerbated by the COVID-19 pandemic, have led to a rise in hunger 

“Scientists are clear on the facts. Now leaders need to be just as clear in their actions,” said United Nations Secretary-General António Guterres.

He added: “The door is open; the solutions are there. The 26th session of the Conference of the Parties (CoP26) to the United Nations Framework Convention on Climate Change (UNFCCC) must be a turning point for people and the planet.” 

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