Wednesday 18 May 2022 09:07 AM Greenhouse gases, sea-level, ocean heat and ocean acidification all reached ... trends now
Four key climate change indicators reached record highs last year, a damning new report has revealed, as experts warn that global warming is 'leaving no corner of Earth untouched'.
Greenhouse gas concentrations, sea level rise, ocean heat and ocean acidification all broke records in 2021, according to the World Meteorological Organization (WMO).
Its State of the Global Climate in 2021 report also confirmed that the seven years from 2015 to 2021 have been the warmest since the industrial revolution, with 2016 being the warmest year on record.
WMO Secretary-General Professor Petteri Taalas said it was further evidence that 'our climate is changing before our eyes'.
He also added that it was 'just a matter of time before we see another warmest year on record'.
Greenhouse gases, sea levels, ocean heat and ocean acidification all broke records in 2021, according to the World Meteorological Organization. The graphic above shows the near-surface temperature differences relative to the 1981–2010 average for 2021
The graphic above shows sea levels after the global mean trend has been removed, from 1993 to 2020, based on satellite data. It reveals that sea levels have increased almost everywhere
Its State of the Global Climate in 2021 report also confirmed that the seven years from 2015 to 2021 have been the warmest since the industrial revolution, with 2016 being the warmest year on record. Pictured, firefighters battling wildfires in Corrientes, Argentina in February
Greenhouse gases reached a new global high in 2020, when the concentration of carbon dioxide (CO2) hit 413.2 parts per million (ppm) globally, or 149 per cent of the pre-industrial level.
Data from specific locations indicate that they continued to increase in 2021 and early 2022, with monthly average CO2 at Mona Loa in Hawaii reaching 416.45 ppm in April 2020, 419.05 ppm in April 2021, and 420.23 ppm in April 2022.
The global annual mean temperature in 2021 was around 1.11 ±0.13 °C above the 1850-1900 pre-industrial average, less warm than some recent years owing to cooling La Niña conditions at the start and end of the year.
The most recent seven years, 2015 to 2021, are the seven warmest years on record.
This reached a record high in 2021.
The upper 2,000m depth of the ocean continued to warm last year and it is expected it will keep doing so in the future — a change which is irreversible on centennial to millennial time scales.
All data sets showed a particularly strong increase in ocean warming rates over the past two decades.
The warmth is penetrating to ever deeper levels, experts said, while much of the ocean experienced at least one 'strong' marine heatwave at some point in 2021.
The ocean absorbs around 23 per cent of the annual emissions of anthropogenic CO2 to the atmosphere.
This reacts with seawater and leads to ocean acidification, which threatens organisms and ecosystem services, and hence food security, tourism and coastal protection.
As the pH of the ocean decreases, its capacity to absorb CO2 from the atmosphere also declines.
Global mean sea level
This also reached a new record high in 2021, after increasing at an average 4.5 mm per year over the period 2013 -2021.
This is more than double the rate of between 1993 and 2002 and is mainly due to the accelerated loss of ice mass from the ice sheets.
Experts said it has major implications for hundreds of millions of coastal dwellers and increases vulnerability to tropical cyclones.
Extreme weather – the day-to-day 'face' of climate change – has led to hundreds of billions of dollars in economic losses and wreaked a heavy toll on human lives and well-being, the WMO said.
It added that its report was yet another clear sign that human activities are causing planetary-scale changes on land, in the ocean, and in the atmosphere, with harmful and long-lasting ramifications for sustainable development and ecosystems.
'Our climate is changing before our eyes,' Professor Taalas said.
'The heat trapped by human-induced greenhouse gases will warm the planet for many generations to come.
'Sea level rise, ocean heat and acidification will continue for hundreds of years unless means to remove carbon from the atmosphere are invented.
'Some glaciers have reached the point of no return and this will have long-term repercussions in a world in which more than 2 billion people already experience water stress.'
The WMO report confirmed that the past seven years have