“Alarming new records” for sea-level rise, ocean heat and acidification, and greenhouse gases in the atmosphere were set in 2021, according to the latest evaluation by the World Meteorological Organisation (WMO).
These critical global indicators of the climate crisis were signs of humanity’s impact on the planet, the WMO said in its State of the Global Climate in 2021 report issued on Wednesday.
“This is 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,” it concludes – in addition, the past seven years have been the hottest recorded.
Extreme weather, which the WMO called the day-to-day face of the climate emergency, wreaked a heavy toll on human lives last year and led to hundreds of billions of dollars in damage, the UN agency says, while droughts and floods triggered food price rises that have been exacerbated in 2022.
“Today’s State of the Climate report is a dismal litany of humanity’s failure to tackle climate disruption. Fossil fuels are a dead end – environmentally and economically,” said UN secretary general António Guterres.
“The only sustainable future is a renewable one. The good news is that the lifeline is right in front of us. Wind and solar are readily available and, in most cases, cheaper than coal and other fossil fuels. If we act together, the renewable energy transformation can be the peace project of the 21st century,” he added.
WMO secretary general Prof Petteri Taalas said: "Our climate is changing before our eyes. Human-induced greenhouse gases will warm the planet for many generations to come. 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.
"Extreme weather has the most immediate impact on our daily lives," he said. This was evident today with a drought emergency unfolding in the Horn of Africa, recent deadly flooding in South Africa and extreme heat being experienced in India and Pakistan.
Early warning and better weather forecasting systems were critically required, yet these are only available in less than half of WMO’s 187 member nations, Mr Taalas added.
Leading Irish climate scientist Prof Peter Thorne of Maynooth University called for greater urgency in responding to the worsening scenario.
“One of the fundamental challenges here is that climate is the story of our lifetimes but it is very rarely the story of today; there are always more pressing needs, more pressing issues, that take greater bandwidth in the media cycle,” he told RTÉ News.
“The truth is the climate will affect each of us deeply in the remainder of our lifetimes and...not just us but our children, our grandchildren and many generations hence,” he added.
The world’s oceans absorb more than 90 per cent of the heat trapped by greenhouse gases – and 2021 set a record. The increasing warmth in the ocean, which is “irreversible over timescales of centuries to millennia”, has been especially strong in the past 20 years. Much of the ocean experienced at least one strong marine heatwave in 2021, the WMO report says.
Global sea level also reached a new record high in 2021, up by 10cm since 1993 and the rise is accelerating, driven by the melting of ice sheets and glaciers and the thermal expansion of the ocean. The rise imperils hundreds of millions of coastal dwellers, the WMO added, and increases damage caused by hurricanes and cyclones.
Almost a quarter of carbon emissions are absorbed by the oceans, but this causes them to become more acidic, which threatens shell-forming wildlife and corals and therefore food security, tourism and coastal protection. The WMO warned the oceans are now more acidic than anytime over the past 26,000 years.
CO2 and the powerful greenhouse gas methane are at record levels, with CO2 concentration 50 per cent higher than before the industrial revolution, which has burned vast quantities of fossil fuels.
The global temperature in 2021 was 1.1 degrees above the pre-industrial average, moving closer to the 1.5-degree limit agreed by the world’s nations to avoid the worst climate impacts.
The WMO highlights exceptional heatwaves in 2021 in western North America and the Mediterranean; deadly flooding in Henan, China, and western Europe, and rain being recorded on the summit of Greenland's ice sheet for the first time.
The agency warns eastern Africa is facing a high risk of rains failing for a fourth consecutive season, meaning the worst drought in 40 years.
Prof Andy Turner of the UK National Centre for Atmospheric Science said the report was another stark reminder of the consequences of humanity's continuing generation of carbon emissions through burning of fossil fuels.
On the latest findings he said: “These are not speculative theories about the future: they are real changes that we are experiencing now. As the IPCC [Intergovernmental Panel on Climate Change] 6th Assessment Report noted last year, every region across the globe is already experiencing changes to weather and climate extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones.
“It is already clear that to avoid worsening the extreme events associated with global warming, we need to make rapid and sustained reductions in emissions of carbon dioxide and other greenhouse gases such as methane. In order to prevent warming of 1.5 degrees, these reductions in emissions need to be immediate.”
Dr Shaun Fitzgerald director of the Centre for Climate Repair at Cambridge University said the figures were "horrible", underlining the need for immediate action. "We will see many more millions of climate refugees as severe weather events increase in frequency and severity, and with sea level rising every year we will see more and more coastal regions being overcome," he predicted.
He believed the need for “climate repair” had never been greater. “Reducing emissions is absolutely critical, but our actions there will simply reduce the rate at which the problem is getting worse. We therefore need to go beyond zero emissions, and urgently develop schemes to remove greenhouse gases from the atmosphere” he said.
The report laid bare changes in Greenland, Dr Fitzgerald said. "Rain for the first time fell at Summit Station, the highest point on the Greenland ice sheet at an altitude of 3,216m. We must preserve the Arctic. So, we have to develop techniques to refreeze it."
Climate scientist Prof Richard Allan of the University of Reading said the record level of ocean heating that clearly measures the accelerating trajectory of climate change was receiving less fanfare.
“Sea levels are 4.5cm higher than 10 years ago and are not only rising, but rising progressively faster as the warmer oceans expand and melt water from land ice pours into the rivers and seas. Slowing the rate of sea level rise and avoiding further damage from more extreme weather events requires the urgent transition toward a net zero world, slashing carbon emissions to the extent that they are balanced by extra uptake from the land and ocean,” he said.
Prof Dave Reay of the Edinburgh Climate Change Institute said the new record on the key climate indicators was also pushing the emergency alarm on food security.
“Through an unholy trinity of climate, Covid and conflict, the number of people around the world classed as undernourished has already risen steeply: from 650 million in 2019 to 768 million in 2020. Without rapid action to shore up food security in hard-hit regions like the Horn of Africa, and sustained action to buffer everyone from the spiky shocks of global food consumer prices, hunger is where climate change is really going to bite,” he said.