The United Nations’ World Meteorological Organization issued yet another grim report about the state of our planet this week. In 2021, four of the seven major climate indicators – a set of parameters that hold key information about climate change – set “alarming” new records.
In what the WMO said is a “clear sign” that humans are causing “harmful and long-lasting” effects across the globe, the report found that greenhouse gas concentrations, sea level rise, ocean heat and ocean acidification all set new records last year. The report also found that the past seven years have been the warmest seven years on record.
In a press conference about the findings, U.N. Secretary-General António Guterres said that the records set are “alarming” and that the findings portray a “dismal litany of humanity’s failure to tackle climate disruption.”
“I will give you the bottom line – the global energy system is broken and bringing us ever closer to climate catastrophe. Fossil fuels are a dead end, environmentally and economically,” he said. “…The only sustainable future is a renewable one.”
Here are the indicators that set the new records and what they mean as humanity continues to fight the climate crisis.
Greenhouse gas concentrations
Greenhouse gas emissions are the driving force behind global warming and climate change. Carbon dioxide, which is mostly released into the atmosphere through the burning of coal, natural gas, oil, solid waste and biological materials, is the most potent of these gases. As greenhouse gases are released, they create a thick barrier in the atmosphere that traps heat, and reducing these releases is essential to limit warming of the planet.
These gases reached new highs in 2020, and the latest report shows that three gases in particular – carbon dioxide, nitrous oxide and atmospheric methane – continued to increase in 2021. Scientists expressed particular concern over atmospheric methane, which is the second-largest contributor to global warming.
Last month, NOAA scientists reported that this gas saw an increase of 17 parts per billion in 2021, the largest annual increase recorded since they started taking measurements in 1983 and an amount about 162% larger than pre-industrial levels.
WMO issued a report last year that found cutting human-caused methane by 45% by 2030 would have a substantial impact on global warming and keep it to 1.5°C compared to pre-industrial levels. This would avoid nearly 0.3°C of warming by the 2040s, researchers said, and prevent 255,000 premature deaths, 775,00 asthma-related hospital visits and 26 million tons of global crop losses.
Ocean heat
More carbon dioxide in the atmosphere means more carbon dioxide in the ocean, a fact that can have a disastrous effect on global systems. As explained in WMO’s report, about 90% of the heat on Earth is stored in the ocean, and as the planet warms, so does the ocean.
In 2021, ocean heat hit a record high.
The top 2,000 meters of oceans in particular were observed to have warmed last year. Scientists believe that it will only continue to do so, saying that it is “a change which is irreversible on centennial to millennial time scales.”
That heat can cause a cascading effect, contributing to sea level rise, marine heat waves, coral bleaching and ice melting — threatening marine ecosystems, fisheries and the ability for people to live near coastlines.
Sea level rise
Driven by a warming ocean, sea level rise also hit a record high in 2021, increasing at an average of 4.5 millimeters per year from 2013. Scientists said its “more than…