Earth Was Due for Another Year of Record Warmth. But This Warm?
Scientists are already busy trying to understand whether 2023’s off-the-charts heat is a sign that global warming is accelerating.
Unprecedented Warmth in 2023
Earth is finishing up its warmest year in the past 174 years, and very likely the past 125,000.
Unyielding heat waves broiled Phoenix and Argentina. Wildfires raged across Canada. Flooding in Libya killed thousands. Wintertime ice cover in the dark seas around Antarctica was at unprecedented lows.
This year’s global temperatures did not just beat prior records. They left them in the dust. From June through November, the mercury spent month after month soaring off the charts. December’s temperatures have largely remained above normal: Much of the Northeastern United States is expecting springlike conditions this week.
Investigating Climate Change
Scientists are already sifting through evidence — from oceans, volcanic eruptions, even pollution from cargo ships — to see whether this year might reveal something new about the climate and what we are doing to it.
One hypothesis, perhaps the most troubling, is that the planet’s warming is accelerating, that the effects of climate change are barreling our way more quickly than before. Researchers are looking for corroborating evidence to support this claim.
As extreme as this year’s temperatures were, they did not catch researchers off guard. Scientists’ computational models offer a range of projected temperatures, and 2023’s heat is still broadly within this range, albeit on the high end.
The Interplay of Greenhouse Gases and Aerosols
One thing researchers will be watching is whether something unexpected might be happening in the interplay of two major climate influences: the warming effect of greenhouse gases like carbon dioxide and the cooling effect of other types of industrial pollution.
Governments have begun reducing aerosol pollution for public-health reasons, causing temperature increases to speed up since 2000. The effect of aerosols on global warming is challenging to determine due to the complexity of clouds, which are influenced by aerosols.
Recent arguments about faster warming due to aerosol reduction are hard to reconcile with patterns in recent decades. The distribution and movement of heat across the planet further complicates conclusions about accelerated warming.
