When it comes to climate change, to invoke one of Al Gore’s favorite sayings, the biggest challenge is not what we don’t know, but what we know for sure but just isn’t so. [emphasis, links added]
Two new studies show that the Earth’s climate is far more complex than often acknowledged, reminding us of the importance of pragmatic energy and climate policies.
One of them, led by researchers at China’s Tongji University, finds that after years of ice sheet decline, Antarctica has seen a “surprising shift”: a record-breaking accumulation of ice.
Since the first GRACE satellite was launched in 2002, Antarctica has seen a steady decline in the total mass of its glaciers.
Yet the new study found the decline reversed from 2021 to 2023.
Melting Antarctic ice contributes to global sea-level rise, so a reversal of melting will slow that down. Understanding the dynamics of ice mass on Antarctica is thus essential.
The recent Antarctica shift makes only a small dent in the overall ice loss from 2022, but comes as a surprise nonetheless.
A second new paper, a preprint now going through peer review, finds a similar change at the opposite end of the planet.
“The loss of Arctic sea ice cover has undergone a pronounced slowdown over the past two decades, across all months of the year,” the paper’s US and UK authors write.
They suggest that the “pause” in Arctic sea ice decline could persist for several more decades.
Together, the two studies remind us that the global climate system remains unpredictable, defying simplistic expectations that change moves only in one direction.
In 2009, then-Sen. John Kerry warned that the Arctic Ocean would be ice-free by 2013: “Scientists tell us we have a 10-year window — if even that — before catastrophic climate change becomes inevitable and irreversible,” he said.
Today, six years after that 10-year window closed, catastrophic climate change has not occurred, even as the planet has indeed continued to warm due primarily to the combustion of fossil fuels.
Partisans in the climate debate should learn from Kerry’s crying wolf.
On one side, catastrophizing climate change based on the most extreme claims leads to skepticism when the promised apocalypse fails to occur on schedule.
On the other side, studies like the two surprising polar-ice papers reveal climate complexities, but don’t prove climate change isn’t real and serious.
Policymakers today appear to be embracing energy realism over a myopic rush to net zero at all costs.
But their newfound pragmatism should still embrace decarbonizing the economy, as well as reducing the costs of energy, expanding global energy access and ensuring secure and reliable energy supplies.
These multiple objectives are not always in concert, which is why energy policy is so challenging.
We know that humans affect the climate system in many ways — greenhouse gas emissions in part, but also through land management, air pollution and vegetation dynamics.
At a planetary scale, the net effect of these changes is a warming of the planetary system.
Yet anticipating regional and local consequences is far more difficult, and irreducible uncertainties mean that adapting to climate variability and change comes down to risk management as we balance competing objectives.
Fortunately, pragmatic energy policy has plenty of low-hanging fruit — expanding nuclear power and accelerating the retirement of coal are good places to start.
The surprises revealed by the two new papers about polar ice also remind us that we need to be prepared for unexpected behavior of the climate system, regardless of the underlying causes of change.
History tells us that climate can shift abruptly, with profound consequences for society.
Top photo by Hans-Jurgen Mager on Unsplash
Read rest at NY Post
