Is Global Warming Accelerating?

That’s what a new study concluded. But its lead author – James Hansen – is viewed with skepticism in the climate community.

So who’s right?

The unfortunate answer is that no one really knows with certainty. What I do know is that people opposed to the effort to combat global warming will seize upon this division and claim climate science is faulty. And that is an undesirable outcome.

Personally. I think opposing climate change efforts is tantamount to playing Russian Roulette with the planet. We have no idea when the point of no return is, or whether one even exists. But if one does exist, then it behooves the human race to act quickly.

As for this particular study, the research suggests that a decline of sulfuric air pollution particles known as aerosols could cause average global temperatures to rise much faster than previously thought. The study also concludes that widely used climate models downplay how fast global ice sheets could melt.

To reach those conclusions, the study’s authors reevaluated thousands of years of paleoclimate records. After conducting their reanalysis, they determined that the most important ocean heat transport currents could slow or completely shut down.

I did a previous post on the Atlantic Meridional Overturning Circulation and the potential of it shutting down. If it did, it would be irreversible.

The Hansen study has some company. Researchers from the Stockholm Resilience Center recently published findings that six of nine climate-related planetary boundaries have been breached.

But the paper drew criticism for being published as a draft. That seems like a technical point. The key question is: what is the basis for believing the findings are inaccurate?

Opponents of Hansen’s work claim that he shops papers around. Kevin Trenberth, a professor emeritus with the National Center for Atmospheric Research basically thinks Hansen is a hack (my word not his) and claims that the new paper relies on data that was proven wrong in a 2021 study.

Yet Hansen has some “impressive” credentials. In 1988 his testimony to Congress has been described as politically groundbreaking. He’s held key positions at NASA and now heads Columbia University’s Climate Science Awareness and Solutions think tank.

 This appears to be a case of seemingly qualified experts with differing opinions. Such disagreements happen all the time in various disciplines. But when it happens in climate change, the impact goes beyond a disagreement between academics.

My advice:

1. Stop making specific predictions.
2. Focus on the trends and not the specifics.
3. Be honest about what you don’t know with certainty and position it as an expert opinion in need of further study.
4. And last, make the uncertainty your friend. The fact that we don’t know exactly what damage we’re doing suggests that urgent action should be taken.