In 1968, fresh out of college with a degree in physics and a concentration in thermodynamics, I attended a lecture at Harvard.

It asked: “Where is the missing carbon dioxide?”

The speaker’s team had inventoried the global sources of CO2 and compared the results to the measured rise in atmospheric CO2.

Roughly half of the CO2 wasn’t showing up in increased atmospheric concentration.

Where was the missing half going?

The conclusion was that it was being soaked up into the world’s oceans.

The projections were horrific. If the absorption continued at that rate – acidifying the oceans with carbonic acid (which is dissolved CO2) – by the end of the 21st century, shellfish would be unable to grow their shells and coral reefs would be a thing of the past.

The speaker had reason to believe, however, that the rapid absorption might slow and reverse, as the warming ocean water ceased to absorb CO2 and started putting it rapidly back into the atmosphere.

That outcome would accelerate global warming.

Some combination of disruptions between the oceans and the land seemed certain, though which would hit first and hardest was uncertain.

The term “tipping point” hadn’t been invented.

Forty-six years have passed. The 50 percent ocean absorption estimate from 1968 is now pegged at about 40 percent. With the ocean acidification projected by 2100, fish will become addled and lose their instincts to avoid predators.

Coral bleaching is well underway.

From the 1968 projections, climate change is ahead of schedule.

Looking into the face of my baby granddaughter, I wonder what kind of world her children will enter.

Joe Seale

Gorham