Last week, I went to see Henry Pollack, one of the world’s leading geophysicists, and an internationally recognized expert on climate change.  On Sunday, I will publish a longer piece on what he thinks about that, and we can do to save the planet, and ourselves.

But he reminded me of something else during our conversation, which is how hard it is most of the time to predict the future. Pollack does a lot of work with former Vice-President Al Gore, probably the world’s best known activist against the dangers posed by climate change.

The scientist reminded me of a story Gore likes to tell. Back in 1980, AT&T wanted to calculate how many people would be using cell phones by the year 2000, so they commissioned an extensive study, which projected that by the turn of the century there would be 900,000 cell phones in use in the United States. That is how many were sold in the first three days that year.

Clearly, what was then seen as one of the world’s premier technology companies didn’t take into account the likelihood that technology would improve and that both size and price would come down.  Not many people would have wanted to use one of the big, clunky portable phones that were available back in 1980, and even fewer could afford them.

That popped into my head again earlier this week, when I was looking at the president’s proposed fiscal 2020 budget.  Clear vision for 2020, it certainly is not.  Trump attacked President Obama’s budget deficits when he ran for office.  Well, that was then and this is now. The Obama deficits were caused primarily by decreased revenues and the need to stimulate the economy during the Great Recession.

While campaigning, Trump promised, in fact, to not only eliminate the federal budget deficits but to wipe out the national debt itself by the time he left office. Instead, he is increasing both, largely because of a tax cut for the richest Americans, plus runaway defense spending.

Trump now is calling for balancing the budget by 2034, a statement which, when I read it, caused me to laugh out loud.  Nobody can have any idea what the economy or the world will be like in 2034, any more than anyone in 1980 could have predicted cell phone usage, the rise of the Internet or the fall of the Soviet Union and the Berlin Wall within fifteen years.

What we do know is that the President’s projection of a balanced 2034 budget is based on assumptions of economic growth far more optimistic than those of most economists, including the International Monetary Fund.  These are nonsense numbers.

Instead, the President is not only continuing our long-established practice of borrowing from future generations to avoid having to tighten our belts now. He’s making it worse.

We can’t predict the future. But I think we do have an obligation to not so heavily mortgage that future that our grandchildren will be faced with a choice between defaulting on our nation’s obligations or living with crippling debt.

We need to ask our politicians why we aren’t asking our citizens to pay for what we need. By the way, Lyndon Johnson’s administration did manage to balance the budget during his last year in office, but that was done mostly by what you might call creative accounting.

But can you name the only President since the Great Depression to actually not only balance the budget but post sizable surpluses, not for just one year, but for four years in a row?

Would you guess a conservative Republican, like Eisenhower or Gerald Ford? Not even close.  It was … Bill Clinton.

I bet he wishes we remembered him more for that than some other things.