Holocene graph
It is colder right now than throughout almost all of history. I understand that you've been lead to believe that global warming is a problem, but that is not true. Please look at this chart. The blue line shows temperatures for the past 600 million years.

Look at the far right side of the chart (today), and you'll see that temperatures have plunged to their lowest point in almost 250 million years.

There have been only two periods in the past 600 million years when it has been colder than today.

We are now living through one of the coldest periods in geologic history. The last few year's minor rise in temperature is too minuscule to even show up on the chart.

Anyone who tries to tell you that we're enduring "unprecedented global warming" is lying or woefully misinformed.

Your father's instincts about the global warming hoax are absolutely spot on. Please, please do not try to push him in the opposite direction.

If this doesn't convince you, please look at this chart from the past 8,000 years:
ice age graph
You will see that the last millenium, from 1000AD to 2000AD, has been the coldest millennium of the entire Holocene interglacial.

Again, anyone who tries to tell you that we're enduring "unprecedented global warming" is flat out wrong.

So please, please do not try to push your father in the wrong direction.

Top graph from "Climate and the Carboniferous Period"

2nd graph from "Now the coldest millennium in 8,000 years"