If by "they" you mean thermometers, sure. I don't need to do anything more than look at temperature readings to see how the climate is changing.

I also see that it's clearly an exponential graph. We've already reached the 1.5 degree threshold the Paris Agreement was supposed to avoid, we have done fuck all to avoid it. The next 1.5 degrees will come much faster and the next 1.5 after that faster still. At that point we're 4.5 degrees above the baseline and that's widely regarded as apocalyptic.

We will see famine, water scarcity, mass migration, probably wars, possibly nuclear war.

If you want to bring a child into that world go ahead. I wouldn't want to be born into it so I won't.