Just because two things happen at the same time does not mean that one is caused by the other. They may be two unrelated events that happen to be occuring at the same time.
The Medieval Warm Period also produced global scale warming, but hundreds of years before the Industrial Revolution.
The climate of the Earth has changed drastically over the past million or so years. We did have several ice ages, the last one ended about 10,000 years ago. So obviously, there was global warming 10,000 years ago.
By the way, America is one of the cleanest countries on Earth. China and India are huge polluters and are not being pressured into doing anything about this problem... maybe you ought to be arguing with them about it.
How do you tell a Communist? Well, it's someone who reads Marx and Lenin. And how do you tell an anti-Communist? It's someone who understands Marx and Lenin. - Ronald Reagan
"A nation can survive its fools, and even the ambitious. But it cannot survive treason from within. An enemy at the gates is less formidable, for he is known and carries his banner openly. But the traitor moves amongst those within the gate freely, his sly whispers rustling through all the alleys, heard in the very halls of government itself."
Tullius Cicero (106-43 BC)
My wife is a high level scientist, therefore I associate with many scientists on a regular basis and they all think it's manmade. Maybe they're stupid.
But I think better safe than sorry, if it is manmade, reduce emissions. If it's not manmade and we reduce emissions, no harm done.
To say it "might" not be manmade as an excuse not to reduce emissions, and to keep polluting indiscriminately because it "might" be natural is lazy.
You are definitely right about the major threat from India and China. And while America may be a somewhat clean country we still use massive percentages of resources per capita compared to the rest of the world.
Pork, good for you, bad for Muslims and Jews.