The modern threat is unnecessarily high due to the greater use of air conditioners and refrigerators. Places in China remain cover in smog. Icebergs near the poles are melting which would lead to the rise in the level of sea water and hence flood several low lying areas. Therefore I think the modern threat of global warming is unnecessarily high.
And what do you suggest we should do? Ban air conditioners, refrigerators, cars, lights, heat, heck, the computer I'm writing this on? No. It is true that global warming is a threat, but now that we know that, we should be working to create more environmentally-friendly appliances, not making them our scapegoats.
If you do not ban it then what will you do? Do you want to use an appliance which causes more harm than good to you? It is better to live a simple life and live long rather than enjoy the comfort of the world for a short period of time.
It is true that appliances cause at least minor harm to the environment...but may I ask, what is your proof that they cause harm to humans, physically? We are already working on solutions to the environmental problems, and our technology advances more each day. It's not the least bit unfathomable that within the next decade or so, we will find a solution that makes our everyday objects environmentally friendly.