Actually, global warming has been going on, with minor interruptions, for the last 14,000 years, beginning whent he last ice age ended.
In the last century the world's overall temperature rose by a whopping one degree.
I have seen some studies that suggest that moderate global warming would actually be beneficial to mankind. A lengthened growing season would increase food supplies for the earth's burgeoning human and animal populations. Rising ocean levels would cause our major port cities the expense of rebuilding their dock areas. Otherwise, who else is it going to hurt, the well-to-do who own expensive beach-front properties?
The environmental and atmospheric sciences are barely out of their infancy. While there is little doubt that modern industrialization is a contributing factor of global warming, some scientists point out that it is mainly a natural phenomenon.
A cursory examination of the history of the earth's ancient environment shows that the lengthy ice age periods are separated by relatively short 14 to 20 thousand year periods of warmth. If you think global warming poses a threat to mankind, just imagine what the onset of another ice age would do. Some of the largest food producing areas of the northern hemisphere would be covered by continental glaciers more than two miles thick. Since we are already more than 14,000 years into this latest "warm period" we should, perhaps, consider ourselves lucky to have a little global warming to stave off the start of the next ice age.
I don't question the sincerity of our environmental scientists. I simply believe that they have more than one agenda. Having an agenda could cause them to wear blinders when analyzing their data.
Regards, Shuckins