Whether or not you believe in climate change, the evidence appears to be mostly in favor of climate change. The fact that the piece presented used the words "global warming" instead of "climate change" speaks of a biased work.
Of course climate changes. We have solid evidence of ice ages, separated by warmer periods such as the current one. But the theory that CO2 causes the warm periods is completely bogus; the record shows that increases and decreases in CO2 -=FOLLOW=- global temperature changes by ~800 years. It's bad enough when people commit the logical fallacy "Post hoc, ergo propter hoc", but this is "Pre hoc, ergo propter hoc"!
Al Gore had the cajones to put graphs of CO2 and temperature up on the wall, vertically separated so as to make the eight century lag difficult to see, and won a damn Nobel prize for his trouble. It's rank dishonesty, and we can't make intelligent decisions based on misinformation. (ObOnTopicRef: Garbage In, Garbage Out)