One telling sign is that months of climbing gas prices have produced only grumbles from American motorists. Of course they would. Krugman won't say, but it would have to be steep enough that most of us would be willing to use far less energy than we do now and start junking our Jeep Cherokees and Ford Explorers for Geo Metros and Volkswagen Golfs. Perhaps your concern for the environment is such that you consider this a good, if tough, solution a small price to pay for saving the environment. In fact, many scientists admit that we can't be sure how much of an impact human activity has on global temperatures.
Many uncertainties surround even the theory of global warming.
As greenhouse gases increase, so do average temperatures. Industrial activities pump these gases into the atmosphere, trigger warming, and invite environmental calamities. But recent scientific research throws these assumptions into doubt. In fact, temperature records are spotty before the 1950s and only cover a tiny portion of the globe mostly over land. Yet, despite the immense void in data, warming is touted as scientific fact .