issue guide: Global Warming

Pro & Con

See also the skinny, background & facts, links

We tease the debate out into three issues: how much humans are adding to global warming, how bad or good warming will be for the earth, and how much the McCain-Lieberman Climate Stewardship Act would put the pinch on our economy.

Human activity contributes to warming...

A lot

Much of the scientific community agrees that human activity plays a good sized role in global warming. Since the industrial revolution, atmospheric concentrations of the three biggest greenhouse gasses – carbon dioxide, methane, and nitrous oxide – have increased by 32%, 151%, and 17%, respectively. (IPCC). Almost all scientists agree that human activity contributed to this increase and most agree the rise in green house gases are responsible for the recent spike in temperatures. These scientists admit that the earth's temperature has natural ups and downs, but when they compare temperature predictions that factor human activity in and out, they come up with graphs of temperatures that don't match up.

These scientists are eager to curb CO2 emissions now, warning that even if we stopped putting more CO2 into the atmosphere this century, the impact of the higher levels of green house gases will be felt for a long time to come. (But this argument goes both ways - afterall, if the horse is already out of the barn, what's the point of closing the door?)

A little/none

A smaller group of scientists place much greater emphasis on the earth's natural temperature fluctuations. They point to phenomena such as the Medieval Warm Period or the Little Ice Age and other factors such as the position of the Earth's axis and solar activity as the source of the warming. Some say there is not even conclusive evidence that increased CO2 levels in the atmosphere are responsible for warming. Others warn that even if they are, our contribution is so small that any change in our activities would have not effect in reversing warming. They argue for waiting for conclusive evidence one way or the other before doing anything; after all, if it's true that if we have no impact on the temperature, cutting back on emissions would hurt our economies for no benefit. (CJ should note that scientists who believe humans have little or nothing to do with warming are in the minority. The consensus of the scientific community is that humans are somewhat to significantly responsible for climate change. We include the views of the minority, however, because we believe that sometimes even the "experts" get things wrong.)

The effects...

Are negative

The list of possible negative effects of warming is long, but it doesn't mean that all, or any, will happen. Scientists warn of both droughts and flooding as rain patterns radically shift. Air pollution may intensify in some areas, creating higher rates of related diseases, such as asthma. In the long run, effects can get more serious; such as rising sea levels and more storms and hurricanes. Such changes could jeopardize the balance of ecosystems, impact the water supply in US, cause the extinction of species, and dislocate millions of people who are flooded out of their homes. Indeed, some say we've already paid a lot in damages from extreme weather events over the past decade (IPCC). Warming could also - in a bizarre twist - have a cooling effect in parts of the world: the Gulf Stream, for example, which keeps Europe warm could be thrown off course by melting ice caps, chilling that continent. (FT) Other "tipping point" scenarios include irreversibly melting the polar ice sheets or killing off the coral reefs and the fisheries that they nurture. (WP)

Are positive, or overstated

Many people believe that the effects of global warming could be positive, particularly in the short term. The most commonly cited possible benefit of warming is a longer growing season, especially in the North; that could spell good news for the U.S. economy (according to a Pew report which also says the economics could swing the other way).

Although some global warming skeptics say the benefits could be positive, most simply think that claimed negative effects are overstated and alarmist.

Economic costs of McCain-Lieberman will be...


Because it imagines the U.S. economy to be more adaptable than the Charles River Associates and Energy Department reports (see Big), a study by MIT predicts that the economic costs of the Climate Stewardship Act would be minimal; just 0.02% of GDP would be lost in 2025. That pans out to $15 per household in 2010; $19 per household in 2020.


Two studies suggest that if we voted for McCain-Lieberman Climate Stewardship Act, the costs to our economy could be significant. The Deparment of Energy predicts that by 2025, $76 billion (in 1996 dollars) would be lost from our gross domestic product (EIA): that equals 0.4% of the gross domestic product. A report put out by Charles River Associates calculates even greater losses: up to $164 billion would be lost in 2025 (CRA) or $525 per household in 2010 and $1043 per household in 2020 (CRA). A CBO report from April, 2007, predicts that a 15% decrease on CO2 emissions would spell a 3% increase in household costs (for all but the richest 20%).

Hedging your climate bets

A middle of the road view - advocated most notably by the Economist - argues that, while we still may be far from certain about the science of global warming, there's enough evidence out there that CO2 could cook our climactic goose in future years to make it reasonable for us to hedge our bets today.

The Economist looks at efforts to bring down CO2 emissions as a kind of "insurance policy" - while homeowners buy fire insurance to cover them on the small chance their house will burn down someday, likewise it makes sense for us to cut CO2 emissions on the small chance that the global warming doomsayers are right. The price of buying that insurance policy today, though expensive, is small compared to the price of global warming worst case scenarios.

Did we miss something, let some slant slip in, lose a link - or do you just have something to say? Drop a line below! In the spirit of open dialogue, cJ asks you keep it civil, keep it real and keep it focused on the message, not the messenger. See our policy page for more on what that all means.

Thanks for providing me the

Thanks for providing me the first even handed view of this subject. With all the informaiton out there it is very hard to tell what is going on.


a random Joe (not verified) | November 10, 2007 - 5:22am