5 Global Warming Myths Debunked

Global warming skeptics have several pet arguments that they use over and over again. I'll deal with a few of them here.

Myth #1: The methodology behind the Mann Hockey Stick graph, which shows global temperatures trending dramatically upward, is flawed.

Climate scientists have compared multiple datasets - ice samples, treerings, boreholes, historical documents, marine sediments, etc. I'll quote from the executive summary of the National Academy of Sciences "Surface Temperature Reconstructions for the Last 2000 Years":

It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries....less confidence can be placed in large-scale surface temperature reconstructions for the period from AD 900 to 1600. Presently available proxy evidence indicates that temperatures at many, but not all, individual locations were higher during the past 25 years than during any period of comparable length since AD 900....Very little confidence can be assigned to statements concerning the hemispheric mean or global mean surface temperature prior to about AD 900....

snip

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on icecaps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from AD 900 onward.

Myth #2: Increased solar activity could cause global warming, and this is not being taken into account by climate scientists.

From a 2003 Science Daily article NASA Study Finds Increasing Solar Trend That Can Change Climate:

"Although the inferred increase of solar irradiance in 24 years, about 0.1 percent, is not enough to cause notable climate change, the trend would be important if maintained for a century or more. Satellite observations of total solar irradiance have obtained a long enough record (over 24 years) to begin looking for this effect." (emphasis mine)

Note that we are only at the beginning stages, and there is not conclusive evidence of any significant solar effect. If the observed changes had been consistent over a century, they could have contributed a small amount to global warming. Indeed, the scientist who performed the study said: "Solar forcing would provide only about one-fourth as much warming [as GHG], if the solar trend persists over the same period. Solar forcing could be significant, but not dominant." Quoted from here.


Another science daily article, dated 1999, mentions a study that concludes that the sun does indeed affect Earth's climate. But:

According to Shindell, the new study also confirms that changing levels of energy from the sun are not a major cause of global warming.... The GISS model agrees that the solar increases do not have the ability to cause large global temperature increases, leading Shindell to conclude that greenhouse gasses are indeed playing the dominant role."

If you're still not convinced, back to the NAS report on Surface Temperature Reconstructions I quoted above:

"The rising temperatures observed since 1978 are particularly noteworthy because the rate of increase is so high and because, during the same period, the energy reaching the Earth from the Sun had been measured precisely enough to conclude that Earth's warming was not due to changes in the Sun."


Myth #3: Nuclear power is the only solution to global warming.

Quote:

"Even under the most favourable conditions, the nuclear cycle will produce approximately one-third as much CO2 emission as gas-fired electricity production. Furthermore, nuclear power could only supply the entire world electricity demand for three years before sources with low uranium content would have to be mined. Given that one of the main factors is the amount of carbon dioxide produced by the mining and milling of uranium ore, the use of the poorer ores in nuclear reactors would produce more CO2 emission than burning fossil fuels directly, and may actually consume more electricity than it produces.20 Furthermore, the problems of the depletion of uranium mineable at economic prices would become as serious as the depletion of oil and gas if a significant nuclear renaissance were to occur."

Nuclear power plants take about 12 years to build, at about 5 billion dollars each. If we make a substantial switch to nuke power, the plants will have no effect on greenhouse gas emissions for another decade or more.

From here.(pdf)


Myth #4: Environmentalists killed the nuclear power industry.

I wish environmentalists had the power to shut down an entire power industry. If we did, we would have stopped coal a long time ago, as it is much worse than nuke power in terms of emissions and mining.

The truth is, nuclear power isn't economically viable. You can't scale nuclear power production. If power demand increases, you can't pump in more fuel, like you can with coal, and building a new reactor costs millions of dollars. It's a huge investment, not something you want to get into lightly. The government has pumped billions of dollars to the nuclear industry, and still, no new plants have been built since the 70s. With a coal or gas plant, you can build according to demand, instead of building and hoping the demand comes to you.

It takes about 12 years to build a nuke plant, at a cost of about 5 billion dollars. Once you have invested this money, you will have energy for about 30 years until your license expires - at a cost of around 60 million dollars per year just for payroll expenses.

In contrast, a proposed coal power plant in Illinois, the Prairie State Energy Campus, is expected to cost about 2 billion dollars to build, and produce 1600 megawatts - energy production equal to the biggest nuke plants in Illinois, at half the construction cost.

Nuke power requires massive subsidies to operate - the US government has given 97 billion dollars to the nuke industry since 1950. There is also the fact that there are many countries that we don't want to have nuclear technology (Iran, anyone?)

Myth #5: Global warming can be both good and bad.

Global warming might be good for countries that see favorable changes - longer growing seasons, better rainfall, etc. But for poor countries that can't adapt quickly to drought or flooding or other unforeseen consequences, it will be catastrophic. Look at the problems in Sudan right now - a direct result of regional climate change.

The problems of those poor countries will become the problems of the more fortunate nations, as they deal with political instability of the affected nations and problems with immigrants and refugees. I recommend this editorial by Jeffrey Sachs for further reading on this point.

Global warming will be good for some species that thrive in a wide variety of environments: jellyfish, gulls, certain kinds of insects, birds like crows and starlings, fish like the Snakehead which are damn near impossible to kill... but it will accelerate the extinction that we are currently facing on this planet - the largest extinction since the dinosaurs. Lost biodiversity will be no picnic.

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