| There is an ungoing dispute among global warming | | | | influence of the oceanic mass and water vapour |
| scientists about the so-called Global Warming | | | | on climate change which are more difficult to |
| Swindle Hypothesis, but most of this hypothesis | | | | confute. Water vapour makes up about 98% of |
| seems to be a misinterpretation of scientific data. | | | | the greenhouse gases by volume and provides |
| One example of the complexity of climatic | | | | something between 40 to 80 percent of the |
| simulations is the prediction of future storm | | | | natural greenhouse effect. It probably has the |
| events considering global warming effects. | | | | largest impact on the planet's temperature and |
| According to a recently published and | | | | climatic conditions, much larger than CO2. Water |
| controversially discussed study, global warming | | | | particles in the form of clouds act to reflect |
| isn't to blame for the recent jump in hurricanes in | | | | incoming solar heat, but the film argues that the |
| the Atlantic. | | | | effects of clouds cannot be accurately simulated |
| In February 2007, the Intergovernmental Panel on | | | | by scientists attempting to predict future weather |
| Climate Change (IPCC) stated in their Fourth | | | | patterns and their effects on global warming. This |
| Assessment Report that human actions are "very | | | | argument probably is correct and it is well |
| likely" (i.e. with 90% or greater probability) the | | | | recognized that water vapor is responsible for the |
| cause of global warming, indicated by an increase | | | | natural warming up of the surface temperature to |
| of 0.75 degrees in average global temperatures | | | | approximately 30-35ºC. Anthropogenic |
| over the last 100 years. This statement is the | | | | greenhouse effect, according to the film's |
| result of very tough discussions on a worldwide | | | | argumentation, is only about 2% of the total |
| scale between thousands of climate researchers | | | | "natural" greenhouse effect, which corresponds to |
| whether human activity is the main cause of | | | | a 0.6-0.7 ºC increase in temperature. This |
| global warming. The results of this discussion were | | | | estimate is somewhat smaller compared to the |
| presented to the public in many publications, for | | | | results of much more sophisticated simulations |
| instance in Martin Durkin´s documentary "The | | | | (0.9 - 2.7ºC), but there is undoubtedly an |
| Great Global Warming Swindle", presented in | | | | anthropogenic effect of CO2 increasing the |
| March 2007 at UK´s Channel 4. The main | | | | average surface temperature. |
| message of this production was that man-made | | | | One example of the complexity of climatic |
| global warming is "a lie" and "the biggest scam of | | | | simulations is the prediction of future storm |
| modern times." Martin Durkin and coworkers | | | | events considering global warming effects. |
| argue that the scientific consensus on climate | | | | According to a recently published study, published |
| change is the product of "a multibillion-dollar | | | | online by research meteorologist Tom Knutson in |
| worldwide industry, created by fanatically | | | | the journal Nature Geoscience and resumed in the |
| anti-industrial environmentalists, supported by | | | | New York Times (May 18, 2008), global warming |
| scientists peddling scare stories to chase funding | | | | isn't to blame for the recent jump in hurricanes in |
| and propped up by complicit politicians and the | | | | the Atlantic. The study predicts that by the end |
| media". The documentary showcases scientists, | | | | of the century the number of hurricanes in the |
| politicians, economists, writers, and others who | | | | Atlantic will fall by 18 percent. In the past, Knutson |
| are sceptical of the scientific consensus on | | | | has raised concerns about the effects of climate |
| anthropogenic (or man-made) global warming. | | | | change on storms. His new paper has the |
| Some of the scientists, opposing the main stream | | | | potential to heat up a simmering debate among |
| of greenhouse gas theories, simply argue that it | | | | meteorologists about current and future effects |
| has not yet been ascertained whether humans | | | | of global warming in the Atlantic. And Knutson is |
| are the primary cause of global warming or if | | | | not alone with this view. Another group of |
| there are other natural variations responsible for | | | | experts, those who study hurricanes and who are |
| this phenomenon like increased solar activity, | | | | more often skeptical about global warming, also |
| cosmic rays or variations in natural climatic cycles. | | | | say there is no link between global warming and |
| There is also a series of scientists questioning the | | | | hurricane frequency. They attribute the recent |
| temperature records used in the databases as | | | | increase to a natural multi-decade cycle. According |
| temperature differences attributed to the | | | | to the prediction, the number of hurricanes |
| greenhouse effect are reasonable small (fractions | | | | touching land in the US and its neighbors will drop |
| of a ºC). The so-called "urban heat island" | | | | by about 30 percent because of wind factors. |
| effect leads to a local warming in more populated | | | | However, the biggest storms, those with winds |
| areas, showing slightly higher temperatures due to | | | | of more than 110 mph, would only decrease in |
| to increased heat generated by cities, rather than | | | | frequency by 8 percent. The biggest decrease is |
| a global temperature rise. Anyhow, this argument | | | | forecasted for storms with winds between 39 |
| was confuted by the IPPC, indicating that the | | | | and 73 mph (normal tropical storms), who would |
| effect of the urban heat island on the global | | | | decrease by 27 percent. |
| temperature trend is no more than 0.05 °C | | | | It's not all good news from Knutson's study, |
| (0.09 °F) degrees through 1990. | | | | however. His computer model also forecasts that |
| Other facts presented by the film were shown to | | | | "hurricanes and tropical storms will be wetter and |
| be incorrect or misinterpreted. The film asserts | | | | fiercer. Rainfall within 30 miles of a hurricane |
| for instance that records of atmospheric CO2 | | | | should jump by 37 percent and wind strength |
| levels since 1940 show a continuing increase, but | | | | should increase by about 2 percent", Knutson's |
| during this period, global temperature decreased | | | | study says. |
| until 1975, and has increased since then. Anyhow, | | | | There are already critical reactions on this new |
| it is well recognized that this cooling was driven | | | | publication. MIT hurricane meteorologist Kerry |
| mostly by aerosols (i.e. pollution) in the | | | | Emanuel claims that the computer model used by |
| atmosphere. There is nothing contradictory about | | | | Knutson is not adequate enough to look at |
| this cooling when all sources of radiation changes | | | | storms and according to Kevin Trenberth, a |
| are considered. A second argument that easily | | | | climate scientist from the National Center for |
| can be invalidated is the impact of the so-called | | | | Atmospheric Research in Boulder, Colo., Knutson's |
| "solar variation theory" on global warming. | | | | computer model is poor at assessing tropical |
| According to the authors, solar activity (and | | | | weather and 'fail to replicate storms with any kind |
| involving cosmic rays as well as heat from the | | | | of fidelity.' It also does not considering well enough |
| sun aiding cloud formation) is currently at an | | | | the intensity, duration and size of the storm |
| extremely high level and directly linked to changes | | | | events, as not only the number of hurricanes is |
| in global temperature. The film argues that solar | | | | important to evaluate. |
| activity is far more influential on global warming | | | | Positive feedback comes from NOAA hurricane |
| than any other anthropogenic or natural activity | | | | meteorologist Chris Landsea , who wasn't part of |
| on Earth. What the film does not mention is that | | | | this study, praised Knutson's work as 'very |
| solar activity has declined over the last 30 years - | | | | consistent with what's being said all along. I think |
| at the same time as the major spike in global | | | | global warming is a big concern, but when it |
| temperature. | | | | comes to hurricanes the evidence for changes is |
| But there are some statements related to the | | | | pretty darn tiny,' Landsea said. |