This restriction does not apply to the cable-only channels CTV Two Atlantic, which has been co-owned with the local CTV stations since its launch (their news operations have been fully integrated since 1998), and CTV Two Alberta, which produces a current affairs program, Alberta Primetime, using resources from local CTV stations. Furthermore, in case of large abrupt release in the Arctic, local methane concentrations can be expected to remain higher for a long time. Will those clients stay for extended periods of time? Large abrupt releases will overwhelm the system, especially in the Arctic where there is already very little hydroxyl present. Lack of bacteria and depletion of oxygen in the waters of the Arctic could make it hard for oxidation to take place of methane that rises in the waters there. In the Arctic, low temperatures mean there are less bacteria that need more time to break down the methane. Yet, at the same time the EPA website still features a figure of 25 as methane's GWP, as illustrated by the two images on the right.


Meanwhile, the EPA has meanwhile changed its website somewhat, as illustrated by above image, which notes that methane has a GWP of 84 to 87 over 20 years. Among others, the EPA has been spreading this myth for many years, as illustrated by above image. Myth 7.: Methane is "only 20 or 21 times" as potent as carbon dioxide. Reality 9b.: Historically, atmospheric levels of methane (CH4) have risen much faster than those of carbon dioxide (CO2) and nitrous oxide (N2O), as illustrated by the image on the right. How much methane is present in sediments under the seabed of the Arctic Ocean, in the form of free gas and hydrates? 700 Gt in free gas beneath the gas hydrate stability zone. Paull et al. describe pingo-like-features on the Beaufort Sea Shelf, adding that a thermal pulse of more than 10 degrees Celsius is still propagating down into the submerged sediment and may be decomposing gas hydrate as well as permafrost. Pay cash -- Here's a no-brainer: The price of gas is usually cheaper if you don't use a credit card.


Furthermore, when methane escapes a hydrate, it expands to 160 times its earlier volume; this explosive expansion itself can cause further destabilization of sediments that contain methane in the form of hydrates and free gas. Hydrates can not only become destabilized by a rise in temperature, but also by pressure changes, such as caused by earthquakes or landslides. As the sea ice disappears, more open water allows more storms to develop that mix the waters, while tidal pressure differences will also become more pronounced. In the Arctic, the danger is much larger that methane releases will overwhelm the capacity of bacteria to break it down in the water. That's quite an understatement, if not a deliberate downplaying of the danger by the IPCC. Reality 7.: IPCC AR5 (2013) used the following figures for methane's Global Warming Potential (GWP) and or its lifetime. The IPCC figures do take into account the fact that methane extends its own lifetime by depleting hydroxyl. In other places, currents may bring bacteria back to the location of the methane plume repeatedly. In the Arctic, many currents are long, so once bacteria flow away from the location of the plume, they may have been driven out of the Arctic Ocean or may return only after a long time, i.e. too long to survive in Arctic waters which are cold and often ice-covered, so a lot of time little or no sunshine penetrates the waters.


Reality 4.: It can indeed take a long time for heat to propagate down the sediment. It will be broken down in "about a decade". The suggestion that methane only stays in the atmosphere for "about a decade" downplays methane's importance. Myth 6.: Methane has a short lifetime in the atmosphere. Myth 9.: Methane levels have "not risen (much) over the past few years". These shares stayed about the same for 1981, but on much lower volume of 182,552 units. The IPCC highlights this in AR5, as shown on the image below. Reality 6.: According to the IPCC (AR5, 2013), the perturbation lifetime for methane is 12.4 years. Earlier IPCC figures did not reflect oxidation of methane to carbon dioxide, which contributes to the CO2 burden. The IPCC also mentions higher figures (87 and 36) for methane's GWP (over 20, respectively 100 years). In 2009, Shindell and others further improved methane's GWP by including both direct and indirect effects, increasing methane's GWP to 105 over 20 years.