1 00:00:00,658 --> 00:00:04,800 What is hydraulic fracturing – or fracking ? 2 00:00:04,800 --> 00:00:09,800 Since the industrial revolution our energy consumption has risen unceasingly. 3 00:00:09,800 --> 00:00:17,383 The majority of this energy consumption is supplied by fossil fuels like coal or natural gas. 4 00:00:17,383 --> 00:00:21,800 Recently there has been a lot of talk about a controversial method of extracting natural gas: 5 00:00:21,800 --> 00:00:25,800 Hydraulic fracturing or fracking. 6 00:00:25,800 --> 00:00:30,577 Put simply, fracking describes the recovery of natural gas from deep layers inside the earth. 7 00:00:30,577 --> 00:00:34,632 In this method, porous rock is fractured by the use of water, sand and chemicals 8 00:00:34,632 --> 00:00:39,497 in order to release the enclosed natural gas. 9 00:00:39,497 --> 00:00:42,777 The technique of fracking has been known since the 1940s. 10 00:00:42,777 --> 00:00:48,856 Nonetheless, only in the last ten years has there been quite a “fracking boom”, 11 00:00:48,856 --> 00:00:51,134 especially in the USA. 12 00:00:51,134 --> 00:00:57,633 This is because most conventional natural gas sources in America and on the European continent have been exhausted. 13 00:00:57,633 --> 00:01:03,299 Thus prices for natural gas and other fuels are rising steadily. 14 00:01:03,299 --> 00:01:10,658 Significantly more complicated and expensive methods, like fracking, have now become attractive and profitable. 15 00:01:10,658 --> 00:01:17,098 In the meantime, fracking has already been used more than a million times in the USA alone. 16 00:01:17,098 --> 00:01:22,498 Over 60% of all new oil and gas wells are drilled by using fracking. 17 00:01:22,498 --> 00:01:26,800 Now let’s take a look at how fracking actually works: 18 00:01:26,800 --> 00:01:31,800 First, a shaft is drilled several hundred meters into the earth. 19 00:01:31,800 --> 00:01:37,097 From there, a horizontal hole is drilled into the gas-bearing layer of rock. 20 00:01:37,097 --> 00:01:42,098 Next, the fracking fluid is pumped into the ground using high-performance pumps. 21 00:01:42,098 --> 00:01:46,049 On average, the fluid consists of 8 million liters of water 22 00:01:46,049 --> 00:01:50,133 which amounts to about the daily consumption of 65,000 people. 23 00:01:50,133 --> 00:01:55,656 plus several thousand tons of sand and about 200,000 liters of chemicals. 24 00:01:55,656 --> 00:02:01,048 The mixture penetrates into the rock layer and produces innumerable tiny cracks. 25 00:02:01,048 --> 00:02:05,264 The sand prevents the cracks from closing again. 26 00:02:05,264 --> 00:02:07,965 The chemicals perform various tasks 27 00:02:07,965 --> 00:02:10,465 among other things, they condense the water, 28 00:02:10,465 --> 00:02:11,965 kill off bacteria 29 00:02:11,965 --> 00:02:14,884 or dissolve minerals. 30 00:02:14,884 --> 00:02:18,216 Next, the majority of the fracking fluid is pumped out again. 31 00:02:18,216 --> 00:02:22,050 And now the natural gas can be recovered. 32 00:02:22,050 --> 00:02:26,337 As soon as the gas source is exhausted, the drill hole is sealed. 33 00:02:26,337 --> 00:02:32,578 As a rule, the fracking fluid is pumped back into deep underground layers and sealed in there. 34 00:02:32,578 --> 00:02:37,216 However, fracking is also associated with several considerable risks. 35 00:02:37,216 --> 00:02:41,099 The primary risk consists in the contamination of drinking water sources. 36 00:02:41,099 --> 00:02:44,097 Fracking not only consumes large quantities of fresh water, 37 00:02:44,097 --> 00:02:49,216 but in addition the water is subsequently contaminated and is highly toxic. 38 00:02:49,216 --> 00:02:56,216 The contamination is so severe that the water cannot even be cleaned in a treatment plant. 39 00:02:56,216 --> 00:02:59,965 Even though the danger is known and theoretically could be managed, 40 00:02:59,965 --> 00:03:06,337 in the USA already sources have been contaminated due to negligence. 41 00:03:06,337 --> 00:03:09,616 No one yet knows how the enclosed water will behave in the future, 42 00:03:09,616 --> 00:03:14,298 since there have not yet been any long-term studies on the subject. 43 00:03:14,298 --> 00:03:17,576 The chemicals used in fracking vary from the hazardous to the 44 00:03:17,576 --> 00:03:24,738 extremely toxic and carcinogenic, such as benzol or formic acid. 45 00:03:24,738 --> 00:03:32,577 The companies using fracking say nothing about the precise composition of the chemical mixture. 46 00:03:32,577 --> 00:03:39,178 But it is known that there are about 700 different chemical agents which can be used in the process. 47 00:03:39,178 --> 00:03:43,537 Another risk is the release of greenhouse gases. 48 00:03:43,537 --> 00:03:47,418 The natural gas recovered by fracking consists largely of methane, 49 00:03:47,418 --> 00:03:53,465 a greenhouse gas which is 25 times more potent than carbon dioxide. 50 00:03:53,465 --> 00:03:57,457 Natural gas is less harmful than coal when burned. 51 00:03:57,457 --> 00:03:59,383 But nonetheless, the negative effects of fracking 52 00:03:59,383 --> 00:04:02,134 on the climate balance are overall greater. 53 00:04:02,134 --> 00:04:07,496 Firstly, the fracking process requires a very large consumption of energy. 54 00:04:07,496 --> 00:04:11,738 Secondly, the drill holes are quickly exhausted and it is necessary to drill 55 00:04:11,738 --> 00:04:16,633 fracking holes much more frequently than for classical natural gas wells. 56 00:04:16,633 --> 00:04:24,496 In addition, about 3% of the recovered gas is lost in the extraction and escapes into the atmosphere. 57 00:04:24,496 --> 00:04:27,258 So how is fracking and its expected benefits to be assessed 58 00:04:27,258 --> 00:04:31,497 when the advantages are balanced against the disadvantages? 59 00:04:31,497 --> 00:04:34,258 When properly employed, this technique offers one way 60 00:04:34,258 --> 00:04:41,050 in the short to medium term for meeting our demand for lower-cost energy. 61 00:04:41,050 --> 00:04:44,633 But the long-term consequences of fracking are unforeseeable 62 00:04:44,633 --> 00:04:49,258 and the risk to our drinking water thus should not be underestimated.