In a surprising turnaround, the amount of carbon dioxide being released into the atmosphere in the US has fallen dramatically to its lowest level in 20 years, and government officials say the biggest reason is that cheap and plentiful natural gas has led many power plant operators to switch from dirtier-burning coal.
Many of the world’s leading climate scientists didn’t see the drop coming, in large part because it happened as a result of market forces rather than direct government action against carbon dioxide, a greenhouse gas that traps heat in the atmosphere.
Michael Mann, director of the Earth System Science Centre at Penn State University, said the shift away from coal is reason for “cautious optimism” about potential ways to deal with climate change. He said it demonstrates that “ultimately people follow their wallets” on global warming.
“There’s a very clear lesson here. What it shows is that if you make a cleaner energy source cheaper, you will displace dirtier sources,” said Roger Pielke Jr, a climate expert at the University of Colorado.
In a little-noticed technical report, the US Energy Information Agency, a part of the Energy Department, said this month that total US CO2 emissions for the first four months of this year fell to about 1992 levels. The Associated Press contacted environmental experts, scientists and utility companies and learned that virtually everyone believes the shift could have major long-term implications for US energy policy.
While conservation efforts, the lagging economy and greater use of renewable energy are factors in the CO2 decline, the drop-off is due mainly to low-priced natural gas, the agency said.
A frenzy of shale gas drilling in the Northeast’s Marcellus Shale and in Texas, Arkansas and Louisiana has caused the wholesale price of natural gas to plummet from US$7 or $8 per unit to about $3 over the past four years, making it cheaper to burn than coal for a given amount of energy produced. As a result, utilities are relying more than ever on gas-fired generating plants. . .
. . . The boom in gas production has come about largely because of hydraulic fracturing, or fracking. Large volumes of water, plus sand and chemicals, are injected to break shale rock apart and free the gas. . .
. . . Despite unanswered questions about the environmental effects of drilling, the gas boom “is actually one of a number of reasons for cautious optimism,” Mann said. “There’s a lot of doom and gloom out there. It is important to point out that there is still time” to address global warning.
This might not be a long-term change but market forces and fracking are reducing carbon emissions.
There are questions about the safety of fracking. Drew Hutton, president of the Lock The Gate Alliance in Australia; and Rosalind Archer, Associate Professor at the Department of Engineering Science at Auckland University debated the issue on Nine to Noon last Thursday.
Professor Archer (at about 15:50) said there is evidence of a small number of problems caused by very bad practices, shoddy well construction and very poor monitoring. But:
. . . there are other jurisdictions where, or instance, the US State of Ohio has records of 80,000 fractured wells with no evidence of ground water contamination.
In my opinion this is something that can be done right . . the head of the US Environmental Protection Agency said she thinks it can be done right. Recently the Royal Society for Science and Engineering in the UK also came out saying that fundamentally this is a process that can be done right so I think New Zealand just needs to learn from international best practice. . .
That practice is improving all the time and it is possible the debate could be overtaken by technical advances:
Chimera Energy Corporation of Houston, Texas, has announced that they are licensing a new method for extracting oil and gas from shale fields that doesn’t contaminate ground water resources because it uses exothermic reactions instead of water to fracture shale. . .
. . . Despite the fact that fracking is used mainly in deep, sealed geological deposits, there is the fear that it may pose a danger to groundwater. Depending on the method involved and the type of oil field, various other materials are added to the water used in fracking, such as sand, foaming agents, gels and friction reducers. The concern is that the water, which is pumped out after the process, may either leak these substances plus radioactive radon from the well directly into aquifer layers, or contaminate water supplies after pumping out.
For this reason, some fracking engineers prefer non-hydraulic methods. One of these, used recently in New York State, swaps the water for gelled propane. The idea being that the propane reverts to a gas at the end of the process and can be pumped out, leaving any additives behind in the well, much like boiling seawater and leaving behind the salt.
The Chimera process takes this a step further by eliminating any working liquid. Details of the process have not been made public yet due to patent concerns, but Chimera Energy uses what is called “dry fracturing” or “exothermic extraction.” First developed in China, this involves using hot gases rather than liquid to fracture the shale. This was originally intended for wells in arctic regions where water used in fracking freezes, but Chimera Energy has developed it for general use. . .
If this proves to be practical and safe it still might not be good enough for everyone who opposes fracking.
But then some opposition isn’t to fracking in particular it’s just the means of demonstrating opposition to mineral extraction in general.