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Issue No. 56 - May 15, 2015

1. Oil and gas drilling causing enormous loss of biomass in North America

Landscape impacts of oil and gas development
Biomass, or net primary production (NPP), is being destroyed on an enormous scale in North America after 12 years of oil and gas drilling in 11 US states and three Canadian provinces, according to a new study in the journal Science.

Since 2000, 50,000 new oil and gas wells have been drilled every year in central North America. According to the researchers, "the space and infrastructure required for horizontal drilling and high-volume hydraulic fracturing are transforming millions of hectares of the Great Plains into industrialized landscapes". This is causing ecosystem services to be degraded or lost.

The researchers used high-resolution satellite data, information from industry, and public records to calculate that between 2000 and 2012, up to 10 million tonnes of dry vegetation was lost of removed due to extensive oil and gas drilling.

As Climate News explains, this vegetation is the equivalent of 4.5 million tonnes of carbon that would have otherwise been removed from the atmosphere. It is also the equivalent of one month's fodder for five million cattle from the rangelands, and 120 million bushels of wheat from the croplands -- the study's authors point out that this is equal to 13% of US wheat exports in 2013.

According to the scientists, the amount of land taken up by wells, roads and storage facilities between 2000 and 2012 is 3 million hectares. For comparison, this is about twice the area of Northern Ireland, and about 43% of the area of the Republic of Ireland. As 90% of all drilling infrastructure is on private land, federal regulations concerning land reclamation requirements do not apply, and much of the infrastructure is being left in place after drilling is complete. The area in which the gas drilling is occurring is not conducive to natural reclamation by vegetation.

The study's authors compare the current environmental degradation to that which took place in the years preceding the Dust Bowl, noting that:

"In the early 20th century, rapid agricultural expansion and widespread displacement of native vegetation reduced the resilience of the region to drought, ultimately contributing to the Dust Bowl of the 1930s. It took catastrophic disruption of livelihoods and economies to trigger policy reforms that addressed environmental and social risks of land-use change."

2. Air pollution from hydraulic fracturing may travel hundreds of kilometres

Air pollution from hydraulic fracturing operations
A study published in the journal Atmospheric Environment indicates that increased ethane concentrations measured in Baltimore, Maryland and in Washington, DC are probably the result of natural gas drilling in upwind states, notably Pennsylvania and West Virginia, although this drilling is hundreds of kilometres away. The same hourly air quality measurements were conducted in Atlanta, Georgia, a city with no upwind gas drilling, and the ethane concentrations there were not found to have increased. The researchers, from the University of Maryland, found that from 2010 to 2013, ethane concentrations in Baltimore and Washington, D.C. increased from around 7% to around 15% of total measured non-methane organic carbon. The findings are summarised by ThinkProgress.

After methane, ethane is the second most abundant compound in natural gas. Measuring ethane rather than methane allowed the researchers to rule out local sources of contamination from natural gas in the atmosphere. The authors point out that "Landfills and waste water treatment plants are known sources of methane, but do not emit ethane." Although there are natural gas storage fields in Maryland, the authors consider it unlikely that they had started to degrade rapidly since 2009, despite no change in usage. The researchers also rule out other sources such as transportation and power generation, and fugitive emissions from pipelines, and conclude that "the emissions associated with hydraulic fracturing appear to be the only plausible source" for the increased ethane concentrations they found.

According to the researchers, the increased ethane concentrations found in Essex, Maryland (outside of Baltimore) and in Washington, DC indicate that "a substantial fraction of natural gas is escaping uncombusted, and the signal is detectable hundreds of kilometres downwind."

3. Oil and gas is sector top source of US methane emissions, ahead of agriculture

Scientific American reports that in 2013, despite a decrease in the number of wells being drilled, the oil and gas sector was responsible for 29% of overall US methane emissions, while the cattle industry contributed 26%. The information comes from the US Environmental Protection Agency (EPA) greenhouse gas inventory report for the years 1990-2013.

According to Mark Brownstein of the Environmental Defense Fund (EDF), the more than 7.3 million metric tonnes of methane released into the air by the oil and gas industry is "enough to meet the needs of 5 million households, and packs the same climate punch over the first 20 years as the CO2 emissions from more than 160 coal-fired power plants."

Brownstein points out that the EPA figures are "almost certainly an understatement", citing a 2014 Stanford University study which reviewed more than 200 previous studies and confirmed that US methane emissions were around 50% higher than official estimates. (Ed.: Another study in late 2013 came to similar conclusions.) He notes that methane is responsible for around 25% of global warming, and traps 84 times more heat over 20 years than CO2.

Recent research has revealed fundamental flaws in a commonly used scientific instrument approved by the US EPA for measuring methane leaks, finding that it severely underestimates emissions.

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