New EPA data show US oil/gas-related GHG emissions continue to fall

EPA data shows methane leakage rate from natural gas systems just 1.5%

By Seth Whitehead, EnergyInDepth

The U.S. Environmental Protection Agency (EPA) released the latest draft of its annual Greenhouse Gas Inventory (GHGI) on Tuesday, and the new EPA data show that methane emissions from oil and natural gas systems continue to fall at the same time production has continued to ramp up.

From the report,

“Methane emissions from natural gas systems and petroleum systems (combined here) decreased from 254.8 MMT CO2 Eq. in 1990 to 201.5 MMT CO2 Eq. (53.3 MMT CO2 Eq. or 20.9 percent) from 1990 to 2015.”

The new EPA data is all the more relevant as the U.S. Senate is expected to vote soon on repealing the Bureau of Land Management (BLM) venting and flaring rule aimed at regulating methane emissions on federal lands.

The U.S. House of representatives voted to repeal the rule using the Congressional Review Act earlier this month.

Notably, the new EPA data show that petroleum system methane emissions have decreased significantly — just under 29 percent since 1990, 13.5 percent since 2005 and 17 percent since 2011 — primarily due to “decreases in emissions from associated gas venting.”

A huge chunk of those reductions occurred between 2014 and 2015, according to the EPA,

“[P]roduction segment methane emissions have decreased by around 8 percent from 2014 levels, primarily due to decreases in emissions from associated gas venting and flaring.”

The following EPA chart illustrates these significant decreases, which have occurred as oil production has increased 81 percent since 2005 and 28 percent since 1990.

The EPA also reports that methane emissions from natural gas systems have decreased 18.6 percent since 1990 “largely due to a decrease in emissions from transmission, storage, and distribution.”

Equally notable is the fact that methane 2015 natural gas system methane emissions are 1.3 percent below 2005 levels and 1.1 percent below 2011 levels, as the following EPA chart shows.

These reductions are quite remarkable, considering natural gas production was 52 percent higher than 1990 levels, 50 percent higher than 2005 levels and 18 percent higher than 2011 levels in 2015.

Industry efforts to reduce methane emissions have helped the U.S. reduce overall methane emissions by 16.7 percent since 1990, according to the EPA, and enteric fermentation has replaced natural gas as the top source of anthropogenic methane emissions.

At the same time that methane emissions from oil and gas systems have fallen as production has skyrocketed — thanks to the shale revolution — increased natural gas use continues to drive down greenhouse gas emissions, according to the new EPA data.

EPA reports that overall greenhouse gas emissions are down 2.2 percent from 2014 to 2015 and 11.2 percent below 2005 levels, as the following chart illustrates.

Increased natural gas use is the first reason on EPA’s list of explanations for these decreases,

“The decrease in total greenhouse gas emissions between 2014 and 2015 was driven in large part by a decrease in CO2 emissions from fossil fuel combustion. The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors, including: (1) substitution from coal to natural gas consumption in the electric power sector; (2) warmer winter conditions in the first quarter of 2015 resulting in a decreased demand for heating fuel in the residential and commercial sectors; and (3) a slight decrease in electricity demand. Lastly, since 1990, U.S. emissions have increased at an average annual rate of 0.2 percent.”

Most importantly, EPA data shows overall CO2 emissions continue to plummet, as carbon emissions are down 11.7 percent from 2005 levels and 2.7 percent from 2014.

Again, EPA gives credit where credit is due: natural gas use for electrical generation.

“The process of generating electricity is the single largest source of CO2 emissions in the United States, representing 35 percent of total CO2 emissions from all CO2 emissions sources across the United States.”

“Recently, a decrease in the carbon intensity of fuels consumed to generate electricity has occurred due to a decrease in coal consumption, and increased natural gas consumption and other generation sources. Including all electricity generation modes, electricity generators used natural gas for approximately 33 percent of their total energy requirements in 2015.”

EPA reports that electricity generation-related emissions decreased 6.7 percent from 2014 to 2015 alone “primarily due to decreased CO2 emissions from fossil fuel combustion due to an increase in natural gas consumption…” Natural gas use for power generation increased 18.7 percent during this time.

All told, this latest EPA data further confirms what EID has reported many times before: Fracking is the No. 1 reason the U.S. is the only major country that is reducing GHG emissions.

Furthermore, EPA data shows the methane leakage rate from natural gas systems is just 1.5 percent, agreeing with numerous reputable reports that show the rate ranges from 1.2 percent to 1.9 percent — well below the rate needed for natural gas to maintain its climate benefits.

So considering this new EPA data show methane emissions continue to fall at the same time production increases, this is just the latest example of why costly and duplicative methane regulations on the oil and gas industry are completely unnecessary.