Professor Robert Howarth:

I appreciate the opportunity to speak to the committee remotely. I am sorry I cannot be there in person. I am an earth systems scientist with a PhD awarded jointly by MIT and the Woods Hole Oceanographic Institution. I am the David R. Atkinson Professor of Ecology and Environmental Biology at Cornell University in New York State. I have been a tenured professor at Cornell since 1985 and I have conducted research and taught on climate change since 1980.

I am an expert on the global methane cycle, on the role of methane as a driver of global climate change and on methane emissions from the oil and gas industry. I am the lead author of the first ever peer-reviewed analysis of methane emissions from shale-gas development from fracking and I have published ten additional papers on this topic in the past eight years since my original paper was published in 2011. My research on methane and shale gas is cited more in the peer-reviewed literature than that of any other research scientist, with more than 2,700 citations. I have given hundreds of presentations on shale gas and climate change, including a briefing to senior staff in the White House.

Shale gas is a form of natural gas obtained from shale rock using high-volume hydraulic fracturing and high-precision directional drilling. These technologies have only been used by industry in the past 15 years. Virtually all of the shale gas ever produced has been produced in this century, largely in the past decade and almost entirely in North America. Two thirds of the increase in production of all natural gas over the past decade globally has been shale gas development in the United States. Natural gas production in the United States is now dominated by shale gas. If Ireland were to import liquefied natural gas from the United States, it would largely be shale gas.

Methane is the major component of natural gas, including shale gas. Methane is an incredibly powerful greenhouse gas, more than 100 times more powerful than carbon dioxide. Of the current global warming we have experienced in the past decade or two, methane contributes approximately 1 watt per square metre compared to 1.7 watts per square metre for carbon dioxide. It is important to note that the Earth's climate system responds more quickly to methane than to carbon dioxide and, therefore, reducing emissions of methane is critical to reaching the United Nations COP21 target of keeping the planet well below 2°C compared to the pre-industrial baseline. We simply cannot do that with CO₂emissions alone. If we do not reduce methane emissions, the Earth will shoot through the 2°C mark within the next 20 to 30 years, with devastating consequences.

Unfortunately, society has not so far acted to reduce methane emissions. Rather, methane in the atmosphere has been increasing rapidly over the past decade. My latest research, published in the journal Biogeosciencesthis summer, demonstrates that shale gas development in North America is the single largest driver of this increase in global methane. Shale gas in the US accounts for one third of the increase in all global emissions from all sources.

In the US, approximately 3.5% of the shale gas that is developed is emitted to the atmosphere as unburned methane due to leaks all along the chain from wells to the final consumer and purposeful emissions as the gas is processed, stored and transported. On account of these methane emissions, the use of shale gas in the United States has an even greater negative impact on the climate than coal, when we consider methane on the timescale of 20 years after it is emitted.

LNG imported to Ireland from the United States would have an even greater greenhouse gas footprint. To liquefy and transport the gas requires a substantial volume of energy. To import 1 cu. m of gas as LNG requires the production of 1.2 cu. m of gas with 0.2 cu. m of that gas burned to provide the energy for liquefication, etc. With that we increase the CO₂emissions as well as methane emissions and, therefore, I estimate the use of shale gas imported as LNG to Ireland would create greenhouse gas emissions of 156g of CO₂equivalents per megajoule, or a footprint that is 40% greater than that of coal. My written testimony provides a figure that demonstrates this. This is a minimum estimate, since it does not include the additional methane emissions associated with storing and transporting the LNG. Few if any data are available on methane emissions during transport but they could be substantial.

From the standpoint of climate change, LNG is a poor fuel choice, worse than using shale gas in the US. I urge Ireland to prohibit the importation of fracked shale gas from the US. I thank the committee for the opportunity to contribute remotely today.