2020-10-27_PERMIT FILE - C1981035 (22)

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of Earth's climate influencing systems, such as feedbacks and the forcing and response associated with the non-0O2 GHG species. The uncertainty range associated with the new estimate is ±400 GtCO2. The large uncertainty range (relative to the target budget) illustrates just how difficult climate analysis is. These uncertainties are more important to the probability of success for a given budget estimate the closer warming is observed to the target limit. As such, it is likely that the absolute budget targets, or at the very least the estimated remaining time until emissions are required to reach carbon neutrality (net zero), is likely to change over time as emissions trajectories fluctuate and climate science continues to evolve. In the most basic terms,the uncertainty suggests that emissions need to start declining in the next decade to maintain reasonable progress.Staying within the remaining carbon budget of 420 GtCO2 implies that CO2 emissions reach net zero in about 20 years, or 30 years for a 580 GtCO2 budget.Additionally,the neutrality timelines assume an emissions trajectory following newly devised 1.5 pathways which limits cumulative GHGs to a higher degree than pledges made under the Paris Agreement afford. The 1.5 pathways have a global 2030 emissions target of approximately 25 to 30 GtCO2 in contrast to the Paris Agreement 2030 targets of 52 to 58 GtCO2 per year. Some of the latest research suggests that interim warming would exceed or overshoot the temperature targets prior to the end of the century. In these scenarios,the models assume negative emissions(sequestration)after net zero to regain the temperature target by 2100. The majority of these scenarios also employ uncertain technologies known as Carbon Dioxide Removal (CDR) measures to neutralize emissions from sources for which no known mitigation measures have been identified. Deploying CDR at scale is unproven, and reliance on such technology represent major risks, however CDR is needed less in mitigation scenarios with a particularly strong emphasis on energy efficiency and low demand for carbon-based fuels. Despite global awareness and acknowledgement of the climate change issue, emissions rates around the world continue to rise and are projected to continue doing so under most pathway scenarios in the short term. Modernization, population growth, and standard of living advances have all contributed to increased energy demand and land use changes that on balance have led to higher emissions year after year. According to the Global Carbon Project, cumulative CO2 emissions from fossil fuels were estimated to have reached 37.1 Gt in 2018.This value is equivalent to 9.83 PgC, and most closely approximates the RCP4.5 scenario relative to the 2020 emissions year. At current emissions rates the average face value of the budget (500 GtCO2) would be exhausted in approximately 13.48 years. Relative to the mean 2030 emissions budget target, existing global emissions would need to drop by approximately 26 percent over the next decade to maintain reasonable progress. Recent data from the EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks and estimates of U.S.emissions from the Global Carbon Project show that on average, the U.S. emits 14.2 percent of the global fossil fuel CO2 emissions on an annual basis (since 2015). In terms of the carbon budget, the annual U.S. emissions are equal to approximately just over 1 percent of the average face value. According to the Energy Information Administration (EIA) domestic energy production accounts for about 90 percent of all U.S. energy consumption.The three major fossil fuels— petroleum (28 percent), natural gas (31.8 percent), and coal (17.8 percent) —combined accounted for about 77.6 percent of this production, while renewable energy sources (12.7 percent) and nuclear electric power (9.6 percent) provide the remainder. The EIA's Annual Energy Outlook (AEO) report provides modeled projections of Dunn Ranch Area LBA and Mining Plan Modification 41 Technical Resources Report