Q1.4. Please document your statement that “The nine warmest years of the century have occurred in the past 11 years." A1.4. NOAA's National Climatic Data Center receives and archives data from land stations, ships of opportunity and NOAA satellites around the world. Based on these data and an extensive list of peer-reviewed articles, they have compiled statistics for global surface temperatures during the past century. The details of these data are provided on the NCDC home page at the Web site address: http://www.ncdc.noaa.gov/ol/climate/research/1997/climate97.html. Temperature Record: Land-Based Versus Satellite Data Q2. A2. Your testimony refers to the recent announcement that 1997 was the warmest year in the temperature record. However, the land-based temperature data do no comport with satellite data, which show a slight cooling trends (-0.05°C per decade) over the last 19 years. In fact, 1997 was the 8th coolest year in the satellite record, just slightly less than the 19-year average. How do you explain the discrepancy between these two data sets? There is a discrepancy between surface measurements of temperature and satellite observations because these data records are derived from two distinct techniques that measure different aspects of the global temperature. In the first place, the satellite record is a calculation of atmospheric temperature in two layers of the atmosphere (the lower troposphere, from 1-7 km above ground (or ~5,000 to 30,000 feet), and the lower stratosphere, which is between 17 and 21 km above the ground), while the surface measurements are of temperature at the land and ocean surface. It is also important to remember that the satellite record is quite short compared to the surface-based instrumental record, which makes it very difficult to establish a meaningful trend with the satellite data and also makes comparison of the two records difficult. There are also additional factors that complicate comparison of the two records. Both techniques of measuring temperature are influenced by a variety of sources such as localized pollution or aerosols, volcanic eruptions, and the inherent differences in temperature variability depending on the nature of the substance being measured (e.g., ocean water, land, or air), but in different ways. When these and other factors are taken into account, however, both records indicate a warming trend over land. བ་་ The Lancet Study on Particulate Matter-Related Health Impacts of Greenhouse Gas Mitigation and Reduction in Deaths and Greenhouse Gas Emissions Doe to EPA's Recently Promulgated Fine Particulate Standard “A second development relates to a study published in November in the medical journal Lancet. Most studies have examined the impacts of climate change on human health in terms of increased fatalities due to heat stress or the spread of infectious diseases. While by themselves, these areas represent considerable human health risks, this new study by the Working Group on Public Health and Fossil Fuel Combustion looked at the short-term impacts on mortality from air-borne particulate matter assuming no changes in estimates of energy use from fossil fuels. The analysis found that an estimated 8 million deaths globally due to exposure to fine particulates could be avoided between 2000 and 2020 if substantial steps were taken to limit greenhouse gas emissions from burning fossil fuels. In the United States alone, the study reports that thousands of deaths annually could be avoided during the 2000-2020 period. This study presents an important near-term benefit from actions to reduce greenhouse gas emissions that must be considered in addition to the long-term benefits of avoiding climatic disruptions. EPA's recently promulgated fine particulate standard begins to address this public health concern and should result in both some reductions in greenhouse gas emissions along with reducing the number of deaths associated with exposure to fine particulates.” Q3.1 Please provide a copy of The Lancet article referred to above. THE LANCET Articles Short-term improvements in public health from global-climate policies on fossil-fuel combustion: an interim report Working Group on Public Health and Fossil-Fuel Combustion* Summary Background Most public-health assessments of climatecontrol policies have focused on long-term impacts of global change. Our interdisciplinary working group assesses likely short-term impacts on public health. Methods We combined models of energy consumption, carbon emissions, and associated atmospheric particulatematter (PM) concentration under two different forecasts: business-as-usual (BAU); and a hypothetical climate-policy scenario, where developed and developing countries undertake significant reductions in carbon emissions. Findings We predict that by 2020, 700 000 avoidable deaths (90% CI 385 000-1034 000) will occur annually as a result of additional PM exposure under the BAU forecasts when compared with the climate-policy scenario. From 2000 to 2020. the cumulative impact on public health related to the difference in PM exposure could total 8 million deaths globally (90% CI 4-4-11-9 million). In the USA alone, the avoidable number of annual deaths from PM exposure in 2020 (without climate-change-control policy) would equal in magnitude deaths associated with human immunodeficiency diseases or all liver diseases in 1995. Interpretation The mortality estimates are indicative of the magnitude of the likely health benefits of the climate-policy scenario examined and are not precise predictions of avoidable deaths. While characterised by considerable uncertainty. the short-term public-health impacts of reduced PM exposures associated with greenhouse gas reductions are likely to be substantial even under the most conservative set of assumptions. Lancet 1997; 350: 1341-49 "Investigators listed at end of paper Correspondence to: Dr Devra Lee Davis. World Resources Institute. 1709 New York Avenue, NW, Washington, DC 20006, USA, Introduction Since the industrial revolution, the contribution of anthropogenic sources of greenhouse gases to the global environment has increased significantly.' Atmospheric concentrations of greenhouse gases, including carbon dioxide (CO), methane (CH), and nitrous oxide (N,O), are of greater importance today than at any other time in human history. These trends can be largely attributed to human activities, primarily fossil-fuel combustion, and change in land use and agricultural practices. In the absence of efforts to reduce greenhouse gases, the concentrations of these gases are expected to grow significantly throughout the next century. The mid-range estimate from the Intergovernmental Panel on Climate Change (IPCC) is that human-induced climate-change will increase surface temperatures by about 2°C by the year 2100; many uncertainties exist about this projection. In an effort to protect the global-climate system for future generations, over 150 nations signed the UN Framework Convention on Climate Change (UNFCCC) in June, 1992.' The UNFCCC established the objective of stabilising atmospheric greenhouse-gas concentrations at levels that would avoid dangerous anthropogenic interference with the global-climate system. Signatory countries will be considering options to control greenhouse gases at the third conference of parties in Kyoto, Japan, in December, 1997. Short-term public-health impacts have generally not been considered in assessments of global-climate change. Two studies," for example, have projected that well into the next century, weather patterns resulting from climate change are expected to affect the health of future generations. Heat-related mortalities and illnesses, physical and psychological traumas, and changes in vector-borne and infectious diseases, food supplies, and coastal sea-levels are expected to become evident. With various models, we estimate likely public-health benefits of current and future global-climate-change mitigation policies in the first two decades of the 21st century in developed and developing countries. Many of the fossil-fuel combustion processes that produce CO, and other greenhouse gases also produce a host of air pollutants such as particulate matter (PM), sulphate, ozone, and other pollutants, all of which have short-term adverse effects on public health. We use PM as a sentinel air pollutant because it is commonly associated with fossil-fuel combustion. Extensive publichealth literature in several countries has shown that both mortality and morbidity are significantly associated with exposure to PM. Most air pollutants from fossil fuels have local impacts but some airborne pollutants (eg, fine particulates) can be transported thousands of miles and have global impacts.' Estimation of the consequences for public health of projected global events requires the development of scenario-based impact assessment that relies on complex models of environmental change. Our study develops two possible CO, emission scenarios: a business-as-usual (BAU) scenario which updates IPCC's 1992 analysis of expected trends in energy consumption and associated CO, emissions;" and a hypothetical climate-policy scenario, which considers the stated intentions of the European Union regarding proposed reductions in CO, emissions for developed countries," coupled with additional measures by developing countries. Under our hypothesised climate-policy scenario, developed countries would undertake concerted and binding efforts to reduce energy-related CO, emissions 15% below 1990 levels by the year 2010. Under this same climate-policy scenario, developing countries are assumed to reduce their emissions 10% below their levels of greenhouse-gas emissions forecast for 2010-that is, 10% below what would otherwise be their BAU trends by 2010. This is consistent with agreements made by developing countries under the Berlin Mandate to advance implementation of existing commitments to promote technologies, practices, and processes that reduce greenhouse-gas emissions. Both these scenarios assume that total energy use and efficiencies in the developing countries continue to increase to meet the needs of economic growth. The differences between them lie in the rates of growth in energy use, the fuel mixes, and their combustion and end-use efficiencies. Under each of these scenarios, emissions of PM are taken as representative of general ambient air pollution associated with fossil-fuel combustion and CO, emissions. Based on projected concentrations of PM, estimate annual and cumulative numbers of avoidable deaths in the years 2010 and 2020 among adults aged over 30 years and infants of up to 1 year in developed (annex 1) and developing (non-annex 1) countries (UNFCCC we nomenclature). Avoidable deaths refers to the estimated annual premature mortality associated with PM from modelled fossil-fuel combustion (ie, attributable risk) that could be avoided by adopting the hypothesised climatepolicy scenario. Because the aerodynamic size of the particles produced is of great importance, our model estimates the emissions and concentrations of particles that are less than 10 μm (PM) and fine particles of less than 2.5 μm (PM,,). A host of other adverse acute and chronic health effects are also associated with PM and other air pollutants, but are not analysed here. 12 Fossil-fuel consumption and carbon emissions Future fossil-fuel consumption and resulting emissions of greenhouse gases and other air pollutants reflect complex interactions of several key variables, including economic activity, transportation modes, demographic trends, the rate and nature of technological innovations, and energy prices. The IPCC devised six well-documented projections of greenhouse-gas emissions in 1992." The IPCC used the Atmospheric Stabilisation Framework (ASF) model to relate socioeconomic scenarios to carbon emission trajectories. The ASF model contains detailed representations of fossil-fuel consumption for four sectors (electric utility, residential/commercial, industrial, and transportation) for nine global regions. All CO, emission estimates in this paper refer to emissions attributable to the combustion of fossil fuels, which represent about 75% of current global anthropogenic emissions of CO,." The CO, emission projections presented in this paper fall within the range of other emission projections documented in the literature. The 8.3 billion metric tonnes of carbon (BMTC) from fossilfuel combustion presented in this paper for 2010 is slightly lower than the estimate of 8-8 BMTC as predicted by Energy Information Administration." Our 2020 projection of 10-7 BMTC is higher than the ПIASA/WEC projection of 8-4 BMTC" and similar to the Shell Oil sustained-growth scenario estimate of 10-5 BMTC." The input in this study has been updated to reflect more recent population projections, the breakup of former Soviet Union, and lower anticipated fossil-fuel prices. The model assesses CO, emission-reduction goals, by choosing the most efficient and least cost emissionreduction opportunities available in each region, and recognises efficiency improvements in many developing countries." The global-population data used for these scenarios are consistent with the World Bank's mediumgrowth assumptions. The gross national product (GNP) growth assumed for the BAU scenario is slightly higher than the one used in the IS92a scenario, which reflects several economic, energy, and climate-change-related studies." Table 1 and figure 2 indicate several trends and associations of fossil-fuel consumption patterns modelled under both the BAU and climate-policy scenarios. In 1990, despite having only 24% of the world's population, annex 1 countries accounted for 70% of global fossilenergy consumption and 68% of carbon emissions from fossil fuels. Under BAU, overall growth in CO, emissions from annex 1 countries is relatively moderate through the projection period, 1990-2020, rising by only 17.5% through 2020. This moderate growth may be explained by current trends of fossil-fuel consumption patterns in Russia and the former Soviet Union. These regions A1=developed (annex 1) countries; NA1=developing (non-annex 1) countries; BAU-business-as-usual scenario: CP-climate-policy scenario. Table 1: Fossil-fuel energy use (10J) under business-as-usual and climate-policy scenarios markedly differ from other annex 1 countries, in that sharp declines in energy consumption are not assumed to reach 1990 levels again before 2020. As a consequence, future increases in emissions in annex 1 countries under the BAU scenario are masked by these reduced consumption patterns in Russia and the countries of the former Soviet Union. The expected growth in energy-related CO, emissions of non-annex 1 countries under BAU by 2020 exceeds the total level of emissions of annex 1 countries in 1990. Non-annex 1 countries' carbon emissions resulting from consumption of fossil fuels are expected to rise from 1.9 BMTC in 1990 to 4-1 BMTC in 2010, a 116% increase over 30 years. In 1990, annex 1 countries produced 68% and non-annex 1 countries produced only 32% of total global carbon emissions. Under the BAU scenario, by the years 2010 and 2020, non-annex 1 region's projected contributions will be 4.1 and 6 BMTC, respectively. On the other hand, if the climate-policy scenario is implemented, by the years 2010 and 2020, non-annex 1 region's projected carbon emissions could be reduced to 3.7 and 5-4 BMTC, respectively. Figure 2 shows the relative contributions of developed and developing countries to fossil-fuel use for the years 1990, 2010, and 2020 under both scenarios. The global fossil-fuel consumption is expected to be less under the climate policy scenario, which reflects increased fuel-combustion efficiencies, conservation measures, and improved technologies. We assume that there is no cross-border trading of greenhouse gases. Under the climate-policy scenario, CO, emissions decrease more than fossil-fuel consumption as countries switch away from coal to less polluting fuels, such as natural gas. smoothed, area-wide averages of PM, and PM, concentrations for each IPCC region and does not estimate local airborne-pollutant levels at specific receptor sites; the latter air-pollutant estimates are generally calculated with Gaussian air-dispersion models that incorporate only local emission inventories and meteorological data. To do this analysis, we assume that airborne fine particles travel hundreds of miles through the atmosphere and their estimated regional concentrations are not very sensitive to the details of the modelling matrix. This contrasts with the well-known difficulty of modelling for short-term ozone episodes over a small geographic area. Evidence supporting the longrange transport of fine particles can also be found-eg, in Pollutant emissions and concentrations The following discussion outlines the modelling protocol followed in this study along with a brief description of key assumptions and sensitivity analyses. 200 150 A PM source-receptor matrix" was used to derive concentration patterns for PM,, and PM,, per unit of energy use for each of the four sectors and three fossilfuel types (coal, oil, and natural gas). The source-receptor coefficients were calculated with large-scale air-dispersion models that were based on emission inventories calibrated with and matched to extensive monitoring data in USA for 1990-1994." In addition to calculation of concentrations of primary particles (those emitted directly by sources), the model also incorporates the secondary conversion of gaseous precursors (SO, and NO) to fine particulates as they are transported through the lower aumosphere. The source-receptor-matrix model yields Business Climate Business Climate -as-usual -policy -as-usual -policy scenario scenario scenario scenario 2010 2010 2020 2020 Year Figure 2: Fossil-fuel use under business-as-usual and climate-policy scenarios in developed (annex 1; A) and developing (non-annex 1; B) countries |