Carbon Dioxide Emissions from Fossil Fuel ConsumptionPublications containing historical energy statistics have made it possible to estimate fossil fuel CO2 emissions back to 1751. Since 1751 more than 265 billion tons of carbon have been released to the atmosphere from the consumption of fossil fuels and cement production. Half of these emissions have occurred since the mid 1970s. The 1996 estimate for global CO2 emissions, 6518 million metric tons of carbon, is the highest fossil-fuel emission estimate ever. The 1996 estimate represents a 1.7% increase over 1995, continuing a trend of modest growth since a 1990-1993 decline in global CO2 emissions.
Globally, liquid and solid fuels accounted for 77.5% of the emissions from fossil-fuel burning in 1996. Combustion of gas fuels (e.g., natural gas) accounted for 18.3% (1196 million metric tons) of the total emissions from fossil fuels in 1996 and reflects a gradually increasing global utilization of natural gas. Emissions from cement production rose to 202 million metric tons of carbon, a twenty-fold increase since the 1920s. Emissions from gas flaring for 1996 were estimated to be 67 million metric tons of carbon, well below the levels of the 1970s. Collectively, emissions from cement production and gas flaring contributed less than 5% to the total emissions for 1996.
These temperature anomaly time series are derived from a global database of corrected land and marine temperature data. The land portion of this updated database is comprised of surface air temperature data (land-surface meteorological data and fixed-position weather ship data) that have been corrected for nonclimatic errors, such as station shifts and/or instrument changes. A reanalysis of land surface data by the Climatic Research Unit (CRU) has resulted in (1) the inclusion of more than 1000 additional stations, (2) a new reference period common to all stations (1961-1990; previously 1950-1979), and (3) increased grid-box resolution of the temperature anomalies (5° × 5°). The marine data consist of sea surface temperatures (SSTs) that incorporate in situ measurements from ships and buoys. The resulting data set has been used extensively in various Intergovernmental Panel on Climate Change (IPCC) reports, and the global-mean temperature changes evident in the record have been interpreted in terms of anthropogenic forcing influences and natural variability.
Trends in annual mean temperature anomalies for the globe show relatively stable temperatures from the beginning of the record through about 1910, with relatively rapid and steady warming through the early 1940s, followed by another period of relatively stable temperatures through the mid-1970s. From this point onward, another rapid rise similar to that in the earlier part of the century is observed. Like 1997, 1998 has seen a new global mean temperature record set; 1998's anomaly was 0.57°C above the 1961-1990 reference period mean temperature. The six warmest years of the global record have all occurred since 1990 and are, in descending order, 1998, 1997, 1995, 1990, 1991, and 1994. The record shows that the average surface air temperature of the globe has warmed ~0.5°C since the middle of the nineteenth century.
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