State of the Climate - 2014
- Atmospheric greenhouse gas concentrations continue to increase due to emissions from human activities, with global mean CO2 levels reaching 395 ppm in 2013.
- Global CO2 emissions from the use of fossil fuel increased in 2013 by 2.1 per cent compared to 3.1 per cent per year since 2000.
- The increase in atmospheric CO2 concentrations from 2011 to 2013 is the largest two-year increase ever observed.
Carbon dioxide emissions
Global anthropogenic CO2 emissions into the atmosphere in 2013 are estimated to be 38.8 billion tonnes of CO2 (10.6 billion tonnes of carbon), the highest in history and about 46 per cent higher than in 1990. Global CO2 emissions from the use of fossil fuel are estimated to have increased in 2013 by 2.1 per cent compared with the average of 3.1 per cent per year from 2000 to 2012.
Since the industrial revolution more than two centuries ago, about 30 per cent of the anthropogenic CO2 emissions have been taken up by the ocean and about 30 per cent by land vegetation. The remaining 40 per cent of emissions have led to an increase in the concentration of CO2 in the atmosphere.
The origin of CO2 in the atmosphere can be determined by examining the different types (isotopes) of carbon in air samples. This identifies the additional CO2 as coming from human activities, mainly the burning of fossil fuel, and not from natural sources.
Greenhouse gas concentrations
Atmospheric concentrations of major greenhouse gases, including CO2, methane (CH4), nitrous oxide (N2O), and a group of synthetic greenhouse gases, are increasing.
Atmospheric greenhouse gas levels have exceeded the record levels reported in the State of the Climate 2012 report, continuing the increase observed over the past century. The global mean CO2 level in 2013 was 395 parts per million (ppm) — a 43 per cent increase from pre-industrial (1750) concentrations, and likely the highest level in at least 2 million years.
The global CO2 annual increase from 2012 to 2013 was 2.5 ppm, and the increase of 5.1 ppm since 2011 is the largest two-year increase observed in the historical record. Global atmospheric CH4 concentration is 151 per cent higher, and N2O 21 per cent higher than in 1750, and they are at their highest levels for at least 800 000 years.
The impact of all greenhouse gases in the atmosphere combined can be expressed as an ‘equivalent CO2’ atmospheric concentration, which reached 480 ppm in 2013.
The Bureau has been observing, reporting and researching Australia’s weather since 1908. CSIRO has been undertaking atmospheric and marine research for more than 60 years. Together our scientists continue to build the body of knowledge that allows people to understand the changes in our climate that we are observing and prepare for any future changes.
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