Carbon dioxide levels rose dramatically in 2012, and scientists are warning that this makes it highly unlikely that we will be able to limit global temperature rise to 1.9°C by 2050.
A new report, released by the National Oceanic and Atmospheric Administration, revealed that carbon dioxide levels increased by 2.67 parts per million (ppm) since 2011, which is the second highest increase since record keeping began in 1959. The only year that showed a larger increase was 1998, which saw a rise of 2.93 ppm.
These carbon dioxide levels were measured at Mauna Loa, Hawaii, far from any urban sources, where the total atmospheric carbon dioxide concentration is now up to just shy of 395 parts per million. 'Parts per million' means that for every million particles of air, 395 of those particles will be carbon dioxide. That may not seem like much, but the concentration of CO2 in the atmosphere before the industrial revolution was 280 ppm, so current levels represent a 41% increase over that 'base' level.
Measurements taken at sea surface level were also high last year, at 2.59 ppm, the third largest increase since 1959 (highest was 2.84 ppm in 1998 and second highest was 2.71 ppm in 1987).
This latest spike in CO2 levels is being attributed to increased fossil fuel burning, mostly in the developing world, offsetting reductions in other parts of the world.
According to climate scientists, a global temperature rise of more than 1.9°C by the year 2050 represents a dangerous level of climate change. Keeping the temperature rise below 1.9°C by that time should allow for Earth's climate system to properly adapt to changes, and thus "ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner," according to the United Nations Framework Convention on Climate Change (UNFCCC).
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Since the mid-1800s, the global temperature has risen by 0.7°C, and according to John Reilly, co-director of Joint Program on the Science and Policy of Global Change, temperatures are projected to rise by 1.3 to 2.3°C between now and 2050.
"The prospects of keeping climate change below that (1.9-degree goal) are fading away," said Pieter Tans, Senior Scientist at NOAA's Climate Monitoring and Diagnsotics Laboratory.
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