Climate change: Greenhouse gas concentrations again break records
https://www.bbc.com/news/science-environment-50504131
Climate change: Greenhouse gas concentrations again break records
By Matt McGrath
Environment correspondent
1 hour ago
Atmospheric concentrations of carbon dioxide and other greenhouse gases once again reached new highs in 2018.
The World Meteorological Organization (WMO) says the increase in CO2 was just above the average rise recorded over the last decade.
Levels of other warming gases, such as methane and nitrous oxide, have also surged by above average amounts.
Since 1990 there's been an increase of 43% in the warming effect on the climate of long lived greenhouse gases.
The WMO report looks at concentrations of warming gases in the atmosphere rather than just emissions.
The difference between the two is that emissions refer to the amount of gases that go up into the atmosphere from the use of fossil fuels, such as burning coal for electricity and from deforestation.
Concentrations are what's left in the air after a complex series of interactions between the atmosphere, the oceans, the forests and the land. About a quarter of all carbon emissions are absorbed by the seas, and a similar amount by land and trees.
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What concerns scientists is the overall warming impact of all these increasing concentrations. Known as total radiative forcing, this effect has increased by 43% since 1990, and is not showing any indication of stopping.
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"It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was three to five million years ago. Back then, the temperature was 2-3C warmer, sea level was 10-20m higher than now," said Mr Taalas.
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