Carbon dioxide levels rise at record pace to worst in three million years - Sky News
Global Carbon Dioxide Levels Increase Yet Again - Time
Carbon dioxide levels in atmosphere hit alarming new high, says UN
The unprecedented levels of CO2 could lead to dangerous rises in sea levels and temperatures
Andrew Griffin a day ago
The amounts of CO2 could cause sea levels to rise dangerously Getty
The amount of carbon dioxide in the air is growing at alarming rates and is now at levels not seen for millions of years, according to the UN.
The dangerous levels of CO2 could fuel a dramatic rise in sea levels and add three degrees to temperatures, its World Meteorological Organisation (WMO) said.
Levels are accelerating far faster than before, with last year’s growth more than 50 per cent above the average for the last decade. That has led CO2 levels to rise 45 per cent above pre-industrial levels and further outside the range of 180-280ppm seen in recent cycles of ice ages and warmer periods.
As far as anyone can tell, the world has never experienced a rise in CO2 levels as quick or intense as this. The increase has happened 100 times faster than when the world was emerging from the last ice age.
“Today’s CO2 concentration of around 400ppm exceeds the natural variability seen over hundreds of thousands of years,” the WMO bulletin said.
The latest data adds to the urgency of a meeting in Bonn next month, when environment ministers from around the world will work on guidelines for the Paris climate accord backed by 195 countries in 2015.
The agreement is already under pressure because US President Donald Trump has said he plans to pull the United States out of the deal, which seeks to limit the rise in temperatures to “well below” 2°C (3.6F) above pre-industrial times.
Human CO2 emissions from sources such as coal, oil, cement and deforestation reached a record in 2016, and the El Nino weather pattern gave CO2 levels a further boost, the WMO said.
Scientists know prehistoric levels from tiny air bubbles found in ancient Antarctic ice cores, and they can derive even older data from fossils and chemicals trapped in sediment.
The last time carbon dioxide levels reached 400 ppm was three to five million years ago, in the mid-Pliocene era.
“During that period, global mean surface temperatures were two degrees warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica’s ice retreated, causing the sea level to rise 10-20m higher than that today,” the WMO bulletin said.
Since 1990, the global warming effect of CO2 and other long-lived greenhouse gases has risen by 40 per cent. The two other main gases – methane and nitrous oxide – also grew to record concentrations last year, although at a slower rate of increase than carbon dioxide.
Carbon dioxide levels in atmosphere hit alarming new high, says UN | The Independent
The Mail says its actually even worse:
Climate change might be WORSE than we think after scientists find huge mistake in temperature estimates of Earth's ancient oceans
- Until now, ocean temperatures were based on the oxygen content in fossils
- But a new study suggests oxygen level may change regardless of temperature
- Findings suggest that oceans in the past were much colder
- This indicates that ocean temperatures are now rising quicker than realised
Climate change might be even worse than we think, according to a new study that is challenging the way we measure ocean temperatures.
Scientists suggest that the method used to understand sea temperatures in the past is based on a mistake, meaning our understanding of climate change may be flawed.
The findings indicate that oceans in the past were much colder than thought, meaning that temperatures may be increasing quicker now than realised.
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According to the methodology widely used by the scientific community, the temperature of the polar oceans 100 million years ago were around 15°C higher than current readings.
But in a new study, researchers from the French National Center for Scientific Research (CNRS) are challenging this method.
Instead, they suggest that ocean temperatures may in fact have remained relatively stable throughout this period, which raises serious concerns about current levels of climate change.
Dr Anders Meibom, one of the researchers who worked on the study, said: 'If we are right, our study challenges decades of paleoclimate research.'
'Oceans cover 70 per cent of our planet. They play a key role in the earth's climate.
'Knowing the extent to which their temperatures have varied over geological time is crucial if we are to gain a fuller understanding of how they behave and to predict the consequences of current climate change more accurately.'
For over 50 years, scientists have based their estimates on what they learned from foraminifera - fossils of tiny marine organisms found in sediment cores taken from the ocean floor.
Foraminifera form shells called tests, in which the content of a form of oxygen, called oxygen-18, depends on the temperature of the water in which they live.
So changes in the ocean's temperature over time were calculated on the basis of the oxygen-18 content of the fossil foraminifera tests found in the sediment.
According to these measurements, the ocean's temperature has fallen by 15°C over the past 100 million years.
But these estimates were based on the principle that the oxygen-18 content of the foraminifera tests remained constant while the fossils were in the sediment.
To test whether oxygen-18 levels changed, the researchers exposed foraminifera to high temperatures in artificial sea water that contained only oxygen-18.
For over 50 years, scientists based their estimates on what they learned from foraminifera - fossils of tiny marine organisms found in sediment cores taken from the ocean floor (pictured)
An instrument called NanoSIMS was then used to analyse the chemical content of the fossils.
Results show that the level of oxygen-18 present changed without leaving a visible trace.
Dr Sylvain Bernard, lead author of the study, said: 'What appeared to be perfectly preserved fossils are in fact not.
'This means that the paleotemperature estimates made up to now are incorrect.'
Rather than showing a gradual decline in temperature over the past 100 million years, the researchers suggest that the foraminifera had changed their oxygen-18 levels simply to equilibrate with the surrounding water.
The findings indicate that temperature in the oceans have been overestimated.
In terms of next steps, Dr Meibom added: 'To revisit the ocean's paleotemperatures now, we need to carefully quantify this re-equilibration, which has been overlooked for too long.
'For that, we have to work on other types of marine organisms so that we clearly understand what took place in the sediment over geological time.'
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