Research confirms how global warming links to carbon emissions

Research has identified, for the first time, how global warming is related to the amount of carbon emitted.

 

A team of researchers from the universities of Southampton, Bristol and Liverpool have derived the first theoretical equation to demonstrate that global warming is a direct result of the build-up of carbon emissions since the late 1800s when human-made carbon emissions began. The results are in accord with previous data from climate models.

The theoretical equation reveals the complex relationship between carbon dioxide levels and the ocean system. Burning fossil fuels increases atmospheric carbon dioxide levels leading to global warming and the greenhouse effect, which is partly offset by the oceans taking in both heat and carbon.

The results show every million-million tonnes of carbon emitted will generate one degree Celsius of global warming. They also show that the build-up of carbon emitted over the last 200 years will then last for many centuries to millennia, even if carbon emissions are subsequently phased out.

The results also reveal that surface warming is related to the total amount of carbon emitted from fossil fuels, with little change over time as ocean carbon and changes in heat uptake almost cancel each other out.

Dr Phil Goodwin, from Ocean and Earth Science at the University of Southampton, said: "Our analysis highlights the nearly irreversible nature of carbon emissions for global warming. Once carbon has been emitted into the atmosphere the warming effect will last many centuries, even after much of the carbon has been absorbed by the ocean."

"We cannot wait until after significant anthropogenic warming has occurred to reduce carbon emissions and hope the climate goes back to normal by itself, it won't."

Professor Ric Williams, Chair in Ocean Sciences at the University of Liverpool's School of Environmental Sciences, added: "Given the complexity of the climate system, it was a surprise to find out how simple the relationship is between global warming and how much carbon we emit.

"The ocean turns out to be crucial by taking up both heat and carbon, which lead to nearly compensating effects in how surface warming depends on carbon emissions.

"These findings potentially address the most important finding from the Intergovernmental Panel on Climate Change (IPCC) report last year, which is how global warming increases with how much carbon we emit.

"In terms of wider policy implications, our theory reiterates a simple message: the more cumulative carbon emissions are allowed to increase, the more global surface warming will also increase.

"This policy implication reinforces the need to develop carbon capture techniques to limit the warming for the next generations."

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Emergence of modern sea ice in Arctic Ocean, 2.6 million years ago

"We have not seen an ice free period in the Arctic Ocean for 2,6 million years. However, we may see it in our lifetime." says marine geologist Jochen Knies. In an international collaborative project, Knies has studied the historic emergence of the ice in the Arctic Ocean. The results are published in Nature Communications.

The extent of sea ice cover in Arctic was much less than it is today between four and five million years ago. The maximum winter extent did not reaching its current location until around 2.6 million years ago. This new knowledge can now be used to improve future climate models.

"We have not seen an ice free period in the Arctic Ocean for 2,6 million years. However, we may see it in our lifetime. The new IPCC report shows that the expanse of the Arctic ice cover has been quickly shrinking since the 70-ies, with 2012 being the year of the sea ice minimum," Jochen Knies.

He is marine geologist at the Geological Survey of Norway (NGU) and Centre for Arctic Gas Hydrate, Climate and Environment, UiT The Arctic Univeristy of Norway.

In an international collaborative project, Jochen Knies has studied the trend in the sea ice extent in the Arctic Ocean from 5.3 to 2.6 million years ago. That was the last time Earth experienced a long period with a climate that, on average, was warm before cold ice ages began to alternate with mild interglacials.

Fossils reveal past sea ice extent

"When we studied molecules from certain plant fossils preserved in sediments at the bottom of the ocean, we found that large expanses of the Arctic Ocean were free of sea ice until four million years ago," Knies tells us.

"Later, the sea ice gradually expanded from the very high Arctic before reaching, for the first time, what we now see as the boundary of the winter ice around 2.6 million years ago ," says Jochen Knies, who is also attached to CAGE, the Centre for Arctic Gas Hydrate, Environment and Climate at the University of Tromsø, the Arctic University of Norway.

Arctic Ocean likely to be completely free of sea ice

The research is of great interest on the international stage because present-day global warming is strongly tied to a shrinking ice cover in the Arctic Ocean. By the end of the present century, the Arctic Ocean seems likely to be completely free of sea ice, especially in summer.

This may have major significance for the entire planet 's climate system. Polar oceans , their temperature and salinity, are important drivers for world ocean circulation that distributes heat in the oceans. It also affects the heat distribution in the atmosphere. Trying to anticipate future changes in this finely tuned system, is a priority for climate researchers. For that they use climate modeling , which relies on good data.

"Our results can be used as a tool in climate modelling to show us what kind of climate we can expect at the turn of the next century. There is no doubt that this will be one of many tools the UN Climate Panel will make use of, too. The extent of the ice in the Arctic has always been very uncertain but, through this work, we show how the sea ice in the Arctic Ocean developed before all the land-based ice masses in the Northern Hemisphere were established," Jochen Knies explains.

Seabed samples from Spitsbergen

A deep well into the ocean floor northwest of Spitsbergen was the basis for this research. It was drilled as part of the International Ocean Drilling Programme, (IODP), to determine the age of the ocean-floor sediments in the area. Then, by analysing the sediments for chemical fossils made by certain microscopic plants that live in sea ice and the surrounding oceans, Knies and his co-workers were able to fingerprint the environmental conditions as they changed through time.

"One thing these layers of sediment enable us to do is to "read" when the sea ice reached that precise point," Jochen Knies tells us.

The scientists believe that the growth of sea ice until 2.6 million years ago was partly due to the considerable exhumation of the land masses in the circum-Arctic that occurred during this period. "Significant changes in altitudes above sea level in several parts of the Arctic, including Svalbard and Greenland, with build-up of ice on land, stimulated the distribution of the sea ice," Jochen Knies says.

"In addition, the opening of the Bering Strait between America and Russia and the closure of the Panama Cannel in central America at the same time resulted in a huge supply of fresh water to the Arctic, which also led to the formation of more sea ice in the Arctic Ocean," Jochen Knies adds.

All the large ice sheets in the Northern Hemisphere existed around 2.6 million years ago.

Scientists at Norwegian Geological Survey (NGU), CAGE, UiT The Arctic University of Norway,University of Plymouth, Universitat Autònoma de Barcelona, Stellenbosch University in South Africa and Institució Catalana de Recerca i Estudis Avançats in Barcelona have collaborated in this work.

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January-October 2014 temperatures highest on record

The global average temperature over land and ocean surfaces for January to October 2014 was the highest on record, according to NOAA. October was the hottest since records began in 1880.

The global average temperature over land and ocean surfaces for January to October 2014 was the highest on record, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). It said October was the hottest since records began in 1880.

NOAA said the combined global land and ocean average surface temperature for the January-October period was 0.68°C (1.22°F) above the 20th century average of 14.1°C (57.4°F). For October, it was 0.74°C (1.33°F) above the 20th century average of 14.0°C (57.1°F).

The high October temperature was driven by warmth across the globe over both the land and ocean surfaces and was fairly evenly distributed between the Northern and Southern Hemispheres. The Southern Hemisphere had its hottest October on record and the Northern Hemisphere its third warmest.

October marked the third consecutive month and fifth of the past six with a record high global temperature for its respective month (July was fourth highest).

The Tokyo Climate Center, which is a WMO Regional Climate Centre, also reported that October was the hottest on record. The record was also confirmed by data from NASA's Goddard Institute for Space Studies.

WMO uses a combination of datasets to compile its annual Statement on the Status of the Global Climate. Additional information is drawn from the ERA-Interim reanalysis-based data set maintained by the European Centre for Medium-Range Weather Forecasts.

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Deep-Earth carbon offers clues on origin of life: New organic carbon species linked to formation of diamonds -- and life itself

New findings by a Johns Hopkins University-led team reveal long unknown details about carbon deep beneath Earth's surface and suggest ways this subterranean carbon might have influenced the history of life on the planet.

The team also developed a new, related theory about how diamonds form in Earth's mantle.

For decades scientists have had little understanding of how carbon behaved deep below Earth's surface even as they learned more and more about the element's vital role at the planet's crust. Using a model created by Johns Hopkins geochemist Dimitri Sverjensky, he, Vincenzo Stagno of the Carnegie Institution of Washington and Fang Huang, a Johns Hopkins graduate student, have become the first to calculate how much carbon and what types exist in fluids at 100 miles below Earth's surface at temperatures up to 2,100 degrees F.

In an article published this week in the journal Nature Geoscience, Sverjensky and his team demonstrate that in addition to the carbon dioxide and methane already documented deep in subduction zones, there exists a rich variety of organic carbon species that could spark the formation of diamonds and perhaps even become food for microbial life.

"It is a very exciting possibility that these deep fluids might transport building blocks for life into the shallow Earth," said Sverjensky, a professor in the Department of Earth and Planetary Sciences. "This may be a key to the origin of life itself."

Sverjensky's theoretical model, called the Deep Earth Water model, allowed the team to determine the chemical makeup of fluids in Earth's mantle, expelled from descending tectonic plates. Some of the fluids, those in equilibrium with mantle peridotite minerals, contained the expected carbon dioxide and methane. But others, those in equilibrium with diamonds and eclogitic minerals, contained dissolved organic carbon species including a vinegar-like acetic acid.

These high concentrations of dissolved carbon species, previously unknown at great depth in Earth, suggest they are helping to ferry large amounts of carbon from the subduction zone into the overlying mantle wedge where they are likely to alter the mantle and affect the cycling of elements back into Earth's atmosphere.

The team also suggested that these mantle fluids with dissolved organic carbon species could be creating diamonds in a previously unknown way. Scientists have long believed diamond formation resulted through chemical reactions starting with either carbon dioxide or methane. The organic species offer a range of different starting materials, and an entirely new take on the creation of the gemstones.

The research is part of a 10-year global project to further understanding of carbon on Earth called the Deep Carbon Observatory. The work is funded by the Alfred P. Sloan Foundation.

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