Equation 'confirms' global warming/carbon emissions link

A team of researchers from the universities of Southampton, Bristol and Liverpool has, for the first time, derived a theoretical equation to demonstrate that global warming is a direct result of the build-up of carbon emissions since the late 1800s.

The equation is designed to reveal the ’complex relationship’ between carbon dioxide levels and the ocean system - which has reinforced the need to develop carbon capture and storage (CCS) technologies to “limit the warming for the next generations”, researchers said.

Though the researchers are clear that CCS would be an option to reduce the total amount of carbon emitted into the atmosphere, the research is not directly linked to how such CCS might be best achieved.

“Once carbon has been emitted into the atmosphere the warming effect will last many centuries

Lead researcher Phil Goodwin

According to initial results, every million-million tonnes of carbon emitted will generate one degree Celsius of global warming.

Results also revealed the build-up of carbon emitted over the last 200 years will last several centuries, even if carbon emissions are subsequently phased out, the research team said.

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.”

Likewise, Ric Williams, at the University of Liverpool, a co-author of the paper, expressed surprise at how simple the relationship between global warming and how much carbon we emit is - given the complexity of the climate system.

“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,” Williams said.

“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.”

Goodwin confirmed that the next steps of the team’s research will be to look at each of the terms in its equation in more detail.

“[This will include] processes that affect heat uptake by the ocean and carbon uptake by the ocean and terrestrial systems,” Goodwin said.

“A better analysis of these terms will increase our ability to predict future warming.”

A full account of the study has been published in the journal Nature Geoscience.