If greenhouse gas emissions stopped now, Earth still would likely get warmer: study

Feb 15, 2011

While governments debate about potential policies that might curb the emission of greenhouse gases, new University of Washington research shows that the world is already committed to a warmer climate because of emissions that have occurred up to now.

There would continue to be warming even if the most stringent policy proposals were adopted, because there still would be some emission of heat-trapping greenhouse gases such as carbon dioxide and methane. But the new research shows that even if all were stopped now, temperatures would remain higher than pre-Industrial Revolution levels because the greenhouse gases already emitted are likely to persist in the atmosphere for thousands of years.

In fact, it is possible temperatures would continue to escalate even if all cars, heating and cooling systems and other sources of greenhouse gases were suddenly eliminated, said Kyle Armour, a UW doctoral student in physics. That's because tiny called aerosols, which tend to counteract the effect of greenhouse warming by reflecting sunlight back into space, would last only a matter of weeks once emissions stopped, while the greenhouse gases would continue on.

"The aerosols would wash out quickly and then we would see an abrupt rise in temperatures over several decades," he said.

Armour is the lead author of a paper documenting the research, published recently in the journal . His co-author is Gerard Roe, a UW associate professor of Earth and space sciences.

The global temperature is already about 1.5 degrees Fahrenheit higher than it was before the Industrial Revolution, which began around the start of the 19th century. The scientists' calculations took into account the observed warming, as well as the known levels of greenhouse gases and aerosols already emitted to see what might happen if all emissions associated with industrialization suddenly stopped.

In the best-case scenario, the global temperature would actually decline, but it would remain about a half-degree F higher than pre-Industrial Revolution levels and probably would not drop to those levels again, Armour said.

There also is a possibility temperatures would rise to 3.5 degrees F higher than before the Industrial Revolution, a threshold at which scientists say significant climate-related damage begins to occur.

Of course it is not realistic to expect all emissions to cease suddenly, and Armour notes that the overall effect of aerosols – particles of sea salt or soot from burning fossil fuels, for example – is perhaps the largest uncertainty in climate research.

But uncertainties do not lessen the importance of the findings, he said. The scientists are confident, from the results of equations they used, that some warming would have to occur even if all emissions stopped now. But there are more uncertainties, and thus a lower confidence level, associated with larger temperature increases.

Climate models used in Intergovernmental Panel on Climate Change assessments take into consideration a much narrower range of the possible aerosol effects, or "forcings," than are supported by actual climate observations, Armour said. The Nobel Peace Prize-winning panel, sponsored by the United Nations, makes periodic assessments of climate change and is in the process of compiling its next report.

As emissions of continue, the "climate commitment" to a warmer planet only goes up, Armour said. He believes it is helpful for policy makers to understand that level of commitment. It also will be helpful for them to understand that, while some warming is assured, uncertainties in current climate observations – such as the full effect of aerosols – mean the warming could be greater than models suggest.

"This is not an argument to say we should keep emitting ," he said. "It is an argument that we should be smart in how we stop emitting. And it's a call to action because we know the warming we are committed to from what we have emitted already and the longer we keep emitting the worse it gets."

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More information: The paper was published in the Jan. 15 edition of Geophysical Research Letters.

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User comments : 8

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omatumr
1.5 / 5 (8) Feb 15, 2011
The future of Earth's climate cannot be predicted without considering the latest information on Earth's heat source - the Sun:

"Neutron Repulsion” (19 pages, in press, 2011)
arxiv.org/pdf/1102.1499v1

With kind regards,
Oliver K. Manuel
kaasinees
4.3 / 5 (3) Feb 15, 2011
Uhm... its impossible to stop gas emmsions. Even water is a greenhouse gas. Also there is gasses coming from the ocean floor and volcanos. (its impossible to stop greenhouse gasses!)

What we are doing wrongs is damaging forests and soils, the ocean, ecological processes, biodeviversity etc, it causes our environment to change, and because of that the number of people the planet can support will drop. I dont know if we can damage the earth in such a manner that it will turn into mars #2 but we better change the way we treat the planet want we to survive long.
omatumr
1.5 / 5 (8) Feb 15, 2011
The future of Earth's climate depends on the nature of Earth's heat source - the Sun:

"Neutron Repulsion” (19 pages, in press, 2011)
arxiv.org/pdf/1102.1499v1

With kind regards,
Oliver K. Manuel
Doom1974
3 / 5 (4) Feb 15, 2011
Dear OKM,

What latest information? You have been advocated the neutron repulsion and supernova theory for the sun since before 2000. Same old recycle of cooky ideas.
RayCherry
5 / 5 (2) Feb 16, 2011
Oliver ... sigh ... The Sun is an important factor, but ultimately beyond our control even more so than the climate of the Earth. Your comments are of great interest to solar observation and analysis of effects on or near Earth. However, the topics concerning climate change are (generally) concerned with the observation of human activity on Earth and the effects of that activity on the Earth's climate. Of course the misunderstood life cycles of the Sun affect the Earth's climate, but mixing the subjects together only causes confusion for most readers/commentators here. Surely by now, if you had evidence that the Sun had changed behaviour at the beginning of the Industrial Revolution and was the cause of the measurable climate change, you would have a Nobel Prize for your research.
RayCherry
5 / 5 (2) Feb 16, 2011
Oliver ... can you actually measure any effects of the Sun's behaviour during the past five hundred years that bare any correlation with changes in climate on Earth?

If so, please communicate those measurements complete with sources and analysis process to the IPCC for qualification and reassessment of the human/industrial involvement in the climate change problem. All of us would appreciate that.

Otherwise ... The product of your mind, your work, your life is going to continue being interpreted as noise in the background of an unrelated field of study and 'popular' debate. That interpretation is something that I sincerely consider an injustice, and a shame.
omatumr
1 / 5 (3) Feb 16, 2011
Thanks for your comments.

1. Mankind has always suffered from an illusion of self-importance.

2. Earth's climate is ever changing - because the Sun is a variable star with cycles of surface magnetic activity induced by gravitational interactions of planets with the compact neutron star at the center of the glowing ball of waste products (91%H and 9% He) that is erroneously called the Sun.

See: "Earth's Heat Source - The Sun", Energy & Environment 20 (2009) 131-144. arxiv.org/pdf/0905.0704

3. Earth's changing climate, the evolution of life, the evolution of Earth's atmosphere, and the evolution of the Sun all occurred together.

Origin of the solar system: youtube.com/watch?v=AQZe_Qk-q7M

and manuscript, in preparation
Doom1974
not rated yet Feb 16, 2011
Now that is sad.....

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