Stronger evidence for human origin of global warming

July 30, 2007

A recent statistical analysis strengthens evidence that human activities are causing world temperatures to rise. Most climate change scientists model Earth systems from the ground up, attempting to account for all climate driving forces. Unfortunately, small changes in the models can lead to a broad range of outcomes, inviting debate over the actual causes of climate change.

Physicist Pablo F. Verdes of the Heidelberg Academy of Sciences in Germany has found a way to avoid the subjective flaws of climate models by applying sophisticated analysis techniques to data from the past hundred and fifty years.

The approach mathematically stitches together known facts about the global climate into a more objective and coherent picture.

Verdes, now at Novartis Pharma, examined data on temperature anomalies, the strength of the radiation emitted from the Sun, and volcanic activity. The relatively recent increases in solar radiation, combined with reduced volcanic activity, contribute to the increase in world temperatures. However, Verdes' analysis demonstrates that these natural causes do not completely explain the observed warming.

Verdes calculated the amount of non-natural influence required to match the increases in temperature observed in the last 150 years. He plotted the influence over time. Then, he compared it to the evolution of greenhouse gasses, taking into account the cooling due to aerosols. With allowances for error, he found that influences attributable to greenhouse gasses mirror the graph of non-natural influence needed to explain the observed temperature increase of recent decades.

His research shows that, if you look at global warming as a puzzle, and you put together the natural factors such as increased solar radiation and reduced volcanic activity, a hole remains. The human factors of greenhouse gas and aerosol emission complete the picture.

Citation: Pablo F. Verdes, Physical Review Letters (forthcoming article)

Source: American Physical Society

Explore further: Cracking open diamonds for messages from the deep earth

Related Stories

Cracking open diamonds for messages from the deep earth

August 25, 2015

Geochemist Yaakov Weiss deals in diamonds. Not the brilliant jewelry-store kind, but the flawed, dirty-looking ones used more for industry than decoration. Gem-grade diamonds are generally pure crystallized carbon, ...

What is the Earth's average temperature?

August 19, 2015

Earth is the only planet in the solar system where life is known to exists. Note the use of the word "known", which is indicative of the fact that our knowledge of the solar system is still in its infancy, and the search ...

1,800 years of global ocean cooling halted by global warming

August 17, 2015

Prior to the advent of human-caused global warming in the 19th century, the surface layer of Earth's oceans had undergone 1,800 years of a steady cooling trend, according to a new study. During the latter half of this cooling ...

'Snowball earth' might be slushy

August 3, 2015

Imagine a world without liquid water—just solid ice in all directions. It would certainly not be a place that most life forms would like to live.

Recommended for you

ATLAS and CMS experiments shed light on Higgs properties

September 1, 2015

Three years after the announcement of the discovery of a new particle, the so-called Higgs boson, the ATLAS and CMS Collaborations present for the first time combined measurements of many of its properties, at the third annual ...

Tiny drops of early universe 'perfect' fluid

September 1, 2015

The Relativistic Heavy Ion Collider (RHIC), a particle collider for nuclear physics research at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, smashes large nuclei together at close to the speed of ...

New material science research may advance tech tools

August 31, 2015

Hard, complex materials with many components are used to fabricate some of today's most advanced technology tools. However, little is still known about how the properties of these materials change under specific temperatures, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.